Normal females of the mud shrimp, Upogebia major, have a pair of pleopods on the first abdominal segment, while normal males do not. We have investigated nine populations in the Seto-Inland Sea, Japan, and found morphological disorders on the first abdominal segments of both males and females. In males, the first pleopods occurred. Morphology and arrangement of these additional pleopods were classified into four types. The pleopods of Types M-1 and M-2 were similar in structure to those of normal females. These males could be considered as de-masculinized individuals, and the occurrence of males with these morphological disorders showed local variation: while their frequency was high in two specific sites in Kasaoka Inlet (11.5% in Site 6 and 5.5% in Site 7), it was less than 3.5% in other sites. Other types had abnormal additional appendages similar to the walking legs (pereiopods) (Type M-3) or biramous leaf-like pleopods (Type M-4), but their frequency was extremely low (only 3 out of 1558 males inspected). Morphological disorders in males (Types M-1 and M-2) occurred independently of gonadal development, and did not affect the sexual characteristics as revealed by analyses of allometric growth and gonadal index. In females, morphological disorders were classified into five types: incomplete first pleopods (Type F-1); lack of the first pleopods (Type F-2 and F-3); transformation into the pereiopod-like pleopods (Type F-4); and biramous leaf-like pleopods (Type F-5). The frequency of Types 1–3 was especially high in Site 6 in Kasaoka Inlet (24.4%), but was less than 9.4% in other sites. A feature was that cuticular lesions often co-occurred with the morphological disorders. Possible causal factors of these abnormalities are discussed.

In addition to the spicules typically produced by sponges, about twenty hypercalcified species belonging to both classes Demospongiae and Calcispongiae secrete a massive basal calcareous skeleton composed of calcite or aragonite. Skeletal growth rates and growth mechanisms are still poorly known in those hypercalcified Calcispongiae. In situ calcein staining experimentation on the Mediterranean calcisponge Petrobiona massiliana revealed a mean annual growth rate of the massive skeleton of 236 µm/y (±90). Scanning electron microscopy (SEM) revealed that some spicules are entrapped within the massive skeleton (a solid mass forming apical crests with multidirectional growth axes) during its formation. Whole actines were observed within the massive skeleton of fractured specimens, indicating that they do not dissolve after entrapping. Calcein incorporation bands seen through epifluorescence microscopy and SEM morphological observations of the skeletal surface revealed cone shaped protuberances corresponding to active growth areas. A spatially discontinuous growth was highlighted, but the annual growth rates were similar at the tip of crests and at the bottom of depressions separating them. The skeleton of P. massiliana is composed of magnesium calcite with strontium as the main trace element. Significant differences in skeletal chemistry of specimens collected in different Mediterranean locations revealed a possible temperature dependence of Mg/Ca. Although such temperature signature exists in the massive skeleton of P. massiliana, its use as an accurate environmental recorder is limited by several factors including multidirectional and spatially discontinuous growth.

FæecalPellets of the following species are described:—

Gibbula cineraria (Linn.).

G. umbilicalis (Da Costa).

G. tumida (Montagu).

G. magus (Linn.).

Cantharus (Jujubinus) clelandi (Wood).

Calliostoma zizyphinum (Linn.).

Until recently there has been very little information on the quantities of phytoplankton nutrients in the Irish Sea. Slinn (1958–1966) has reported the weekly variations in the nutrient concentrations at a station off Port Erin, Isle of Man, and studies on the nutrient conditions in the Menai Straits have been carried out by Jones (unpublished) and Ewins & Spencer (1967). Liss (1969) has reported on the results of winter surveys of reactive silicate near the Irish coast, and from three stations near the Welsh coast (Anglesey, the Lleyn Peninsula and Fishguard). The present paper describes studies carried out in the inshore waters near Aberystwyth in Cardigan Bay during 1967 and 1968. This investigation formed part of a study of the seasonal occurrence of the phytoplankton and the growth conditions in this shallow, inshore region.

In this paper a rare case of a double swordfish mortal attack against an adult blue shark (Prionace glauca) is reported. A female blue shark, with a total length of 3 m, was found stranded along the southern Sicilian coast (Strait of Sicily, Mediterranean Sea) on 30 May 2018. The analysis of this carcass revealed the presence of two swordfish bill fragments, impaled in the shark head; the former on the snout, the latter near the eye. The results of anatomical and computed tomography scanning analysis on the head of the blue shark showed that the larger bill fragment (19.7 cm) probably determined the death of this animal, having been impaled in a vital point, just behind the right eye. The analysis of both these events and other similar swordfish-shark interactions reported in the literature makes possible the hypothesis that young swordfish specimens put in place a precise defensive strategy against their potential predators or competitors, aimed at hitting vulnerable and vital points and delivering a mortal blow.

The present paper is the first scanning electron microscope (SEM) description of a protonymphon larva of an Ammotheidae. The morphology of the first larval instar of Achelia assimilis is described in detail and illustrated for the first time. The morphological characters are compared to previous larval descriptions of other pycnogonid species. The larvae are integrated into Bain's classification of larval types within the pycnogonids (Bain, 2003a) as a ‘typical protonymphon’. Larvae were obtained from ovigerous males, caught in Punta Huinay, Huinay, Chile and analysed with light microscope and SEM. Descriptions of pycnogonid protonymphons at a species-specific level in the future will contribute to a deeper understanding of larval pycnogonid taxonomy at the level of differential diagnoses.

The growth bands in the plates of the echinoid Spharechinus granularis settled on the Algerian coast were analysed. Two distinct groups of sea urchins were identified with different growth patterns related to the period of recruitment, i.e. spring or autumn. The growth rate of the autumn cohort was higher over the year following the first winter after settlement. From the second winter there was little growth difference between the two cohorts. Compared to populations from Atlantic sites, the Algerian population has a lower growth rate and reduced longevity.

More than 127 specimens of the bivalve mollusc Idas simpsoni were collected from the skull of a fin whale Balaenoptera physalus. The skull was trawled up from a depth of 430 m near Mljet Island in the south Adriatic Sea. This is the first finding of I. simpsoni in the Adriatic Sea.

Based on specimens collected in the Mediterranean and Red Sea coasts of Israel, the first lessepsian flatworm (Boninia neotethydis sp. nov.) is described. The genus Boninia includes cotylean polyclads characterized by the presence of multiple accessory (prostatoid) organs. The three species described are distributed in the western Pacific (B. mirabilis) and in the Caribbean (B. antillarum and B. divae). The new species differ from congenerics in the number and arrangement of the prostatoid organs, and in the number of marginal eyes. Specimens of the new species feed on mussels, and their possible effects on Mediterranean mussel cultures should be monitored.

During studies performed on the ecological conditions of Izmir Bay and its biota, a population of Fulvia fragilis was observed to have recently colonized the bay. In this study, some comments are provided on the anatomical, ecological, taxonomical and distributional aspects of the species, which was first encountered during late 2001 in Izmir Bay.

Colonies of the phlebobranch ascidian Perophora japonica were found in August 2003 in Humboldt Bay, northern California, growing on a submerged settling panel. This species has a unique terminal budding in addition to the usual subterminal stolonial budding: bright yellow stellate plaques form at the tips of many stolons. The plaques break off, float away and reattach, subsequently forming new stolons and new colonies. The presence of these plaques, and the larger size of the zooids, distinguish it from the native Perophora annectens. This is the first North American record for this species.

The cruise, of which the zoological results are given in this report, was undertaken at the suggestion of Capt. Wharton, R.N., F.R.S. hydrographer to the Admiralty, who kindly advised me that H.M.S. “Research” was to make a fresh series of soundings off the entrance to the Channel, and put me in communication with the captain of the ship. To Capt. Aldrich I am indebted for unbounded hospitality. and attention whilst I was on board, and I take this opportunity of expressing my most hearty thanks both to him and to the officers on board for the hospitality and kindness which they afforded me, and, for the help which they gave me in the trawling operations. The “Eesearch” is a paddle vessel of 520 tons register, built last year for the express purpose of surveying, and provided with a steam winch, deep-sea trawls and dredges, and 1000 fathoms of wire rope, with accumulators and accessory tackle. The available space on board was limited; there was no separate cabin at my disposal, so Capt. Aldrich most kindly made me his guest and gave me a berth in his own cabin, and I was given as much room, as could possibly be allowed for storing my bottles and other apparatus.

Species definition is not an easy task, when considering the more than 27 known species concepts. Among them, the morphospecies concept has been one of the most applied since it is based on the use of observable morphological features. Morphometry has been used to delimitate morphospecies or similar taxa complementing the morphological observations and contributing to clarify taxonomic problems. Specimens from the sympatric species Perinereis anderssoni and Perinereis ponteni, collected from the north-eastern to southern coast of Brazil and considered synonymous by some authors, were compared through morphometric analyses for the evaluation of their taxonomic status. Morphometric analysis indicates that notopodial cirri lengths in the median and posterior regions on the body clearly allowed differentiation between the two species. Our results indicate that the number and arrangement of paragnaths demonstrate a pattern of variation that effectively differs and could be used to discriminate these two Perinereis species. This distinction was confirmed by the restricted among-population variability within each species, even when populations that are geographically very distant from each other were considered.

The ovaries of 31 franciscana dolphins (19 immature and 12 mature) by-caught in coastal waters of Argentina were examined to describe the reproductive biology. No ovarian polarity was found, both ovaries were functional and showed similar amounts of corpora. A positive trend was observed between the number of corpora and age (3–8 years old), indicating that ovulation scars are detectable for at least 4 years, and a ovulation rate of 0.39 was found for the sampled population. Age, length and weight at sexual maturity were estimated at 3.92 ± 0.09 years, 133.47 ± 11.11 cm and 32.68 ± 2.72 kg, respectively. The annual pregnancy rate was 0.36 ± 0.02 (95% CI = 0.10–0.65). The proportion of lactating and resting females found were 0.25 and 0.33 respectively. These outcomes constitute the first reproductive and life history information on franciscana dolphins from the southernmost population and are important in relation with adequate conservation management plans for this small cetacean.

Geographical information system analysis was applied to assist in the re-identification of records of Chaetozone setosa from the north-east Atlantic. Previously this species was considered to have a world-wide distribution. The aim of this study is to clarify and illustrate the distribution patterns associated with sediment and water characteristics of C. setosa and other Chaetozone species.

The observations of Schlieper (1929) established the lugworm Arenicola marina (L.) as an osmoconformer which remains virtually isosmotic with the external medium over a wide range of salinities. In a recent comprehensive review of salt and water balance in lugworms, Oglesby (1973) describes ‘the extensive swelling associated with transfer of lugworms to lower salinities’, and ‘when maintained in salinities lower than about 50% s.w. in the laboratory, lugworms are rendered incapable of such vital physiological activities as burrowing and burrow ventilation’. Under these conditions, lugworms exhibit little or no ability to regulate their volume or water content.

This study presents the first extensive investigation of echinoderm distribution in the area of mobile bottoms in the open part of the northern and middle Adriatic Sea. Five hundred and eighteen bottom trawl hauls were performed at 56 predetermined permanent stations along ten transects over different sediment types, at depths of 10 to 430 m. A total of 34 species of Echinodermata were identified (9 from the class Holothuroidea, 12 from the class Asteroidea, 4 from the class Ophiuroidea and 9 from the class Echinoidea). The list of the species, together with data on depth and sediment distribution, and the stations where individual species were found, are presented.

A series of results is presented on the barnacle larvae population of an area of the Firth of Clyde, over a 15-day period in the spring taken by means of a modified Hardy Plankton Recorder.

The records and observations on barnacle settlement indicate that the larval population was considerably greater than usual.

The total larval population showed no great fluctuations from day to day, and on a given day the composition of the population over a wide area was often reasonably constant.

Evidence is presented that there is no great depletion of the population between Nauplius III and cyprid stages. It is suggested that the depletion previously reported may be due in part to the method of sampling or to the conditions at the time of sampling.

During the time when the evidence indicates no depletion of population there was a heavy diatom outburst, which in this instance did not appear to interfere with the larval development.

Data are given on the density of settlement.

Diversity is one of the most frequently used attributes of ecological communities, and there is a long-standing discussion about their adequate use, calculus and interpretation. One of the most conspicuous and simple diversity estimators is species richness, but it has been criticized by recurrent pitfalls, which has biased comparisons and the testing of hypotheses. Otherwise, synthetic ecological indices of diversity are difficult to interpret due to the underlying complex or cryptic concepts. Most of the studies in soft-bottom macroinvertebrate communities trying to estimate species richness, have actually quantified species diversity as species density; the number of species per unit area. In the present study, the diversity of a tropical Pacific soft bottom community is analytically decomposed using two null models to assess species richness and evenness, and the slope of species–area curves to estimate species density. A declining trend of species richness was observed along a 2-year period and could be related to the cumulative effects of interannual environmental variability and fishing disturbance. The species–area relationship could be considered a good indicator of spatial heterogeneity, specifically to illustrate the depth gradient. Local abundance was negatively correlated with evenness, showing that high-density communities are the result of increases in abundance of a few dominant species. Here we demonstrate that seasonality, depth and abundance could explain diversity in soft-bottom macroinvertebrate communities of coastal waters and propose a robust procedure to survey diversity as a part of monitoring programmes of coastal management.

A new species of tube-dwelling anemone of the genus Ceriantheopsis (Cnidaria: Ceriantharia), Ceriantheopsis lineata sp. nov., is described and can be found in fine sand or mud in the sublittoral zone (0–200 m) from Argentina to Brazil (Warm Temperate South-western Atlantic). This new species is distinguished from its congeners by a number of features, however some characters (directive tentacles, line on tentacles and length of P2) allow a conclusive identification among the other Ceriantheopsis species.