PRELIMINARY REPORT ON THE GEOGRAPHICAL
DISTRIBUTION OF THE BRYDE'S WHALE IN
THE NORTH PACIFIC WITH SPECIAL
REFERENCE TO THE STRUCTURE
OF FILTERING APPARATUS
AKITO KAWAMURAAND

YUKO SATAKE
Whales Research Institute, Tokyo

ABSTRACT

Some external characters of the Bryde's whales caught during thesummer of 1975 in the waters off Sanriku, northwest Pacific were studied.
Although no prominent external characters which may suggest an intraspecific variation in distinguishing the differenciation of possible races
were found among the fourteen animals examined, one animal, Sy7518(12.5 m, male, see Table 6 and Appendix III) showed considerably distinct characters which make the animal be distinguished clearly fromthe others. It is, however, still obscure whether or not the animal
could be said as allopatric forms since no reproductive conditions were
examined. It was suggested that one of the most important external
characters should be examined for the North Pacific Bryde's whale was
the overall morphological characters for the filtering apparatus such as
the length of baleen series, whole shape of the apparatus, nature ofbristles and the filter area. There found at least two types ofBryde's whales in the regions concerned: the first one is quite less inthe number of ventral grooves, lower but broad based in dorsal fin,very coarse and considerably small in its filter area. All of these suggests its closer character to the Bryde's whale. proper whereas thesecond one is almost opposite character to the former in may respects
with some intermediate varieties and showed somewhat similarity to
sei whale. There seems two more possible populations in the North
Pacific Bryde's whales: the first one is largely f9und in the pelagic
waters of the North Pacific, and the other is in the waters off west
coast of Kyushu. A possible invasion of the former population into
Sanriku, Northwest Pacific is suggested.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976, 1-35.

2

KAWAMURA AND SAT AKE

INTRODUCTION
The North Pacific Bryde's whale is one of two mysticete species to be caught
currently by Japanese whaling both in pelagic and coastal waters, and provides
an important components among the total catches. Although its taxonomical
problem against sei whale in the North Pacific region seems to have been
settled by establishing the species which occurs and predominates widely over
the warmer waters in the Pacific region (e. g. Omura, 1966a; 1974), little has
been studied concerning to its general biological characteristics including thediagnosis for the subspecies or the races. A considerable variations in external
appearance for the North Pacific Bryde's whales such as the case known in theSouth African population (Best, 1970; 1974) have been noticed through theprevious studies (Omura et al., 1932; Omura and Fujino, 1954 ;. Omura, 1959,1962), but the matter was left behind from the further consideration. One ofsuch problem may be found in the intraspecific and morphological variations
by occurring localities over the world oceans in large and/or small scale, andthe variations are, to some extent, possibly related to the difference by local
populations or stocks. It is, therefore, the current problem to elucidate whether
any racial defference or allomorphological forms could be found in the North
Pacific Bryde's whale. Althouh it has been noticed that there must be somedifferences in the character of baleen plates taken from the Bryde's whalescaught in the North Pacific region, little attention was paid for this matter
until we got the knowledge from the South African waters. More recently,
however, Masaki (1975) compared the baleen plates of North Pacific Bryde's
whales with a hope to distinguish their local populations by examining widthlength ratio and some morphology for the bulk of baleen plates collected atmany localities over the North Pacific regions along with the recovery data oftagged whales. Masaki (1975) considered that there must be at least two possible
subpopulations of Bryde's whales in the North Pacific: the first one is restrictedin the waters west of 150°E longitude, while the second one is found in the
pelagic region lies between 160°E and 160°W longitudes. However, as far as
the figures given by Masaki (1975) are concerned, there seems some differencein the pelagic population which could be separated each other somewhere between l 70°E and 180° longitutdes. Under these circumstances, the main purposeof our study was to know and, if it was present, was to find out some criticaland well representing external characters showing an intraspecific variation bywhich the racial difference of Bryde's whale population might be suggested.
In the course of examining Bryde's whales at the landstations both in Ayukawa
and in Onagawa, northernjapan, we noticed that there were some intraspecificdifferences in the general structure and the nature of filtering apparatus for the
Bryde's whales although the present result should be considered still tentative
due to so small number of animals observed. The result is presented briefly
in this report along with some considerations.
Sci. Rep. Whales Res. Inst.,
No. 28, '1976.

3

NORTH PACIFIC BRYDE'S WHALE

MATERIAL AND METHOD
During 24 July to 3 August 1975 following number of whales were caught andexamined in Sanriku region :Land Stn.

Company

Ayukawa
Ayukawa
Onagawa

Taiyo Gyogyo
Sanyo Hogei
Nippon Suisan

Bryde's

Fin

91)

4
22)

1) No observations for one carcass.
2) Examined only baleen plates for one of two carcasses.

A total catch figure for the Bryde's whale at four land stations during
baleen whaling season, May to October 1975, was 116 animals (045, ~71) inall, of which the majority (86.2%) was caught during the months of May to
July, so the time when we examined the animals was almost near at the endof Bryde's whaling season. One out of fifteen Bryde's whales landed was not
examined. Observed result on a fin whale at Taiyo Gyogyo was not treatedin this report except an item for Table 2.
An ordinal biological observations on carcasses were carried out as muchas possible for 14 animals. However, the observations on carcasses have had
to be done by only one person in the field, no measurements of so-called bodily
proportions were made except several measurements for minor part of body forthe later convenience (Appendix I). In this survey we focussed our observations
especially on mearnring the structure of filtering- apparatus in general since it
was sup?osed that the differenciation of intraspecific variation as an external
character in Bryde's whale would likely be well resulted both in feeding habits
and in the form or the character of filtering apparatus through the cetacean
evolution.
As for counting the number of so-called baleen plates we followed to thesuggested definition by Williamson (1973), that is, when the width of baleen
plate has three or more times of its thickness at gum level, we counted it as
the ' real baleen plates'. Diameter of baleen bristles was measured at threepoints, tip, middle and base, under the microscope with a aid of micrometer
mounted in the eyepiece. To calculate the whole area of filtering apparatus
we measured the overall length of baleen series along gum level and also thelength from the base of palatal ridge to the tip of baleen plates section bysection so as to be figured out the unfold shape of filtering apparatus on thesectioned paper. By this treatment the filter area was calculated by counting
the number of unit squares encircled by the figure. Another minor ways ofobservations and measurements were described elsewhere in the text where it
was thought to be necessary.
Sci. Rep. Whales Res. Inst.,
No. 28, '1976.

KAWA MURA AND SAT AKE

4

RESULT

General descriptions
The Bryde's whales examined were consisted of 8 male and 6 female withthe body length of ranging 10.l-12.7m (Av. 11.78m) in the former and 10.814.2 m (Av. 12.93 m) in the latter. All these animals were caught in the whaling
ground formed some 140-280 nautical miles east off the coast of Sanriku region
where relatively high surface sea temperature of above 23°C prevails during
mid summer (Figs. 1-a, 1-b). Shift in the location of Bryde's whaling groundwas not found when it was compared with the locations occupied in 1953
operations (Omura and Nemoto, 1955). One female of 14.2 meter (Sy7519 animal)
carried a well burried steel tag (No. 0789, Fishery Agency Japan) in the midstof her right side back between blow-holes and dorsal fin. The tag had been
shot at 26°08'N, 143°00'£ on 8 May 1950 and has been reported as sei whaleof 38 feet ( 11.6 m). Thickness of the blubber ranged 4.0-5.5 cm in six measured
animals, and that of mammary gland in two animals was 1.5 cm (Sy7519) and
3.0 cm (Ty7544) respectively. No lactating animals were found. Since carcasses
are largely cut opened at their ventral cavity to keep the meat more fresh, thestomach contents, reproduction organs and foetus are washed off and lost very
( 1)

140
145
150
E
Fig. 1-a. Distribution of surface sea temperature (Japan Meteolological Agency, 1975)
and the location of catch in the late July, 1975. (1) Sy7518, (2) Ty7544, (3) Ty7541,(4) Sy 7519, (5) Ty7543, (6) Ns7564, (7) Ns7563, (8) Ty7546, (9) Sy7520.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

5

often while the animal was on the way towing back to the land station. Neither
foetuses nor the condition of reproductive organ for female were observed, andconsequently the data on the reproductive condition are unavailable in thisstudy. Contrary, weight of testis was obtained from three animals; it was 1.2, 2.1(Sy7518); 0.4, 0.3 (Ns7563): and 0.2, 0.1 (Ns7564) (Kg) respectively. Comparing
these figures with those found in South African waters (Best, 1974), the above
animals were adolescence of sexually immature.
Number of ventral grooves was counted at the anterior insertion of flipper
on the visible half of body and the number was doubled. The obtained number
varied from 50 grooves to 70 (A v. 62) through four animals. It is note worthy
that one animal (Sy7518) showed only 50 grooves while another three wereover 62.
Abundance of white scar on the epidermis varied considerably by eachanimals. Number of scar counted i.n most animals was found somewhere between
15-40 scars on the visible half side of abdomen, and it gave an appearance ofmoderate state in scarring except two animals which were quite heavily scarredwith an appearance of like a newly galvanized iron or zinc plate. One animal(Sy7518), however, was exceptionally smooth in its epidermis with very little
number of white scars and, still more, the open pit was completely absent from

140

145

150

Fig. 1-b. Distribution of surface sea temperature (Japan Meteolological Agency, 1975)
and the location of catch in the early August, 1975. (10) Ty7541, (II) Ty7548, (12)Ty7550 (13) Ty7549, (14) Sy7521.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

6

KAWAMURA AND SAT AKE

its surface. Usually 1-4 of oval shaped open pits was found in lumber part,flipper and in the upper surface of the rostrum. The measured dimensions ofopen pit was 8.0 x 4.5 cm and 3.9 X 6.7cm or thereabouts, and these sizes foropen pits are likely to represent through the animals examined. It is unknown
whether the scratched scars were on the under surface of tail flukes.
There found at least three kinds of ectoparasites in some animals though
they were not infected altogether on a definite carcass. The parasitic organisms
found were Xenobalanus, Pennella and stalked barnacles, but both juvenile andadult forms of Balaenophylus sp. were found on the surface of larger sizedbaleen plates in every animals.
Very few of stomach contents were observed, since it was, as mentioned
before, also cut open while towed back to the land station. However, fouranimals had luckily kept some amount of stomach contents. The kind offoodstuff was consisted of young pacific mackerel, Pneumotophorus J aponicils
japonicus of about 13.5-15.6 cm in fork length in three animals. P. japonicus
japonicus occurs very abundantly over the Sanriku region toward considerable
pelagic region (Kawamura, 1973) during northern summer, and even migrates
into the Ayukawa harbour. The another one was said to have kept euphausiids.
Although no specimen of this euphausiids was collected, it might considered
probably be Euphausia pacifica, since the bulk of this species occurs in thewhaling ground off Sanriku region (Komaki, 1967) and also having beenfound in the stomach of blue, fin, sei (including Bryde's) and humpback whales(N emoto, 1959).
C0llected ear plug and female reproduction organ are usually sent to the
Far Seas Fisheries Research Laboratory, Fisheries Agency, when the whaling
season was closed, and the age of whales concerned is not yet known to theauthors as of March 1976.
In the observations on the general external appearance of Bryde's whales
examined, there found no distinct characteristics which may enable to distinguish from one another. However, as it was suggested before, one animalof 12.5 m female (Sy7518) was found to be rather different in its external
characters, viz. so small number of ventral grooves along with smooth and little
scarred good looking epidermis. This coasely grooved throat well corresponds
to that of ' sei whale' caught in the Bonin Islands whaling ground (Omura etal. 1952).
0Proportions
It does not seem to enable in obtaining any conclusive different charactersfrom the present data on body proportions since only several minor measurements
were made sporadically (Appendix I). However, some measurements would be
worth to be mentioned in connection with the results on the filtering apparatus.
To show rather distinct difference in some animals from the rest, we extracted
some figures from the overall data and summerized in Table 1.
Measurements other than Table 1 showed very well coincidence with all
2)

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

7

NORTH PACIFIC BRYDE'S WHALE
TABLE 1.

PERCENT FIGURES FOR SEVERAL NUMBER OF MEASUREMENTS
AGAINST BODY LENGTH SHOWING THE ANIMAL WHICH
LARGELY DIFFERED FROM THE OTHERS.
No. of animalmeasured

Average8

21. 8511

11. 20Distance between Yakobson's organ
and the tip of snout
Dorsal fin: (a) anterior edge(b) width

12

0. 76

8
9

5. 10
4.24

( c) Height

12

2.47

12
12

12.60
2.44

Measurements
Length of a row of baleen plates
along the gum level
Length of ridge on the head

Flipper: (a) anterior edge(b) width(3&)

Figures for prominent
difference from theaverage (%)
19.20
17.59
6.80
9.27
1. 43
1. 31
6.56
{ 5.843. 14{ 1. 93
2.04{14.2914.38
1. 69

Animal
Sy 7518
Sy 7521
Sy 7518
Ty7546
Ty7543
Sy7519Sy7518
Sy7518
Ty7550
Ty7546
Ty7550
Ty7547
Ty7550
Ty7548animals examined, and could be discarded from the considerations. As far as
Table 1 is concerned, several animals which showed different proportions could
be picked up. Among those animals enlisted in Table 1, Sy7518 animal which
was very coarsely grooved and smoothly skinned animal, showed significantly
different proportions from the others especially in the length of rostrum, palatalridge, baleen series, and dorsal fin, giving highest frequency in the number ofdeviated measurements. Proportions for dorsal fin in Sy7518 animal showedvery low and broad triangle which was quite characteristic from the others.
The dorsal fin of like this shape had been also known in the 'sei whale' ofsouthern type which occurs in the Bonin Islands waters (Omura et al. 1952).
This animal as going to be metioned later was also different at two mostimportant measurements while majority of the rest were only distinct at more lessimportant ones. Best (1974) suggested the difficulty to distinguish both inshore
and offshore forms of Bryde's whales only by a morphometric examinations
due to so frequent occurrence of intermediate forms. From the overall results
already mentioned, however, it might be considered that there seems to be atleast two or three unusual animals which could be distinguished at several
measurements on the external characters.

Filtering apparatus
Filtering apparatus in baleen whales would be one of the most important
external characters should be examined closely for the consideration of
intraspecific variation or racial problem of whale population until we will have
got more biological, physiological, and ecological knowledge on the species
concerned. Results obtained are summerized and given in Appendix II.
a) Row of baleen plates
3)

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

8

KAWAMURA AND SAT AKE

Both the length of a row of baleen plates along gum level and that alongpalatal ridge are indispensable agents for calculating the area of filtering
apparatus. For those animals which had not measured those length above
mentioned, it was able to estimate reasonably by drawing the actual unfolded
shape of filtering apparatus with the aid of measurements for inside of thefilter obtained section by section at every 30 to 50 cm intervals.
The overall length along gum level varied for 190.0-314.0 cm through ten
examined animals while the length along palatel ridge was 190.0-285.0 cm. As
it was given in Appendix I and Table 1, proportional figures for the length
along gum level was small in Sy7518 and Sy7521 animals. Fig. 2 demonstrates
290

8$
bO
"' 250"d

Sy7520 /

·c

/

(ii

"'cii

,,,,
""

(ii
0.

Cl
.0::

tO

Sy7518

/

/

/

"'"

o-l

200
Ns7564

•

200

250

300

Length of a row of baleen plates along gum level (cm)Fig. 2.

Length both for a row of baleen plates and for the palatal ridge.

TABLE 2. RA TIO FOR THE TRANSVERSE LENGTH OF FILTERINGAPPARATUS(A) AGAINST ITS MAXIMUM SPREADALONG BALEEN SERIES(B).
Body length (m)Animal

B/A

Male

10. 1
12.5
12.6
12. 7

Ns7564
Sy 7518
Ty7543
Sy7520

0.35
0.37
0.45
0.42

Female13. 7

Ty754414.2
15. 3 (Fin)Sy7519Ty7542

0.44
0.40
0.42

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

9

the relationship between both above mentioned lengths. From this figures it
is observed that there are two different characters in the general structure offiltering apparatus, that is, rather slender shaped apparatus as shown by theline A in Fig. 2 and more oval shaped one which belongs to the line B. This
relationships are more well represented in Table 2. The calculated ratio forthe maximum spread connecting tip to tip of both sides of baleen plates against
the length of palatal ridge showed that there are two kinds of clearly different
figures which are comparable with Fig. 2. Both Ns7564 and Sy7518 animals
showed considerable slender shape in their filtering apparatus, but they must
be considered separately as being different each other since the former seems
to be possibly resulted from its younger age, while the figures for Sy7518 animal,must be noted along with the large enough body length. Although those twodifferent figures are found among male animals, the difference would not be
due to the sex.
b) Number of baleen plates and hairs
A total number of so-called baleen plates in a series of baleen plates wascounted. The figures as given in Appendix II varied between 254 and 325
plates through eleven animals with 283.5 plates as an approximately averaged
number. By comparing these figures with those by Omura et al. (1952), majorityof the number of baleen plates in the present study was less than 290 plates,
and well agrees to that known in the southern type of ' sei whales' from Bonin
Islands waters except Ty7541 and possibly Ty7544 animals both of which showedsomewhat more ordinal sei-whale-like characteristics. However, the overallvariation between each animal seems to be still within an allowable range as
Bryde's whale species, and the data provided by Best (1974) for the Bryde's
whales of both South African and Chilean waters also suggest variable in thatcharacter, though the number of baleen plates of somewhere between 270 and
290 may be a reasonable figures for the Bryde's whales over the many localities.
Quite insufficient data are available for the number of creamy white hairs
and plates arranged on the distal end of baleen series as it has been known in
fin, minke and some sei whales. As far as the available data are concerned,
there was found no clear difference or tendency between animals and also
between both right and left baleen series in the amount of creamy white hairs
and plates. lntraspecific variation is unlikely to be figured out from this kindof character although there found some noteworthy difference between bothright and left sides in Sy7518, Sy7519 and Sy7520 animals. It is, however, still
unknown whether those difference or variation are significantly responsible tosuch a extent as to show a difference of races or allopatric forms.
c) Baleen plates
The shape of cross sectioned beak at cranial to blow-holes was reported as
relating agent at least to the morphological difference in both sei and Bryde's
whales (Omura, 1962). In connection with this relative angle ({}) which is formedby the outer edge of baleen plate against vertical axis was measured (Table 3).
To measure the angle actually, the gum line was adopted as one of two angle
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

10

KAWA MURA AND SAT AKE
TABLE 3. RELATIVE ANGLE FORMED BY THE LINE AT GUM
LEVEL AND THE OUTER EDGE OF BALEEN PLATES.

Male

FemaleAnimalBody Length (m)Angle (8)Ns7564
Ns7563
Ty7547
Ty7541
Sy7518
Ty7549Ty7543

50.4
53.6
48.5

Sy 7520

10. !
11. I
11. 2
11. 5
12.5
12.5
12.6
12. 7

49.8

Sy 7521
Ty7548
Ty7550
Ty7544
Ty7546

10. 8
11. 2
13. 7
13. 7
14.0

47.4
43.6
50.0
53.4
48.8

Sy 7519

14.2

56.3

53. I
49.2
53.6
52. I

38
e Ty7550• Ty7544
Sy7520

Ty7546• ••Ty7543 •Ty7547•
Ty7549

8

~
U)

<l.l

.µ

ro

-a
c:

<l.l
<l.l

ea
..0

30

......
0~c:<l.l.....120
Width of baleen plates (cm)Fig. 3.

Width and length of largest baleen plates.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

II

forming basal lines. Consequently, it means that the larger in this angle themore well the baleen plates hanged vertically. The upper and lower extremes
for this angle were 56.3° and 43.6° respectively. The general trends in thefrequency of this angle seem to change proportionally with the increase or
decrease in body length, and this tendency could be considered along with thewhole shape of filtering apparatus, viz. length-spread ratios in a series of baleen
plates (see Table 2). Some animal showed well horizontally spreading baleenseries while another were not. The angle varied so randomly over the examinedanimals and no significant relationship for the better understanding of an
intraspecific variation was found among this characters.
The width-length ratio (=quotient) for the largest baleen plates has been
one of the most well examined characters in many previous studies. This figure
as given in Appendix II and as demonstrated in Fig. 3 varied between 1.45
and 2.03 with an average of 1.79. From Table 3 and Figs. 4 and 5 which were
given by Omura et al. (1952), it can be said that the lower the value in thisratio the more closer character is seen as orignally known Bryde's whale itself.
In this point ,of view, following three animals, Sy7518, Sy7519 and Ty7546
showed relatively small width-length ratio than the rest and, consequently, theyshould be considered to keep somewhat distinguishable character in their baleen
shape than the others. Only in Ty7541 animal exceeded in the ratio. Although
all the figure obtained was in the range which had been found in Bonin Islands
population (Omura and Fujino, 1954) when Fig. 3 is compared with the result
as demonstrated by Best (1974), it might be said that the majority of animals
in this study carried a similar character with that known in offshore form of
the South African waters while those above mentioned three animals were morecloser character to one of two forms found in Brasilian waters.
In Bryde's whale, however, there found no only one or two most prominent
size of baleen plates but they are found for a section of baleen series consistingof several tenth number of baleen plates to be the same size while their widthvaries as shown by the function of width-length ratio among them for about
0.5 (Fig. 4). This suggests that it would be very hard to consider and/or try
to find out the variations only by means of the width-length ratio of baleen
plates unless one gets larger enough difference in that figures.
d) Number of minor baleen plates
Small brush-like baleen plates (=minor plates) are furnished between the
inner most end of main plates and the base of palatal ridge (see Williamson,
1973, Fig. 8). The minor baleen plates form also an important filtering mesheson the ceiling of upper jaw. The number of minor plates including a very
tiny stump of hairs varied along with both the position of main baleen plates
and animals within 5 to 13 plates with three exceptions. Usually the number
did not vary much within an animal and may not be so significant characterfor the purpose of this study (Fig. 5).
e) Baleen bristles
The character of hair-like bristles (=fringes) which finally form straining
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

KAWA MURA AND SAT AKE

12
7.0

6.0

5.0

~
" 4.0
t::
.<::
<])

'Cl

-.

~ 3.0

•

2.0

•

:
I

. ..

r • [ .• I .I

·rqlltL!l~;.d!~:I •• F • L • •

•

r

1

!

•

:

•

•

:.,

•

S.

I

Z

1

•

I

1

•

•

1.0

0

1

20

40

60

80 100. 120 140 160 180 200 220 240 260 280 300 320

Ordinal number of baleen plate
Fig. 4.

Variation in the width.length ratio by the part of baleen series.

25116
15
214
.a13
H 12

g 11

"§10
'+-<

9

~ 8

1l 7

zs

6
5
4
3
2
1

1

20

40

Fig. 5.

60

80 100 120 140 160 180 200 220 240 260 280 300
Ordinal number of baleen plate
Variation in the number of minor plates.

meshes of filtering apparatus are considered as to be one of the most important
agents should be examined more closely. Since baleen bristles are easily
damaged through the sampling and examining process on baleen plates, nomeasurements on their length were made but examined and measured only their
thickness in terms of diameter and the number of bristles per unit length of
inner margin of baleen plates.
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

13

As it is noticed in the figures on Plate II there were found two kinds ofbristles which can be easily distinguished by their appearance: the first one isvery long and thick structured in its diameter and streches out straight. This
bristles obviously form the main body or structure of the fringe of baleen plates.
The second one, on the other hand, is very thinly structured bristles with a
trace or an appearance of folding in zigzag shape at one or more angles.
This kind of bristles make the filtering apparatus to be more finer netting byentangling with both kind of another bristles from several neighboring baleen
plates to result a role as a sort of ' connecting tissue' throughout the baleenseries. This thin and zigzagged bristles are very fragile at their angled corners
where the bristles are rather flattened like a ribbon string, and are easily
damaged by the angles.
By distinguishing above two kinds of baleen bristles, one of author (A. K.)
counted their number per unit length of inner edge of baleen plates to give adensity which may show the extent of coarseness of netting in filtering apparatus. The determination of density in baleen bristles was made approximately
at the halfway of inner margin of the largest baleen plates by sampling allbristles within 2.0 cm length since 1.0 cm as a sampling unit length wasconsidered to be too small for this purpose. The number combined both kinds ofbristles varied for 39-85 per 2.0 cm unit length with an average of 60.9 bristles
per 2.0 cm. To see the overall result most animal carried the straight andthick bristles of about 1/3 to 1/4 of the number of zigzagged ones. On closer
examination, however, it can be noticed that these proportional balance in thenumber of both kinds of bristles are deformed in both Ty7541 and Sy7518
animals. The former completely lacks the zigzagged bristles and the latter wasvery little in the number of slightly zigzagged bristles which can be consideredalmost straight appearance (Fig. 6). The latter was very similar to those foundin the animals from Bonin Islands waters previously. In Fig. 6 some additional
data which were obtained from another baleen plates of Bryde's whales fromvarious localities were plotted. The result make the authors complicated at theirconsiderations: that is, the all results obtained from our previous collections
showed almost or complete lack in the number of zigzagged baleen bristles.
They were very similar to the character found in Sy7518 animal. Some ofthem undoubtedly must have been damaged to result bearing no thin andzigzagged bristles. However, the number of straight bristles as demonstrated
in the figure suggests that the animals of previous collection were well
luxuriously furnished with straight bristles than the majority of animals in
the present study, and only Sy7518 animal corresponds to those figures fromthe preserved materials. Besides, Ty7541 animal showed also an exceptional
character in the number of straight bristles. As far as Fig. 6 is concerned, it
can be said that most animals in the present study showed a character of more
sei-whale-like Bryde's whales. In Fig. 6 the position where the Bryde's whales
from the pelagic waters of the North Pacific or those from the coastal waters
off western Kyushu would be placed may be an another interests. This will
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

KAWAMURA AND SAT AKE

14

Sy752070•<l):E""" 60
'O

E
u

0

N

<n

50

.0
'O

40

'-

~
·~

"'
"'""""
N

7549
Ty7543 Tr
Sy7519.\ eNs7563
Ty7548 .;Ns7564
Sy7521 •Ty7550

1 Brasil, Cabo Frio
2 Oshima, Kii, Japan
3 Brasil, Cabo Frio(Omura, 1962)
4 Ayukawa, Sanriku, Japan
5 Bonin Islands, Japan
6 Kyushu, Japan
7 Calamajue, Baja California

Ty7546• eTy7544
eTy7547

"" 30

·;:;

4-<

0

c5

z

20
Sy7518

•

10

1

•

( 5 '~
I ,_, I

6 7
4
40
50
60
30
No. of straight bristles/2.0cm of fringe

23
10

20

Ty754170

80

Fig. 6. Density of the two kinds of baleen bristles by the animals fromvarious localities.
TABLE 4. PROVISIONAL CLASSIFICATION FOR THE TYPES OF BALEEN
PLATES BASED ON THE MEAN DENSITY OF BRISTLES (N0./2.0 cm).
Kind of bristles
Type
Straight

Total

Corresponding animal

Zigzag

I

50

6.5

67

Ty7541, Sy7518

II

10

36.3

43.3

Ty7547, 7544, 7546

III

13

49

62

Ty7543, 7548, 7550
Ns7564, Sy7519, 7521

IV

17.3

58+

76

Ty7549, Sy7520
Ns7563be mentioned later in Addendum and demonstrated in Fig. 12. The result
seems very important external character for the better understanding of an
intraspecific variations though the matter needs still more accumulation offurther evidences. In connection with this the present data concerning to thecharacter in the density of baleen bristles can be summerized by distinguishing
the four provisional types of characteristics in the netting of filtering apparatus(Table 4).
Thickness of straight bristles was observed under the micrometer by
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

0.7

15

O Sy7519
Ty7550Sy751800eTy7549 Ty7544 0Ty7546
Sy7520•0.6
Ty7541•

0.5
Ns7564

E 0.4

s

U)

Q)

0.3
tl
·.:

•

Ty7547
Sy7521 e
0
OTy7548•Ns7563
11

Ty7543

•

12

(a)

13

15

14

..0
.µ

..c:
OJ)

·;;;
b

0.5

Sy7518

U)

Q)

..c:
.µ

... 0.4

Ty7547

0

Q)

<::
u

""~

0.3

Ns7564•

Ty7541

• •

4-<
U)
U)

•
•

Sy7519Ty75440
0 0Ty7550
eSy75200
Ty7546

Ty75-19

O Ty7548
0
Sy?S 2l e Ns7563

eTy7543

(b)

0.2
11

<::

ro

13

12

15

14

Q)

::8
0.4

•••

Ty7549 Sy7520
0.3
Ty7548 Ty7547

c. •

0.2

Ty7541

Ns75640.1

Ts7518•

Ty7543

Ty7546
Ty7550 0
000
Sy7519Ty7544

Sy?~21 e Ns7563
11

(c)

12
13
Body length (m)1415

Fig. 7. Thickness of straight baleen bristles at the base (a), middle (b), and at thetip (c) for 14 animals. Shaded circles are males and open ones are females.

measuring their diameter on five pieces of the bristles per animal at their base,middle, and at the tip, and each measurements were averaged. Measurements
at the base may give the most reliable figures since those bristles, mere or less,might have possibly been damaged. The straight bristles are tapered toward thetip, and grow thicker with an increase in body length (Fig. 7). Each measurement distributes within some reasonable ranges in many animals with varying
trends with their body length. However, as clearly shown in Fig. 7, diameterat the base for Sy7518, Ty7541 and Ns7564 animals were rather unusually thicker
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

16

KAWAMURA AND SATAKE

than the rest while Ty7543 animal was quite thin in the diameter. The former
two are note worthy for their corresponding figure to the type I of baleen plates
which almost or completely lack the zigzagged bristles (see Table 4). Comparing
the figures at the base with those at the middle and tip, the latter two animals,
Ty7543 and Ns7564, both are considered to be rather normally charactered in
the nature of their bristles. No difference by sexes was observed. As far as
the Fig. 7 is concerned, the Bryde's whales which bear on no zigzagged bristles
are furnished with robust and thicker baleen bristles to give a typical characterof general qualities of baleen plates having been b10wn in the 'southern type'of sei whales (Omura and Fujino, 1954). Table 5 shows averaged diameter ofbristles, and Table 6 does similar data obtained in the animals from various
localities. By comparing those figures, it might be suggested that there wereat least two forms of bristles. The first one is very thick bristles of more than
0.5-0.6 mm in diameter at the base, and the second one is more thin bristles
less than about 0.5 mm. In connection with the South African animals (Best,1974), the occurrence of Bryde's whale similar to those offshore form in Japanesewaters is evident. Although the details about animals from various localities
are not known well, all data suggest similar character to those obtained inpresent study. Some animals, however, clearly showed their more prominent
character with finer netting which can be distinguished easily from the anotherextremes.
In addition to morphometrical difference, coloration of the bristles was
distinct in Sy7518 animal : in this respect the bristles of this animal showed
completely creamy white even at the base of bristles while the others showedrather greyish white with brownish coloration at the base.
f) Area of filtering apparatus
The row of baleen plates was measured section by section at both its lengthfrom the gum level to the tip of baleen plates and from the base of palatalridge where the arrangement of minor baleen plates ends to the tip of mainplates. Using this two series of measurement, filter areas which are formed byboth outer surface of a row of baleen plates (expressed by So in Appendix II)
and inner surface (expressed by Si in Appendix II) were calculated on elevenanimals. The filter area for inner surface possibly effects on substantial abilityof animals to straining out the foodstuff engulfed, and consequently, it gives
much larger figures than that formed by the outer surface. The averaged filter
area through examined animals was 1.14 squaremeters for the outer surface
while it was 1.82 squares meters for the inner surface respectively. As we cansee in the column of Si/So in Appendix II, the area for the inner surface keeps
1.46 to 1.76 (Av. 1.61) times larger figures than that for the outer surface. Fig. 8
demonstrates the type of whales by the schema which may be classified by the
relationship of the filter area between both outer and inner surfaces. In theschema the ratio for Si/So in right whale, for instance, may possibly show close
to 1.00 and give a regression of an angle of about 45 degree. When the schemais introduced to the case in Bryde's whale, then the figures can be expressed
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

17

NORTH PACIFIC BRYDE'S WHALE
TABLE 5.

AVERAGED THICKNESS OF BALEEN BRISTLES.

r----'~

Midst______,.____,------''-,_

Str.

Zig.

Str.

Zig.

Str.

Zig.

Ty7541
Ty7543
Ty7544
Ty7546
Ty7547
Ty7548
Ty7549Ty7550Sy7518
Sy7519Sy 7520
Sy 7521
Ns7563
Ns7564

0.49
0. 35
0.59
0.54
0.42
0.36
0.56
0.62
0. 60
0.69
0.49
0. 39
0.32
0.41

0.45
0.28
0.48
0.41
0.27
0. 30
0. 35
0.45
0.44
0.37

0.35
0.27
0.41
0.38
0.35
0.28
0.40
0.42
0.46
0.45
0.37
0.27
0.24
0.27

0.30
0.25
0.32
0.32
0.26
0.22
0.29
0.28
0.32
0.26
0.26
0.20

0. 19
0.22
0.21
0.26
o. 19

0.22
0.18
0. 18
0.21
0.19
0. 16
0.22
0.20
0. 32
o. 17
0.19
0. 14

Av.

0.4879Base

Animal

0.28
0.27
0.23
0.37

0. 19

Tip

0.19
0.29
0.22
0.28
0.23
0.20
0. 13
0.12
0. 12

0.14

TABLE 6. THICKNESS OF STRAIGHT BALEEN BRISTLESIN BRYDE'S WHALES FROM VARIOUS LOCALITIES.
Body
length(m)

Thickness of bristles (mm)
Sex

13. 1
13. l

M
F
F
M

13.4

F

12.5
12.2

Locality
Base

Midst

Tip

0.43
0.58
0.55

0.38
0.32
0.48
0.46
0.40
0.24
0.33

0.29
0.24
0.27
0.31
0.29
0. 18
0.23

0.67
0.64
0.35
0.59
0.46 (0. 19~0.84)
0.49(0.22~1.11)

Baja California 1l
Cabo Frio, Brasil 2l
Oshima, Kii, Japan
Bonin Islands
Cabo Frio, Brasil
Kyushu, Japan
Ayukawa, Japan
South Africa, inshore 3l
offshore 3l

1) Collected by Dr. R.L. Brownell Jr. Baleen plate was possibly not from the largest
part, and no details about the animal are known.
2) For further details, see Omura (1962b).
3) Best (1974).

as given in Fig. 8. As far as the Fig. 8 is concerned, there seems to exist twoslightly different groups among the examined Bryde's whales : one shows morecloser character to sei whale (suggested by line I) and the other does more
likely to Bryde's whale proper (II). One of another data for the filter area
in Bryde's whales is available (Nemoto, 1970). By quoting Nemoto's data,
Kawamura (1974) figured the filter area of slightly less than 1.7 square meters m
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

KAWAMURA AND SAT AKE

18
2.6

II

More closer characterto bryde's whale

2.4

2.2
~

""- More closer character' t o sei/right whales

..§

§ 2.0

"

"t:l

:~

ui

3 1.8

"'
....

"'
§:

"' 1.6
2
bJ)

.s

I

'i'i

/sy751s'0I"' 1.4
<l.)

....

<

1.2
/

1.0

.9/Sy7521/•Ns7564'Right''Sei''Bryde's'

A

~'

"!\so

Si>So

Si >So

Si~So

0.6

1.2
1.0
1.4
1.6
0.8
Area of filtering apparatus, outside (So) (m 2 )

1.8

2.0

Fig. 8. Filter areas for both outside and inside surfaces along with the schema ofshowing area size relationships.

15 meter Bryde's whale. This relative figure well corresponds with the area
found in Sy7518 animal. If we extraporate this size of whale into the regression
as given in Fig. 9, then we will obtain about 2.5 square meters of filter area (seealso Kawamura, 1974, Fig. 8-6). What the above mentioned suggests is that
there might present at least two different types of Bryde's whales both of which
are presumably distinguishable by comparing their filter area. It is still unknown
whether above mentioned grouping is valid for distinguishing the intraspecificvariation in the North Pacific population of Bryde's whales, those figures forfilter area strongly suggest a validity for this purpose of study by accumulating
more amount of data.
Fig. 9 demonstrates the relationship between the areas of filtering apparatus
for both inner and outer surfaces and their corresponding body length. To see
the figure it may be noticed that there are two important characters among
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

9

10

11

12

13

14

15

16

Body Length (m)Fig. 9. Area of filtering apparatus against body length. Black spot and (Si)indicate the filter area for inside surface, and open circle and (So) indicate
the filter area for outside one.

the examined animals. The first is found in relatively small filter areas
compared with body length such as Sy7518 animal. The second one is found inboth Sy7521 and Ns7564 animals. It should be noted, however, that these latter
two animals do not differ from the relationship shown by the majority attheir outer surface area (So), but agree well to the regression in general. By
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

20

KAWAMURA AND SA TAKE

consulting also with the data given in Table 2, the filter area for the inner surface
in two above mentioned animals would be on the half way of quite rapid
development by growing their width of skull or a corresponding structure at
somewhere around 10-11 meters in body length while the filter area of outersurface remains unchanged so much. That is, the smaller animals in their bodylength are narrower in their skull or head dimensions than the larger animals.
Relative increase in the size of head region with growth is a well known
evidence through several species of baleen whales (e. g. Mackintosh and Wheeler,
1929; Matthews, 1937, 1938) and, similarly, growth in width of skull could bealso considered.
Apart from the main purpose of the present study, it is also suggested by
the unusual figure in those above mentioned two animals that they might had
been under a quite rapid development in their feeding apparatus. A rapid
development in the structure relating to more active feeding, which is said tooccur in coincidence with the weaning of animal, has been known both in somedolphins such as Stenella (e. g. Perrin 1975a, b) and in baleen whales (Mackintosh
and Wheeler, 1929). According to Mackintosh and Wheeler (1929), the southern
blue whale weans at 16 m, and relative size of its head increase from 15.3%(13.5 m in body length) to 21.2% (26.5 m). Similarly, mean curve for the growthof baleen plates in fin whale changes steeply pointing upward at 12.0-14.5 m ofbody length (Mackintosh and Wheeler, 1929).
More recently, Best (1974) reported that a stranded female Bryde's whaleof 8.5 m (28 ft) was found to be a calf under suckling with only remains of milkin her stomach. By considering these facts along with the result obtained inthis study, it seems then that both Sy7521 and Ns7564 animals might have
weaned slightly before of the current season, and supposed to be under aphysiological condition between nursing and adolesecence. Their weaning might
took place at somewhere around 8-9 meters in body length. From these
considerations the difference in the areas of filtering apparatus in both Sy7521
and Ns7564 animals could be supposed quite normal. In summerizing the data
concerning to the filter area only one animal, Sy7518 showed a quite small
filter area against its body length and it may be one of significant external
characters which make the animal be distinguished almost completely from theothers.
DISCUSSION

As it has been mentioned in the previous sections, the Bryde's whale which
occurs in the Sanriku region during mid summer shows to some extent themorphological variations by each animal in its external characters; someshowed quite different external characteristics from the others in a measurement
or a nature over the general appearance of body while the matter wascompletely different from each other in another respect of observations. As tothe purpose of this study, which aims to find out some valid external characters
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

21

NORTH PACIFIC BRYDE'S WHALE

for distinguishing the difference of animals by localities the matter seems,
therefore, to go into fairly complexities when the animal is examined moreclosely.
To make the matter more clear the results which have been mentioned
elsewhere in the previous sections were summerized in Table 7. From this table,
it may be obvious that an animal, Sy7518 was quite distinct in its external
characters in many observed respects which enable the animal be distinguishedwell from the rest. Another two animals, Sy7519 and Ty7541, will come to thenext but more less characteristic than the former. The another six animals
differed to some extent only in one or two items of observations and/or
measurements. When we consider about those results or evidences, it can besaid in general that an actually important morphological variation could befound in the difference of the character of filtering apparatus and relating
functions or structures such as the number of ventral grooves and filter area.
TABLE 7.

DISTINCT EXTERNAL CHARACTERS FOUND IN NINE BRYDE'S WHALES.
CONCRETE DETAILS FOR THE PARTICULARS ON THE LEFT
COLUMN ARE FOUND IN APPENDICES, TABLE, AND
FIGURES GIVEN ELSEWHERE IN THE TEXT.
Sy

Ty

Sy

Sy

7518 7543 7519 7521
Scarring
No. of ventral grooves
Proportion
Creamy white baleen series
Length of baleen series
Shape of baleen series
No. of baleen plates
Breadth-length ratio forthe largest baleen plate
Density of baleen bristles
Thickness of baleen bristles
Area for filtering apparatus

Sy

Ty

Ty

7520 7546 7541

Ty

Ty

Ns

7547 7544 7564

+
+
+

+
+
+

+

+

+

+

+

+
+

+

+
+
+

+

+

+

+

+
+

As it was shown in Table 4 and Fig. 5, the difference in the density andgeneral appearance of baleen bristles in addition to the filter area may be one of
the most important characters which are valid for distinguishing the intraspecificvariations at least in the North Pacific Bryde's whales. Unfortunately wehave had no occasion to examine the baleen plates and the bristles of both
inshore and offshore forms of Bryde's whales in South African waters (Best,
1970; 1974), and it is still unknown whether or not all animals examined inthis study belongs to those offshore form. However, as far as the descriptions
by Best (1970; 1974) are concerned, the Bryde's whales examined in this study
should belong to the offshore form without any exceptions as stated previously
by Omura (1959). Since those more sei-whale-like Bryde's whale in the shape
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

22

KAWAMURA AND SAT AKE

of baleen plates have not been known at present from the North Pacific region,'
it may be possible that the animals other than Sy7518 and possibly Ty7541 could
be considered as rather an inshore like type of character among the North
Pacific Bryde's whales although the habitat for both types of whales, as far as
the catch location is concerned, does not seem different from each other.
The recovery of whale tags suggests that most of Bryde's whales occur
during winter in the waters of Bonin Islands head directly to Sanriku region
in the following northbound migrations but some of them also head to bothKii and Kyushu regions although some animals headed to Kii region may enter
finally into the Sanriku region (Omura, 1974). Recent tag recovery suggeststhat one of Bryde's whales in the south-western -of the North Pacific, which
was tagged at 02°20'N, 135°26'E, on 4 February 1975 was found to be relating
to the so-called North Pacific pelagic stock by recoverying the tag at 29°20'N,
175°20'E on 19 July 1975. The baleen plates which were collected previously in
the Bonin Islands waters, as examined and classified by four types in this study(see Table 4), do not include such character of more finer netting with many
zigzagged bristles.
According to Omura (pers. comm.) all baleen plates of Bryde's whales
examined at Bonin Islands were those robust nature ones with coarse and thicker
bristles (see Plate III, figs. 1-2). These characters are considered very similar
to those found in Sy7518 animal which is, at present, supposed to be very scarceamong the Bryde's whales caught throughout the whaling season in Sanriku
region (it occupies the share of only about 7.0 percent of total catch in thisstudy). When we consider this along with whale movements by the recovered
tags, there might occur some changes such as niche shifts among Bryde's whale
populations that make northward migrations close to the northern Japan. When
we assume that majority of Bryde's whales in the Bonin Islands waters migrate
up to Sanriku region, then the question arises where those more sei-whale-like
Bryde's whales come close to that region and/or whether any possibilities tooccur these whales too in the Bonin Islands waters.

CONCLUSION

Although no decisive conclusion was drawn in this study, it may be said that
there occurs at least two types of Bryde's whales in the waters off Sanriku
reg10n. It is still unknown whether or not they could be called as allopatric* There is only one baleen plates which suggests the occurrence of inshore form of Bryde's
whale in Japanese waters (see Best, 1974, fig. 4). We examined the same baleen plate again
and found that the specimen lacks some inner most part by damage (Breadth: 14.0 cm,
Length: 35.0 cm). The bristles of baleen plate were really finer than the ordinal ones (seeTable 5 in the text). However, the position from where the specimen was collected is
unknown. As it was shown in Fig. 4 in the text the width-length ratio for baleen plates varies
much with the position in baleen series, the treatment for this specimen seems better to beheld for the time being.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

23

forms untill we will have more information on their reproductive conditions.
One of them, however, clearly shows analogous characters with the animals
known in Bonin Islands waters, but it occurs with less prominent among thenumber of migrating animals head to Sanriku region. The external characterswhich make both types of Bryde's whales be distinguished from each other arevery slight, and could not be distinguished by an overall treatment of the data
since those chracteristics in external characters might be greatly reduced bydilution through the analysial process.
Addendiim
In the course of finishing the manuscript there was an opportunity to
examine the baleen plates of Bryde's whales caught in both Kyushu and pelagic
region of the northern North Pacific through the courtesy of the Far Seas
Fisheries Research Laboratory, Fisheries Agency. The obtained result· seems
to contain some indispensable evidence and worth to be presented here for thefurther corn parison and considerations of concerning to those racial problem
in the North Pacific population the Bryde's whales.
One of present authors (A. K.) made the baleen plate measurements on
thirty-eight animals from the catch in Kyushu region and thirteen animals fromthe pelagic waters of the northern North Pacific. As to the thickness and thedensity of baleen bristles, 17 out of 51 materials were counted and measured
their diameter at the base by following similar procedure as having been
described in the previous section. Although the number of animals and materials
above mentioned consists only a part of total catch figures for both regions,animals to be examined were selected randomly from the bulk of material kept
at the above mentioned laboratory, and the result can be considered to represent
the whole.
In regard to the relationships between width and length in largest baleen
plates, it was clearly shown that the length of baleen plate against its width
in the animals from pelagic region of northern North Pacific was undoubtedly
larger enough to be distinguished from the majority being found in the animals
from the waters off the west coast of Kyushu except one instance (Fig. 10;
Plates VI, VII). In the material from Kyushu, there found no such slim shaped
baleen plate as mentioned before, and each baleen plate was rather small but
furnished with more thicker bristles than the former and robust nature in
general. It should be noted that there were no baleen plates which exceeded
31cm or more in their overall length in the materials from Kyushu, and also
there were no overlapping figures of baleen plate dimensions between the
populations of both the pelagic waters of the North Pacific and the coastal waters
off Kyushu. In comparison with the results found in Sanriku region, figures
for width-length relationships were shown by encircling them with broken line
(Fig. 10 and, see also Fig. 3). With this figure the isolated plots for both North
Pacific pelagic and Kyushu are completely filled up by overlapping each other,and make Fig. 10 be completed as to present a series of variation in the shape
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

24

KAWA MURA AND SAT AKE

42

i

;!;

: Male and female forNorth Pacific pelagic

40

38

6

! t

: Arakawa, Kyushu: t: Tamanoura, Kyushu

36

~
00

3

c."'

34

"'"' 32

<ii"'

.0
~

0

.s 30
""
"'"'
....l

28

26 -

24

22

Width of baleen plates (cm)Fig. 10. Width and length relationships of largest baleen plates for the animals caught
in the North Pacific pelagic and in the coastal waters off western Kyushu .

......

0.7

a

0

0

• •

5 0.6

o
o

Q)

tl

ii 0.5~//•-----.,,,,,,...-----.....0

.6

0.4

''~

.!<:

u

//

- - _____ - _____.......

..- /_......

I

I

I

/
/

/~

00

/

(/)

~

0

--M

...... - /

(/)

,,,,

--,

,/''

/

,,.,,.,

.6.

/ .6.

:.a
E-< 0.3 ' - - - - - - - ' - - - - - - - ' - - - - - - _ L_ _ _ ___J__ _
10

11

12

13

14

Body length (m)Fig. 11. Thickness of straight baleen bristles at the base for the animals both Kyushu
and North Pacific pelagic. Plot distribution for Sanriku region is indicated by anencircle. Shaded circles indicate the animal from Tamanoura, open ones from Arakawa,and triangles are from the North Pacific pelagic.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

25

NORTH PACIFIC BRYDE'S WHALE

TABLE 8. THICKNESS AND DENSITY OF BALEEN BRISTLES OF BRYDE'S WHALESBOTH FOR KYUSHU AND FOR THE NORTH PACIFIC PELAGIC REGIONS.
Range of
Averaged no. of
No. ofNo. ofthicknessstraight A''.eraged bristles/2.0 cm
animal for straight bristles thicknessof fringe
examinedbristles,---'~
measured (mm)(mm)
straight zigzag
30.244-0.647

3

0.388-0. 734

64

0.316-0.691

44
22

0.437
0.545

15.0
8.0

38.0+
32.0

4

66
30
50

0.491

0.496-0. 766
0.334-0.637

0.635
0.523

11. 5
16.25
16.0

35.0
12.25
20.5

3
11

0.453-0. 710
0.428-0. 704

24
104

0.609
0.589

9.0
13. 75

20. 7
17.82

Remarks

NPP-3N, 1972 1l
NPP-3K, 1974 2 J
Av. for both NPP-3N & NPP-3K
JCAK, 1973 3 J
JCAK, 1974
JCTK, 19744 J
Av. for both JCAK & JCTK

1) North Pacific, pelagic, Nisshin Maru No. 3.
2) North Pacific, pelagic, Kyokuyo Maru No. 3.
3) Japan, coastal, Arakawa land-station, Kyushu.
4) Japan, coastal, Tamanoura land-station, Kyushu,

of baleen plates from northern to southern regions.
The thickness for straight appearance of baleen bristles and the densityof bristles are given in Table 8. The averaged thickness for the pelagic
population of the northern North Pacific was 0.491 mm while that for the Kyushu
region was 0.589 mm. When these figures along with their body length werecompared with those in Sanriku region (Av. 0.488 mm, Table 5), it can be said
that the baleen bristles for Kyushu are distinctly thick enough to be separated
from those in another regions (Fig. 11), and overall figures for the Sanriku
population make complete the thickness distribution for both the North Pacificand Kyushu populations as it was seen in the width-length relationships forbaleen plates.
Density of baleen bristles in terms of the number of straight and zigzag
shaped bristles per 2.0 cm of baleen fringe differed much between two above
mentioned regions : the density for zigzagged bristles in the North Pacificpelagic animals was 35.0 bristles/2.0 cm on average whereas it was only 17.82
bristles/2.0 cm in Kyushu animals. The former seems to correspond to someof types II to IV of baleen plates (Table 4) and the latter would possibly beto type I. An important character in the density of bristles is not the absolute
number or abundance of bristles but relative dominancy between straight andzigzagged shape of bristles since baleen fringe is apt to be damaged throughmany occasions prior to examination. When the number of straight baleen
bristles is plotted against that of zigzagged ones, it is clearly noticed that very
little number of zigzagged bristles are found in the animals from Kyushu, while
they are more prominent in the animals from the pelagic waters of the northern
North Pacific. The latter shows well coincidence with the character of baleen
bristles found in the animals from Sanriku region (Fig. 12).
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

KAWA MURA AND SAT AKE

26
70+ Sy7520

Q)

g 60
~

,,,-,

......
0

E 50
u

I

I

q

...__

/
I/',
I

I

""

I

<fJ

~<fJ 40
·;:::

•'I

.A.II

..0

I

"b

\ ... / 0

"

~
~

OS

N
~

'I

/

I

30
0

''1
......

Jt,.

0

z 20
ci

oLl
0

0

0
0

Jt,.

10

Sy75180+0Ty7541
10

20

30
40
50
60
No. of straight bristles/2.0cm of fringe

70

80

Fig. 12. Density of the two kinds of baleen bristles for the animals from
Kyushu and North Pacific pelagic. Corresponding distribution for Sanriku
region is indicated by an encircle and cross marks. Open circles indicate
the animal from Kyushu and triangles indicate that from the North Pacificpelagic.

TABLE 9. STOMACH CONDITION FOR FIFTY-ONE BRYDE'S WHALESWHICH BALEEN PLATES WERE ADDITIONALLY EXAMINEDFOR THE COMPARISON OF PRESENT STUDY.
Sardine Mackerel Fish Unknown 1l Unknown 2l Euphausiid Empty
May
Arakawa3l

June

2

July

4

August13

93

September
Tamanoura

rune
July
AugustNorth Pacific {Julypelagic 4l August

5
2

8

2

I) Unknown kind of stomach contents.
2) Unknown whether there were any food or not.
3) Data for both 1973 and 1974 are combined.
4) Data for both 1972 and 1974 are combined.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

27

The result which was found by treating the materials under grouping eachindividuals suggests that the filtering apparatus in the animals of the North
Pacific pelagic region is structured more finer in its netting than those of
Kyushu region, and that the animals in Sanriku region shows an intermediatecharacter as a whole. However, it must be remembered that there were somuch variations in the latter animals. To support this tendency the stomach
condition for the animals of both North Pacific pelagic and Kyushu is given
in Table 9. The kind of food organisms in Kyushu region is represented bymackerel, sardine and some small fishes, which are somewhat similar to thatfound in Sanriku region, while euphausiids predonimated in the animals caught
in pelagic region of the northern North Pacific.
To summerize the result presented as addend'itm, it may be said andspeculated to some extent that there must be two possible different populationsof Bryde's whales in the northwestern North Pacific region: the first one ischaracterized by relatively longer and finer netting of baleen bristles, and isfound in the pelagic waters of the northern North Pacific where they prey on
the euphausiids and small swarming fishes. The second one, on the other hand,
is found widely over the waters off western Kyushu, which sometimes extend
even to the midst of the Yellow Sea. Animals found there carry very small but
more coarse netting in filtering apparatus, which is possibly similar characterto that has been found in Sy7518 animals in the Sanriku region. The Bryde's
whale population off west Kyushu is possibly consisted of the animals both fromsouthern waters of the western Pacific and of an endemic populations possibly
from the Yellow Sea and the East China Sea regions. The animals caught in
the Sanriku region show an intermediate external character in an overall
treatment by dilution but each animal can be distinguished as to be placed in
one of both above mentioned extremes. This suggest a possible mingling ofdifferent populations in that region. The Bryde's whales in Bonin Islands keep
migratory relationships to Sanriku region, but it is still unknown whether or
not they show a similar external characters to those have had been known
previously in that region. If there were no niche shifts and Bonin Islands
population has been remained unchanged in those region, then a considerable
invasion of the North Pacific pelagic population into the Sanriku region must
be considered so as to give an intermediate characters for the population in
Sanriku region.

ACKNOWLEDGMENTS

We are much indebted to the whaling land-stations of Taiyo Gyogyo K. K.,
Nippon Hogei K. K. both in Ayukawa and of Nippon Suisan K. K. in Onagawa
for their kind assistance and offering their facilities in collecting the data andmaterials through this work. Courtesy of the Whales Research Section of the Far
Seas Fisheries Research Laboratory, Fisheries Agency in Shimizu made us enable
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

KAWAMURA AND SAT AKE

28

to compare the result on the animals in Sanriku region with that both inKyushu and in the pelagic region of the northern North Pacific. Personally, we
are indebted to Dr. Seiji Ohsumi of above mentioned laboratory for permittingof our sampling the baleen bristles, and also Mr. Siro Wada of the samelaboratory for prepering and assisting our laboratory work in Shimuzu. Without
their kind help no data were available for the animals both in Kyushu andin the northern North Pacific, and these circumstances are greatly appreciated.

REFERENCES
BEST, P. B., 1970. Two allopatric forms of bryde's whale on the west coast of South Africa.
Paper submitted to Scientific Committee, 22nd Meeting of IWC, Sc/22/15.
BEST, P. B., 1874. Two allopatric forms of bryde's whale off South Africa.
Scientific Committee, Special Meeting, La Jolla.
JAPAN METEOROLOGICAL AGENCY, 1975.

The ten-day marine report.

Paper submitted toNos. 1037-1038.

KAWAMURA, A., 1973. Food and feeding of sei whale caught in the waters south of 40°N in
the North Pacific. Sci. Rep. Whales Res. Inst., 25: 219-236.
KAWA:VJURA, A., 1974.
KOMAKI, Y., 1967.
448.

Food and feeding ecology in the southern sei whale.

On the surface swarming of euphausiid crustaceans.

MACKINTOSH, N. A. and J. F. G. WHEELER, 1929.
I : 257-540.
MASAKI, Y., 1975.
bryde's whales.

Ibid., 26: 25-144.

Pacific Science, 21: 433Discovery Rep.,

Southern blue and fin whales.

A provisional study on the subpopulations for the North Pacific stocks ofGeiken Tsushin, 288: 61-66. (in Japanese)

MATTHEWS, L. H., 1938.

The humpback whale, Megaptera nodosa.

MATTHEWS, L. H., 1938.

The sei whale, Balaenoptera borealis.

Discovery Rep., 17: 7-92.

Ibid., 17: 183-290.

NEMOTO, T., 1959. Food of baleen whales with reference to whale movements.
Res. Inst., 14: 149-290.
NEMOTO, T ., 1970. Feeding pattern of baleen whaes in the ocean.
Steele( ed.), Oliver & Boyd, Edinburgh, 552 p.

Sci. Rep. Whales

In: Marine food chains. J.H.

Sci. Rep. Whales Res. Inst., 14: 1-33.

OMURA, H., 1959.

Bryde's whale from the coast of Japan.

Olv!URA, H., 1962a.
7-18.

Further information on bryde's whale from the coast of Japan.

OMURA, H., 1962b.

Bryde's whale occurs on the coast of Brazil.

OMURA, H., 1966. Bryde's whale sn the northwest Pacific.
(ed. K.S. Norris): 70-78. Univ. Calif. Press.

Ibid., 16:

Ibid., 16: 1-5.

In: Whales, Dolphins and Porpoises.

OMURA, H., 1974. Review of the bryde's whale stock in the northwest Padific.
to Scientific Committee, Special Meeting, La Jolla.

Paper submitted

OMURA, H., S. NISHIMOTO, and K. FUJINO, 1952. Sei whales (Balaenoptera borealis) in theadjacent waters of Japan. Japan Whaling Association, pp. 1-80.
OMURA, H., and K. FUJINO, 1954. Sei whales in the adjacent waters of Japan.
studies on the external characters. Sci. Rep. Whales Res. Inst., 9: 89-103.

II. Further

OMURA, H., and T. NEMOTO, 1955. Sei whales in the adjacent waters of Japan.
between movement and water temperature of the sea. Ibid., 10: 79-87.

III. Relation

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

29

PERRIN, W. F., 1975a. Variation of spotted and spinner porpoise (Genus Stenella) in the eastern
Pacific and Hawaii. Bull. Scripps Inst. Oceanogr. Univ. Cali]. 21: 1-206.
PERRIN, W. F., 1975b. Distribution and differentiation of populations of dolphins of the genus
Stenella in the eastern tropical Pacific. ]our. Fish. Res. Bd. Canada, 32(7): 1059-1067.
WILLIAMSON, G. R., 1973. Counting and measuring baleen and ventral grooves of whales. Sci.
Rep. Whales Res. Inst., 25: 278-292.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

KAWAMURA AND SAT AKE

30

APPENDIX I.

BODY PROPORTIONS OF THE BRYDE'S WHALES

Serial No.

Ns7564

Ty7547

Sex

Male

Male

Body Length (m)Length, row of baleen plates along gum level
Length, anterior end to largest baleen plates in baleen series

10. l

11. 2
10.8

Length, largest baleen plate
Length, palatal ridge
Spread of filtering apparatus across both sides (maximum)

18.81
6.53

Width, palatal ridge close to anterior end
Ratio, item 6/item 5
Spread of arch across both lower jawbones (maximum)

0.84

8. 75
I. 07

0. 35
8.61
12.27

10.09

Distance between right and left side ridges at their anterior end

I. 98

I. 12

Distance between right and left side ridges at their posterior end

5.34

Distance, tip of snout to anterior end of side ridges
Distance between both depressions of Yabobson's organ

0. 12

0.09

0.64

0.67

Length, side ridges on the head

Distance, tip of snout to Yakobson's organ
Distance, Yakobson's organ to anterior end of baleen series
Length, dorsal fin (anterior insertion to tip)

13. 30

5.00

Length, dorsal fin at base
Height, dorsal fin (fin tip to base)

3.86

2. 77

Concavity, dorsal fin (deepest part of posterior border to line between fin tip
and posterior base)

3.80
2.41
I. 07

Length, flipper (posterior insertion to tip)
Length, flipper (anterior insertion to tip)

11. 58

8.81

10.09
14.29

Width, flipper (maximum)
Length, fluke (notch to tip)

2.37
11. 882.50
12.86

Length, fluke (anterior insertion to tip)

13.93

Width, fluke (shortest distance between anterior border of flukes and notch)

6. 13

6.34

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

31

CAUGHT OFF SANRIKU, NORTHWESTERN PACIFIC IN 1975.
Ty7541 Sy7518 Ty7549 Ty7543 Sy7520 Sy7521 Ty7548 Ty7550 Ty7544 Ty7546 Sy7519
Male Male Female Female Female Female Female Female
Male Male Male
11. 5
28.69
9.91
2.56
20.35
I. 13

10. 26
12.69

12.5
19.20
12.96

12.5

12.6
22. 14

12. 7

19.84
8.88
I. 03
0.45

19.84
8.27
0.94
0.42
9.84
11. 26
0.39

8.95
12.08
2.60
12.43
12.43

11. 2
21. 25
11. 88

13. 7

13. 7
21. 97

14.0
21. 86

14.2
22. 11

4.50
18.64
6.96
0.88
0.37
10.96
11.66

6.80
0.56

0.13
0.65
0. 17
5.04
5.04
2.69

10.8
17.59
10.83

I. 36
0. 16
0.52

I. 11

11. 76

19.93
8. 76
0.88
0.44
9.92
12.07

10.00
9.27

8.29
0.93

8.57
0. 76

I. 02

9.82
11. 30
I. 12
3.57

10. 73
11. 61
I. 53
2. 34

0.54

0. 10
0. 73

0.09
0.66

0.09
0.64

5.58
3.57
2.59

4.82
4.60
2.63

4.57

3. 14
2.04

0.10
o. 76

I. 34
0.91
I. 43

6.56
5.84
2.88

2.48

4.32
3. 41
2.26

2.52

4.91
2.41

I. 28

I. 08

. 0. 67

1.10

0. 74

0.85

0.37

I. 09

0.34

8.24
11. 52
2.60

9.04
12. 72
2.48
13. 12
13.84
6.24

8.49
12. 14
2.53
12. 14

9.61
11. 57
2. 76
12. 13
12.91
6.46

7.96
11. 85
2.32
12.22
13. 15
6.20

8.66
13.26
I. 69
12. 14
12.95
6.25

10.07
14.38
2. 70
12. 7013. 14
6.35

8. 76
13. 14
2.26
12.66

8. 71
12. 79
2.46
12.57

6.22

6.07

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

6.26

0. 12
0.59
4.88

I. 93

20.07
8.02
0.94
0.40
10.98
3.09

0.09
I. 31

32

KAWAMURA AND SAT AKE

APPENDIX II.

MEASUREMENT ON THE FILTERING APPARATUS OF BRYDE'S

Measurement

Ns7564

Sy7521

Ns7563

Length, total (m)10.1
201. 510.8
190. 0

11. 1

190.0
66.0
24.0

27.5

28.5

12.6

14.5

14. 7

1.90

1.90

1.94

Length, row of baleen plates along gum level (cm)Length, row of baleen plates along palatal ridge (cm)
Maximum spread of filtering apparatus across both sides (cm)
Largest baleen plate

Length: L
With: W!

L/W
Number of baleen plates (total)lJ

261

Right
Number of creamy white hairs and plates (number/length) {
Left

282
15/10. 5

?

19

19

19

lO+a 4
10

12
12

18

Number of bristles on largest baleen plate (number/2.0 cm) 3 Zigzag

49

48

52

Total

61

60

0.41

0.39

70
0.34

Number of hair of stump of hairs in baleen series

Anterior{ Posterior

Number of minor plates at largest baleen plates 2JStraight

!

0. 27

o. 27

0.24

0. 13
0. 67
1. 10

0.12

Outside: So
Inside: Si

0. 12
0. 65
1. 04

Si/So

1. 59

1. 65

Averaged thickness of straight baleen bristles (diam. mm) at 1:is;dle
Tip
Areas for filtering apparatus (m 2 )!

I) Definition for so-called baleen plates was based on that by Williamson (1973)
2) Number of small brush-like plates which are arranged between main row of blaeen
plates and the palatal ridge
3) Length of bristles was not measured due to poor condition of preserved materials
for this purpose

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE

33

WHALES CAUGHT OFF SANRIKU, NORTHWESTERN PACIFIC IN 1975.
Serial No. of animal
Ty7547 Ty7548 Ty7541 Ty7518 Ty7549 Ty7543 Sy7520 Ty7550 Ty7544 Ty7546 Sy7519
11. 2

11. 2
238.0

11. 5
237.0
234.0

12.5
240.0
233.0

12.5

12.6
279.0
250.0

12. 7
252+
252.0

87.0
112. 0
96.0
105.0
29.0
32.0
31. 5
33.5
32.5
33.5
17.2
16.5
18.5
18.3
18.5
16. I
2.03
I. 69
I. 73
I. 78
I. 81
I. 96
286
325
266
267+a 2260+a 1-/57.0?/39.0 -/39.0
15/8.59/2.
727~28/8.0-/19.038/19.0 20/11.0
22
23
21
18
23
18
13
21
21
14
12
II
6
7
7
10
14+59·l) 26
17
17
15
10
12
]35J
51
ca.68
34
48
54
44
74
39
66
85
60
73
0. 42
0.60
0.56
0.35
0. 49
0. 36
0.49
0.46
0.27
0.37
0.35
0.28
0.35
0. 40
0.22
0.20
0.28
0.29
0. 19
0.19
0.19
I. 24
1.16
0.97
I. 06
I. 06

98.0
33.0
17.5
I. 89
254
45/27.0

I. 75

I. 76

I. 65

I. 65

I. 65

I. 50

I. 53

I. 81

I. 82

I. 92

I. 46

I. 66

13. 7

13. 7
301. 0
273.0

14.2
314.0
285.0
116.0
114.0
120.0
32.0
33. 7
37.0
36.0
22.0
21. 2
20.5
21. 0
I. 75
I. 75
I. 60
I. 45
273 or 283
3ll+a 3 293
50/22.0 24/- 27/17.0-/26.0 23/6. 7 53/38.0
1012
17
25+a 1730+a 21
II
13
II +a 4 II
13
II
9
14
47 5l
37 5l
38
51
48
47
60
65
0.62
0.59
0.54
0. 69
0. 41
0.42
0.38
0.45
0.22
0.21
0.26
0.23
I. 32
I. 48
I. 43
I. 53
2.32
2.20
2.44
2.31
I. 49
I. 71
I. 76
I. 51

4) 15 thick long bristles and 59 slender ones of straight features
5) Not heavily zigzagged features of almost straight.
Possible number for alpha letter:a=unknown, a 1 =10-15, a 2 =20, a 3 = 1-2, a 4 = I, respectively

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

14.0
298.0

34

KAWAMURA AND SAT AKE

EXPLANATION OF PLATESPLATE I
Fig. I. Baleen plate of type I (see Table 4 in the text): Sy7518 animal of 12.5 m,
male caught at 34-56N, 145-37E on 24 July, 1975. Ayukawa, Sanriku, Japan.
Fig. 2. Baleen bristles of the above ·animal.
Fig. 3. Baleen plate of type II: Ty7547 animal of 11.2 m, male caught at 37-16N,
144-58E on 1 August 1975. Ayukawa, Sanriku, Japan.
Fig. 4. Baleen bristles of the above animal.
PLATE II
Fig. I. Baleen plate of type III: Sy7519 animal of 14.2 m, female caught at 36-00N,
146-12E on 27 July, 1975. Ayukawa, Sanriku, Japan.
Fig. 2. Baleen bristles of the above animal.
Fig. 3. Baleen plate of type IV: Sy7520 animal of 12.7 m, male caught at 37-16N,
146-lOE on 30 July, 1975. Ayukawa, Sanriku, Japan.
Fig. 4. Baleen bristles of the above animal.
PLATE IllFig. I. Baleen plate of No. 134 animal of 13.08 m, female caught in the waters of
Bonin Islands on 15 May, 1950.
Fig. 2. Baleen bristles of the above animal.
Fig. 3. Baleen plate of Bryde's whale from Kyushu, southwestern Japan. No details
about the animal is known.
Fig. 4. Baleen bristles of the above animal.
PLATE IV
Fig. I. Baleen plate of No. 16 animal of 12.19 m, female caught at 33-35N, 136-25E
on 31 May, 1952. Ohshima, Kii, Japan.
Fig. 2. Baleen bristles of the above animal.
Fig. 3. Baleen plate of No. 19 animal of 13. 41 m, female caught at 37-07N, 141-20E
on 4 July, 1953. Ayukawa, Sanriku, Japan.
Fig. 4. Baleen bristles of the above animal.
PLATE V
Fig. 1. Baleen plate of 13.11 m (43ft), male animal caught at 23-13S, 41-53W on
14 September, 1961. Cabo Frio, Brasil (see also Table 2 in Omura, 1962 for body
proportions of this animal).
Fig. 2. Baleen bristles of the above animal.
Fig. 3. Baleen plate of 12.5m, male animal caught at 22-56S, 41-52W on 27 September,1960. Caba Frio, Brasil (see also Omura, 1962). Note completely different shape andcharacter of this specimen from the above shown one.
Fig. 4. Baleen bristles of the above animal.
PLATE VI
Fig. I. Baleen plate of 10.9m, male animal caught at 32-36N, 128~05E on 10 August,
1974, Tamanoura, Kyushu, Japan.
Fig. 2. Baleen bristles of the above animal.
Fig. 3. Baleen plate of 11.2 m, male animal caught at 31-42N, 128-51E, on 13 June,
1973, Arakawa, Kyushu, Japan.
Fig. 4. Baleen bristles of the above animal.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

NORTH PACIFIC BRYDE'S WHALE
PLATE VII
Fig. I. Baleen plate of 13.1 m, female animal caught at 37-41N, 167-05E on 9 July,
1972, pelagic region of the northern North Pacific.
Fig. 2. Baleen bristles of the above animal.
Fig. 3. Baleen plate of 13.6m, female animal caught at 37-07N, 168-41E on 9 July,
1972, pelagic region of the northern North Pacific.
Fig. 4. Baleen bristles of the above animal.

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

35

I:
:
I.
LVi
c
i

し ／f
l
ザ.
f3ll

9ど6!'
8
?
:"
ON
f
3
]
V
l
/
J
l
‑
1・r
f
a
H ・：
1
s

ヨ
！
）VムVS(IN V Vllf
凡附 Vt¥
へ・V)[

PLATE 1
1

S
c
i
. Re
戸
. WhalesR
e
s
.I
n
s
t
.
,

N
o
.2
8
,1
9
7
6
.

。

'
9
L
6
1'
8
l ・oN

＂

ザ
ル1≪
/
a
u・ S

E／
・l
'
l
l/ 'SJ(J SJJlJ

＠−

ヨ
下l
v.
1vsa:
‑
.
i
vv<1n附 VN¥V予
｛

I
ll 3.
.
LV1d

KAWA恥fURA .
¥N DSATAKE

PLATE I
V

1
0

：・

＠
S
c
i
.R
e
p
. WhalesRes.l
1
1
s
t
.
,

No
.2
8
,1
9
7
6
.

八 :
J.
LV1d

・
9
ど6
￡ 06 '
ON
"1SU
[・
s
a
uSl/Vl{Jl1 ・
Q
l
l
l・
！
＇S

ヨ
！
）VJ.VS O NV v ~ n 附 V.V\ ¥i)IPl.ATE VI

KA'v¥IAMURA ANDSA1・
AKE

S
c
i
. Re
戸 Whal
e
sRe
s.I
ns
t
.
,
.
V
o
.2
8
,1
9
7
6
.

Vld
.¥ 3J.
I
I

: 'ON
?
8
1'
6
L
9
'
'S
!
u'
a
f
11・t
1
1
1
v
7
a
ys
a
1・s
u
s
1
"

V V~l nJぺ \IN\ V:t
:
¥
J
T
SC
i
¥
L
.
tV.
3: