As part of an investigation into the impact of commercial trawling on the benthos of Strangford Lough a map of the distribution of the benthic communities in the Lough was required. To provide this an acoustic bottom classification survey of the Lough was carried out using a commercially available system, RoxAnn. RoxAnn processes the information from a conventional echo-sounder to determine the nature of different substrata. Underwater cameras were used to obtain ground truth data to compare with the RoxAnn data. Used in conjunction, the two surveys provided valuable information on the different bottom substrata and associated epibenthic communities present in the Lough.

INTRODUCTION

The littoral/sublittoral hoplonemertean (phylum Nemertea) species Oerstedia dorsalis (Abildgaard, 1806) is described as polymorphic in external characters (Örsted, 1844; Burger, 1895; Brunberg, 1964). Sundberg (1984) grouped specimens in three classes based on external morphology and asked, using multivariate morphometrics, if there was a consistent correlation between external and internal characters. Such a correlation would have indicated a restricted gene flow between the externally different morphs, and thus the possibility of a group of species instead of one, polymorphic, species.

One of the forms in Sundberg (1984) appeared to be different from the other two morphs but the morphometric analysis was inconclusive. Later, Sundberg & Janson (1988) established by enzyme electrophoresis that this form was genetically different and it was later described as Oerstedia striata (Sundberg, 1988). A problem both in Sundberg (1984), and Sundberg & Janson (1988) was that one of the groupings (class ‘C’ in both studies) of specimens subsumed a number of morphs, all speckled or dotted but to varying degrees. These morphs may in fact represent different species, which would have been concealed in the electrophoretic and morphometric analysis as merely increased intraspecific variation. One of the ‘C’ morphs in Sundberg (1984) and Sundberg & Janson (1988) is light brown with numerous small dark brown/black dorsal spots. Based on one specimen from Anglesey, North Wales, Gibson (1988) described Oerstedia (Paroerstedia) nigrimaculata which is externally similar to this variety. Envall & Sundberg (1993) could not find any differences in internal characters between the type specimen of O. nigrimaculata and the brown form of O. dorsalis but hesitated to conclude that O. nigrimaculata is a variety of O. dorsalis.

This first description of behavioural interactions between benthic pyjama sharks Poroderma africanum (Chondrichthyes: Scyliorhinidae) and spawning squids Loligo vulgaris reynaudii (Cephalopoda: Loliginidae) was made from underwater video recordings. The behaviours are described and illustrated to show that the sharks searched for squids in egg beds, then rested there partially hidden and immobile. The pyjama sharks at-tempted to ambush the squids when they approached to lay their eggs after they had apparently habituated to the predators. Although normally nocturnal, the pyjama sharks had emerged by day from caves and cracks in the rocky reef to attack the spawning squids, thereby benefiting from an occasionally available resource.

Deep-water suprabenthic species of Mysidacea were studied in the Catalan Sea (western Mediterranean). Twenty-one samples were taken at depths from 385 to 1859 m, using a Macer-Giroq type sledge. Sixteen mysid species have been collected. Boreomysis arctica was the commonest species and Parapseudomma calloplura, Paramblyops rostrata and Erythrops neapolitana were also notable for their high occurrence. The genus Dactylamblyops, Mysidella biscayensis and Pseudomma affine were recorded for the first time in the Mediterranean. The greatest total abundance of mysids was found over the middle slope. On the upper slope P. calloplura and E. neapolitana formed the dominant species, and deeper B. arctica dominated. Species richness and diversity (H’) declined with increasing depth. The decrease in H’ was attributable to the growing dominance of B. arctica over the middle and lower slopes. Swimming coefficients near the bottom showed intraspecific differences. In general, the species collected inhabit the water column between 0.1 and 0.5 m above the bottom. The bathypelagic species Eucopia hanseni had high swimming coefficients. Amongst the suprabenthic species, B. arctica showed the highest swimming coefficients, and rose from the near-bottom during night on the upper and middle slope stations.

Iron-containing precipitates, present within the organic matrix of the poriferan Ircinia oros were identified as crystalline lepidocrocite (γ-FeOOH) by electron diffraction and57Fe Mössbauer spectroscopy. The crystals were located specifically within the spongin filaments, suggesting that the binding and subsequent accumulation of iron by macromolecules present in these filaments were responsible for mineralization. Iron biomineralization did not appear to serve any specific structural role, but may be involved in biological processes such as detoxification.

It is well recognized that Porifera are active in the biomineralization of calcium carbonate and silica, producing beautiful and intricate skeletons (Simpson, 1984). However, the formation of other biominerals is less well documented. Iron biomineralization has been reported in a few species of keratose sponges (Töwe & Riitzler, 1968; Vacelet et al., 1988), and the mineral has been identified as lepidocrocite (γ-FeOOH). Lepidocrocite is a relatively uncommon biomineral, having previously been identified as only a minor phase in chiton teeth (Webb et al., 1989; Lowenstam & Weiner, 1989).

This communication presents the first records of mated female Loligo gahi in Falkland Island waters. In October 1993 fully mature mated female L. gahi were identified in samples taken from the commercial fishery in waters east of Lively Island, East Falkland, at depths of 145–174 m. Spermatophores were found in both the mantle cavity and buccal sites of deposition. These records, combined with past records of spent females, suggest spawning periods in late October/early November and April/May. These concur with two of the three periods of spawning suggested from previous studies of juvenile and adult L. gahi.

Post-traumatic regeneration of arms in Cephalopods is a common occurrence. It was described by Aristotle and, in more modern times, by Steenstrup (1856). Féral (1978) summarizes the information on regeneration of arms, tentacles and suckers in cephalopods. He reports only one case, experimental, involving a Sepiolidae species, namely Sepiola atlantica.

This paper gives an account of regeneration of the copulatory arm in three wild-caught male sepiolid squids, two of which were Sepietta oweniana (d'Orbigny, 1841) and one Sepiola ligulata Naef, 1912 (Sepiolidae: Sepiolinae). The copulatory arm, or hectocotylus, is the left dorsal arm in Sepiolinae. It represents a most important means of species identification (Naef, 1923; Bello, in press). The squids were caught by bottom trawl in the southern Adriatic Sea during routine sampling. Measurements and observations were made on preserved specimens.

A species of balanomorph barnacle with solid plates and basis, Solidobalanus fallax, is recorded for the first time in the English Channel off Plymouth, at 44–56 m depth. It occurs exclusively on the valves of the queen scallop, Aequipecten opercularis. Only one out of 15 scallops carries the barnacle. Morphological details of the species are re-described in comparison with Balanus crenatus and B. spongicola, with which it co-occurs. Solidobalanus fallax ranges from Angola through West Africa and Morocco to Algeria but has not been reported previously from Europe. Some specimens were incubating embryos in late May, indicating a potential for local recruitment. Solidobalanus fallax is unlikely to be a recent immigrant but its abundance may have increased as a result of changing climate.

Most studies on the pore signature of calanoid copepods have been made on adult femalessemicolon very little is known of the ontogenetic development of the pore signatures and their sexual differences. Males, females and copepodids of five species in the metridinid genus Pleuromamma are examined. Interspecific differences in the pore signatures occur as early as copepodid III. Differences in the signatures of the copepodids arise from two sources: (1) species-specific rates of development of the adult signaturesemicolon (2) development of the species-specific components of the adult signature. The cephalosomal signature is complete in copepodid V, and the metasomal and urosomal signatures are complete in copepodid VI, the adult stage. Sexual differences in the pore signature are found in copepodid IV and are primarily evident in the urosome of the adult. The species-specific components of the urosomal signature are greater in the female than in the male.

Squids have more than two accessory reproductive glands, namely oviducal and nidamental glands which release gelatinous substances at the time of spawning to produce an egg mass and in some sepiolids and loliginids there also exist accessory nidamental glands (Hamabe, 1962; Boletzky, 1986; Mangold, 1987). An exception are some enoploteuthid squids which lack the nidamental glands but have large oviducal glands (Naef, 1923). Ikeda et al. (1993) showed experimentally that the gelatinous substance from the oviducal gland has the role of generating the elevation of the chorion at fertilization, which causes the formation of the perivitelline space in squid such as Todarodes pacificus; the perivitelline space became larger during embryonic development in the presence of the oviducal gland jelly. Since T. pacificus lacks accessory nidamental glands (Sasaki, 1921), we address the question as to whether the gelatinous substances of nidamental gland origin also induce the formation of perivitelline space, as does the oviducal gland jelly in T. pacificus, based on the observations of artificial insemination.

The cirri of the digital tentacles of Nautilus pompilius are covered by annular ridges, more pronounced on the oral (adhesive) than the aboral side. On the oral side the epithelium is thicker on the proximal and outer surfaces of the ridges than on their distal surfaces. Prominent electron-dense granules occur in the cells of the thick epithelium, but are absent from the thin epithelium and the epithelium of the aboral surface. These granules contain mucopolysaccharide and may be responsible for adhesion.

The digital tentacles of Nautilus are used for attachment to, for example, prey, the substratum, or the partner's shell during mating. Their general structure and histology have been described by Owen (1832), Willey (1898), Barber & Wright (1969), Fukuda (1987) and Kier (1987). The mechanism of adhesion is still uncertain. Barber & Wright (1969) report epithelial cells of two types: pigmented cells containing pigment granules 0–5–1 µm in diameter, interspersed with a small number of mucus-producing cells which may help with the adhesive process.

The oxygen content of air-equilibrated haemolymph from three species of hyperiid amphipods, Hyperoche medusarum, Parathemisto sp. and Hyperia galba was similar to that of air-equilibrated sea-water. The concentration of haemolymph protein was low in each case. Both features, taken together with the fact that we were unable to detect the presence of copper in the haemolymph in any of the species examined, suggests that hyperiids, unlike gammaridean amphipods, do not possess the respiratory pigment haemocyanin.

All the information available on the O2-binding properties of amphipod haemolymph has been derived from members of the amphipod sub-order Gammaridea. In common with many other crustaceans (Truchot, 1992), O2 carriage in gammarid haemolymph is facilitated by the presence of the copper-containing respiratory protein, haemocyanin (Spicer, 1994). Unfortunately no comparable data exist for the other major amphipod sub-orders, the Hyperiidea, the Caprellidea and the Ingolfiellidea. Consequently we have examined haemolymph from three species of hyperiid amphipod, Hyperoche medusarum (Miiller, 1777) and Parathemisto sp., from the west coast of Vancouver Island, Canada, and Hyperia galba (Montagu, 1813) from the Clyde Sea area, Scotland.

The armoured planktonic dinoflagellates present at a site adjacent to a floating fish-farm in Loch Eriboll, North Scotland, were studied by surface net-sampling, mainly at two-weekly intervals, over a period of four years 1990–1993. A total of 62 species was recorded. Some dinoflagellates were present at all times of the year but they reached their lowest numbers in May, during the spring diatom bloom, and their highest numbers in mid-summer. There was usually a seasonal pattern in which the most abundant dinoflagellate during the early summer was the heterotrophic species Protoperidinium ovatum, and this was followed in the later summer by the autotroph Ceratium fusus. In 1993 the pattern was rather different, with Gonyaulax species abundant in June and, later in the year, both Protoperidinium cerasus and P. excentricum having periods of abundance. Potential toxin-producing dinoflagellates, Alexandrium tamarense (PSP) and Dinophysis acuminata (DSP), were found in small numbers.

Bryozoans are an important component of the sessile, suspension-feeding fauna on the Antarctic continental shelf, (Knox & Cameron, 1970; Dell, 1972; Winston, 1983; Winston & Heimberg, 1988). Antarctic bryozoan faunas are systematically diverse, and display a broad range of colony morphotypes; they include fast-growing, short-lived species and long-lived perennials (Winston & Heimberg, 1988). Very little is presently known about the reproductive biology of Antarctic bryozoans, although it seems that a preponderance of species brood lecithotrophic larvae with a short, free-swimming phase. Planktotrophic larvae with a free-swimming phase of several weeks occur in a variety of gymnolaemate families, principally distributed in temperate coastal waters, and most often associated with specialized microhabitats or substrates. This type of larva, referred to as a cyphonautes (Zimmer & Woollacott, 1977), has not previously been reported from polar seas, and its occurrence in the Bellingshausen Sea, Antarctica, is thus of considerable interest.

The age and population structure of Parablennius sanguinolentus parvicornis (Valenciennes) (Pisces: Blenniidae) from the Azores have been studied. Total length and weight relationships are given for each sex. Age study was based on otoliths readings. The von Bertalanffy growth function was applied to describe the growth in total length with age. At the end of the first year mean (±SD) total length was significantly different in males (7.1 ±1.5 cm) and females (6.1 ±1.2 cm). One-year-old males participate in reproduction as satellites, whereas females do not. The implications of this in early growth rate of the males is discussed. During the two most important months of the reproductive season (i.e. June and July), the sex ratio was significantly biased towards males, particularly in the larger size classes.

Samples historically collected and analysed by the Continuous Plankton Recorder (CPR) survey were used to describe the distribution of coccolithophores (class Prymnesiophyceae) in the north-east Atlantic and the North Sea. In the routine CPR analysis, members of this group are simply identified as ‘coccolithophores’ and not to any further taxonomic level. From this analysis, the 200-m depth contour marked a point of distinct transition between high coccolithophore occurrence (off the shelf) and low coccolithophore occurrence (on the shelf). Thirty-three CPR samples that had been collected between 1979–1992, were re-examined and the coccolithophores identified to a more detailed taxonomic level. Among the species identified was the bloom-forming coccolithophore, Emiliania huxleyi. Thus archived CPR samples could potentially be re-analysed to assess regional, seasonal and decadal changes in the occurrence of this species.

This paper reports the results of a hydrographic survey and the successful deliberate deep droguing of a meddy (Pinball) and the seeding of its core with two ALACE floats. The drogued buoy results give important kinematic properties of the eddy core in real timesemicolon the ALACE have allowed the position of the meddy to be tracked for seven months. Pinball was found against the continental slope near Lisbon canyon. The maximum core salinity was 36·564 psu, at a depth of 1260 m, but the maximum rotation rate with period ~2·5 d was in the upper core near 700 m, where temperatures reached 13·2°C. The azimuthal transport to a radius of 50 km was ~13 Sv. Pinball moved from the continental slope near Lisbon to the central Tagus Abyssal Plain, returned towards the continental slope and then moved westwards crossing the central Tagus Abyssal Plain a second time. At times it had a marked remote sensing infra-red sea-surface signature. It moved ~550 km over 204 d and the near real-time data meant that, in principle, this eddy could have been re-surveyed, redrogued or reseeded with floats during this period.

Earlier descriptions showed that the community of appendicularians off the British coast was mainly composed of Oikopleura dioica (Appendicularia; Müller, 1846) and Fritillaria borealis (Appendicularia; Lohmann, 1896), rarely by Oikopleura fusiformis (Appendicularia; Fol, 1872) and Fritillaria pellucida (Appendicularia; Quoy & Gaimard, 1833) and exceptionally by Oikopleura longicauda (Appendicularia; Vogt, 1854). Based on weekly samples collected during 1989 at a single station off the coast of Plymouth, we describe the first complete seasonal cycle of appendicularians in this area. The results suggest that rather than being occasional visitors, O. fusiformis, F. pellucida and O. longicauda are consistently present and abundant from mid to late summer. Moreover, the seasonal shifts in structure of the community of appendicularians in the area, as depicted by multivariate analysis, are consistent with those of the more southerly central Cantabrian coast (Spain). This suggests that they are viable populations rather than occasional expatriates from other areas.