We have recently begun to receive from the French Ministère de la Marine a monthly journal entitled Pêches Maritimes, and published as a supplement to the Revue Maritime et Coloniale. The number for August of this journal commences with an article on La biologie de la sardine, by M. Paul Guéry. This article consists chiefly of summaries of the researches of four zoologists on the reproduction and life-history of the sardine. We have the summaries given under the following headings:

The poorly known sponge species Axinella vellerea (Topsent, 1904), Acarnus levii (Vacelet, 1960) and Haliclona poecillastroides (Vacelet, 1969) are reported from bottom-trawl samples off the Balearic Islands, Western Mediterranean. A re-description is provided for all three species and the Folmer fragment of cytochrome oxidase subunit I (COI) obtained for A. levii and H. poecillastroides. This is the second report of A. vellerea in the Mediterranean, the first time that A. levii is reported outside Corsica and the first time that H. poecillastroides is documented outside the Gulf of Lion, France. The systematic allocation of A. levii and H. poecillastroides is discussed based on a COI phylogenetic analysis and morphology. The poorly understood phylogeny of the Haplosclerida does not permit us to find a proper allocation for H. poecillastroides, although its current position in the genus Haliclona or the family Chalinidae is not defensible. On the other hand, A. levii currently fits best in the family Microcionidae, and seems related to some Clathria species with mixed features between Clathria and Acarnus. Considering that the species of the genus Acarnus shares a strong synapomorphy (the possession of Cladotylotes), it is plausible for all Acarnus species to be Microcionids. We conclude that H. poecillastroides needs to be reallocated to a new genus: Xestospongia poecillastroides comb. nov. (Petrosiidae). However, a reallocation of A. levii is not advisable for the moment, as this would imply major systematic changes such as the reallocation of the whole genus Acarnus to Microcionidae, and the redescription of Microcionidae and Acarnidae.

During the winter of 1927–28 the progress of the herring fishing at Plymouth was followed for the fourth consecutive season. A diary of market events was again kept by Mr. A. J. Smith of the Laboratory staff, while statistics of commercial landings and of the number of visiting drifters were kindly supplied by Mr. T. Edser of the Statistical Department, Ministry of Agriculture and Fisheries, and by Mr. E. C. Nelder of the Sutton Harbour Improvement Company, respectively. In the examination of age and growth of random samples of herrings, Mr. F. J. Warren, Laboratory Assistant, again acted as recorder. Details of the methods of treatment of the data collected will be found in Part I of this series of Reports (Ford, 1).

A description is given of a filamentous red alga which was found growing within a sponge collected from the sublittoral off Santander, Spain. The plant appears to be closely related to Acrochaetium spiculiphilum Dawson. A survey is given of the specific characters available for the typification of the known partially and completely endozoic Acrochaetium species, and some suggestions made on the more important lines of study.

Introduction

During the summer of 1957 some specimens of the keratinous sponge Haliclona were collected from the sublittoral off Santander, Spain, by Mr G. R. Forster. Certain of the specimens bore extensive areas of red, and on preliminary examination this colour was found to be due to the filaments of a red alga showing an extensive ramifying growth within the skeleton of the sponge. The drawings and cell measurements to be reported were made from the plant material by A. D. B. soon after its collection. This information has been retained pending a more comprehensive study of endophytic and endozoic red algae. Work is now in progress on these lines (mainly by E. B. W.), and a re-examination of the Santander material has enabled us to make a critical study of the data available for a precise typification of plants of this habit. Further, since the association of endozoic filamentous red algae with sponges appears to be of rare occurrence, any examples need to be fully described.

Description of Plant

The cells were of variable shape and size, and contained much-dissected parietal chromatophores (Fig. 1 a). Individual filaments tended to be closely packed together within the host (Fig. 1 b), and there was no extensive growth of erect filaments outside of the host material.

On the one hand, a recent study on sea turtle by-catch during surface longline fishing targeting swordfish in the western Mediterranean Sea showed that sea turtle by-catch is independent of fishing effort and other technological factors. When the distance to the coast increases, there is a higher probability of catching a loggerhead turtle. The authors proposed to avoid fisheries further than 35 nautical miles (approximately 65 km) from the coast. However, the proposed 35 nautical miles limit could be useful where the continental shelf is narrow, as in the Balearic Sea, and useless where it widens. On the other hand, ecological model validation is considered essential for management application. The objective of the present paper is to validate the new fisheries loggerhead by-catch model in different areas outside the Balearic Sea with wider continental shelves, aimed at maintaining sustainable fishing activity compatible with the conservation of the loggerhead populations. Our present results validate the previous model, and stress the importance of the eco-geographical variable distance to the coast in understanding the loggerhead by-catch (or incidental capture) per unit effort for the longline fisheries targeting swordfish.

The oilfish, Ruvettus pretiosus, is an incidental by-catch of the drifting surface longlines targeting swordfish and Thunnidae in the Mediterranean and elsewhere. Despite its global distribution and frequent occurrence in the catch of many fishing gears, little is known about its biology. In this study we examined the dietary preferences and reproductive biology of this species from specimens caught in the eastern Mediterranean. The most numerous and frequently occurring prey items were benthopelagic fish, followed by cephalopods. The sex-ratio was highly skewed in favour of females (1:8.4), while histological examination of the collected ovaries displayed six developmental stages (perinucleolar, early and late lipid stage; early, middle and late vitellogenesis). Oocyte diameter ranged from 23–69 μm at the perinucleolar stage to 224–366 μm at the late vitellogenesis stage. Spawning is expected to occur during mid and late summer; however there were no individuals available from this period. The findings are discussed in relation to the ecology of the species.

Stromateoid fishes form a small group among the Perciformes, characterized by remarkable toothed saccular outgrowths in the gullet just behind the last gill arch (Haedrich, 1967). Most are associated with medusae when young but are poorly known as adults. In addition to the diagnostic oesophageal teeth, a striking feature of many stromateoids is the curious subdermal canal system, whose function is unknown and whose structure has not been described in detail. The present note describes observations upon the biology of Schedophilus medusophagus Cocco, and upon the structure of its integument.

The prevalence and infestation intensities of Octolasmis lowei in the branchial chambers of Libinia spinosa were evaluated according to the host's sex, size, and moult condition. Epibionts were classified as cyprid larvae, non-ovigerous or ovigerous according to their developmental stage. A median intensity of infestation of 21 epibionts/host was found (range = 1–644; Q3 = 81). Epibiont prevalence values (88%) were higher on ovigerous female hosts than on males (55%) or on non-ovigerous females (31%). Intensity of infestation was positively correlated with host size in both sexes for non-ovigerous and ovigerous epibionts. No preference between host sex by cyprid larvae was observed, nor any correlation between cyprid abundance and host size. Cyprid larvae abundance was positively correlated with settled epibionts on both host sexes. The duration of the intermoult phase was the main factor linked to the establishment of sessile epibionts. These observations are important in relation to crabs that have a terminal moult, because these animals cannot eliminate their epibionts in future moults, thus increasing the importance of density-dependent mechanisms on epibiont establishment; in that way, prevalence of infestation alone can underestimate the real impact of infestation on the host's life cycle.

During the progress of the work on Gammarus chevreuzi it became increasingly evident that heterozygosity must exist in the wild population.

The larva of the dolichopodid fly Aphrosylus celtiber Haliday is an omnivorous carnivore in the intertidal zone. It pupates in an air-filled cocoon of debris and a secretion of the labial glands. The pupa has plastron-bearing spiracular gills that have been evolved from respiratory horns similar to those of recent terrestrial Dolichopodidae.

Although the spiracular gills are pupal structures, they are the chief respiratory organs of the young adult, i.e. the pharate adult, before it emerges from the cocoon. At the pupal-adult apolysis the layer of epidermis that secreted the gill wall and the layer that secreted the spiracular atrium are left behind in the lumen of the gill, together with blood, as the body wall epidermis retracts away from the pupal cuticle. A thin sheet of cuticle, the basal membrane, is secreted across the opening into the gill lumen at this time. The epidermis and blood in the gill lumen are thus completely isolated from the haemocoele of the living animal by the basal membrane, a layer of moulting fluid, and the adult cuticle. The tissue contained in the respiratory horns of terrestrial Dolichopodidae is isolated in a precisely similar manner.

The tissue isolated in the lumen of the gill of Aphrosylus does not degenerate until after the pupal-adult ecdysis. It seems to be discarded because, on balance, its loss is less damaging than the cost that would be incurred in other ways by its absorption or retraction into the body of the adult. For instance, in order to absorb the tissue in such long appendages, or to retract all of the epidermis from within them, would necessarily prolong the moulting period, a period when the insect is particularly vulnerable.

On the 6th of January, 1892, Dr. Elliot of Kingsbridge most generously presented to the Marine Biological Association a large and interesting Cephalopod which was captured off Salcombe.

Dr. Elliot brought the squid to the Plymouth Laboratory, and it was subsequently purchased for the Oxford Museum by Prof. Ray Lankester, who requested me to identify it, giving me much kind help, for which I wish to express my sincere thanks.

The larva of the fly Canace nasica Haliday feeds on Enteromorpha in the intertidal zone. Its pupae, like those of a number of other intertidal flies, have plastron-bearing spiracular gills. The gills are unlike those of any other known Diptera in that they are modified spiracles: those of other flies are modifications of the body wall adjoining the spiracle, or of both the body wall and the spiracle. Although the spiracular gills are pupal structures, they are the respiratory organs of the adult before it emerges from the puparium.

The fifth paper of this series (1930) was the author's last, after which the work was handed over to L. H. N. Cooper. It was resumed by the author in 1948 to compare the early years with the post-war, since the determinations had lapsed. Measurements of the extinction coefficient of the water were also resumed, and it was desirable to obtain the chemical data at precisely the same time.

The phosphate results are, as before, expressed as P2O5 in mg./m.3, since for crop calculations this old unit is convenient; to convert to mg. P, which is more rational, multiply by 0437; to bring to milligram atoms multiply by 0–0141. The analyses have not been corrected for salt error, since the early results were not^ and the factor for this correction has not as yet been agreed upon.

The silicate results are given as mg./m.3, of SiO2, but though the standard used in Plymouth was checked for me by Dr E. J. King in Canada and agreed with his (King & Lucas, 1928), yet a different value had to be assigned to the silica factor of the picric acid solution. All values have accordingly been multiplied by I.44.

The phosphate results for E1, surface, from 11 February 1948 to 1 February 1949 are shown in Fig. plotted against the dates.

Little is known about colonization of remote island coasts by marine invertebrates, other than corals. The structure of hard substrata assemblages was investigated across Ascension Island's littoral zone in comparison with other sites. Arrays of acrylic panels were deployed at two sites for 2 years at Ascension Island to measure subtidal recruitment. Colonization of panels at Ascension I. was low, though space occupation, abundance and richness varied considerably. After ~1 and 2 years Ascension panels were <17 and <37% covered by fauna and each had <22 recruits and 54 recruits (per 100 cm2) respectively, amongst the lowest density of recruits reported. Recruitment rates of corals (25 m2 year−1) at Ascension I. were also similar to the lowest levels reported elsewhere (e.g. at Bermuda or Midway islands). Less dispersive animal types, e.g. cheilostome bryozoans, were poorly represented. Panels immersed in Tanzania and Scotland were >30% covered, with >76 recruits per 100 cm2 and with bryozoans well represented after 1 year. Across-littoral surveys of established macrofauna at five remote islands (Ascension I., Easter I., Azores, South Georgia and Signy I., Antarctica) revealed similar trends of a rich sublittoral and lower littoral reducing drastically up-shore; molluscs dominating abundance and species numbers, whilst polychaetes, crustaceans and echinoderms were well represented. Established sessile animals occurred patchily at a mean density of 8.26 m−2 but recruits had mortality levels >99%. Polar or remote temperate/tropical sites are typically less colonized than at non-remote, low latitudes but the lowest levels reported are at remote polar sites. Reduced colonization at Ascension island reflects remoteness.

Four multidisciplinary oceanographic surveys were conducted in November and December from 2007 to 2010, along the Mauritanian coast (NW Africa). A total of 10,514 brachyuran crabs belonging to 33 species were captured in 316 hauls at depths between 79 and 1867 m. The most specious family was Inachidae represented by nine species; the remaining 24 species belonged to 16 other brachyuran families. Monodaeus cristulatus is reported for the first time since its original description. Seven other species, Ethusa rugulosa, Pseudomyra mbizi, Inachus grallator, Macropodia gilsoni, Macropodia hesperiae, Solenolambrus noordendei and Spinolambrus notialis extend their range of distribution northwards and, together with Goneplax barnardi, are reported here for the first time in Mauritanian waters. New data about depth ranges are reported for Acanthocarpus brevispinis, Ethusa rugulosa, Inachus aguiarii, Inachus grallator, Inachus nanus, Macropodia macrocheles, Solenolambrus noordendei, Spinolambrus notialis, Liocarcinus corrugatus and Monodaeus cristulatus. New data relating to the spawning period for most of the species are also included, as are some biogeographic and bathymetric considerations about brachyurans studied in the area.

Until the year 1881, when Balfour wrote on the subject, the pronephros was generally believed to be a functional kidney, not only in the larval condition, but also in those adult forms described as possessing the organ.

Balfour, in his more detailed paper, published later, states that in the fishes examined—pike, eel, smelt, and angler—although the pronephros had all the appearance, externally, of a true functional kidney, no uriniferous tubules were present, and that a minute examination only disclosed a degenerate trabecular tissue which he describes as lymphatic.

The angler (Lophius), it may be observed, is generally considered to possess only a head kidney. This organ Balfour found to be in a perfectly functional condition, but he declines to believe that it is a persistent head kidney, and argues from the highly modified structure of the fish that the organ in question is in reality the mesonephros. shifted forward from its normal position. He also maintains that in adult Ganoids the head kidney has no longer a renal function. His general conclusion, therefore, is, that since the pronephros was only supposed to persist in Ganoids and Teloosteans, it must be now considered as non-existent except in the embryonic or larval conditions.

A net sample of phytoplankton taken in the outer Moray Firth in which there were many cells of R. hebetata forma semispina and several cells of R. hebetata forma hiemalis (Fig. 1 a, b) was also found to contain cells either with one forma semispina calyptra or one forma hiemalis calyptra, in which the cell wall changed abruptly at the opposite end to a thin weakly silicified, sometimes almost membranous structure, ending in a central, broadly conical apex with a delicate hollow spine (Fig. 2j, k). The perizonium like appearance of one end of these cells suggested that they might be a stage in the development of the auxospore in R. hebetata Bailey (sensu Gran).

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.

Stomach content analysis was used to assess the feeding habits of Acanthocybium solandri based on samples obtained on purse seine fishing trips off the Pacific coasts of Central and South America. A total of 226 samples were obtained; 160 stomachs contained food and 33 prey taxa were identified. Based on the Prey Specific Index of Relative Importance (%PSIRI), cephalopods and fishes were the main prey groups (50.4 and 49.5% PSIRI). Dosidicus gigas (23.4% PSIRI), Stenoteuthis oualaniensis (9.9% PSIRI) and Argonauta spp. (9.4% PSIRI) were the most representative prey. Acanthocybium solandri is a generalist predator based on the results of the Amundsen analysis and niche breadth (Ba = 1).