FIN WHALE SUBPOPULATIONS IN THE ANTARCTIC
WHALING AREAS II, III AND IV
KAZUO FUJINO
Investigation on identifying breeding populations of wild-life is not only ofsignificance as the first step of the stock assessment for management of the commercially exploited animals in fisheries, but also itself provides the biological bases forthe physiological and the ecological studies and for the population genetics. For thispurpose, marking investigations which were initiated by the ' Discovery Committee' in 1932 have been succeeded by the National Institute of Oceanography,
United Kingdom. This program has been continued under a scheme for the international co-operation since 1953 (Clark & Brown, 1957). Bi-lateral investigations
under the immunogenetical concepts were commenced in 1960/61 season (Fujino,1962).
Reviewing knowledges obtained so far in relation to identification of stocks,
major results of marking investigations for the Antarctic fin whales reported byBrown (1954 a, 1954 b, 1962 a and 1962 b) can be summarized as follows. 1)
There distribute one or more populations in each area of the Antarctic whaling
grounds. 2) Different stocks from separate breeding areas mingle in the feeding
grounds each other. 3) The majority do not disperse more than 50° east or westof the positions of marking.
Basing upon the blood typing investigation which was undertaken in the 1960/61
Antarctic whaling season for the first time, Fujino (1962) states that there distributeat least two populations of fin whales which have different incidences of Ju blood
types each other in area III and that this support the items 1) and 2) of the resultsof marking investigations stated above.
When the migratory ranges of different populations overlap each other, situation of problems concerned becomes to be much more complicated. After summarizing results of blood typing study obtained during three seasons from 1960/61
to 1962/63 and of marking investigations undertaken since 1932/33 season, thepresent paper deals with problems in 1) identifying breeding subpopulations, 2)
migratory ranges and rates of intermingling of different populations in the feeding
grounds of the Antarctic, and 3) some problems in physiology and in ecology relating to the differences of population.
The author acknowledges co-operation in collecting and transporting blood
specimens of inspectors, biologists, and officers and crews of the whaling factoryships. Staffs of the Kyokuyo Hogei Company kindly offered some detailed logs
on their whaling operations. The author would like to express his sincere thanks
in using the precious materials which were compiled from a series of publicationsof Mr. S. G. Brown, National Institute of Oceanography, United Kingdom.
Sincere thanks also due to Dr. H. Omura, Director of the Whales Research

K. FUJINO

2

Institute who organized extensive collection of bloods, Dr. E. Matsunaga at the
National Institute of Genetics and Dr. Y. Nose at the University of Tokyo whogave to the author valuable suggestions and advices.
BLOOD TYPING INVESTIGATIONS
Relative incidences of hereditary characteristics, of which the phenotypes reveal
polymorphism, are of worth as genetic marker for identifying isolated breeding populations. Blood type antigen is generally inherited in simple way, so that it is understood to be one of the most useful characters for such analysis. In the present
investigation, Ju blood type system was utilized similarly to that in the previous
paper (Fujino, 1962)
Materials and Methods
Bloods spout out from the cut at the tip of snout or in the palate or
remaining in the heart were collected into 50 ml. plastic bottles. In 1960/61 season,
the fresh samples were used for examination which was made on board Kyokuyomaru no. 2. In 1961/62 and 1962/63 seasons, the samples were collected by inspectors boading on Japanese seven whaling factory ships, and were successively
kept frozen until the examination was undertaken at the laboratory of the '!\Thales
Research Institute, Tokyo. As shown in Fig. 1, localities, where blood specimens
were taken, cover areas II, III and IV, including lower latitudinal portion of area
III of north of 50° south. Number of whales examined and their percentages against
the catch in each year was shown in Table 1. Approximately 6000 fin whales were

Whale bloods

TABLE 1.

NUMBER OF BLOOD SAMPLES EXAMINED IN THE THREESEASONS DURING FROM 1960/61 TO 1962/63

No. of samples
examined*

No. of fin whales
taken byJapanese fleets

1960/61
1961/62
1962/63

1,266 (14.2%)
2, 188 (18.5%)

8,912
11,861

2,483 (23. 7%)

10,475Sum

5.937 (19.0%)

31,248

SeasonRemarks
Tested for fresh samples+}

Tested for preserved samples(Cushing et al., 1959)++* Samples, from which no cells were recovered, are excluded. In addition 21 and 41 whales
were examined in 1961/62 and 1962/63 respectively, but no information was given. Numbersof hemolysed samples are 244 and 240 in the seasons 1961/62 and 1962/63 respectively.
Figures in parentheses show percentages of samples examined against total catch.
+ Examination was made on board Kyokuyo-maru no. 2 only.
++ Collected by inspectors and biologists boarding on Japanese seven whaling fleets.

examined during the three seasons, and this corresponds 19.0 per cent of the total
number of this species taken by Japanese fleets in these periods.
Reagents After being diluted and absorbed, were used the following serums whichwere prepared by immunizing fowls or rabbits intraveneously with Jul type or Ju2positive type erythrocytes of fin whales.

ANTARCTIC FIN WHALE SUBPOPULATIONS

3

Anti-Jul immune fowl serums nos. 47 and 70
Anti-Ju2 immune rabbit serum no. 34
Anti-Ju2 1 immune rabbit serum no. 61
Anti-Ju2 5 immune rabbit serum no. 65
A part of each serum of no. 47 and no. 34, being prepared by injecting the erythrocytes of the north Pacific fin whales, had been used in the previous investigations(Fujino, 1960 & 1962). Serums nos. 61, 65 and 70 were prepared by immunizing
with erythrocytes of the Antarctic fin whales which were taken in 1961/62 season
and were successively stored by glycerol-freezing (Cushing et al., 1959).
Testing methods Test-tube method and slide-glass method were used for blood
typing tests. To treat the large numbers of specimens taken in the 1961/62 and
1962/63 seasons efficiently, were made the following procedures. At first, allsamples obtained during one whaling season were tested by 1 : 10 diluted anti-Ju2
no. 34 or 1 : 10 diluted anti-Ju2 5 no. 65 serums which were in advance sufficiently
absorbed with Jul cells. After being classified into Jul and Ju2-positive groups
by these tests, the samples of the latter group were subdivided into sub-specificities
of Ju2 antigen complex, and were successively identified as heterozygous or homozygous types.
Reagents for subtyping five specificities in Ju2 antigen complex were prepared by absorbing nos. 34 and 61 serums with various subtypes of erythrocytes.
A part of these absorbed reagents, being used for testing 1961/62 samples, were kept
frozen for about one year to be used for 1962/63 samples.
Classification and Genetics of Ju Blood Groups

In the previous paper, Fujino (1962) states that bloods of the Antarctic fin
whales can be classified into three major types of Jul homozygote, Ju1·2 heterozygote, and Ju2 homozygote similarly to those of this species in the North Pacific
TABLE 2.

FIN WHALE JU BLOOD TYPES CLASSIFIED BY SIX KINDS
OF ANTISERA*

Jui homozygote**

Specificity ofreagents**
Anti-Jui
Anti-Ju2 5
Anti-Ju2 4
Anti-Ju2 3
Anti-Ju2 2
Anti-Ju21

I***+

Jui• 2 heterozygotes**

Ju2 homozygotes**l ·21 l ·22

1.2.

l •24

l ·25***

+

+
+
+
+

+
+
+

+
+

7-

+
+
+
+

+
+
+
+
+

21

22

2.

24

2s***

+
+
+
+
+

+
+
+
+

+
+
+

+
+

+

* Cited from Fujino (1963b).

* * Major three types.
* * * Eleven types subdivided by five specificities of Ju2 antigen complex.
by agglutination with the anti-Jul and the anti-Ju2 reagents, including three subtypic specificities in each group of the latter two. Large scale collection of frozen
samples in 1961/62 season made it possible to make further detailed analysis by

4

K. FUJINO

repeated tests, and led to subdivide Ju2 antigen complex into five specificities.
Then the blood types of this species amount to eleven kinds in all as shown in Table

2.
Table 3 shows differential partial agglutinin titres between immune serums
nos. 65 and 61 after being absorbed with various types of erythrocytes. AntiJu25 no. 65 serum absorbed with Jui type erythrocytes agglutinates Jul ·2 1 typecells up to dilution I : 320 and Jui· 25 type cells up to I : 40, and the relative highest
dilution against these two different subtypes of cells is only 8 : I. On the other hand,anti-Ju2 1 no. 61 serum absorbed with Jui type cells agglutinate Jui ·2 1 cells up
TABLE 3. AGGLUTININ TITRES AGAINST SUBTYPIC PARTIAL
SPECIFICITIES IN DIFFERENT IMMUNE SERUMSa)

Anti-fin Ju2 5 serum (No. 65)

cells ofno.
typeabs. by Jui
cells (2K 270)

JO 20 40 80 160 320

JO 20 40 80 160 320

+
-!ft
-!ft
+It
-!ft
+It

+It
+It
+It
+It
+It

**
**

2K 270 Jui
3K 70Jul ·25
3K 148 Jui ·2 4
3K 83Jul·23
3K 127 Jui ·2 2
3K 12Jul·21

20

40

80 160 320

+ +
+

**

+It
+
+It +It++It -!ft +It++It +It +It +It +It +It

***

10

20

* *+ +

abs. by Jui
cells (2K 270)

unabsorbed
10

5

+It
+
+It
+
+It +It++It +It +It+It +It +It +It*+It *+ ++It +It++It +It * ++It +It *+It*

Anti-fin Ju2 1 serum (No. 61)

cells ofno.
typeabs. by Jui ·2 5cells (3K 70)~

2K 270 Jui
3K 70 Jui ·2 5
3K 148 Jui ·2 4
3K 83 Jui ·23
3K 127 Jui ·2 2
3K 12 Jui ·2 1b)unabsorbed

2

5

JO 20 40 80 160*+It *+ ++It +It++It+It +It ** + ++It +It +It +It +It +It +It*

abs. byJul ·2 2cells (3K 127)
10 20 40 ... 1280 2560

+It +It +It ...

* +* Positively agglutinated up to dilution I : 2560.
to dilution 1 : 2560 and Jui· 25 cells up to 1 : 5, and the relative titre reveals marked
difference. According to these observations, it was noticed that degree of dilutionof the latter serum (no. 61) should be carefully adjusted to avoid mistyping Ju2 5or Ju2 4 specificities of cells into Ju2-negative types.
As regards the allelic system of Ju blood groups of the Antarctic fin whales,
Fujino (1962) states that no significant difference was seen in the relative incidencesof the major three blood types between the observed and the calculated figures
expected from two equal allelic system. Table 5 shows the observed and thecalculated (parenthesized) figures of frequency of occurrence of the major three
types for each population which are expected from the allelic system noted above.
Both these figures are well consistent each other, and this might support the hypothesis proposed.

ANTARCTIC FIN WHALE SUBPOPULATIONS

5

Relative Incidences of Blood Types and Stock Identification

Existence of local subpopulations as shown by geographical non-random distribution of blood
types In 1960/61 season localities, where blood typing investigation was made,cover mostly the southern part of 50° south of area III ranging from 0° to 70° east
(Fujino, 1962). In the successive two seasons, further informations were added forthis area, and the investigations were extended to the lower-latitudinal portion ofarea III of north of 50° south, eastern portion of area II, and western portion of area
IV (Fig. 1). Table 4 shows the summary of relative incidences of the major threeblood types for different localities obtained during the successive three seasons.
' Lower latitude ' of area III in this table correspond the portion north of 50°
south ranging from 20° to 50° east. Most samples (83.3 per cent) of area II wereobtained from a sector ranging from 0° to 10° west. It can be seen from this tablethat percentage incidences of Ju2-positives (sum of Jul ·2 heterozygote and Ju2
TABLE 4. NON-RANDOM GEOGRAPHICAL DISTRIBUTION OF JU MAJOR
BLOOD TYPE INCIDENCES IN THE AREAS II, III AND IV*
Area III
Major bloodtypes

Area II***

High. latitude

Low. latitude**

Jui
Jul·2
Ju2

692
48
4

3,323
194
16

Sum

744

3,533

% of Ju2-positives

Area IV

Sum

889
33

704
32

5,608
307
22

923

737

5,937

7.0
5.9
3.7
* Summarized data obtained during from 1960/61 to 1962/63.
* * North of 50°S, 20°E to 50°E.
* * * 620 samples out of these were taken from a sector of 0° to 10° W.

4.5

5.5

homozygote) reveal the geographical dine in order of area II>southern part of
50° south of area III>area IV> northern part of 50° south of area III. This factsuggests that the fin whales which distribute in these areas do not belong to one
homogeneous stock, but rather consist of at least two or more populations that havedifferential incidences of the blood types each other.
As noted in the previous paper, percentage incidence of Ju2-positive types
reveals generally to be low figure of approximately 2 percent in the southern part of
50° south of area III, representing that of a population of which the major stock
distributes in area III. Though previously being called as the aboriginal population in area III, this may be more appropriately named as the West Indian population. Superimposed upon the usual daily frequency of occurrence, sharp upward
fluctuations in the take of Ju2-positive whales in the south-western portion of area
III occurred in an intermittent series of days, and the upper limit of Ju2-positive
incidence was estimated from the daily incidences as a constant figure of approximately 30 per cent. These whales were interpreted to represent a part of theAtlantic population which migrates eastwards in the previous paper by basing uponknowledges of marking returns (Brown, 1954). Figures of Ju2-positive incidences

6

K. FUJINO

of 30. 7 per cent for the Atlantic population in Table 5 were drawn by summarizing
data of days when incidence of Ju2-positive types jumped up markedly as noted
above. In the west portion of area IV, Ju2-positive incidence reveals nearly thesame figure as that of the West Indian population, but upwards fluctuations wereobserved in some days. Although these are not so marked as those in the case ofmingling with the Atlantic population, this fact show that another population, which
has some higher incidence of Ju2-positive types than that of the West Indian
population and may be named as the East Indian population, distributes in thisarea. There can be seen some inconsistency in the estimates of the incidence ofJu2-positives between the results of both years in 1961/62 and 1962/63, which might
TABLE 5.

FREQUENCIES OF OCCURRENCE OF JU MAJOR BLOOD TYPESIN EACH PURE POPULATION*
East Indian population
Lower latitudinal West Indian
population
population

Major bloodtypes

Atlantic
population

Jul
Jul·2
Ju2

278 (276.2)
109 (114.2)
15 ( 11.6)

41 (41.8)
19 (17.4)
1 ( 1. 8)

Sum

402

61

% of
Ju2-positives

30.7

32.8

Sum

1961/62

1962/63913 (910. 9)21 ( 23.9)( 0.2)

370
13
0

86
6
0

456 (456.2)
19 ( 18.6)
0 ( 0.2)

935

383

92

475

(6.5)

4.0

2.4

(3.4)

Remark, Figures in parenthesis show those expected from hypothetical major two equal allelic system.
* Summarized from data of days when whales belonging to each pure population were postulated
to be taken in the seasons during from 1960/61 to 1962/63.

be derived from errors in summarizing the data, because they were taken from thelocalities where two different populations mingle each other. Actual figure forthis population might be about 4.0 per cent of average for both seasons or higher.
Precise estimation for this figure could be made by extending the investigation to
the eastern portion of area IV where pure East Indian population may distribute.
In the lower latitude of area III also daily incidence of Ju2-positive types
jumped up significantly in an intermittent series of days against the lower percentagesof the backgrounds of the West Indian population. Ju2 incidence being summarized from data of these days is more than 30 percent which is shown as thefigure for the 'Lower latitudinal population' in Table 5. The Ju2-positive types
incidence is close to that of the Atlantic population noted above, but these twogroups of whales can be distinguished by the differential Ju2 subtypic incidences.
As shown in Table 6, relative incidences of Ju2 1 antigen among total Ju2-positives which can be definitely distinguished by its specificity and the strongest reactivity with reagents from other Ju2-positives are 33.7 per cent (35 out of all 104 Ju2
positives) for the Atlantic population and 50 percent (21 out of all 42 Ju2-positives)
for the Lower latitudinal population, the difference can be accepted to be significant. In Table 6, it is also characteristic that no Ju2 1 antigen has been found in
the East Indian population. Thus it became to be obvious that the four different
breeding populations distribute in areas II, III and IV. These might support theresults of marking investigations described by Brown (1954 a, 1954 b, 1962 a, &

y

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~)

&(_

r--

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"-

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~

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<'

.

.

7

\

-: :

.

\

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'

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,_,,

: • •.

0.. v

A;

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('

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'1'

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.....

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'"d

c:to

[JJ

i:rj

r-<

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z

>rj

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~.....

~:i>'.Z-______ _j

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[JJ

0
z

~

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... . / . '

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"

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--------~

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L.--------------i

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I '1

''-~

A; (j

s •' ~

~~

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",

----

30°r I' ~------- - - · -Fig. l. Geographical areas II, III and IV where blood typing investigations were undertaken in the threeseasons during from 1960/61 to 1962/63. Four circles summarize data given in the text and Table 5.
Black sectors correspond relative incidences of total Ju2-positive whales for the Atlantic, the aboriginals
of areas III (West Indian), the aboriginals of area IV (East Indian), and the Lower latitudinal populations. Small circles, triangular spots, and crosses show the localities (noon positions of factory-ships)
where whales belonging to the Atlantic, the Lower latitudinal, and the East Indian populations weretaken respectively.

~

'?-

"" "'

,v

0

c,"-

~

K. FUJINO

81962 b), however, in which no remark was given for the existence of the Lower
latitudinal population.
TABLE 6. DIFFERENTIAL FREQUENCIES OF OCCURRENCE OF SUBTYPES IN
JU2 ANTIGEN COMPLEX CONFIRMING EXISTENCE OF DIFFERENTPOPULATIONS*
Ju2-subtypic
specificities

Atlantic
population

Lower latitudinal**
population

West Indian**
population

East Indian**
population

Ju2 1
Ju22
Ju2 3
Ju2 4
Ju2 5

35
21
9
16
23

21
2
7
3
9

19
11
9
10
21

0
9
5
6
4

Sum

104

42

70

24

* Summarized results of 1961/62 and 1962/63 seasons.
**.Including data of days when whales belonging to both of different populations were taken.

Direct evidences showing overlaps ef migratory ranges ef different populations in feeding grounds
Basing upon results of marking investigations, Brown (1962 a) states that in the Antarctic feeding grounds, whales from two separate breeding areas are to be found in
l 9'E

54' s

20' E

2 I' E

54'5

x ~
xx
xx
oox;-xx

0
00
00

x

l

2

55' s

.. .

.

0

~~

~"o

~.·ii

x

3
x
00

55°5

.
l 9' E

20' E

21° E

Fig. 2. Evidences showing mixing of the different populations in the feeding grounds
as revealed by data of days when whales belonging to both the Atlantic and the West
Indian populations were taken in a day. Population differences of whales groupedby three localities where whale carcasses were gathered, drawn by basing upon thelogs in Feb. 23, 1961. Concrete lines with arrow show wakes of factory-ship. Threepoints with Nos. 1, 2 and 3 mean localities where factory ship gathered whales taken.
Crosses, open and closed circles mean localities of capture of individual whales belonging
to groups Nos. 1 (West Indian population), 2 and 3 (Atlantic population) respectively.
(See Table 7).

ANTARCTIC FIN WHALE SUBPOPULATIONS

9association in summer, and Fujino (1962) also states that a portion of the Atlantic
population from area II migrates to area III and mingles with the population
there by basing on the immunogenetical study. No description, however, on
direct evidences for overlaping of migratory ranges of different populations has
been given. Detailed informations in some days when the whales belonging toboth the Atlantic and the West Indian populations were taken might serve as the
direct proof for intermingling of different populations in feeding grounds. Fig. 2
shows localities of capture for 54 whales taken by one fleet in Feb. 23, 1961.
Carcasses of these whales were successively gathered at three points nos. 1, 2 and3 on the wake of the factory-ship shown by concrete lines. Some remarks on thesethree groups of whales are given in Table 7. Number of Ju2-positive whales ·were
TABLE 7.
Locality no.,gatheringwhalescaptured2
3

LOG OF FEB. 23, 1961 SHOWING OVERLAPS OF MIGRATORYRANGES OF DIFFERENT BREEDING POPULATIONS
Blood type
incidencesTimeofcaptureNo. ofwhalescapturedJui

6.5512.45*

24

23. taleWest Indian
population
female

16

10

6

r•k

14

8

6

10.3520.20
13.0020.00

Populations'.J u2-postives belonging to

Adomk
population

Group-composition2
13 {imm.
mat. 11uemm.
lrreg. 4
mat. 10 ovul. O**
rest.

6

i6emm. 2
mat. 14

Atlantic .
female 14emm. 2{preg. 8
populat10n
mat. 12 ovul. 2**
rest. 2*Three out of these captured later (at 14, 16 and 18 o'clock).
* * Having ovaries with functional corpora lutea but lacking fetus.

only one out of 24 examined for point no. 1 group (crosses), six out of 16 for no. 2
group (open circles), and six out of 14 for no. 3 (closed circles). These suggest thatmost whales of point no. 1 group belong to the West Indian population andwhales of points nos. 2 and 3 to the Atlantic population. The later part in therange of time of capture for point no. 1 group overlaps with the early part inthat of no. 2 group. These facts show that groups of whales belonging to different
populations migrate to approximately same locality in the feeding grounds withslight time lags. This is a first example that can be regarded as the direct
evidence for overlaping of migratory ranges of different populations. Further detailed evidences are shown in Figs. 3 and 4. Fig. 3 shows locations of capture ofindividual whales taken in Dec. 12, 1962 as grouped by catcher-boats. Ju2-positive
type incidences were calculated as 27.8 per cent by testing 18 samples (5 Ju2positives) for 26 whales taken by catcher-boats A, B, C, and D, and as 0.0 percent
for 11 whales (alljul) by catchers E, F, G, and H. The former was regarded as
those belonging to the Atlantic population (closed circles) and the latter to the West
Indian population (open circles). Another chart basing on the log in Dec. 14, 1962

10

K. FUJINO

is drawn in Fig. 4 under the similar expression as previous one. There can be seen
characteristic differences between these two figures as follows. Whales belonging
to the Atlantic population were found and captured in the locations southern sideof that for the West Indian population in the case of Fig. 3, but in Fig. 4 whales
belonging to the Atlantic population were found at the both sides of locations for
the West Indian population. While, the blood type incidence is maintained to be
indigenous for each population, so that the observations described above can be
0-------0.-0...,

',, E

G

I'-,

i . . . . . . . o---. . -:,_:":~-----------____ o F'0" ...

1

1

I

I

0

H

A

Fig. 3. Evidences showing mixing of the different populations in the feeding grounds
as revealed by data of days when whales belonging to both the Atlantic and the West
Indian populations were taken in a day. Population differences of whales groupedby catcher-boats, drawn by basing on the logs in Dec. 12, 1962, when 29 whales examinedout of 37 those taken. Open and closed circles show the localities where individual
whales belonging to the Atlantic and the West Indian populations respectively weretaken. These were successively captured from lst catch with alphabet letter showing
different catcher-boats after chasing; All of 11 whales taken by catcher-boats E, F,
G & H were typed as Ju I. 13 and 5 taken by catcher-boats A, B, C & D were typed
as Ju I and Ju 2-positives respectively.

interpreted as the most reliable evidences showing that despite of such interminglingsin feeding grounds the different populations have been completely isolated eachother in breeding from generation to generation.
Boundary of migratory ranges and rate of intermingling Table 8 shows frequency distribution of number of whales daily examined and of Ju2-positive whales occurred inthose. In this table, scattered diagrams are divided into four zones by the threeboundary lines corresponding to Ju2-positive incidences of 50, 33 and 20 percent
respectively, and majority in zones more than 20 percent were identified as those
representing whales which belong to the Atlantic or the Lower latitudinal populations. As stated already the former and the latter can be geographically distinguished each other. In Figure I, are plotted noon positions of factory ships in some

ANTARCTIC FIN WHALE SUBPOPULATIONS

11intermittent days when the whales belonging to the Atlantic, the Lower latitudinal
and the East Indian populations were taken during the three seasons. Small closed
circles show those for the Atlantic population. According to this figure, this groupof whales were taken on a band of ground which runs southeast direction fromthe whaling ground lying south of South Africa and extends to about 60° east, but
did not occur in the catch from the northeastern side of this band in spite of fairly
larger number of whales taken. This might suggest that the above-noted bandmight be interpreted as the east boundary of migratory range in feeding groundfor the Atlantic population. According to the results obtained in the three seasons,
48° E

so· E

q

51° E

\

\

sts

\

\

\

\

\

sts

?

"\

I
I
I
I
I
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I
I
I
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Fig. 4. Evidences showing mixing of the different populations in the feeding grounds
as revealed by data of days when whales belonging to both the Atlantic and the West
Indian populations were taken in a day. Population differences of whales also groupedby catcher-boats, drawn by basing on the logs of Dec. 14, 1962, when 45 whales were
examined out of 50 those taken. 29 whales taken by E', F', G' & H' were typed
as Jui, so that, were regarded as those belonging to the West Indian population. 10
and 6 taken by A', B', C' & D' were typed as Jui and Ju2-positives and were recognized as those belonging to the Atlantic population.

in the east half of area III corresponding to the east end of the migratory range forthis population distribute tolerable number of the Atlantic population in December atthe beginning of whaling season, but hardly occur after January. Some exceptional records taking this group of whales in this ground, however, were made for eachone day in mid- and late-March respectively in 1961/62 season. Ju2-positive type
incidences in the east half of area II reveal fairly lower figures than those of pure
Atlantic population, so that it can be thought that the West Indian population

12

K. FUJINOTABLE 8.

FREQUENCY DISTRIBUTION OF DAILY OCCURRENCE OF
JU2-POSITIVE BLOOD TYPES
No. of J u2-positives

No. of whales
daily examined
2

3
4
5
6
7
8
9
10
II
12
13
14
15
16
17
18
19

0

2

79

4

95
71

4
5

4

3

8

6

5

9

10

11

12

13

14

83

99

I
I
I

77

'

74
67

~~ -~-r;-1
52

48
26
32

26
20
13
8
2
5

8
11

6

s
4
1
4
2
4

3
3
2
2

L ___ l

2

--.

1
3

I I L---,
2
2 u_ 2 L___ _
3
I '
I
:
I

I

I

I

L---i

L .....
I
,

2

:

100%

~13

~---,

I

L__

2

3

2
4

24
25

2

6
6
12
13

L___ ,

I

I

I

i
L---•

I

:
L___I

J

20

I

7
I

6

I

L__

·1

iL __

2

I

L___ ,

4

!

6

'

----,

SO%

I
I

I

L_,

28

2
5
I
3

L---1
I

I

26
27

61
57
33
38
34
23
18

I

I

LL,

21
22
23

L---

29

I

30

L __

31
32
33
34
35

I

3
I
0
2
3

I

'

I

L __

2
2
5
2

I

2

Sum

I

2

36
37
38

39
40
41

0
2
0

I

LL

42
43

44
4;5

2
0
I

I
0
0
I
0

46
47

48
49
53
Sum

642

77

28

13

7

3

4

0

0

0

2 780

ANTARCTIC FIN WHALE SUBPOPULATIONS

13

disperses to this ground beyond the boundary between areas II and III. To makeclear the west boundary of migratory range of the West Indian population should be
extended the investigation hereafter to the western portion of area II. A part of the\Vest Indian population disperses eastwards to the west portion of area IV andmingles with the East Indian population there. On the other hand, little numbersof East Indian population seem to distribute to area III, but inter-relation in boundaries of migratory ranges between West Indian population and East Indian population have not been made so clear as that between Atlantic population and West
Indian population. As shown in Fig. 1 by small triangles, noon positions of factory
ships in some intermittent days, when the whales of Lower latitudinal population
were taken, mostly occur in the portion, of north of 50° south of area III, ranging
from 30° east to 50° east.
Rates of intermingling of different populations can be estimated from blood
type incidences for each pure population in Table 5 and those in various geographicalgrounds in Table 4. In area II (east half) and the higher latitudinal portion ofarea III (south of 50° south), 16 and 12 per cent of the samples respectively consistof the whales of Atlantic population and the residues are of West Indian population.
As fairly large number of samples were tested for area III, the latter might be accepted to nearly represent actual figure of the population there for the periods ofinvestigation. Rate of mingling of the Lower latitudinal population in the northern portion of 50° south of area III does not reach up more than 4.3 percent. As
precise estimation of blood type incidences for the East Indian population has notbeen made, rate of mingling in the areas concerned should be postponed in future.
INTERMINGLING OF DIFFERENT POPULATIONS AS REVEALED BY
RATE OF EMIGRATION OF WHALES MARKED

To obtain informations on migrations and on movements of whales, materials ofmarking investigations have been dealt in various ways (Brown, 1954 a, 1954 b,
1962 a, & 1962 b). For the purpose of identifying stocks, it might be more effective
to analyse materials as geographical groups than to treat those as signs of movementof individual whales. Accordingly, in this paragraph will be mostly discussed theinter-areal relationships especially the problems of intermingling between areas
II and III where different populations distribute respectively as clarified by blood
typing investigations aiready. Calculations of rate of emigration between different
areas will be made by basing on a method which was applied by the present author
to the north Pacific fin whale stocks previously (Fujino, 1960).
Materials used Number of fin whales taken and number of fin whales marked andsuccessively recaptured in the Antarctic during from 1932/33 to 1961/62 seasons wereused to calculation. Table 12 shows the former figures which were cited from theInternational Whaling Statistics, and Tables 9, 10 and 11 show the latter figures
which were arranged by compiling materials described in a series of Brown's reports(1954, '56, '57, '58, '59, '61 b & c). Number of whales taken and those recaptured
at land stations in South Africa are not included in the figures of these tables. Fig.

K. FUJINO

14

5 shows the summarized results of marking investigations which were made mareas II, III and IV during the pre-war and the post-war seasons.
Methods and practice of calculations 1) Major points of calculations of rates of
emigration between different areas follow those which were described in the previous
paper (Fujino, 1960). For this purpose population sizes of the two different
populations I and II of which the main stocks distribute in the grounds A and B neighbouring each other were expressed as N 1 and N 2 , and their relative abundancesin the grounds A and Bas a and 1-a for the population I and as 1-b and b for the
population II respectively as shown in Fig. 6 diagramatically. To make estimation of figures a and b averaging for the periods of investigations is the purposeof the present calculations.
2) In the light of length of lapse of years from marking to recapture and
TABLE 9.

No. of whales
effecti\'ely

NUMBER OF FIN WHALES EFFECTIVELY MARKED IN AREA II AND
SUCCESSIVELY RECAPTURED, 1932/33 TO 1961/62.
In the seasons of:Recaptured in the area II,
Markedin themarked

-\

war
marks

Post-

war
marks

1932/3'35/6·

j

j

299
572
652
447
34

j

j
-

-

l

'lf/

'5516
j

'50/1
j

'45/6

'40/l

1932/3
'33/4
'34/5
'35/6
'36/7
'37/8
'38/9

200

ND*
ND*

s

S1,1m

Sum

1- 1 - - - I 2- 1 2 2 - - 2 1 - - - - 1 - - 1
2 2 ~ I 2 1 2 8 I 3 1 1- 1 2- 2 2 2 2- 1 1- 2- 1 3-- l
13 5a1 4 4bl _cl J _d> I 2 I I _el 3 _o I 4 2 2 2 3 1 1- - - - - - - - - 1-- 1 - - - - - - - - - - -

34
15
56
51

I

15

4

194516-5213·'53/4'5415'.5516
'5617
'5718
'5819
'59160
'6011
'61/2

114
41
84
23

1

-

2

8

3

a 41

16

1

a

1

2 -

s

1

2

6

s

4

6 -

4

10

4

9 14

6

s

s

2

2

7 200

Recaptured in the area III,

p,.,_

w"'

marks

Postwarmarks\!93213
'3314
'3415
'3516
'36/7
'3718.
'3819
194516-52/3
'53/4
'5415
'55/6
'56/7
'5718
'58/9
'59160
'6011
'61/2

Sum

2

I

Remarks, * ND : No available data. In addition, one, two and three whales moved from area
I were recaptured in c) d) f) g) h) j) 1), in b) e) i) and in a) respectively Also excluding one
and two whales moved from lower latitudes and recaptured from j) and k) respectively. One,
three and two whales which were marked in 1935/36, 1936/37 and 1937/38 respectively with noinformation on area recaptured are excluded. Each one whale marked in area II in 1934/35,
1936/37, 1937/38 and 1938/39 was recaptured in area I, and three marked in area II in 1953/4
also recaptured in area I.

10ANTARCTIC FIN WHALE SUBPOPULATIONSTABLE 10.

15

NUMBER OF FIN WHALES EFFECTIVELY MARKED IN AREA III
AND SUCCESSIVELY RECAPTURED, 1932/33 TO 1961/62
In the seasons of:Recaptured Ill the area II,

No. of whales
effectively
marked

p,,.
war
marks

f

463
285
395
II
15

I934/5
'35/6
'36/7
'37/8
'38/9

I934/5

'40/I

'45/6

j

j

j

- -

-

~;

'50/I

'55/6

j

j

'60/1

!

Sum

3· 4

22

2

I945/6-52/3
'53/4
'54/5
'55/6
'56/7
'57/8
'58/9
'59/60
'60/I
'6I/2

7

I94
I02
Postwarmarks

Markedin the

50.

35
ND*
ND*

- - - -

Sum

2

-

--1

I -

I.

4

3

1-

I
2

I

Recaptured in the area III,

Pro-(
marks
war

1934/5
'35/6
'36/7
'37/8
'38/9

Postwarmarks

1945/6-52/3
'53/4
'54/5
'55/6
'56/(
'57/8
'58/9
'59/60
'60/I
'6I/2
Sum.

-

2
-

2

3

I

2

1

1·
I

2

38&)

I

29
5

4''
6
I9
9
I2

3

2

3

3

4 -

-

-

-

-

2

I..

2

3

2 -

5

6·

4·

9

5

2·

9

7

7 22 3II

5!ff

Recaptured in the area IV,war
P.-c-1

I934/5
'35/6
'36/7
'37/8
'38/9

Postwarmarks

I945/6-52/3
•53/4
'54/5
'55/6
'56/7
'57/8
'58/9
'59/60•60/I• '6I/2

marks

·Sum·

~~==---­'=i- --

2----------------

I

1-

9
2

1-

Remarks, *ND: No available data. In addition, in lower latitude (land stations) were recaptured one in a) in 1937, two and one in b) in 1959 and 1962 respectively and two in c) in
1959. One whale moved from area I is excluded. One, two and two whales, which weremarked in 1957/58, 1954/55 and 1961/62 respectively, with no information for area but recaptured, are also excluded.

16

K. FUJINO

complexity of the factors concerned, calculations were made with priority given
to the pre-war marks and with a prospect obtaining complementary knowledges
from the post-war marks.
3) Pre-war marks shot in area II in the five seasons of 1932/33, 1934/35,
1935/36, 1936/37 and 1937/38 and those in area III in the three seasons of 1934/35,
1935/36 and 1936/37 were used. Marks shot in area II in 1938/39 and those inarea III in 1937 /38 and 1938/39 were excluded from calculations because of few
numbers of the whales effectively marked.
TABLE II.

Peewac (marks

Postwac
marks

NUMBER OF FIN WHALES EFFECTIVELY MARKED IN AR~A IV
AND SUCCESSIVELY RECAPTURED, 1932/33 TO 1961/62
In the seasons of:Recaptured in the area III,No. of whales
effectively
markedMarkedin the19
48
58

1934/5
'35/6
'36/7
'37/8
'38/9

14
2

15
59
ND*
ND•

'40/I
)

1934/5
j

'50/1
)

'45/6
)

'55/6
)

1953/4
'54/5
'55)6
'56/7
'57/8
'58/9
'59/60
'60/I
'61/2

'60/1

!

Sum

-~--(----- 1------------- - - - - - - 2 -

-

-

2 -

-

4

~=

Sum

-· -

-

-. -

-

-

-

-

-

I -

-

-

-

-

-

-

I -

-

-

Recaptured in the area IV,p,e- (wa'
marks

PostWUmarks

4.

1934/5
'35/6
'36/7
'37/8
'38/9

3

1953/4
'54/5
'55/6
'56/7
'57/8
'58/9
'59/60
'60/1
'61/2
Sum

-

-

-

1

2 -

-

-

-

-

-

-

I -

-

-

-

-

-

-

-

-

-

l

2

12

4

2

25

Remarks, *ND: No available data. In addition, were recaptured each one in a) and b) andthree in c) which were marked in the area V. Three whales marked in 1959/60 but with noinformation on area recaptured are excluded. One whale marked in 1955/6 and moved toarea V are also excluded.

4) Post-war marks shot in area II in the season of 1953/54, 1954/55 and1955/56 and those in area III in the seasons of 1954/55 and 1955/56 were used.
5) As the numbers of whales effectively marked in area IV were small,calculations were not undertaken for these marks.
6) Number of whales taken and of those recaptured at land stations inSouth Georgia Islands were made together with those of the pelagic operations
in area II for the calculation.

17

ANTARCTIC FIN WHALE SUBPOPULATIONS

7) The following arrangements were made for various parameters necessary for calculations. a) As discussed in the previous paper (Fujino, 1960), errors
in the estimates of rate of confirming (g) whales as ' Hit ' among those effectively
marked and of rate of recovery of marker (f) from whales actually recaptured do
SOUTH

AFRICA

AREA Ill

ANTARCTICCONTINENT

5:~ L-----"\~7ri----_Jwq

Fig. 5. Summarized results of emigration of marked fin whales between areas II, III and
IV during from 1932/3 to 1961/2 seasons (compiled from reports by S. G. Brown).
Figures in circles with alphabet letters C, R and M show summarized numbers of fin
whales taken, of marked whales recaptured up to 1961/2 seasons and number of fin
whales effectively marked respectively. Figures with arrow mean number of whales
recaptured after moving to the different areas.

populationI

populalion

N,

II

N,

00
Area A

Area B

Fig. 6. Diagrammatic interrelationships between different two populations distributedin the neighbouring two areas as shown by movements of marked whales.

hardly effect upon final results of calculation for the rates of emigrations. Then no
Although materials have not been available, however, it could be assumed that there exist significant differences in the figures off

g- andf-corrections were made.

18

K. FUJINO

between Japanese and the foreign fleets in relation to the methods of treating whale
body especially whether or not utilize meats. Therefore the recoveries of pre-war
marks in the seasons after 1960/61 whenJapanese fleets commenced intensive operations in area III were not included. While, for calculation on the post-war marks,
all recovery up to 1961/62 season was used because of avoiding reduction of numberof data. b) Sufficient materials of age-composition, which can be used to estimate
mortality rates for both pre-war and post-war seasons, are not available. It seems
to be impossible, even if materials were available, to estimate precisely mortality rate
for each year. Then figures 0.10 and 0.05 were arbitrarily used as annual rate of
total mortality and annual rate of natural mortality respectively averaging for thewhole periods of investigations involved. The latter figure was applied as annual
mortality rate to five seasons from 1940/41 to 1944/45 for area III and to the
TABLE 12.

NUMBER OF FIN WHALES TAKEN IN THE AREAS II, III AND
IV DURING FROM 1933/34 TO 1961/62*

Area

1933/4

'34/5

'35/6

'36/7

'37/8

'38/9

'39/40

'40/1

'41/2

'42/3

S. Georgia
II
III
IV

I ,728I, 1152, 178
2,177

836
2,246
7,985
1,368

520
3,375
5,236
548

1,079
1,552
6,004 11,505
5,002 8,297
2,285
6,610

1,307
6,252
5,710
5,540

937
7,840
2,218
574

747
831
49

I, 189776

Area

1943/4

'44/5

'45/6

'46/7

'47/8

'48/9

'49/50

'50/1

'51/2

'52/3

S. Georgia
II
III
IV

632
529

987
679

1,456
4,901
2,800

1,670
4,655
4,382
3,355

2, 1426, 136
6,483
4,654

1,922
4,995
6,457
3,068

1,999
7, 1505, 117
2,940

1,982
5,081
4, 133
4,210

2,007
5,977
7, 122
2,141

1,670
4,551
11,364
1,449

Area

1953/4

'54/5

'55/6

'56/7

'57/8

'58/9

'59/60

'60/1

'61/2

S. Georgia

2,673
7,653
11,459,
2,195

2,746
4,963
13,607
2,790

2,669
6,619
7,088
3,208

2,057
10,697
3,812
291

2,251
5,211
9, 197
3,579

1,291
4,298
9,385
7,277

1,160
4,920
9,307
6,501

1,387
5,223
13,269
2,086

661
6,650
11,8473, 129II

III
IV* Cited from the International Whaling Statistics.

six seasons from 1940/41 to 1945/46 for area IV during the World War II. It was
already discussed in the previous paper that these arrangements hardly influence
upon the final results of calculations.
8) As lapse of years from marking to recapture for the Antarctic investigations is generally longer than that for the north Pacific, to obtain the mean value (r)from rate of recapture for each year of marking was made simple arithmetical
averaging instead of that with weight expressed by formula 6 in the previous paper(Fujino, 1960, p.111).
9) According to the results of stock assessments on the Antarctic fin whale
population (Fifteenth Annual Meeting of International Whaling Commission, June,
1963,), it is obvious that the stock of this species has not been in a stabilized statethroughout pre-war and post-war seasons. For the convenience of calculation for
the rate of emigration, however, number of survivors (C') of initial stocks at the time

ANTARCTIC FIN WHALE SUBPOPULATIONS

19

of marking in the annual catches (C) in successive years were obtained by formula
12 in the previous paper (Fujino, 1960). It can be understood, even if such arrangements were made, from the definition of rate of emigration and formulae 5 and 6
in the previous paper that final results of calculation must be little biased from thoseto be obtained by considering annual stock size fluctuations which were demonstrated by the stock assessment.
Results of calculation and their interpretations Table 13 shows the results of calculations
on the rates of emigration between areas II, III and IV. In this table figures are
TABLE 13.

RATE OF EMIGRATION CALCULATED BY MARKING RETURNSFOR THE PRE-WAR AND THE POST-WAR MARKSa>
Pre-war marks*

Rate ofemigration

r22/rl+ra2

A

B

Post-warmarks

rs"/r22+ra2

0.88 (0.88) bl
0.12 (0.12)

0.90
0.10

0.83
0.17

Taa/ra"+r2a
Tz 3/Ta 3+Tz3

0.93
0.07

0.90
0.10

0.58
0.42

r,•/ras+r4a
T4a/ras+r4a

0.88 (0.88)bl
0.12 (0.12)

0.78
0.22

0.68 (0.77)0l
0.32 (0.23)

r28/r2s+raa+r4a
r 33/r23+ra 3+r43

0.11 (0.10) b)
0.69 (0.61)
0.20 (0.29)

0.08
0.71
0.21

0.32 (0.35)0)0.47 (0.50)
0.21 (0.15)

r.8/r2•+ra•+r4 8

Remarks, Calculation was made for the two cases including (A) and excluding (B) recaptures inpost-war seasons, 1945/46 through 1959/60. a) No calculation was made for recapture ofwhales marked in area IV. b), c) Figures in parenthesis correspond to those excluding higher
rate of recovery for area II in 1940/41 and for area IV in 1959/60 respectively.

shown for both pre-war and post-war marks. The former those are further subdivided into two cases of A and B whether or not including the post-war recoveries
respectively. Figures in parenthesis correspond those for the case excluding materials
for the year when high rate of recovery was recognized. At first the results forpre-war marks will be discussed.
As regards inter-relations between areas II and III, rate of emigration fromareas II to III, r3 2 /r 22 +r3 2 , reveals figures of 0.10 and 0.12 for two cases A and B
respectively, and that from areas III to II, r2 8/r 2 3 +r3 3 , 0.07 and 0.10 respectively. These results confirm the non-random distribution of whales in areas II and
III, saying in other words, existence of the different populations, and show thatapproximately 10 percent of the Atlantic population contribute to the stock in area
III and also approximately same percent of the West Indian population distributeto area II. Definite informations for relative stock size between the Atlantic andthe West Indian populations have not been available. If both populations havecomparable sizes of stocks, however, figures of the rate of emigration from areas
II to III noted above correspond to the rate of intermingling of the Atlantic popula-

20

K. FUJINO

tion in area III which is close to that obtained from the blood typing investigations. The results may lead to obain following informations. Although in areas·II and III distribute the different populations which migratory ranges overlap eachother, the facts that both figures of rate of emigration reveal approximately 10
percent suggest that final surplus and deficit of the stock for each area are inconsequence comparatively small. This might be important as a basic information to make stock assessment for each geographical area separately. Rate of emigration from areas III to IV, r4 3 /r4 3 +r3 3 , ranges from 0.12 to 0.22 which are bigger
than those between areas II and III. Reasons that marked inconsistency was seen
between figures for two cases A and B have not been made obvious.
Rates of emigration calculated from post-war marks reveal bigger figures
than those from pre-war marks. Although no sufficient evidence has been given,
the following probable reasons could be assumed to be concerned. Then it might
be impossible to expect nothing more reference informations from the post-war
marks at present. I) In post-war seasons when marking investigations have been
undertaken, the major whaling grounds in area III moved to the lower latitudes,
so that whales of the Lower latitudinal population contribute to the catches inthis area besides the West Indian population. 2) The Japanese fleets utilizing
whale meats commenced their intensive operation in areas III and IV. 3) Scantiness of whales effectively marked might bring larger errors and some biases.

OTHER BIOLOGICAL CHARACTERISTICS RELATED TO
DIFFERENCE OF STOCKSAs discussed in the previous paragraphs, it became to be obvious that in areas II,
III and IV distribute at least four different fin whale populations. Some biologicalcharacteristics related to the difference of population will be described and discussed
in this paragraph.
Differential Sizes of Group of Whales by Stock

As the numbers of samples daily collected by Kyokuyo-maru No. 2 in 1960/61
season and by Kyokuyo-maru Nos. 2 and 3 in 1962/63 season were generally large,
majority of whales taken in these days can be identified as those of Atlantic population and of West Indian populations by basing on blood type incidences and localities
of capture. In Table 14 are shown frequency distributions of' number of whales
observed' for groups from which whales were taken according to four different
classes of blood type incidences. In this table groups of whales, whichJu2-positive
incidences show zero percent, were regarded as those of pure West Indian population, and those more than 11 percent as groups in which whales of Atlantic population
mingle at fairly high percentages. Comparing these distributions between the twodifferent stocks, in the former the classes less than I 0 whales and more than 41
whales occupy 37 and 21 percent respectively on an average 29 whales, and in thelatter those less than I 0 whales only 5 percent and contrarily those more than 41

ANTARCTIC FIN WHALE SUBPOPULATIONS

21

whales 44 percent on an average 48 whales. This result of observations suggeststhat size of group of whales migrating to the feeding grounds in the Antarctic isdifferent by stocks each other. · Although no available data has been obtained to
TABLE 14. FREQUENCY DISTRIBUTION OF NUMBER OF WHALES OBSERVED,SUGGESTING POSSIBLE DIFFERENTIAL SIZES OF SHOALS BY RACESIN THE FEEDING GROUNDS*
Perc~ntage incidence of Ju2-positive types

No. of whales
observed
1- 5
6-10
11-20
21-40
41-80
more than0

more than II

1~} 37%

~} 0%

~} 5%

:} 42

2'
7 J 75

14}
14 50

!}

~} 25

II}
14 45

12
42

56
48

81

Sum
Average no. of whales

I to 1021

38
29*Basing on the logs of catcher-boats.

discuss what other biological characteristics of the population correlates with thisfact, this may bring some problems to the hypothetical basis on 'the geographicaluniformity of distributing concentration of animals ' in stock assessments.
Natural ~election Related to Blood Types

Many discussions on natural selections related to blood types have been publishedin recent years from the view-points of Human Genetics and Anthropology. Althoughsome informations concerning to relationships between blood types and fertility or
age were noted already by the present author (1963b), additional evidences aredescribed in this section.
Differential rates of pregnancy by blood rypes According to the results of the following
observations, Fujino (1963a) describes for the first time that the fairly strong intrauterine selection of Jul ·2 heterozygous fetuses might occur in whales in relation
to the maternal-feta! incompatibility of blood types and states that incidences of the
TABLE 15.

DIFFERENTIAL PERCENTAGE PREGNANCY BY BLOOD TYPESIN THE ATLANTIC FIN WHALE POPULATION

Blood types

1960/61

1961/62

Sum

Jut
(P 1)
Ju2-positives (P 2)

63.9 (36)78.9 (19)55.6 (18)75.0 ( 8)61.1 (54)77 .8 (27)

0.81

0.74

0. 78

Remark, Figures in parenthesis mean the number of mature females examined.

selection will closely relate to the frequency of occurrence of blood types of the population. The observations include that 1) rate of finding fetuses from mature
females is lower in Ju 1 type mothers than in Ju2-positive types those ; the differences
are statistically significant and that 2) isoantibodies from Jul female donors reveal

22

K. FUJINO

hemolytic property and significant high titres were detected for the isoserums ofJui female donors from which fetus was not found in spite of having functional
corpus luteum in their ovaries and congested uteruses. As shown in Table 15,
observations in 1961/62 season confirm the results of differential apparent rate of
pregnancy noted above.
Blood type and age Table 16 shows relative blood type incidences in connection
with age classes which are expressed by number of laminae layers of ear-plug.
It can be seen from this table that incidences of Ju2-positive types decline andcontrarily those of Jui type ascend in accordance with increment of ages and thatthese trends are statistically significant. This observation suggests that relative
viability between different blood types varies in relation to age classes. As reproducibility lastes to fairly older age classes in this species of whales, these facts can be assumed to play an important role in maintaining blood type gene frequencies in a
population together with the differential rate of pregnancy noted already.
Relation between Intra-uterine Selection and Ovulating Cycle

Basing on knowledges in human genetics, Fujino (1963 b) noted that stages of theintra-uterine selection could be broadly divided into pre- and post-fertilization
TABLE 16.

RELATIONSHIPS BETWEEN AGE AND BLOOD TYPES IN
THE ATLANTIC POPULATION*
Blood types**

No. of laminae of
ear-plugJul

J u2-positives

11-20
21-30
31-40
more than 41

19 (55.9)
13 (72.2)
14 (82.4)
14 (77 .8)

15 (44.1)
5 (27 .8)
3 (17 .6)
4 (22.2)

Sum

60 (69.0)

27 (31. 0)

Remark, *Sum of males and females, 1960/61 and 1961/62 seasons.
relative incidences in percent.
** X 2 =4.98, 7 d.f., 0.70>P>0.50.

Sum
34
18
17
18
87
Figures in parenthesis show

those which probably more intensive selective pressure plays in the former. If
the differential rate of pregnancy shown in Table 15 is actually caused by in partdescending ofrate offertilization inJul type mother whales, it should lead to accelerate successive ovulations in the infertilized individuals. The frequencies ofovulation in a breeding period may be different by blood types of mother whales
and also different on the average by races which have different incidences of blood
types each other. In consequence it must reflect on geographical differences inaccumulating rate of ovarian corpora as noted previously. Table 17 shows thecomparison of accumulating rates of ovarian corpora per two laminae layers of earplug drawn by ovulation-lamination keys (Form D) which were submitted to the
Joint Meeting of the Special Committee of Three and the Ad Hoe Scientific Committee of the International Whaling Commission held in Seattle, December, 1962.

ANTARCTIC FIN WHALE SUBPOPULATIONS

23

Figures for area II in this table were cited from those of Laws (1961). Marked
geographical differences are seen in these figures by area. Materials, by whichthese figures were drawn, base on the observations for ovaries and ear-plugs madeby the several biologists of the Whales Research Institute. Even if some individual
errors are involved in readings, it can be said that the geographical differences are
significant. Among the materials for area III of Table 17, readings for numberof ovarian corpora were made by author himself who served as a biologist on board
in 1960/61 season and those for ear-plug laminae by several staffs of the Institute.
The results show fairly marked differences between west-half and east-half of area
III. It was noted aready (Fujino, 1963 b) that types of frequency distribution of
accumulated number of ovarian corpora at an age class expressed by ear-plug !amine
are not always symmetrical, but are rather different by area. Geographical differences in accumulating rate and type of frequency distributions of ovarian corpora
between west- and east-halves of area III seem to support the concept proposedalready. Fig. 7 shows the analysis of frequency distribution for west-half of area
III, which was presented in Fig. 2 in the previous paper (Fujino, 1963 b), by
normal probability paper. This figure shows that the bimodal distribution for thisarea can be divided into two components which correspond 0.6 (83 percent) and1.4 (17 percent) of average rates of accumulating corpora per two laminae of earplug respectively. According to Fujino (1963 a), possible relationships of rates
TABLE 17. ACCUMULATION RATE OF OVARIAN CORPORA OF THE FIN
WHALES TAKEN FROM DIFFERENT AREAS OF THE ANTARCTIC*
Areas

II

W·III**

E·III**IVv

VI and I

2.80-3.00

2.31

1.91

1.84

1.80

1.60

* Cited from Fujino (1963b).
* * Temporarily divided into the two portions of west-half and east-half at 35 degrees east longitude.
of pregnancy between three blood types for the Atlantic population can be expressed
as Jul ;£Ju2 ;£Jul·2. Basing on the above-noted concept, relative rates of accumulating corpora will be arranged in a reverse order. Therefore it can be thoughtthat one components showing higher accumulating rate (1.4) corresponds to Jul
group of the Atlantic population and another component of lower rate (0.6)
consists of Jui ·2 group of the Atlantic population and also of all kinds of Ju bloodgroups of the West Indian population. Although distribution corresponding to
Ju2 homozygote group of the Atlantic population does not appear clearly as a component in Fig. 7 probably because of its low incidence (less than 2 percent), it might
constitutes a component which may have an intermediate mean between abovenoted two figures. According to Fujino (1963a), intra-uterine selection related
to Ju blood type incompatibility little occurs in the West Indian population becauseof the low incidences of Ju2-positive types, so that it can be assumed that type of
distribution is nearly a symmetrical one at least regarding to Ju blood type system.
By these concepts, relative incidences of the two components of the distribution in
Fig. 7 well consistent with those calculated from rate of intermingling of both po-

24

K. FUJINO

pulations for this geographical area (Fujino, 1962). Thus the quantitative relationships will become to be obvious for a pure population between three factorsof the relative incidences of blood types, the incidences of intra-uterine selection
due to blood type incompatibility, and the rate of accumulating ovarian corpora
in females. These observations and analyses could offer some reliable informations.
%

17%

7

99

95

I

90

µ+u
CJ)

u
c

70

~
u

50

0

30

u
0

>.

g µ-<Y
~

rr

!

10
5

15
10
5
o~~--L__JL_-'----'--'-----'L_-'----'---'-~L::=>=._,____,

2

4

6

8

10 12 14 16 18 20 22 24 26 28

accumulated number of ovorion corpora

Fig. 7. Analysis of the bimodal frequency distribution of the accumulated number ofovarian corpora at an age class of 28 laminae of ear-plug for the west-half of area III
by normal probability paper, showing that this consists of more than one component
distributions (see text).

to an essential problems in ovulating cycles especially to the details in frequency
of ovulation, if simultaneous examinations could be precisely made in blood typing,in counting accumulated number of ovarian corpora and in reading number of
ear-plug laminae for each individual females belonging to a pure population suchas the Atlantic one.
SUMMARY

This paper deals with problems of identification of breeding populations, migratory

ANTARCTIC FIN WHALE SUBPOPULATIONS

25

range of each population and some other biological discussions on the fin whales
taken from the Antarctic whaling areas II, III and IV by means of the blood typing
and the marking investigations. These base upon the materials of approximately
six thousands blood specimens collected by Japanese expeditions during three successive seasons from 1960/61 to 1962/63 and those of recoveries of the pre-war andthe post-war marks compiled from data described in a series of Brown's publications. It was emphasized throughout this paper that the facts of overlap of
migratory ranges of different populations made situations of problems in population study much more complex. The observations and the discussions in the present
paper will be summarized as follows.
1. By the agglutination reactions with immune rabbits' and fowls' serums,
erythrocytes of the Antarctic fin whales were classified into Ju major three groups,
i.e., Jul homozygote, Jul·2 heterozygote and Ju2 homozygote, in which the latter
two were further divided into five subtypic specificities, amounting to eleven kinds
in all.
2. Results of X 2 tests for the relative incidences of the major three bloodgroups for the pure population might support that the hypothetical major two equalallelic system is involved as noted in the previous paper (Fujino, 1962).
3. Non-random geographical distributions of Ju blood type incidences showthat four different breeding populations distribute in the Antarctic whaling areas
II, III and IV which can be named as the Atlantic, the West Indian, the East Indian,and the Lower latitudinal populations. Most of these results might support the
Brown's findings (1962 b), but no specific description has been made for the Lower
latitudinal population. Ju2-positive types incidences were estimated as 30. 7, 2.4,
4.0 and 32.8 percent for each pure population noted above. As regards the latter
two figures, more precise estimates will be expected after conducting further investigations. The Atlantic and the Lower latitudinal populations can be distinguishedby the differential Ju2 subtypic incidences.
4. Direct evidences showing overlaps of the migratory ranges of the different
populations in feeding grounds were described by basing on the logs of days when
whales belonging to both the Atlantic and the West Indian populations were takenin the same day.
5. Boundaries of migratory ranges for some populations in the feeding grounds
were estimated. Whales of the Atlantic population disperse eastwards to area III,and the east side boundary of migratory range of this population was became tobe obvious. On the other hand whales of the West Indian population migrate
westwards to the east-half of area II, but its west side boundary has not been madeclear. Then migratory ranges of these two population overlap in the feeding grounds
each other. Major migratory range of the Lower latitudinal population was estimated from locations of capture to cover a part of area III ranging from 30°
east to 50° east, north of 51° south.
6. Rate of intermingling of the Atlantic population in the whales taken fromarea III was calculated to be 14 percent or less by blood typing data. According
to the rates of emigration calculated from marking returns, approximate 10 percent

26

K. FUJINO

of the Atlantic population disperse to area III, and about 10 percent of the West
Indian population disperse to area II. If the both sizes of the two populations
are comparable each other, these figures show the rate of intermingle for each area
as they are.
7. Significant difference was seen in the frequency distribution of numberof whales observed from catcher-boats between the Atlantic and the West Indian
populations in feeding grounds. Although it has not been made obvious what
factors correlate with this result of observation, it may bring some problems to the
hypothetical basis for the ' geographical uniformity in distributing concentrationof animals ' in stock assessment.
8. Additional data were obtained to confirm the occurrence of intra-uterine
selection due to maternal-feta! incompatibility of Ju blood types for the Atlantic
fin whale population which was reported already (Fujino, 1963 a).
9. Relative incidences of Ju blood types were compared by different age
classes for the samples taken from the Atlantic population. Slight but significant
difference was seen between different blood groups in the relative viability in accordance with increment of ages. This fact was interpreted to play an importantrole in maintaining the blood type gene frequencies in a population together withthe fact noted as item 8 in this summary.
10. Possible influences of the intra-uterine selection to the ovulating cycles
were discussed, and the mechanisms that might bring geographical differences in
the rate of accumulating ovarian corpora were considered as a prelimiary meaning.

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BROWN, S.G. (1956). Whale marks recently recovered. Norsk Hvalfangst-Tid., 45(12): 661-4.
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27

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