bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Euphausiidæ in the Neighbourhood of Plymouth. III.Thysanoessa Inermis.
Authors: Lebour Marie V 
Published: May 2009

In a former paper (Lebour, 1924) attention was called to the eggs, Calyptopis and first Furcilia stages of Thysanoessa inermis together with the form neglecta, which was regarded as a different species, mainly on account of the size of the eggs shed by the females in glass jars in the aquarium, those of the neglecta form being much smaller than those of the inermis form. Certain differences were also found between the males of the two forms.Having through the kindness of Mr. C. F. Hickling obtained a number of Thysanoessa from the Atlantic Slope, chiefly in the region of the Smalls trawling ground, I found both forms present, which were usually much larger than those from the Channel, and presented certain other differences. Specimens of the two forms from both localities were sent to Dr. H. J. Hansen, of Copenhagen, who has kindly examined them and pronounced them all to belong to the same species,e.g. Thysanoessa inermis. It is an interesting fact that the specimens from the Smalls district are usually much larger than those from the Channel, and the neglecta form has the long legs much longer and stouter. Specimens from Iceland, for which I am indebted to Dr. Hansen, are also of a large size.As Hansen has already pointed out (1911, 1915), Thysanoessa inermis which has a wide range of distribution has two forms, a short-legged form, formerly known as Rhoda inermisand a long-legged form, formerly known as Thysanoessa neglecta; these may be referred torespectively as the inermis and neglecta forms.
The Vertical Distribution of Marine Macroplankton. II. The Pelagic Young of Teleostean Fishes in the Day-time in the Plymouth Area, with a Note on the Eggs of certain Species
Authors: Russell F. S. 
Published: May 2009

1. Horizontal hauls were made with a “stramin” ring-trawl and a silk net at different depths in 1924 and 1925 to determine the vertical distribution of the pelagic post-larval stages of Teleostean fish in daylight. The depths at which the nets fished on every occasion were obtained by means of a graphic depth-recorder.2. It was indicated that there are specific differences in the behaviour of the post-larvae of various fishes as to their vertical distribution in daylight, some preferring the surface layers, others apparently indifferently distributed from surface to bottom, and others preferring the deeper layers and avoiding the surface; of these last it was found that somespecies became abundant at deeper levels than others. A tentative list of distribution types is given on page 107. 3. Eesults emphasise the necessity when examining the horizontal distribution of young fish of sampling all layers : oblique hauls are to be desired fishing at as many levels as possible. 4. Mention is made of seasonal distribution : the year 1924 appeared to differ from 1925 in that certain post-larvae which were prevalent in the plankton well into June or July in the former year were cut short a month earlier in 1925.The post-larvae of Molva molva and of Lophius piscatorius were unusually abundant in 1924 ; post-larval Gobies (Gobiidce) and Wrasses (Labridce) were extremely scarce in 1925 during the months April to beginning of August.
On the Penetration of Light into Sea Water.
Authors: Poole H. H. , Atkins W. R. G. 
Published: May 2009

1. A description is given of some measurements of the penetration of light into sea-water carried out near Plymouth in the autumn of 1925 by means of photo-electric cells, the current through the cell being, measured by a method, previously described, which is not affected by the motion of the ship.2. The absorption coefficients found for off-shore waters down to 30 metres are smaller than the average of those found by several recent observers in various localities, but considerably larger than those found by Shelford and Gail for the deeper waters of Puget Sound. The coefficients tend.to increase with increase of depth, and are generally larger for in-shore waters. The clearest water, 20 miles out in the English Channel, gave an absorption coefficient 0-110 for the upper 10 metres, 0-117 for the second, and 0-133 for the third. This water, with glassy surface, transmitted 0-54% of the vertical illumination to 34-8 metres, 28-3% to 8-9 metres, at which depth a white disc was just visible, and 71-2% to 1-5 metres.
Experiments on the Mendelian Inheritance of Eye-colour in the Amphipod Gammarus chevreuxi
Authors: Sexton E. W. , Wing. M. B. 
Published: May 2009

1. Twenty-one thousand, five hundred and fourteen (21,514) amphipods of the species Gammarus chevreuxi Sexton have been examined for eyecolour, 21.302 referred to in this paper, and 212 in other experiments, not included.2. The normal eye-colour of this species is black, with a superficial reticulation of opaque white pigment.3. The pigmentation of the eye is very variable within limits. Eyes have been observed either partially or entirely lacking in the coloured pigment of the retinular cells, or with either a partial or entire lack, or else an excess of the opaque white pigment.4. The red strain appears to have arisen as a “sport” in the second generation of offspring of the first animals captured. No red-eyed animals have yet been found in natural conditions, although many thousands have been brought in from time to time and examined. Those counted for the purpose while the work for this paper was in progress numbered 8697, but this figure does not include the many thousands previously observed. Experiments have been made repeatedly with a view of getting the Red strain again from the Pure Black, but with no success.
The Zoea of Eurynome aspera
Authors: Gurney Robert 
Published: May 2009

The Zoea of Eurynome aspera has already been twice described—namely, by Kinahan (1857) and Cano (1893), but there is some discrepancy between the two accounts which an observation made at Plymouth in April, 1922, fully explains.Kinahan observed the larva immediately on hatching and described it as having neither rostrum nor dorsal spine; whereas Cano describes it as having both.
The Vertical Distribution of Marine Macroplankton. III. Diurnal Observations on the Pelagic Young of Teleostean Fishes in the Plymouth Area.
Authors: Russell F. S. 
Published: May 2009

Results are given of collections made with the stramin ring-trawl to study the vertical distribution of post-larval teleostean fishes throughoutthe period from daylight, through the hours of darkness, to daylight on July 15th-16th, 1924, and June 17th, 18th, and 19th, 1925. At the time of collecting in July, 1924, it was full moon ; in June, 1925, there was no moon.In no case, except perhaps that of Sardina pilcliardus post-larvse, was there evidence of marked upward migration at night ; the general impression for most species was that while the type of distribution shown in daylight was somewhat modified at night, only very few individuals moved up to the surface layers. There was, however, a notable increase in numbers of certainspecies at all depths at night, whether this was an indication of a movement up from layers very close to the bottom is not known ; it will need many more observations before the exact significance of this can be fully understood.The numbers of post-larvae taken were in the case of most species unfortunately very small on all occasions; it is not possible, therefore, to come to very definite conclusions.A possible indication of the effect of moonlight was shown by the post-larval Callionymus lyra, for while in July, 1924, at the time of full moon they showed no upward movement at night, in June, 1925, with no moon a certain proportion reached the surface layers.
On a Hermaphrodite Specimen of Amphioxus with Notes on Experiments in Rearing Amphioxus
Authors: Orton J. H. 
Published: May 2009

A hermaphrodite specimen of Amphioxus has been taken at Plymouth having one gonadial pouch filled with ova and the remaining pouches filled with sperm. This specimen closely resembles a similar one taken by Goodrich at Naples.The liver and intestine of the Plymouth specimen are abnormal, but no parasites have been identified in the tissues to account for these abnormalities.It is, moreover, improbable that there is any normal sex-change in Amphioxus, since three independent investigators have found very small specimens of both sexes, therefore no satisfactory explanation can be given of the occurrence of hermaphroditism in the specimen.Amphioxus have been found to spawn in June, and larvae have beenobtained from the captive specimens.It is suggested that the club-shaped gland may secrete a substance for attaching the larva of Amphioxus to objects, and that this function may be correlated with the asymmetry shown in the early development of the Amphioxus .larva.
Styela mammiculata n.sp., a new species of ascidian from the Plymouth area
Authors: Carlisle D. B. 
Published: May 2009

Styela mammiculata n.sp. is based on four specimens collected in the Plymouth area during the summer of 1953. The most noticeable external feature is the extensive mammillation of the test. The mammillae are much smaller than those of Phallusia mammillata and deserve to be called rather ‘mammiculae’.Of the four specimens, two were taken from Drake's Island buoy (National Grid Reference, 20/4753)m Plymouth Sound, growing about half a metre below the water line, and two from the oyster bed of the Lynher river estuary, near Antony Ferry (National Grid Reference, 20/4257), growing about 12 m. below low-tide mark attached to oyster shells. The largest specimen was from the latter locality and measured III mm. long in the contracted, fixed condi- tion. The smallest, from Drake's Island buoy, was 54 mm. long.
Hatching in Calanus finmarchicus and some other copepods
Authors: Marshall S. M. , Orr A. P. 
Published: May 2009

During observations on the development of the eggs of Calanus finmarchicus the process of hatching was watched on many occasions. Since it differs from that described by Ziegelmayer (1926) for cyclopids it seemed worth while examining the process in other groups of copepods as well.Hatching can be followed very easily in Calanus (Pl. I). For some time before, the form of the nauplius can be clearly seen with its limbs folded close to the body (A); in many a red pigment spot develops at this time in the otherwise transparent egg. Shortly before hatching the limbs begin to twitch occasionally and a space is just visible round the body of the nauplius. At this stage the inner and the outer egg membranes cannot be distinguished, but when hatching begins, the outer membrane must crack for the delicate inner membrane bulges out (B). The bulge enlarges rapidly (c), and the nauplius extends into the bulge, sometimes leaving a clear space between itself and the membranes (D). Usually it is either the head or the tail end which pushes into the bulge, but occasionally it is a limb. Probably it is abnormal for a limb to extrude first since such eggs do not always hatch successfully. As the inner membrane expands, the outer slips back and the inner, enclosing the nauplius, pops out (E). This emergence often occurs suddenly, but sometimes it is gradual (as in E), when the outer membrane crumples up on the inner, regaining its original shape only when the inner has slipped out and the tension is released (F).
A preliminary check-list of British marine diatoms
Authors: Hendey N. Ingram 
Published: May 2009

The present list of diatoms may be considered an extension of the recent check-list of British marine algae by Parke (1953). It includes not only truly marine species, both sessile and planktonic, but also species inhabiting brackish waters with a few fresh-water species that manage to live, though somewhat precariously, in estuarine conditions.It has been compiled for the following reasons: (1) to indicate the extent of the diatom flora around British coasts, so that comparisons may be made with that of the other countries; (2) to assist workers in the identification of material by indicating the size of any genus known to inhabit our shores; (3) to check the arrival of new entrants to the British flora; and (4) to provide a basis for a more detailed work, now in preparation. The check-list does not presume to lay down finalized decisions on the taxonomic rank ascribed to any organism or to consider the criteria upon which such ranks are based.
On the Anatomy and Relationships of New or Little known British Actiniaria
Authors: Stephenson Mary 
Published: May 2009

This paper contains anatomical descriptions of some British species whose systematic position has hitherto been uncertain because of the absence of detailed knowledge of their structure. To these descriptions are added notes on anatomical points of interest connected with other species.Some of the facts gained have a general systematic bearing which will be pointed out as they occur in connection with the descriptions, or in the discussion at the end of the paper. I am indebted to Dr. Allen, Mr. W. Edgar Evans, Mr. E. Elmhirst, Miss M. Delap, and Dr. T. A. Stephenson for material, and to Dr. Esdaile for valuable guidance.
Muscle-Tumours in the European Turbot
Authors: Young Maxwell W. , Johnstone Jas. 
Published: May 2009

In 1913 a successful attempt was made to introduce the European Turbot to New Zealand waters. On 12 January of that year 298 young fish, caught in the neighbourhood of Plymouth, and kept for some time at the Marine Biological Station, were put aboard the Waimana. Of these fish 195 were safely transported across the tropics, and were put into the tanks at the Portobello Marine Hatchery. The operation was a very successful one, thanks to the care of the late T. Anderton, who was then Curator of the hatchery.The turbot were originally from one to two inches in length. It was intended to liberate most of them in the sea, but, on consideration, it was decided to keep them in captivity. Three years later (May, 1916) there were still 182 fish, 5 having died and 8 having been liberated in the sea. They grew very rapidly in the tanks, so much so that in May of 1916 many were about 18 inches in length. To keep these large fish healthy was difficult, and so, in 1916, 128 of them were liberated in Taukutu Bay.
Oxidation in Sea Water
Authors: Harvey H. W. 
Published: May 2009

1. Putrefaction in sea-water sets free compounds toxic to Calanus. A portion of these compounds withstands oxidation to non-toxic forms in air saturated water for considerable periods.2. “Deep water” from the English Channel contains a catalyst, probably an iron compound, which increases the rate of oxidation of a number of easily oxidisable organic compounds. Its action is inhibited in surface and inshore waters by dissolved organic matter.3. Hydrogen peroxide decomposes relatively quickly in “deep water” from the English Channel, at a velocity corresponding to that of a monomolecular reaction. A catalyst, probably an iron compound, active towards hydrogen peroxide, occurs in sea-water. The action of the catalyst is inhibited by dissolved organic substances in surface and inshore water, until such substances are oxidised by the hydrogen peroxide.
On Rhythmic Periods in Shell-growth in 0. edulis with a Note on Fattening
Authors: Orton J. H. 
Published: May 2009

SUMMARYContinuous observations on the Upper Fal Estuary oyster beds during the years 1925, 1926, and 1927 have established the fact that 0. edulis exhibits on these beds two definite periods of shell-growth, i.e. increase in shell-area, in one year; one period of general shell-growth occurs in the spring, beginning early in April, and the other in autumn at the end of September or early in October. There is some evidence-but as yet incomplete-that internal shell-growth occurs solely and simultaneously with the deposition and thickening of the new shell-shoots in a period of one to two months.These general bursts of shell-growth occur in the pre-breeding and post-breeding part of the seasonSimilar periods of shell-growth occur on beds in the River Blackwater (AVest Mersea), and also occur mainly in the pre-breeding and postbreeding part of the season; but shell-growth begins in the spring in April-May on these beds, a few weeks later than on the Upper Fal Estuary,
and in the autumn in August-September a few weeks earlier than on the Upper Fal beds.Spring and autumn periods of shell-growth are also known to occur on many other estuarine beds.
The Vertical Distribution of Marine Macroplankton. VII Observations on the Behaviour of Calanus finmarchicus
Authors: Russell F. S. 
Published: May 2009

SUMMARYThe vertical distribution of Calanus finmarchicus adults in the daylight in the Plymouth region as shown by stramin ring-trawl catches in described for the period April to September in 1926. The general results confirmed the indications given in 1925 that there is a, gradual descent of the region of maximum abundance from about 10 metres in April to-metres in June, with a definite rise towards the surface ia July, August, and September.2. The rise towards the surface was evident on sunny days as well as dull, indicating that the suggestion that dull weather and low light intensity was its cause in 1925 may possibly have been incorrect.Measurements of the total lengths of Calanus were made which showed a seasonal change, a brood of small adults occurring in July, August, and September, as opposed to a brood of large adults whichdominated in the spring.It is suggested that possibly these two broods are physiologically different, and that the small type of adult prefers a higher light intensity and lives nearer the surface than the large type.The males and females differed in their behaviour, the males being always slightly deeper in the water than the females.Some indications are given of the course of the life-cycles of Calanus in the Plymouth area.While from April to the end of June the abundance of the last copepodid stage (Stage V) rarely exceeded more than 20% of the total Calanus in any one catch, they became very much more abundant in July, August, and September, reaching even 60% and 70%.
Studies on Conditioned Responses in Fishes. Part I.
Authors: Bull H. O. 
Published: May 2009

SUMMARYIt has been shown by experiments formulated upon the conditioned response principle that the blenny, Blennius gattorugine, is able to perceive and to profit by very small changes in its environment. This fish is able to form conditioned motor responses using food as unconditioned stimulus, towards a momentary increase of 0-4C, or more, in the temperature of the surrounding water.It is also able to form similar conditioned motor responses towards a momentary decrease in the salinity of the surrounding water, of as little as 3 parts per 1000, or towards a change of greater magnitude (up to 37 parts per 1000).Conditioned responses have been established in the wrasses, Crenilabrus inelops and Labrus bergylta, towards visual stimuli of varying kinds. It appears that these fishes can discriminate after differential training between one or two sources of light, and between monochromatic red, green, yellow, or violet light, but not readily between even comparatively large differences in intensity of a luminous source. These results are those obtained upon dark-adapted fishes. More extensive experiments will be necessary before a final statement is made upon their capacity for colour discrimination.
The Larvæ ofPolydora ciliataJohnston andPolydora hopluraClaparède
Authors: Wilson Douglas P. 
Published: May 2009

SUMMARYThe developments of Polydora ciliata Johns, and Polydora hoplura Clap, are described from the egg to a very late planktonic stage in the case of the former, and to young metamorphosed individuals in the case of the latter. Only external characters are described.In both species the eggs are laid in egg-sacs attached to the wall of the parent's burrow.The larvae of P. ciliata are released at a stage with three chsetigerous segments and lead a long planktonic life.The larvae of P. hoplura are provided with special food in the form of yolk-masses ; they undergo most of their development while in the protecting burrow of their parent; are released at a very late stage, and have only a short planktonic life.The larvae of both species have a complicated vestibule surrounding the mouth, and are provided with special sensory cilia on the head.The larvae are provided with a special kind of cilia, situated at the ends of every nototroch, which are used to take hold of the long provisional bristles in swimming. This suggests that one of the functions of the long bristles is that, in conjunction with these grasping-cilia, they increase the rigidity of the swimming larva, and hence the efficiency of its driving cilia.Previous references to Polydora larvae are briefly discussed.
Notes on the Biology of Tellina tenuis da Costa
Authors: Stephen A. G. 
Published: May 2009

SUMMARYThe present paper deals with the results of investigations into certain phases in the life-history of the bivalve mollusc Tellina tenuis carried out during the autumn of 1926 and 1927.Collections in the intertidal zone and below L.W.M., were made in a number of bays in the Cumbrae and neighbourhood, Kames Bay, Millport, being selected for intensive study.In Kames Bay Tellina tenuis ranges from a little below H.W.M. to depths of about 4 fm. The maximum concentration of about 1000 per sq. m. is found at L.W.M. springs and the numbers decrease to zero at H.W.M. and 4 fm.In Kames Bay the density of Tellina tenuis falls in a progressive manner from L.W.M. to H.W.M.The size-frequency distribution shows a regular gradation from the lower to the higher levels. At L.W.M. and below individuals of small size predominate, while at H.W.M. they are proportionately few.At higher levels growth is more rapid than at the lower levels.The size-frequency curves and density of Tellina tenuis in the other bays at L.W.M. correspond with those of half-tide in Kames Bay.The rate of growth may therefore be influenced by the density of population as well as by the habitat.In all areas the 1926 brood predominates.The Tellina tenuis population in Kames Bay seems to be composed of four year-groups, one of which is almost unrepresented. Collections from neighbouring bays indicate that older groups may be present.The amount of young brood on the bottom seems to vary considerably from year to year, being large and small in alternate years.The two closely related species, T. tenuis and T. fabula, are both plentiful in Kames Bay, but their range is not coincident.Eipe sperms were found from May onwards and ova were rounding off in June.Young Tellina tenuis, passing the 2-mm. sieve but retained by the 1-mm. sieve, were found in Kames Bay in August, chiefly below L.W.M., but in October plentifully distributed up to half-tide and in lesser numbers higher up the shore.The food usually consists of vegetable detritus, but during the spring increase diatoms appear almost exclusively in the gut.