The effects of shell resource and interspecific competition on sexual size dimorphism of the hermit crab, Pagurus middendorffii (Decapoda: Paguridae), were examined from population comparisons. Degree of size dimorphism and mean shell size occupied by male and female P. middendorffii differed among adjacent sites, and there was a significant correlation between them. Although most large P. middendorffii occupied large Chlorostoma lischkei shells in both shell-limited and shell-unlimited populations, P. lanuginosus, a sympatric species, occupied large C. lischkei shells more frequently than P. middendorffii did in a shell-limited population. Environmental factors, shell availability and interspecific competition for shells, might play important roles in determining the degree of sexual size dimorphism of P. middendorffii.

Some of the specific and differential characters of these two species have already been enumerated by Pace (1). Subsequently Norman (2) denied that these two forms were different, so that the literature on them was left in an unsatisfactory state. On investigating these two forms, however, I have obtained sufficient evidence-from the characters of the gonadial tubes, the calcareous collars, and the young of both forms-to verify the observations of Pace and to meet satisfactorily the objections put forward by Norman against them. The differential characters of these two species as given by Pace (loc. cit.) have been verified in an unpublished investigation by Mr. W. De Morgan and by the present writer.

Increasingly, baseline knowledge of habitat preferences and movement patterns of marine species is required to inform anthropogenic developments. The aim of this study was to determine baseline spatio-temporal distribution and habitat preference of cetaceans in the coastal waters of Algoa Bay. Areas of potential conflict with anthropogenic activities were also assessed. Monthly sea-based surveys were conducted between June 2008 and May 2011. A total of 500 cetacean sightings comprising six species were recorded in 106 surveys. Tursiops aduncus (Indo-Pacific bottlenose dolphin), Sousa plumbea (Indian Ocean humpback dolphin), Delphinus capensis (long-beaked common dolphin) and Balaenoptera brydei (Bryde's whale) were observed year-round, while Eubalaena australis (southern right whale) and Megaptera novaeangliae (humpback whale) were recorded from May to December. A large portion of sightings were associated with a Marine Protected Area and shipping zones. Eubalaena australis, T. aduncus and S. plumbea were found inshore (water depths < 12 m), while the other species were associated with deeper waters. Tursiops aduncus were most commonly seen (233 sightings). Megaptera novaeangliae were sighted often in austral winter, with 113 sightings. Only nine D. capensis sightings were recorded. Spatial distributions of species were corrected for search effort to identify habitat preferences. A number of key observations were made, including opportunistic foraging in M. novaeangliae, and the expansion of nursery grounds for E. australis, to include Algoa Bay. Four preferred habitat areas are proposed, providing important information for conservation and management of cetaceans in Algoa Bay. The spatial approach can be used to inform future relevant management decisions elsewhere.

A new species of Chalinula (Haplosclerida: Chalinidae), C. saudiensis, is described from the coral reefs of the Red Sea off Jeddah. The new species is remarkable in its vivid blue colour and its bioactivity. Its description includes cytological features in transmission electron microscopy.

Larval development of the parasitic barnacle Heterosaccus papillosus (Cirripedia: Rhizocephala: Sacculinidae) is described from larvae reared in the laboratory. Lecithotrophic nauplii of H. papillosus reached the cypris stage in 3·5 days, at 22–23°C. The development included five naupliar and the single cypris stage, thus following the typical pattern in the Rhizocephala Kentrogonida. Like the nauplii of all sacculinids, those of H. papillosus had a single pigmented nauplius eye, unsegmented frontolateral horns each with two long spines and a tubercle between the furcal rami, but they lack a flotation collar and have no seta on the antennal basipod. The male larvae are larger than female ones, the mean lengths in the two sexes never overlap. The most interesting feature of this species are the morphological differences between the male and female larvae. In the male nauplii III to V the anterior body margin is noticeably convex, that is not characteristic for female larvae. The male cyprid also has a more acuited anterior region, whereas that of the female is rounded.

The sea cucumber fishery has been providing an important means of livelihood to the coastal fishing communities in Sri Lanka for centuries. Stock status, level of exploitation and mortality parameters of eleven commercial sea cucumber species were studied off the north-west and the east coasts of Sri Lanka using data collected from an underwater visual census and fishery-dependent surveys carried out in 2008 and 2009. The total abundance of sea cucumbers was higher in the north-west than the east (P < 0.01). However, the total abundance of all the species declined between 2008 and 2009. The commercial fishery predominantly relies on two nocturnal species: Holothuria spinifera and Thelenota anax. Holothuria spinifera had the highest contribution (73.2%) to the total landings in the north-west while this was provided by T. anax (93%) in the east. Both catch per unit effort and total landings declined in 2009 compared to 2008 having three exceptions (H. spinifera, Holothuria atra and Stichopus chloronotus) in the north-west. Further, the collection of immature individuals, reduced landings of high-value species and temporal shifting of fishing activities were observed in both areas. Two approaches (simple linear regression and random effects models) were used to estimate the natural mortality of sea cucumbers and the estimated values were 0.50 yr−1 and 0.45 yr−1, respectively. Apart from the management of local sea cucumber resources, this information is important to update the regional and global sea cucumber statistics as well as for launching regional management programmes.

Coral reef environments support a great diversity of benthic organisms, of which zoanthids form an integral part. Studies have been carried out regarding the degradation of coral reefs and changes in community structure under the present dynamics of climatic change. Zoanthids are dominant among the observed fauna in these degrading reef ecosystems. Zoanthids are observed at mid and lower intertidal zones beyond 20 m from highest high tide level. In the present study, distribution patterns of zoanthid species along three coastal villages of Saurashtra coast, Gujarat were studied. Line intercept transect method was performed to assess the zoanthid coverage. A total of seven species of zoanthids were recorded during the survey. Palythoa mutuki formed the abundant species in the area with 45.99% coverage, followed by Zoanthus sansibaricus with 33.67% and Zoanthus cf. sansibaricus with 12.26% coverage. Abiotic parameters (sea surface temperature, salinity, dissolved oxygen, pH) and nutrient data (ammonia, phosphate, total suspended solids and nitrate) were also recorded during sampling to determine their influence on zoanthid colonies. Higher levels of DO were found to favour the growth of Palythoa mutuki and Isaurus tuberculatus, whereas increased SST was tolerated by Palythoa tuberculosa only. Ammonia and phosphate were negatively impacting the growth of Palythoa mutuki and Zoanthus spp. The study provides new information on quantitative zoanthid distribution and the dynamic changes exhibited by zoanthids in relation to various environmental parameters. Zoanthids could be looked upon as an adaptive species which may support reef resurgence in degraded reefs under stress from climate change effects.

Thunnus alalunga is an important commercial tuna species widely distributed in the three major oceans and the Mediterranean Sea. The Mediterranean population is currently classified as a data-poor stock and little is known about its basic life history parameters. This study provides the first detailed information on some aspects of the reproductive biology of T. alalunga from the western Mediterranean Sea. A total of 16 104 specimens were measured between 2005 and 2012. The overall sex ratio of females to males was 1.1:1, although the ratio was female biased in fish <70 cm fork length (LF) and male biased in those >75 cm LF. Histological analysis of the ovaries (N = 587) and the monthly variation of the gonadosomatic index for both sexes showed that spawning occurred from June to August, which is a much shorter period than the 7 months reported for T. alalunga in tropical oceanic waters. Thunnus alalunga caught during June and July are capable of spawning daily. The gonadosomatic index values for T. alalunga from the western Mediterranean were up to eight times higher than those of T. alalunga from other oceans. Histological examination of the ovaries showed that the minimum length at sexual maturity of females was 56 cm LF, which is considerably smaller than those estimated for other stocks.

The fish assemblages of rocky intertidal and subtidal (<3 m depth) habitats of the south-western Portuguese coast were sampled between May 1992 and November 1993, using traps, angling and hand-netting, to investigate their structure and seasonal dynamics. The main purpose of the study was to describe the patterns of prey availability for marine-feeding otters (Lutra lutra L., Mammalia) in south-western Portugal, and to compare these with other areas in Europe. A total of 475 fish of 14 species was captured over 150 d of trapping (788 trap-days), and 1575 fish of 15 species were captured over 24 d of angling (76.3h). Hand-netting was carried out occasionally, to supplement the observations from the other methods, and only 96 fish of seven species were captured. The three methods yielded different patterns of the fish assemblage: giant gobies (Gobius cobitis Pallas, 33.7%) and rock gobies (G. paganellus L., 22.9%) were the most frequently trapped fish; corkwing wrasse (Symphodus melons (L.), 81.2%) were the usual species caught by angling; shannies (Lipophrys pholis (L.), 42.7%) and Montagu's blennies (Coryphoblennius galerita (L.), 28.1%) were the most frequently netted species. Conger eels (Conger conger (L.)), giant gobies and shannies showed an uneven distribution along the coast, occurring most frequently in schist shelves, rather than in areas of large sandstone boulders. There was a large seasonal variation, with the catches of most species peaking in winter and early spring, including the majority of those most important in the diet of otters: conger eels, shore rocklings (Gaidropsarus mediterraneus L.), rock gobies and corkwing wrasse. This was also the period when the individuals of several species were heaviest.

Most lithistids occur worldwide in deep-water environments, but can be found in some places in shallow water. They are not well known in the tropical western Atlantic, despite the fact that they were first described in the late 1800s. We report here two species of poorly known theonellid demosponges (Astrophorina), Discodermia dissoluta and Theonella atlantica, and one new species, Theonella wrightae, from the north-west, south-west and south Florida shelf. There is considerable variability in habitus, colour and spiculation in this species. If samples are taken randomly from different specimens and from functionally and structurally different locations on the sponge, the specimens could be mistakenly identified or individuals of the same species could be described as different species. This report increases the number of lithistid sponges reported from the tropical western Atlantic region to 30 species, but our unpublished data suggest a much higher number of species present in this region. It is also the second report of the relatively deep-water (81 m) occurrence of D. dissoluta that is mostly known from depths as shallow as 10–30 m.

The association of invertebrate communities with macroalgae rafts has received much attention over recent decades, yet significant gaps in our knowledge remain with respect to the colonization process. Using laboratory-based experiments and in situ field trials in Strangford Lough, Northern Ireland, this study investigated whether members of the known rafting genus Idotea (sub-phylum Crustacea; order Isopoda) could effectively colonize rafts after shore seaweed detachment, or if their presence merely reflected a passive marooning process. Test tank arenas were used to identify traits that may influence the rafting potential of the dominant shore species Idotea granulosa and the well known rafter Idotea baltica. When released mid-water, I. granulosa initially ascended and associated with floating seaweed whereas I. baltica tended to descend with no clear habitat association. These findings conflict with the differential distribution of these Idotea species among rafts and shore algae, thus highlighting the complex nature of the potential of organisms to raft. In the field we considered the relative ability of different Idotea species to colonize tethered rafts composed of Ascophyllum nodosum and Fucus vesiculosus, cleaned of all vagile organisms and deployed at locations adjacent to established intertidal Idotea species populations. At the end of the experiment (after 44 days) rafts were inhabited by known rafting and shoreline species, confirming that colonization can occur after algal detachment. Previously considered shoreline species on occasion outnumbered well known rafters suggesting that a wide range of Idotea species can readily avail of macroalgal rafts as a potential dispersal mechanism or alternative habitat.

In the present study, carried out in the Spermonde Archipelago, south Sulawesi, Indonesia, an assessment is presented of the farming potential of six sponge species (out of nine candidates considered) possessing pharmacologically promising compounds, i.e. Aaptos suberitoides, Amphimedon paraviridis, Callyspongia (Euplacella) biru, Hyrtios reticulatus, Ircinia ramosa and Pseudoceratina cf. verrucosa. A total of 350 cuttings was threaded on a polyethylene rope and attached to horizontal mooring structures at three experimental sites. Growth and survival were monitored for a period of six months and for some explants for an additional period of ten months. All cuttings were photographed at regular time intervals and growth was measured as increase in length and dry weight. With the exception of P. cf. verrucosa, survival rates were high (80–96%) during the mariculture period. Size increases were too little to be measured in A. suberitoides and P. cf. verrucosa cuttings. Significant growth was only observed for C. biru. The high growth potential and high survival rate of this sponge species suggest that it is a promising candidate for further mariculture development.

Three species of sponges, Axinella aruensis, Phakellia sp. and Acanthella cavernosa, were selected to investigate the extent of intragenomic variation (IGV) in the internal transcribed spacers (ITS-1 and ITS-2) of the ribosomal DNA within the order Halichondrida. The IGV was detected in both the spacers and in the three species. At least three non-identical sequences were found in any single individual with the number of polymorphic sites within species ranging from 6 to 77. Uncorrected distance values up to 29% were observed in the ITS-2 of Axinella aruensis. The levels of polymorphism found in this species are the highest reported for Porifera and comparable to those observed in hybrid species of scleractinean corals. Analyses of ITS sequences from multiple clones from individuals of Halichondrida are strongly recommended if these genetic markers are to be used to depict phylogenetic and/or phylogeographic relationships of closely related species and their populations. Data from other nuclear and mitochondrial markers should be used to complement conclusions derived from studies based on ITS sequences.

As already mentioned (Wilson, 1958), a species of Magelona from clean sand near low water at Mill Bay, Salcombe, has not yet been described. This worm was first noticed in 1939; it is recorded in the 1957 edition of the Plymouth Marine Fauna as ‘Magelona sp.’ and it is there mentioned that artificial fertilizations were made and larvae reared in April-September 1939, and that these larvae differed from those of the other two Magelona species from the Plymouth district (papillicornis F. Müller and alleni Wilson). The worm is still common in the same locality at Salcombe, in the same ground and often in the same spade-full as papillicornis, but it is not as abundant as the latter and probably not as abundant as it was when first seen in 1939. A very good low tide receding below datum is needed to collect it; it is easily overlooked on account of its fragility and fine thread-like appearance, mature females coloured pink by their contained eggs being more readily seen while digging than translucent immature worms or white males. Worms are difficult to collect whole, the tail end usually being left behind in the sand.

A study of the distribution of Trebius caudatus from four species of Raja trawled from two localities of different depths at Plymouth shows that there is a higher infection rate in the deeper water.

Both at Roscoff (France) and at Plymouth the mean total rate of infection is about 20%, and the larger fish are more often infected than the smaller. Both sexes are equally parasitized and the copepods tend to collect near orifices on both surfaces of the fish (regions where the mucus secretion is maximum). Immature forms were found at Roscoff in the mucus of the orifices themselves. The collections from both places contained about equal numbers of male and female parasites.

Intestinal respiration, a feature common to free living and parasiticcopepods, includes the gaseous exchange through the gut wall, the associated movements stirring the oxygen vector (which is either the external medium taken in by the anus, or the food current when this is the blood of the host), and the circulation of the body fluid as a direct result of these movements. The significance of the gut movements, which include the peculiar two-way peristalsis, is examined in detail in Trebius caudatus and Lernaeocera branchialis: the former has a functional anus which admits the external medium and the latter has a closed anus and employs the blood of the host as the oxygen vector.

Spawn and the embryonic development of two species of the genus Polycera were studied. Both species, Polycera aurantiomarginata and Polycera quadrilineata, were collected in the intertidal zone of El Portil (Huelva) in south-western Spain. In the laboratory spawn were collected daily. Length and width of the spawn, number of eggs per mm2, egg size and capsule size were measured. The egg masses were controlled several times a day to provide a timetable for the main developmental events until hatching. Embryonic growth was measured between some characteristic stages (gastrula, preveliger, primordial velum and veliger prior to hatch).

The two species differ in a number of aspects: spawn are longer, eggs and capsules are bigger in P. aurantiomarginata than in P. quadrilineata. The number of eggs per mm2, however, is greater in P. quadrilineata than in its congener. Furthermore, spawn of P. quadrilineata are semicircular whereas those of P. aurantiomarginata are spiral and wavy. Both species show planktotrophic development but embryonic development of P. quadrilineata is faster than that of P. aurantiomarginata. The dynamic of embryonic growth is very similar in the two species, although embryos of P. aurantiomarginata are larger at any measured stage than those of P. quadrilineata.

During the daily maintenance work of a large aquarium many casual observations are made on the habits of the inmates. These are sometimes worthy of record, though too slight in themselves to justify separate papers each under its own distinctive title. It has, however, been thought fit to bring together in the form of a series of notes some of the more interesting of these observations. It is not intended to discuss each with full reference to the comparable literature; rather are they presented as raw material for the use of other investigators in their own specialized fields. Most of these observations have been made since the re-establishment of the Plymouth aquarium in 1946 (after its war damage), and up to the date of writing, November 1948.

On May 30th, 1916, a number of large Buccinum undatum were brought in from the trawling grounds ; 40 of these were examined and 34 were found to contain larval Trematodes. Another lot in the spring of 1917 contained about the same percentage of infected Mollusks. Two species of Trematodes were present, both contained in the digestive gland, which was absolutely riddled with them.

It will be within the recollection not only of the comparatively small section of the community which is consciously interested in fishery matters, but of all those whom a sense of public duty or a lack of other occupation compels to some acquaintance with the current topics of the day, that the question of the deterioration of our sea fisheries commenced some few years back to assume something approaching to prominence. One of the earlier indications of the importance with which the question was invested, in the minds of those principally concerned, was the formation, in 1882, by a number of fish merchants, smack-owners, and others, of the National Sea Fisheries Protection Association,—a title which may well be forgiven for its length, in consideration of the happy augury it holds out of the enduring nature of the Association's services to one of our most deserving industries.

This study aimed to determine the potential impact of an oil spill on intertidal meiofauna at a clean, sandy beach in Korea. This objective was accomplished by examining changes in the structure of meiofaunal assemblages after a controlled oil spill of different concentrations on the beach. The concentration of total petroleum hydrocabon (TPH) in the experimental plots after oil application was expectedly higher for the first 4 d compared to before oil application. The TPH concentrations decreased at a faster rate in the first 4 d, and then progressively. The sharp decline in meiofaunal density in the experimental plots during the first 4 d after the spill might be attributed to the short-term toxic effects of the oil. This suggestion is supported by a significant negative interaction of the TPH on meiofaunal density during the study period. The period of low density of meiofauna also coincided with the maximum concentration of TPH in the sediment. The multivariate indices proved to be highly efficient, showing that samples contaminated with oil had high TPH concentrations, and were partially separated in terms of meiofaunal communities from samples before oil application or samples with low TPH concentrations. The structure of the meiofaunal communities in the experimental plots was similar before and 1 month after oil application. However, the density of meiofauna sharply decreased immediately after oil application in the experiment plots. Furthermore, the meiofaunal density recovered slowly as time passed.