The annelid mitochondrial genomes (mitogenomes) have been well documented, and phylogenetic analyses based on the mitogenomes provide insightful implications for annelid evolution. However, the mitogenomes of some families remain unknown. Herein, we determined the complete mitogenome of the lugworm Abarenicola claparedi oceanica (15,524 bp), representing the first mitogenome from the family Arenicolidae. The gene order of this species is the same as the various lineages in Sedentaria. The maximum likelihood phylogenetic analyses were performed based on six different datasets, including 43 ingroups (oligochaetes, hirudineans, echiurans and closely related polychaetes) and two outgroups (Siboglinidae), namely, aligned and trimmed datasets consisting of the nucleotide sequences of protein-coding genes (PCGs) and rRNAs, and amino acid sequences of PCGs. Phylogenetic analyses based on the nucleotide sequences yielded trees with better support values than those based on the amino acid sequences. Arenicolidae is clustered with Maldanidae in all analyses. Analyses based on nucleotide sequences confirm the monophyly of Terebellidae, which was paraphyletic in recent mitogenomic phylogenetic studies. We also performed the phylogenetic analysis based on the RY-coding of the nucleotide sequences of PCGs only to yield phylogeny with generally low support values. Additional mitogenome sequences of related ingroup species would be needed to comprehensively understand the phylogenetic relationship, which was not present in this study.

Protostyela heterobranchia n.gen. n.sp. is a compound styelid ascidian from Scottish waters. The branchial sac has three longitudinal bars on each side and no folds, and the stigmata are transverse. Both hermaphrodite and unisexual (male) gonads are present.

A new version of a technique, based on telemetric devices, to monitor temporal aspects of the activity of homing species of limpets and the parallel recording of sea level oscillations is described. The home/away status of individual limpets was continually assessed by means of a magnetic reed switch. Signals from the reed sensors were transmitted to a distant automatic scanner/receiver, located away from the shoreline. The system can be easily replicated and employed for extensive long-lasting monitoring in the field, even in those cases where previous versions, based on cable connections, were unsuitable.

This paper is one of a series on the fecundity of the plaice Pleuronectes platessa L. over a wide area of its geographical distribution and is concerned with the number of ripening eggs in the roes of female Icelandic plaice prior to spawning (see Bagenal, 1962, for references to other areas).

Thirty-eight plaice were caught by the Icelandic research vessel ‘Maria Julia’ on 23 and 24 March 1961 in the Midnessjor area. They were measured and weighed and the otoliths were extracted. The ovaries were preserved in modified Gilson's fluid (Simpson, 1951). I am very grateful to Mr Jon Jonsson who kindly made all the arrangements and Mr Gunnar Joakimsson who prepared the material in Iceland. The fish were very ripe and a few had developed translucent eggs, but spawning had not begun. The subsampling and statistical treatment of the results were the same as before (Bagenal, 1962). The otoliths, after being kept dry, were very difficult to read.

The Icelandic plaice are an isolated population, separated by deep water from the rest of Europe, and there are several spawning areas. currents move clockwise round Iceland and will carry the fertilized eggs and young larvae from Midnessjor and the S.W. coast spawning areas (Thomsen, 1948) to the good nursery grounds of Faxa Bay. Tåning (1929, 1948) has given accounts of the Faxa Bay plaice biology and suggests that ‘the eggs and tiny fry, which are found in the Bay in the spring months, seem mainly to come from the outside, for the greater part most probably from S.W. Iceland’. The eggs from the population offish considered in this paper, from Midnessjór, would drift into Faxa Bay which forms a good nursery ground.

A first trial to recognize gelatinous zooplankton using an immunochemical method was carried out. Polyclonal antibodies (rabbit IgG) raised against three cnidarians and four pelagic tunicates were purified and tested for their specificity against various sympatric zooplankton and micronekton. While antibodies to cnidarians were species-specific or at least distinguishable by means of the patterns of the bands appearing, antibodies to the pelagic tunicates cross-reacted with the antigen from the other tunicate species although these did not cross-react with other animal taxa. These results suggest that the present cnidarian antibodies can be applied to the predator identification at the species level. Antibodies to pelagic tunicates would also be effective tools for basic scanning at higher taxonomic levels, i.e. pelagic tunicates or other animals. The antibodies were applied to the identification of the ‘barrel’ of Phronima, indicating that the ‘barrels’ originated from tunicates but not from cnidarians. The present study indicates that the immunochemical method using polyclonal antibodies is a powerful tool for the detection of gelatinous zooplankton.

The aim of this study was to estimate growth parameters of two populations of Ligia exotica inhabiting discrete estuarine areas of Patos Lagoon, Rio Grande do Sul, Brazil. Sampling was performed fortnightly at two different estuarine zones, named Leonideo Island and West Breakwater, to detect different growth patterns for this species by using the von Bertalanffy growth model (VBGM). The VBGM estimated were as follows: TLmm = 34.57 (1−e−0.012(t−2.93)) (males in Leonideo Island), TLmm = 35.61(1−e−0.009(t−5.87)) (males in West Breakwater), TLmm = 30.11(1−e−0.009(t−5.84)) (females in Leonideo Island) and TLmm = 29.65(1−e−0.01(t−4.87)). Significant sexual dimorphism was observed, since males reach larger TL (mm) by higher k value (day) and consequently a faster growth pattern. Different growth patterns of males were also detected comparing both populations, in such a way that the West Breakwater individuals are larger than those from the Leonideo Island. One possible explanation is the higher food availability observed in the former site, as well as favourable environmental parameters, providing better conditions for individual growth. Briefly, two different populations of L. exotica were detected in the studied area, presenting discrete growth parameters highly influenced by environmental factors.

Although Parthenopidae is a brachyuran decapod family comprising almost 140 species, there is little knowledge about its larval morphology. There are only two complete larval developments reared in the laboratory and some larval stages described for seven species. In the present work these data are compared and analysed. A summary is made of the larval features that characterize parthenopids that can be used to distinguish them from other brachyuran larvae. In addition, the megalopa stage of Derilambrus angulifrons and Parthenopoides massena was collected from plankton and identified by DNA barcodes. The morphology of the megalopa of D. angulifrons is described for the first time, and that of P. massena is compared with a previous description.

Three specimens of the spider crab, Maja goltziana, were caught from the southern Adriatic (Mljet Island) and represent the first record of this species in the Adriatic Sea.

Assessing the behavioural patterns of animals is an increasingly important field in conservation biology, as it may assist in the prediction of how animals respond to rapid changes in the environment. Comparing the behavioural patterns of sympatric species can also give insights into the mechanisms that allow similar species to coexist. We undertook dolphin group follows in order to quantify the behavioural patterns of the sympatric Chilean and Peale's dolphins in southern Chile. Markov chains showed that these species differed significantly in time allocated to each of the five different behavioural states, but travelling was the most frequent behavioural state observed for both species. Six (out of 25) behavioural transitions were found to be different between species. In addition, group size and group dispersion were highly associated with specific behavioural states. Larger groups were more likely to socialize, while small groups were more likely to rest. For both species resting was mostly observed in tight groups, while foraging/feeding and travelling were related to intermediate group dispersion. Socializing differed between species, occurring in tight groups for Peale's dolphins and dispersed groups for Chilean dolphins. Overall, there were significant differences in behavioural patterns between the two species. These dissimilarities may represent evidence of different strategies (i.e. habitat use patterns and foraging) these two species employ which allow them to coexist. The information generated in this study will contribute to the development of better predictive models on how animals may respond to a changing environment and to the potential effects of human induced activities.

A new deep-water Actiniaria species, Isanthus homolophilus sp. nov. is described from the French Polynesia. Morphological and ecological differences between the new species and the other known species of the genus Isanthus are discussed. The distinct morphological characteristics that distinguish I. homolophilus, are the presence of a tentaculated columnar margin, the tentacle number (84–96), and its cnida biometry. A further ecological characteristic is the distinct symbiotic relationship that the anemone exhibits towards the decapod Hypsophiys inflata.

During the biological researches of the ‘Service Mixte de Contrôle Biologique’ (SMCB) in French Polynesia (1986–1990) at depths ranging from 100 to 1120 m, a symbiotic association between a deep-water homolid crab, Hypsophrys inflata Guinot & Richer de Forges, 1981 and a sea anemone of the genus Isanthus (Actiniaria: Isanthidae) was collected. Even though this association was described by Guinot et al. (1995) and Chintiroglou et al. (1996), no concise description of the anemone is given. Thus, the goal of the present study was to provide a detailed description of the new anemone species and compare it with other species of the Isanthidae Carlgren, 1938 family.

The methodology followed in our investigation was that of Doumenc & Foubert (1984) and Doumenc et al. (1985). Nematocyst nomenclature used was as proposed by England (1991). Abbreviations: MNHN (Museum National d'Histoire Naturelle Paris).

The parasitic copepod Sphaeronella? callisomae, usually a single female, was occasionally found in the brood pouch of the amphipod Orchomene nanus. It is possible that this parasite consumes its host's eggs. Infected female hosts were significantly smaller than uninfected ones, so the copepod may retard host growth (or select young female hosts). Other associates (ciliates) were found in the body cavity and epizooitically on the host's gill lamellae.

Extensive collections of Orchomene nanus (Krøyer) (Crustacea: Amphipoda) have been made year-round (April 1993 to April 1994) using funnel-traps baited with crushed shore crabs (Carcinus maenas (L.)) deployed overnight (soak time 17 h) in the shallow sublittoral (5–6 m depth) at Keppel Bight, Millport (54°45·75′N 4°54·48′W: for further details, see Moore & Wong, 1995, in press a,b).

The presence of nicothoid copepods (tentatively identified by Mr M. O'Reilly, Clyde River Purification Board, as Sphaeronella? callisomae Scott; an inadequately described species, see Gotto, 1993) in the brood pouch of this amphipod were recorded routinely. At least two species of ciliates were also encountered. A sessile ciliate protozoan (?Lagenophrys sp.) occurred commonly as an epizoite of O. nanus branchiae (Figure 1A–D); and unidentified parasitic ciliates, possibly of three species, occurred in the body cavity (Figure 1E, F).

The incidence of parasitization of female O. nanus with S. ?callisomae was very low (0·81%; 8/990). There was only ever a single mature female copepod per host, although instances occurred of multiple infestations with nauplii or copepodites. Two female O. nanus were recorded with a female nicothoid coexisting with the amphipod's own eggs inside the brood pouch.

Three specimens of Stygiomedusa fabulosa Russell, 1959, identified recently in the collections of the Zoology Department of the British Museum (Natural History) (Table 1) extend the recorded distribution of this infrequently collected genus to the Southern Ocean, and provide the opportunity of assessing the specific distinctness of S. stauchi Repelin, 1967. The specimens are the first of either species recorded from south of the tropics.

Fully ten years having elapsed since the Report on Trawling on the eastern shores was presented to the Trawling Commission (composed of the late Earl of Dalhousie, chairman; Right Hon. Edward Marjoribanks, M.P., now Lord Tweedmouth; Prof. Huxley; Mr. W. S. Caine, M.P.; and Mr., now Sir, T. F. Brady), it appears to be desirable to review the statements contained therein in the light of the information which the impetus given by the Commission has produced. Moreover this examination of results is all the more nececssary, since last year another important body—viz. the Select Committee of the House of Commons on Fisheries, presided over by Mr. Majoribanks, M.P.—issued a new blue-book containing the finding of the Committee, and a mass of evidence.

Seasonal and spatial variations in the distribution and abundance of Ophiothrix fragilis larvae (2-arm to 8-arm stages) were determined from a series of plankton net tows in the Dover Strait in 1995 and 1996. Ophioplutei appeared in the plankton between June and September. Larval population was constituted by ophioplutei from different spatio–temporal origins. A major fraction of the ophioplutei observed in the Dover Strait might come from a population localized southward.

The use of a mixture of copper soap, 5 or 10 per cent, with 1 per cent mineral oil, dissolved in petrol or benzol, increases the life of silk plankton nets by about four or five hundred per cent, and roughly doubles that of a hemp net for a single treatment. The beneficial effects last far longer than does the green colour. Re-treatment at suitable intervals is recommended.

The use of 5 or 10 per cent of resin * with an equal percentage of the soap improves its adherence to the fabric, as does also the addition of tar or anti-fouling paint. For silk nets, to avoid clogging, only one-half per cent of resin should be used with 5 per cent of soap.

A liquid soap mixture, which may be used with paraffin oil, can be obtained by adding one pound of resin to one pound of melted copper soap, and then dissolving in one and a half pounds of carbon tetrachloride. When wanted, this is used to make up a paraffin oil soap solution of the desired concentration, but adherence is less than with petrol.

As certain previous authors have observed, T. larynx is a species subject to much variation. Disregard of this has led to the erection of invalid species.

The descriptive characters used by Allman are discussed. In a comparison with material collected in Plymouth Sound these characters are shown to be so variable that used singly they are valueless. In particular, disregard of the stage of development and over-emphasis on size will be very misleading.

The causes of some of this variability are suggested.

Based on the morphology of the mandible, female maxilliped, and male first endopod, Lichomolgus longicauda (Claus) is transferred to Metaxymolgus Humes & Stock, 1972. M. longicauda is recorded for the first time from Sepia officinalis L. taken in British waters.

The elongated eye of Vitreledonella richardi is described from two specimens caught at 200 m in the North Atlantic. It is shown that the cylindrical shape, with the lens placed centrally, results in a reduced field of view in the horizontal plane. It is argued that the unusual shape is an adaptation which minimises the silhouette of the eye as seen from below, and is part of the animal's camouflage strategy.

Introduction

The majority of fish and cephalopods have two hemispherical eyes, each of which has a field covering roughly the 180° on one side of the animal (Walls, 1942; Packard, 1972). The commonest exceptions to this rule are animals with so-called ‘telescopic’ eyes, found in many species of deepsea fish (e.g. Benthalbella, Argyropelecus, Opisthoproctus, Scopelarchus, see Marshall, 1954; Locket, 1977) and some cephalopods (Amphitretus, see Chun, 1915; Histioteuthis sp., see Young, 1975a). These eyes are tubular, with the lens at the open end of the tube, and a retina with a reduced field of view at the other. The eyes usually point upwards, and it is generally agreed that their shape is determined by the need to concentrate sensitivity and resolution into the rather narrow field above the animal where the residual daylight is still adequate for visual detection. It is 200 times darker in the downward direction (Denton, 1990), and so there must be some depth at which upward vision works, but downward vision does not. These are not the only kind of tubular eyes, however. In some cephalopods, but not to my knowledge in any fish, there are eyes of tubular appearance but with the lens not at the end, but in the centre of the tube (Figure 1).

The reproductive activity of a population of barnacle-dwelling littorinids at Peak Steel, on the north-east coast of England, was investigated. Variation in the number of mature males and females, expressed as a percentage of the whole population, showed a marked difference among the barnacle-dwelling littorinids. Littorina neglecta displayed a distinct seasonal component to its reproductive activity, with a peak in early summer. Littorina arcana B also displayed a distinct seasonal component, with a lull in the summer months. However, L. saxatilis B maintained its reproductive activity all year, but with an increase in output in the summer. The reproductive activity of both L. arcana B and L. saxatilis B follow similar patterns of reproductive activity as their typical non barnacle-dwelling forms, suggesting that these are true barnacle-dwelling ecotypes. The controversy surrounding the specific status of L. neglecta is also discussed.