bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on the spawning behaviour ofSaccoglossus horstiBrambell & Goodhart, and of other Enteropneusta
Authors: Burdon-Jones C.
Published: May 2009

The genital products ofSaccoglossus horstiare discharged within the burrows and expelled after the tide has ebbed. They are not retained in the burrows for any length of time.

Fertilization occurs mainly in the overlying surface water, or during the flood.

An ‘epidemic’ spawning was observed on three occasions in the field.

A rise of temperature to about 160° C. is regarded as the essential factor primarily responsible for initiating the spawning.

The females were observed to spawn before the males. Some reciprocal inducement might have occurred.

The breeding season in the Solent area is mainly confined to the months of May, June and July, and is seemingly dependent on climatic and tidal conditions during these months.

The spawning behaviour of other species of the Enteropneusta is discussed.
Spontaneous activity patterns in animal behaviour: the irrigation of the burrow in the polychaetesChaetopterus variopedatusRenier andNereis diversicolorO. F. Müller
Authors: Wells G. P. , Dales R. Phillips
Published: May 2009

Simple methods for recording the water currents, which many polychaetes drive through their tubes, are described. The circulation may be either open (the worm having access to large amounts of well-aerated sea water) or closed (in which case the worm can circulate a small volume only, and there is no oxygenacion or removal of excretory products).

When on open circulation, bothChaetopterus variopedatusandNereis diversicoloroften trace quite regularly cyclical patterns for hours at a stretch. Each species has several possible patterns, and may change from one to another without evident external cause. The tracings of each species differ from those of the other, and also from those ofArenicola marina, which were described elsewhere.
The grazing rate of planktonic copepods
Authors: Gauld D. T.
Published: May 2009

The filtering rate of four species of marine planktonic copepods was measured by estimating the rate at which they consumed cultures of Chlamydomonas.

The filtering rate was independent of the concentration of the food organism and it is concluded that the copepods were acting as filter feeders.

The filtering rates were much greater than those reported by Fuller & Clarke (1936) and Fuller (1937), but agreed with those reported by Harvey (1937).

Some evidence was obtained that grazing was restricted to some only of the 24 hr., most probably to the hours of darkness.

The filtering rates were approximately proportional to the square of the linear dimensions of the copepod.

The purely mechanical selection suggested by Fuller (1937) to account for differences in filtering rates obtained with different species of diatoms cannot account for all the differences which have been observed.

It is probable that the copepods could obtain sufficient particulate food in the sea by filtering a daily volume of water corresponding to the filtering rates found.
Notes on the growth and biology of the prawn Pandalus bonnieri Caullery
Authors: Pike R. B.
Published: May 2009

Pandalus bonnieri is a dioecious species and no protandrous hermaphrodites have been seen.

The breeding season and incubation period for P. bonnieri are described.

The number of eggs laid increases with the size of the female. At 16 mm. carapace length the number of eggs is c. 1000 and at 24 mm. carapace length the number of eggs is c. 4000. The number for a single mm. size group varies roughly by ±10%.

Both male and female P. bonnieri become sexually mature at about 18 months, and in the Clyde seldom live beyond 3 years of age.

The colour of the eggs in P. bonnieri is sage green, in P. borealis blue green, in P. montagui light emerald green and in P. propinquus fawn.

Juvenile P. bonnieri can be separated into males and females by the shape of the pleopods within 4–6 months of hatching.
The response mechanism in ascidians
Authors: Hoyle Graham
Published: May 2009

A method is described for investigating the reactions and spontaneous activity of two species of ascidian,Phallusia mammillataandAscidiella aspersa, which does not disturb the animals unduly. The method can be used for obtaining graphic records of the so-called ‘reflexes’ of ascidians.

If due attention is paid to certain factors which affect the state ofthe animals, they can be made to respond to electrical stimuli applied to the outside of the test in a way which can be observed repeatedly in the same animal, in other animals of the same species and in at least two genera of ascidian.

Electrical stimuli applied to the test affect the excitable system of the whole animal in an all-or-nothing manner.

Response to graded electrical stimulation reveals a facilitation mechanism which gives enormous enhancement to the size and speed of response to the second of a close pair of effective stimuli. It is suggested that this mechanism is responsible for the production of the rapid squirt of the large sedentary ascidians.

A possible cause of the very rapid fatigue of ascidians to all kinds of stimulation is fatigue of the facilitation mechanism following a period of stimulation.

A parallel is drawn between the responses ofMetridiumand the responses ofPhallusiaandAscidiella. The responses have some common features and the response mechanism appears to serve a similar purpose in the life of the animals.
Note on sea temperatures in the English Channel, 1921 to 1949, and Plymouth sunshine and light
Authors: Atkins W. R. G. , Jenkins Pamela G.
Published: May 2009

International hydrographic station England no. 1 (EI) has been visited regularly for many years, and since 1921 the periods have been (nominally) once a month, or more frequently. Much work has been done on the plankton and chemical changes in the water, but no biological use has been made of the temperature-depth observations, which are primarily of hydrographic importance. The aim of this paper is to render the sea-temperature observations over this long period readily available and to place beside them observations on air temperature, sunshine and light. Such comparisons may be expected to give information upon the causes of variations in temperature, but the adequate investigation of this very difficult problem is outside the scope of this note. The subject is worthy of fuller treatment on the lines suggested by Harvey (1925), based on data for the years 1921 to 1924, and has been considered on broad lines by Sverdrup, Johnson and Fleming (1942).
Effects of A Toxic Bloom ofChrysochromulina Polylepison the Common Dog-Whelk,Nucella Lapilluson the Swedish West Coast
Authors: Robertson Annika
Published: May 2009

A massive toxic bloom ofChrysochromulina polylepisoccurred along the Swedish west coast in May and June 1988 with severe effects on most biota in shallow marine habitats. In the present study, the effects on the common dog-whelk,Nucella lapilluswas investigated in the archipelago at the mouth of the Gullmar Fjord.

Mortality varied throughout the archipelago, with extinction of populations in the inner parts and survivors found only on the outermost islands. Even on these sites, mortality could be as high as 98­99%. Extensive samples of survivors and dead animals were divided into five age groups dependent on size and wear of the shell. The cohort consisting of 3­4 year old individuals suffered the lowest mortality, while mortality was almost total in younger and older cohorts. In each age group, except the oldest, survivors were significantly larger than the dead.

The number of egg capsules laid per female in 1988 seemed normal, but about half of the capsules were empty. The number of young per capsule was significantly lower in 1988 compared to 1989, but the young were significantly bigger.
Fatty Acid Composition of Early Non-Feeding Larvae of the European Flat Oyster,Ostrea Edulis
Authors: Helm M. M. , Holland D. L. , Utting S. D. , East J.
Published: May 2009

A total of 113 broods ofOstrea edulisL. larvae from a closely-controlled hatchery conditioning regime, from specific broodstock treatments, and from brooding oysters taken from a wild population in Poole Harbour, was analysed for fatty acid composition. Major differences in polyunsaturated fatty acids (PUFAs) were detected as the year proceeded, with increased levels of 20:5 (n-3) and 22:6 (n-3) from late June. Significant decreases in the PUFA content of both phospholipids and neutral lipids accompanied development from fertilized eggs to immediately pre-liberation larvae, but there was some evidence that the 20:4 (n-6) and 22:6 (n-3) content of phospholipids was protected. Fatty acid composition and content of newly liberated larvae were influenced by conditions during broodstock fattening and early gametogenesis (phospholipids) and by conditions during the later stages of oocyte development (neutral lipids).
Influence of Temperature on embryonic and larval development inNecora puber(Brachyura, Portunidae)
Authors: Valdes L. , Alvarez-Ossorio M. T. , Gonzalez-Gurriaran E.
Published: May 2009

The influence of temperature on the duration of the embryonic and larval development inNecora puber(L., 1767) was studied. Nine different temperatures were used for the eggs and seven for the larvae, in both cases ranging from 2 to 35°C. The temperature range where visible development was obtained was between 4 and 31°C, with the lowest lethal temperature (temperature at which the eggs did not show any sign of development and development did not resume when the eggs were placed at 15°C) being between 2 and 4°C and the highest lethal temperature between 31 and 35°C for both eggs and larvae.

Temperature was found to be inversely related to developmental time. The incubation period (D) fluctuated between 76 days at 10°C and 17·6 days at 25°C, with an increase in the rate of development (100/D) from 1·13 to 5·55 between these two temperatures. The larval period varied between 48·5 days at 15°C and 28 days at 25°C with rates of development of 2·08 and 3·57 respectively. The adjustment equations used show that temperature has a greater accelerating effect on eggs than on larvae. A simple potential equation, D=aT, describes the relationship between temperature and developmental time better than the Belehrádek equation, D=a(T-t).

Acording to the fitted equations developmental time from spawning to the first postlarval stage is completed in 91–105 days at temperatures of 13–15°C which is very close to our experimental data. The model proposed also fits most of the data from the available literature even those for other species such asLiocarcinus holsatus(Fabricius, 1798) andCarcinus maenas(L., 1758), which suggests that a similar response of developmental timevstemperature could be expected from other related Portunidae.
Plant-Animal Interactions in the Marine Benthos
Authors: Williams Gray A. , Hawkins S. J.
Published: May 2009

A meeting onPlant-Animal Interactions in the Marine Benthoswas held in Liverpool in September 1990, organized by the Sy sterna tics Association in their Symposium Series, and supported by the Marine Biological Association. The following six papers were first presented at this meeting:
Effect of Encrusting Bryozoans on the Physiology of Their Algal Substratum
Authors: Muñoz Jorge , Cancino Juan M. , Molina MarÍa X.
Published: May 2009

Traditionally, colonies of encrusting epiphytic bryozoans have been regarded as biotic factors reducing photosynthetic performance in benthic algae. In this study we determined under laboratory conditions the effects of Membranipora tuberculata on the photosynthetic efficiency of the rhodophyte Gelidium rex.

Encrusting bryozoans reduce to 44% the incident light reaching the algal thallus. However, concentrations of chlorophyll a and other accessory pigments are significantly higher in encrusted than in non-encrusted thalli. Consequently, photosynthetic efficiency is almost identical in both types of thalli. Although non-encrusted thalli showed a higher photosynthetic V due to higher levels of light reaching the algae, encrusted thalli exhibited a compensatory effect at low photon flux density and reached a similar P value. The detrimental effect of M. tuberculata on photosynthesis could be partially compensated by CO released from bryozoan cells, as G. rex preferred CO over HCO3 as a source of photosynthetic inorganic carbon. These results suggest that physiological interaction between bryozoans and algae, involving the interchange of metabolic substances, are likely to be important.
Notes on the Distribution of Burrowing Isopoda and Amphipoda in Various Soils on the Sea Bottom near Plymouth
Authors: Crawford G. I.
Published: May 2009

The earliest detailed account of the nature of the sea bottom near Plymouth is that of Allen (1899), wherein analyses of the soils on the 30 fm. line are coupled with lists of the animals collected by trawl and dredge. Ford (1923) described a number of soils in shallower water, and gave a quantitative list of the bottom fauna, collected with a grab which covered an area of 0·1 sq. m. Smith (1932) described in great detail the soils of the area of shell-gravel which surrounds the Eddystone Lighthouse. By none of these workers, however, was special attention paid to the smaller burrowing Crustacea, which are often overlooked unless they are made the special object of collecting. Some species, e.g. of Bathyporeia and Ampelisca, may be very common, and certainly play an important part in the ecology of the sea-bottom. See Steven (1930) and Hunt (1925).
A Double-tailed Eulalia
Authors: Wilson Douglas P.
Published: May 2009

While examining a bowl of rock dredgings from the Mewstone Grounds near Plymouth, on 10th December, 1926, my attention was attracted by a handsome Phyllodocid worm which had evidently crawled out of a crevice in the broken rocks. On closer investigation the worm proved to be of an unfamiliar species and, of much greater interest, to possess a small secondary tail arising ventrally rather more than two-thirds of the way down the body (Fig. 1). Scale drawings, made at the time from the living animal, have recently been carefully checked by examination of the preserved specimen; only a few slight alterations have been found necessary.
“Organic” Phosphorus in Sea Water from the English Channel
Authors: Cooper L. H. N.
Published: May 2009

Determinations of organic phosphorus (so called) have been made in waters from off Plymouth. The amount varies little with the time of year and averages 0·44 mg. -atom per cubic metre. This is of the same order as determinations in other parts of the North Atlantic. About one-half of this “organic phosphorus” is considered really to be arsenite.
The Seasonal Abundance of the Pelagic Young of Teleostean Fishes in the Plymouth Area. Part IV. The Year 1936, with Notes on the Conditions as shown by the Occurrence of Plankton Indicators
Authors: Russell F. S.
Published: May 2009

In continuation of the three previous reports on the seasonal abundance of the pelagic young of teleostean fishes (Russell, 1930, 1935 and 1936) the corresponding data for the year 1936 can now be given. These are published in the same form as in the previous reports to which reference should be made. The dates on which the collections were taken are given in Table I and the monthly average catches for the young fish in Table II. No observations were available between October 12th and December 16th, but this does not materially affect comparison with other years because normally the young fish present at that time of year are very few in number
The Development of the Hydroid Corymorpha nutans M. Sars from the Egg
Authors: Rees W. J
Published: May 2009

During the summer of 1936 I obtained mature specimens of the medusa of Corymorpha nutans at Plymouth. An account of the early development of the hydroid reared from the fertilized eggs of these is given below. Young polyps of this species have been figured by Allman (1871) and by Hartlaub (1907). Allman found his young polyps developing apparently from the rooting filaments of the parent hydroid which had become free. Hartlaub figures and assigns young polyps which he found in the plankton at Helgoland to this species.
Observations on the ormer population of Guernsey
Authors: Forster G. R.
Published: May 2009

The results of a short investigation of the population of ormers (Haliotis tuberculata) are described and discussed. The average number of ormers found by diving between 0–5 fm. below low tide was 2·4 per m2. The catches were measured, but no separation of year-groups was found.
The taxonomy of monogenean gill parasites fromScyliorhinus caniculaandRaia clavataat Plymouth
Authors: Coupland Anne C.
Published: May 2009

The monogenean gill parasites fromScyliorhinus caniculaandS. stellarisat Plymouth have been found to be identical; their proper taxonomic designation isHexabothrium appendiculatum(Kuhn, 1829) Nordmann, 1832.H. canicula(Cerfontaine, 1899) Price, 1942 is a synonym ofH. appendiculatum.

The hexabothriid collected fromRaia clavataat Plymouth has been identified asRajonchocotyle emarginata(Olsson, 1876) Sproston, 1946, andR. clavataBracey (in Sproston, 1946) has been shown to be synonymous with it.
Preliminary observations on scales and their mode of origin in Chrysochromulina polylepis sp.nov.
Authors: Manton Irene , Parke Mary
Published: May 2009

A species of Chrysochromulina is described which habitually produces four different types of scale on one and the same cell. Scales are more opaque to electrons than in other recorded species of the genus and it has consequently been possible to trace something of their mode of production. They develop within vesicles inside the body and are subsequently deposited on the cell surface. The vesicles responsible are in a compact group beside the Golgi body and below the flagellar bases. Scale-production is at a maximum in the afternoon and greatly reduced or discontinued at night. A marked diurnal rhythm also affects other cell components, mitotic phases being abundant at 4.30 a.m. Some changes occurring in the Golgi body are described and discussed in a preliminary way.
On the effects of some carcinogenic hydrocarbons on the growth of sporelings of marine red algae
Authors: Boney A. D. , Corner E. D. S.
Published: May 2009

Low concentrations of various carcinogenic polycyclic aromatic hydrocarbons cause a considerable increase in cell production when applied to sporelings of certain marine red algae.

Whereas low concentrations of carcinogenic derivatives of benzanthracene stimulate cell production, similar concentrations of structurally related non-carcinogens inhibit it.

The applicability of the method as a rapid screening test for carcinogens is discussed.
Preliminary experiments on the feeding and excretion of bivalves using Phaeodactylum labelled with 32P
Authors: Allen J. A.
Published: May 2009

In a series of experiments to investigate feeding and excretion in bivalves, Mya arenaria, Venus striatula, Ostrea edulis and Cuspidaria cuspidata were fed with suspensions of Phaeodactylum labelled with 32P. Although there is considerable variation in the filtering rates, specimens of O. edulis were found to have an average rate of 6·6 ml./h/mg dry body tissue. This figure is more than six times greater than that recorded for M. arenaria and V. striatula. No filtration was recorded in the carnivore C. cuspidata.
The morphology and larval behaviour of a new species ofSpirorbis(Serpulidae)
Authors: Gee J. M , Knight-Jones E. W.
Published: May 2009

Spirorbis rupestrissp.nov. has a sinistrally coiled, unridged tube and is distinguished fromS. borealisDaudin only by colour, small morphological details and striking differences in larval behaviour. Though the larvae are capable of swimming, they do not usually do so, but crawl about and soon attach themselves to rock surfaces near the tubes of their parents, particularly when stimulated by the presence of the coralline algaLithophyllum incrustans. They will not settle onFucus serratus.

S. rupestrisis found typically on rock surfaces in well-illuminated places throughout the lower half of the shore, generally associated withLithophyllum. It is abundant on the shores of south-west Britain, except where there is scouring by wave-borne particles.
The sexuality and spawning of Manx Pectinids
Authors: Reddiah Kosaraju
Published: May 2009

The results of a comparative study of the breeding biology of the Manx pectinids with special reference to Chlamys varia, C. distorta, C. tigerina, C. striata and C. furtiva are presented.

It is shown that C. varia and C. distorta are protandric hermaphrodites with separate sexual phases similar to those of oysters, and evidence is presented on the possibility of sex reversal. The other species, C. tigerina, C. striata and C. furtiva, are truly dioecious, possessing at no stage germ cells of both sexes in the same gonad and as most individuals produce only one brood, the possibility of sex reversal is excluded.

C. distorta has two large-scale or peak spawning periods, once in summer and for the second time in autumn, although some spawning occurs as a rule in most months of the year. The breeding behaviour of this species is intermittent and therefore the breeding period is prolonged.

C. varia has two mass spawnings in a year, once in June and for the second time during September and October and the breeding period is not markedly different from that observed in French waters. Spawning is usually completed within a short period. C. tigerina and C. striata spawn only once annually in June and August respectively and most individuals have only one breeding cycle during their life time. C. furtiva however, may have two spawnings in a year, but the material available was inadequate to confirm this.
The Saltash Tuck-Net Fishery and the Ecology of some Estuarine Fishes
Authors: Hartley P. H. T.
Published: May 2009

The Saltash tuck-net is used in the estuaries of the Tamar and Lynher for seine netting on soft mud. The fishery is carried on during autumn and winter, from open boats with crews of two men.

Hauls were made with a tuck-net in every month between November 1935 and December 1937.

The fish population of the estuaries is essentially marine: its composition changes from month to month with the arrival from, or departure to, the sea of different species of fish. With the exceptions of salmon (Salmo salar), sea trout (Salmo trutta) and some of the Gobiidae, all the fishes of the estuaries go down to the sea to spawn.
The ecology of the Tamar Estuary IV. The distribution of the fauna and flora on buoys
Authors: Milne A.
Published: May 2009

Buoys differ from the intertidal area in that they are constantly immersed near the surface of the water and the slope and texture of their surface is constant. The horizontal and vertical distribution of the macrofauna and macroflora on a series of buoys stretching from the open sea up the Tamar estuary is given.

There are differences in estuarine penetration even among species belonging to the same genus. Distribution is likely to be affected by the time of laying the buoys and the period in the water. But the six buoys farthest from the sea were laid down and lifted at approximately the same time. For these, at least thirty species were available for colonization, but little more than half that number was found even on the most seaward; and the number decreased up-river.
On the faunas inhabiting intertidal seaweeds
Authors: Colman John
Published: May 2009

This paper gives an account of a survey of the invertebrate populations (omitting Protozoa) of eight species of seaweeds on Church Reef, Wembury Bay, extending over the entire intertidal range.

Above high-water neaps the faunas are poor, except for that in Lichina pygmaea which is the richest in individuals on the shore.

Between high-water neaps and low-water springs the most numerous groups are copepods, acarines, young littorinids and (in Ascophyllum only) ostracods.

In the holdfasts of Laminaria digitata polychaetes are very abundant and make up the majority of the population.

The intertidal faunas are compared with those in the soil on land, and prove to be far more abundant. Even the most plentiful group in the soil, the insects, is rarely as numerous as it is in Ascophyllum around mean sea-level.

Altogether 177 species are recorded, of which 35 are not in the Plymouth Marine Fauna (1931).
A preliminary study of the ecology of a mud-flat
Authors: Rees Colin B.
Published: May 2009

Ten stations, from high water to low water, were investigated along a mud-flat in the Bristol Channel.

The mud was analysed for water content and grade. The values suggested, with other observations, that the stations were distributed over two different areas.

Quantitative analysis of both macrofauna and microfauna revealed a dense mud population.

The operative ecological factors, including the food cycle, are defined.
Observations on the origin and fate of flagellated gametes in multiple tests of discorbis (foraminifera)
Authors: Myers Earl H.
Published: May 2009

It has long been presumed that the gametes of certain Foraminifera are flagellated; however, the lack of conclusive evidence as to the origin and fate of these flagellated gametes has made their existence problematical.

In syzygous species of Discorbis the gametes are flagellated and the genetic relationship of these gametes is easily demonstrated, since gametogenesis, fertilization, and the development of two- and three-chambered multinucleate microspheric agamonts takes place within the excavated tests of two or more mononucleate megalospheric gamonts associated in syzygy.

The life cycle of Discorbis herein described is in general agreement with the life cycle of Polystomella crispa proposed by J. J. Lister, and completes an interesting series of life cycles in which a progressive modification in behaviour and test morphology can be traced.

Behaviour, ecology, and distribution of four syzygous species of Discorbis are discussed.

Multiple tests of these syzygous species of Foraminifera can be found in most rock-bottomed tide pools that supports a growth of coralline algae. These sexual groups provide a sure source of material for the demonstration of flagellated gametes in the Foraminifera.
Notes on the life history of Sacculina carcini Thompson
Authors: Foxon G. E. H.
Published: May 2009

The life history of Sacculina carcini parasitic on Carcinus maenas in the Clyde sea area is discussed and the breeding period and the time of the emergence of the young externa are indicated. The time and duration of the breeding season are compared both with what has been found at Plymouth and Roscoff for the same species of parasite on the same host crab, and also with what was found by Day (1935) who worked in the Mersey area on Sacculina carcini but parasitizing Portunus holsatus.

The length of life of the Sacculina externa and their ultimate fate are discussed. It is shown that in male crabs which act as hosts the liability of the secondary sexual characters to modification is correlated with size.
The development of isolated resting spores into auxospores in Ditylum brightwelli (West.)
Authors: Gross F.
Published: May 2009

The resting spores of Ditylum are formed as a result of a peculiar kind of plasmolysis of the protoplast (Gross, 1939); they are small spherical bodies lying inside the old cell wall. Since one-half of the cell wall is only slipped over the other half it is likely that in the sea they might become separated and the resting spore proper would drop out of the shell. In a previous paper (Gross, 1937) it was stated that in old cultures a considerable number of resting spores could be found outside the parental shells, and when transferred into fresh culture medium they only expanded in volume. Since then more attention has been paid to such isolated resting spores and the formation of new cell walls has been frequently observed.
The solubility of calcium carbonate in tropical sea water
Authors: Smith C. L.
Published: May 2009

In a previous paper (Smith, 1940b) the chemical changes observed in ocean sea water flowing across the shallow banks on the west coast of Andros Island (Bahamas) were reported. High salinities were produced by evaporation and calcium carbonate was precipitated. From the data obtained under natural conditions a maximum value of the solubility product constant of calcium carbonate in sea water was suggested. There was no reason to believe, however, that this value of the constant represented the true equilibrium conditions, and experiments have since been made in the laboratory with a view to bringing water from these banks into equilibrium with solid calcium carbonate.
Saccoglossus horstisp.n., an Enteropneust occurring in the Solent
Authors: Brambell F. W. Rogers , Goodhart C. B.
Published: May 2009

1.S. horstioccurs on the Hampshire coast of the Solent near the mouth of the Lymington River, in glutinous grey mud associated withCorophium volutator.

2. The species is distinguished by the following characters: coloration; dorsal and ventral grooves present on the proboscis throughout its length; collar forming a slight operculum posteriorly; ventral muscle bands of the trunk forming projecting ridges; rounded genital ridges present, the gonads beginning within 1 mm. of the collar; 100–140 pairs of gill slits; longitudinal muscle fibres of the proboscis arranged in nine or more concentric rings; ventral septum of the proboscis short; stomochord straight, with ventral diverticulum and wide lumen throughout; no dorsal glomerulus present; single proboscis pore on the left side; proboscis skeleton embracing half to two-thirds of the circumference of the buccal cavity and extending one-fourth to one-third of the length of the collar; four epidermal zones present in the collar; collar cavities completely separated; anterior extensions of the collar cavities extending into the neck of the proboscis; perihaemal cavities separate posteriorly but confluent in front of the level of the tips of the crura, and extending into the neck of the proboscis as far as the proboscis pore; neural keel well developed and in continuity with the epidermal nerve layer at intervals; no dorsal diverticulum of the buccal cavity; branchial epidermis characterized by the predominant intensely eosinophil glandular elements; tongues broader and projecting further into the lumen of the pharynx than the septa; epibranchial ridge formed by two convex ridges bounding a median groove; oesophagus divided into three regions; 4–8 intestinal pores; hepatic region of gut not sacculated and with an expanded lumen; gonads not lobed; oocytes attain a size of 0·23 × 0·17 mm.; yolk cells present in the ovaries.

3. The probable identity of the specimen ofSaccoglossusfrom the French coast of the English Channel, recorded by Caullery & Mesnil (1916) asS. kowalevskyi, with this species is discussed.
Studies in the biochemistry of cirripede eggs. I. Changes in the general biochemical composition during development ofBalanus balanoidesandB. balanus
Authors: Barnes H.
Published: May 2009

The biochemical composition–water, glucose, soluble and insoluble glycogen, protein and non-protein nitrogen, total lipid–of the eggs of Balanus balanoides and B. balanus has been determined during development.

Preliminary analyses of the pigment content are reported.

The changes in both species are similar; but they take place more rapidly in B. balanus with its shorter period of embryonic development.

During development there is a net loss of all fractions; small increases of glucose and soluble nitrogen are, however, found at certain stages.

The pigment is largely a chromolipid; during the early stages of development this increases, but is subsequently lost; astaxanthin is also present. The visual appearance is a poor guide to pigment content.

The oxygen uptake of the eggs has been measured.

There is a discrepancy between the oxygen uptake measured directly and that required to oxidize the substrate lost; the causes of this are discussed.

The results are discussed relative to the habitats of the species.
The feeding mechanisms of the ophiuroid Ophiocomina nigra
Authors: Fontaine A. R.
Published: May 2009

The feeding mechanisms of Ophiocomina nigra have been re-examined. A new mechanism, the mucus-net method, is described for the first time. This is essentially a method of suspension feeding in which seston is trapped in a net of mucous threads between the arm spines. The entangled material is formed into boluses by simultaneous activities of ciliary currents and the tube-feet and is transported to the mouth by the tube-feet.
Aerial respiration inBalanus balanoides
Authors: Grainger Felicity , Newell G. E.
Published: May 2009

Observation of Balanus balanoides on the shore at Whitstable shows that at all tidal levels a percentage of the animals maintain a connexion between the mantle cavity and the air by means of a minute aperture or pneumostome. A higher percentage of animals at lower shore levels have a pneumostome than those nearer the top of the shore.
On the Foraminiferida of the Plymouth region
Authors: Murray J. W.
Published: May 2009

The seasonal changes in the foraminiferid populations along the Tamar-Eddy-stone profile have been shown for the winter, spring and summer of 1962. No single environmental factor appears to be wholly responsible for these changes but temperature is considered to be important. Variable salinities are of secondary importance in the Tamar. These seasonal changes have been compared with those observed at Christchurch and found to be different, presumably because of the different temperature and salinity conditions prevailing in the two estuaries.

A qualitative assessment of the energy input of the environment from the nature of the deposited sediment has shown a good positive correlation between the distribution of the Miliolacea and a high-energy environment. All other superfamilies show a negative correlation with high energy, but the Cassidulinacea show a preference for a moderate-energy environment during the summer.

Foraminiferids, found not to be very abundant in the Plymouth region, show a trend toward greater numerical abundance and greater diversity in passing out o t sea. The shortage of living foraminiferids is tentatively correlated with a restricted food supply.
Electrophoretic studies on blood proteins in an ecological series of isopod and amphipod species
Authors: Wieser Wolfgang
Published: May 2009

An electrophoretic study of whole blood samples revealed the presence of haemocyanin and of various other proteins in the blood of fifteen species of marine and terrestrial amphipods and isopods.

The amount of haemocyanin per 1 mm3of blood is independent of body weight over a range from 10 mg to 1 kg.

Under laboratory conditions and during starvation the haemocyanin level of the blood is lowered as compared with freshly caught specimens.

No relationship between moulting stage and haemocyanin content could be established in three oniscoid isopods, representingLigia, Oniscus, andPorcellio.

In some species the densities of both haemocyanin and ‘slow proteins’ (i.e. proteins between starting line and haemocyanin) seem to vary in more or less the same direction, over at least part of the total range of variability. In the offshoreConilera, however, an indirect relationship seems to exist between these two protein fractions. This is reminiscent of the situation inMaia squinadodescribed by Zuckerkandl (1960).

The slow protein fractions appear to play a number of roles in the species investigated. InConilerathey consist of various copper proteids (perhaps concerned with the synthesis of haemocyanin?), while in intertidal amphipods and some isopods they carry chromophilic groups that may be of importance in mechanisms of colour change. The colour of the blood of a given specimen ofOrchestia gammarellaandMarinogammarus marinusdepends on the amount of the faster moving, blue chromoproteid present in the blood. These chromoproteids are considered to be carotenoproteids.
On the fecundity of some gammarids
Authors: Cheng C.
Published: May 2009

1. The number of species found in this investigation is six, of which four are marine and two brackish water.

2. The mean value of the body weight and the fecundity varies with the species. The size of a species bears no relation whatever to the reproductive capacity.

3. The fecundity is subject to seasonal variation, being generally higher in the spring than in the winter months.

4. In general, a positive correlation exists between body weight and fecundity of the individuals of each species. This rule does not, however, apply to Gammarus duebeni, in which the fecundity appears to fall after reaching its maximum at the 19 mg. body-weight class.
The relation of Gammarus zaddachi Sexton to some other species of Gammarus occurring in fresh, estuarine and marine waters
Authors: Sexton E. W.
Published: May 2009

Gammarus zaddachi is perhaps the most prolific and widespread of all the estuarine amphipods known to occur in northern Europe, and inhabiting, as it does, the low-salinity estuarine zone and adjacent coasts, it has come to be recognized in recent ecological work as a ‘salinity indicator’.

Unfortunately, there has been constant confusion with the other common species of Gammarus, G. locusta, pulex, and duebeni, which has been greatly complicated by the difference in the appearance of zaddachi according as it lives in a freshwater or a saline habitat. It is shown that this difference is entirely due to the sensory equipment, the greater production of hairs in freshwater conditions, and that the structure of the two ‘forms’ is identical.

The history of the species has been carried back as far as I have been able to trace it (1836) with the actual specimens, described in the different papers, and the more important of these papers are discussed. It will be seen that the material examined was derived from every country of northern Europe; from Russia, the White Sea, Crimea, and the Baltic, the coasts of Scandinavia, Germany, including the Hamburg water-supply, Denmark, the Netherlands, Great Britain and Ireland, and France as far up the Loire as Nantes.

Detailed descriptions and figures of both forms of G. zaddachi are given; and finally, a comparison is made between the species most commonly confused with it, the Arctic species G. wilkitzkii being included because of a suggestion recently made that it might be, not a distinct species, but merely the Arctic form of zaddachi.
Further observations on changes in the bottom fauna of a fertilized sea loch
Authors: Raymont J. E. G.
Published: May 2009

An account is given of the further changes in the bottom fauna of a fertilized sea loch (Loch Craiglin) from 1944 to 1947, and the results are compared with those obtained from 1942 to 1944.

The bottom fauna density fell markedly during 1944, despite the addition of very large quantities of fertilizers. Unfavourable hydrographic conditions, especially low oxygen tensions, are considered to be responsible for the decrease.
Notes on the general biology ofTubularia LarynxEllis & Solander
Authors: Pyefinch K. A. , Downing F. S.
Published: May 2009

A description is given of a number of observations ahd experiments on the larvae and colonies ofTubularia. The experimental material could best be referred to the speciesT. larynxEllis & Solander. Its characters are not wholly consistent with the diagnosis of this species, but the differences which exist are not great enough to warrant the erection of a new species.

Liberation of the actinulae takes place more freely in darkness than in light, and there is evidence which suggests that it only occurs in still water or in weak currents.
The Use of Probability Paper for the Graphical Analysis of Polymodal Frequency Distributions
Authors: Harding J. P.
Published: May 2009

The mathematical analysis of bimodal distributions is very complex. Karl Pearson (1894) investigated the problem and developed equations for the purpose; but found them unsolvable as the ‘majority [of the relations] lead to exponential equations the solution of which seems more beyond the wit of man than that of a numerical equation even of the ninth order’. He did indeed evolve an equation of this order and used it to analyse a few bimodal distributions, but the arithmetic involved was very laborious. Later he (Pearson, 1914) gives a table for ‘Constants of normal curve from moments of tail about stump ’which, as he describes in the introduction, occasionally permits a rough analysis of a distribution which is known to be bimodal. This method is much more rapid than the solution of the nonic equation, but ‘owing to the paucity of material in tails and corresponding irregularity there will be large probable errors’. Gottschalk (1948) discusses the question and shows that inthe special case where the bimodal distribution is symmetrical comparatively simple solutions can be found.
On Manganese in Sea and Fresh Waters
Authors: Harvey H. W.
Published: May 2009

A method of estimating the maximum quantity of manganese available to plants in sea and fresh waters is described.

Samples of sea water collected off Plymouth in 1948 contained 0·7–1·0 mg. Mn/m.3in solution plus any particles soluble at pH 4·6. After storage and sedimentation of particulate matter, the quantity decreased to 0·0–0·25 mg./m.3

Samples collected off the Isle of Man, an area with a rich summer population of flagellates, contained 2·0–2·6 mg./m.3

The river Yealm, south Devon, on leaving Dartmoor contained 1 mg., and after passing through agricultural land 10 mg.\m.3

Lakes and streams in the English Lake District contained 6–40 mg.\m.3The least fertile waters contained the least soluble manganese.
The Biology of Asterias Rubens L.: Growth And Reproduction
Authors: Vevers H. G.
Published: May 2009

Considerable differences were found in the size compositions of populations of Asterias rubens off Plymouth. These differences were not correlated with age.

Laboratory observations on rate of growth showed that well fed starfishes grow fast during summer and autumn and somewhat slower in winter. Poorly fed starfishes did not increase in size, but were able to survive for long periods with a minimum of food.
The Post-Larval Sand Eels (Ammodytidae) of the Celtic Sea and Plymouth Area
Authors: Corbin P. G. , Vati Vidya
Published: May 2009

The post-larval sand-eels (Ammodytidae) occurring in the Celtic Sea and Plymouth area are identifiable as Ammodytes lanceolatus, A. tobianus, A. marinus (not previously recorded from the area), and a fourth species of Ammodytes, the adult of which, it is concluded, is not yet known.

Adult Gymnammodytes semisquamatus (not previously recorded from the Plymouth area), the young of which are not yet known, increases the number of species in the area to five.
Some observations on the effect of fibrous glass surfaces upon the settlement of certain sedentary marine organisms
Authors: Barnes H. , Powell H. T.
Published: May 2009

A description is given of a glass cloth surface which prevents the settlement of larvae of Balanus crenatus and Pomatoceros triqueter, whilst not affecting that of Tubularia larynx. A number of possible causes for this are examined, and its relation to other work on the settlement of sedentary forms is briefly considered.
The reproduction and larval development of Nereis diversicolor O. F. Müller
Authors: Dales R. Phillips
Published: May 2009

An account is given of the reproduction and development of the larva of N. diversicolor O. F. Miiller.

In any one population the number of males was found not to exceed 10 %.

The species is dioecious. Both sexes become green at maturity, but may be distinguished externally.

Ripe oocytes, which vary between 200 and 250μ in diameter mature in a loose coelomic parenchyma, and are released by rupture of the body wall after its partial histolysis. Sperm is released through the nephridia, or possibly by rupture of the body wall as well. In the male histolysis occurs, but the coelomic parenchyma is transitory. Sperm matures in the form of coelomic sperm plates.
Lissoclinum argyllense n.sp., a new ascidian from Scotland
Authors: Millar R. H.
Published: May 2009

In the summer of 1949 a compound ascidian was collected from the shore of Seil Island, Argyll. This proved to be a new species of the family Didemnidae. It is proposed to name it Lissoclinum argyllense, the specific name indicating the area in which it was first found. No species of Lissoclinum has hitherto been included in the British fauna.
The Biology of The Small Planktonic Copepods of Plymouth
Authors: Digby P. S. B.
Published: May 2009

The life histories of the small planktonic copepods of Plymouth were studied during 1947. The samples were taken at Station L4 with Harvey measuring nets, and are thus truly quantitative.

The main species concerned were Pseudocalanus elongatus, Paracalanus parvus, Centropages typtcus, Temora longicornis, Acartia clausi, Oithona similis, O. nana, Oncaea venusta and Corycaeus anglicus.

The species common in summer—all but the last three of the above—behaved in a very similar way, producing probably five generations in the course of the year, but differing from each other in the relative and absolute abundance of the different stages at different times of the year.
Studies of the Plymouth Brachyura. II. The Larval Stages of Ebalia and Pinnotheres
Authors: Lebour Marie V.
Published: May 2009

Further study of the larval crabs of the Plymouth district has resulted in the elucidation of many more life-histories. Amongst these perhaps some of the most interesting are Ebalia and Pinnotheres. These genera, placed by systematists in widely different groups, resemble one another closely in many details in their larval stages and are here purposely described together in order that a comparison may be made.
The Nauplius Larva of Anelasma squalicola (Lovén)
Authors: Frost Winifred E.
Published: May 2009

The Cirripede Anelasma squalicola (Lovén) is parasitic on the smooth dogfish, Etmopterus spinax (Linnæus). These fish, which are caught a depth of about 150–180 fathoms, were brought to the University of Liverpool as material for a chemical investigation by Professor Heilbronn and his colleagues. On finding that some of the fish were thus parasitised, Professor J. Johnstone and myself made a study of the general morphology of Anelasma (3).
The Identification and Validity of Certain Species of Ascidians
Authors: Berrill N. J.
Published: May 2009

There has existed in the past, and still does exist, considerable confusion both in the question of a satisfactory basis for the classification of ascidians and that of the validity of many species.

The principal orders and families are fairly stereotyped, and confusion and divergent opinion is mainly confined to the internal classification of the various families. These differences have a twofold origin, in that classifications have been constructed by various authors on three distinct bases, and that it is very difficult to distinguish between structures which are similar through relationship and those which are similar through convergent or parallel development. Further difficulty arises from the fact that authors describing a new species with a view to fitting it into one particular classification, have often given insufficient details for its accurate inclusion in another scheme. There is also divergent opinion as to the correct nomenclature that should be employed, but with that this paper is not concerned.
Nitrate in the Sea. II
Authors: Harvey H. W.
Published: May 2009

1. Observations made subsequent to December, 1925, confirm the conclusion that the nitrates in the water of the English Channel, twenty-two miles south-west of Plymouth, are almost entirely utilised by phytoplankton in the summer, and are reformed in early autumn at a greater rate than they are utilised.

2. Movements of the water masses are shown to affect the quantity of nutrient salts available for phytoplankton in the waters immediately north of Ushant.

3. The effect of land drainage on the quantity of nitrate in the sea is not apparent beyond a few miles to seaward from Plymouth Sound, being masked by the nitrate which is regenerated from dead marine organisms.

4. The nitrate in the river and estuarine waters entering Plymouth Sound is nearly all utilised by plants in the rivers and estuaries themselves before reaching the open sea during summer.