The first account of mating in a myodocopine using evidence from video recordings is presented herein for Skogsbergia sp. (Cypridinidae). After initial courtship the male and female ostracods, with ventral margins adjacent and anterior ends directly opposite, join their mandibular claws and furcae. Both furcae are pushed in a posterior direction until the ventral margins of the carapace meet. In this position, with genitalia directly opposite, copulation presumably occurs. This mating procedure lasts for five seconds.

Myodocopine ostracods are diverse marine crustaceans occurring world-wide at depths from 0–6000 m (Kornicker, 1975). All myodocopines reproduce sexually (Cohen & Morin, 1990). Some bioluminescent cypridinids (Myodocopina) use luminescent signalling during courtship; males produce species-specific patterns of flashes in the water column to attract females (Morin, 1986). Although myodocopines may be amongst the most abundant macroinvertebrates on the continental shelf (J.K. Lowry, personal communication), they have been the subject of relatively few behavioural studies, and in particular their copulation process is poorly documented (Cohen & Morin, 1990).

Two accounts of myodocopine mating have been reported. In 1914 the cypridinid Vargula hilgendorfii (Muller, 1890) was observed mating in a Petri dish (Okada & Kato, 1949). The male clasped the female using the first antennae while swimming with the natatory second antennae. After 30 to 60 min they rested on their lateral sides, with ventral margins touching and heads facing in opposite directions; the penis (lying between the paired copulatory ‘limbs') was protruded into the female carapace and the spermatophore was transferred. This copulation lasted more than 30 min (Okada & Kato, 1949).

During the course of a survey into the distribution and growth of the fan mussels Pinna nobilis and Pinna rudis from the coastal waters of the Spanish Mediterranean the presence within the mussels of Pontonia pinnophylax has been recorded. Pontonia pinnophylax typically occurred in adult pairs, but occasionally solitary male individuals were found. The width of the cephalothorax is greater in females than males, whereas the chelae of the second periopods, which are unequal, are larger in males. There is a general relationship between the size of P. pinnophylax and its pinnid host; the largest individuals were found in the largest Pinna and vice versa.

The ligament of the bivalve Mya arenaria was previously described as being composed of two layers: a fibrous and a lamellar one, the fibrous layer being more extensive. Other features described, such as the three-dimensional extent of the layers and their mode of attachment to the chondrophores, have been found to be inaccurate to a certain extent. The ligament is therefore redescribed here. It is conical in appearance and attached to the left chondrophore only at its margin, its interior being occupied by an epithelium, which is an extension of the mantle isthmus. The lamellar layer is a pyramidal body which merges into and constitutes the posterior extension of the fibrous layer. The whole structure is internal and may rotate around the dorsoventral axis, thus being suited to allow rocking of the valves. This kind of movement is used when Mya contracts the anterior adductor muscle to eject water from the mantle cavity during burrowing. In this respect the ligament is unique among those known in bivalves.

A detailed analysis of beak length to body length and weight measurements was carried out for the onychoteuthid squid Moroteuthis ingens, in the Falkland Islands region of the South Atlantic. Lower and upper rostral lengths were both good predictors of mantle length and body weight. In addition, the relationships of freshly dissected beaks to mantle length and body weight were significantly different to those of beaks dried before measuring, with dried beaks being better predictors of both variables.

A considerable amount of information on Southern Ocean squid biology has been obtained from analysis of beaks in the stomach contents of predators (Clarke, 1980,1983). Beak analysis can be particularly useful as it provides information on the species preyed upon as well as estimates of squid size and biomass ingested (Clarke, 1983, 1986).

Four cases of anomalies of the copulatory arm in Sepiolinae (Cephalopoda: Sepiolidae) are reported. In one case (Sepietta oweniana), both dorsal arms were modified resulting in double hecocotylization. In another specimen probably of the same species the copula-tory apparatus was formed by two fleshy multilobed formations situated on the dorsal and ventral side of the arm base. In one specimen of Rondeletiola minor the copulatory apparatus was inversely positioned on the arm base, and in one Sepioh intermedia specimen the inner free portion of the wrinkled tubercle was markedly enlarged.

The chromatophore system of the small loliginid squid Alloteuthis subulata (Mollusca: Cephalopoda) is very simple and the repertoire of body patterns limited. There are red and yellow chromatophores only. On the dorsal mantle there are more yellows than reds; on the ventral mantle and there are more reds than yellows. The dorsal reds are larger than the yellows and bear more radial muscles. The significance of these findings is discussed.

Alloteuthis subulata Lamarck is a small loliginid, common in shallow water near Plymouth (Holme, 1974; Lipinski, 1985; Rodhouse et al., 1988). Little is known of its natural history and behaviour and chromatophores and body patterns of adults have never been described, although the skin of this species has been used in physiological studies of colour change (Messenger, 1991; Messenger et al., 1991; Cornwell & Messenger, 1995).

Over 100 adult animals of both sexes, caught by trawl at depths of 10–60 m, were examined; their mantle lengths ranged from 70 to 130 mm. Living animals were observed in large aquaria with circulating sea-water. Counts and measurements of chromatophores were made on colour photographs (taken through a Nikon dissecting microscope) of pieces of fresh skin (20×20 mm) dissected from animals killed by decapitation or after MgCl2 anaesthesia (Messenger et al., 1985). Chromatophores were counted first when fully retracted (by 1×10−3 M 5-HT) and then when fully expanded (with 1×10−3 M L-glutamate: Cornwell & Messenger, 1995). All measurements were made in the same area of the body: the central and anterior part of the mantle, dorsally and ventrally (Figure 2).

The skin of Loligo vulgaris and Illex illecebrosus contains a thick layer of amorphous material. In Loligo it lies above and in Illex below the chromatophore layer. We can find no mention of this layer in the considerable literature on squid skins despite its potential importance as a protection to underlying tissues and as a possible barrier to cutaneous oxygen uptake.

Cephalopods have soft complicated skins. Embedded in the skin, most species have chromatophores, small bags of pigment that can be expanded by muscles that are under direct nervous control from the brain. There is an extensive literature on the physiology of chromatophores (Packard, 1988) and on their function in the behaviour of the animals (Hanlon & Messenger, 1996; Packard & Hochberg, 1977). Further cutaneous structures concerned in the determination of the colour of living cephalopods, the reflecting iridophores and leucophores (Cloney & Brocco, 1983), and the light generating photophores (Herring, 1988), have been the subject of a number of reports but other skin features such as the distribution of blood vessels have attracted little attention.

The adhesion of single podia of Asterias rubens (Echinodermata) was tested under different conditions in order to determine those factors which have an effect on the adhesive forces. In common with many other marine organisms, the adhesion of the podia is sensitive to surface properties of the substratum. The effect of immersion and emersion on tenacity (force per unit area) has been tested. Working with the asteroids completely immersed in sea-water appears to be the best technique to measure the adhesive forces of the podia. The mean tenacity of the podia of A. rubens on glass underwater is 1·98×105 Nm−2.

The measurement of the adhesion strength of marine invertebrates and of its variation under different conditions may give clues to how marine bioadhesives function. Adhesive forces have usually been measured in invertebrates using either permanent or transitory adhesion, but only rarely recorded in animals using temporary adhesion (for review see Walker, 1987).

Of all macrobenthic organisms, echinoderms have exploited temporary adhesion most efficiently. In echinoderms, adhesive systems are usually associated with the podia and are involved in locomotion, attachment, feeding, or burrowing (Flammang, 1996). The paucity of information regarding the adhesive strength of echinoderm podia is due possibly to the fact that these animals possess a multitude of podia that are not all attached at the same time, making it difficult to evaluate the exact number of podia involved in adhesion at any precise instant in time. For example, maximum detachment forces involving many podia have been measured for several asteroid species. Feder (1955) measured up to 4 kg (39·64 N) in Pisaster ochraceus, Lavoie (1956) over 3 kg (29·43 N) in Asterias forbesi, and Christensen (1957) 5 kg (49·05 N) in Evasterias troscheli. Unfortunately, the number of podia adhering to the substratum was not estimated in any of these studies. It is not possible, therefore, to calculate tenacity (adhesive force per unit of surface area) which makes comparisons impossible either between these different asteroids or with other marine invertebrates (see Walker, 1987). Tenacity has been considered in only one study (Paine, 1926) where the mean adhesive force using single podia of the asteroid A. vulgaris was 17·2 g (0·17 N), giving, when divided by a mean measurement of the surface area of the podial discs, a tenacity of 1·25×105 N m2.

Stomach contents from an adult male sperm whale (Physeter catodori) stranded at Penzance, Cornwall, included a total of 125 upper and 110 lower beaks (mandibles) of cephalopods. All but two of the cephalopod species represented by lower beaks were oceanic squid belonging to four species in four families comprising: Histioteuthis spp. (44·5% by number and 10·7% by estimated wet weight); Architeuthis spp. (42·7% by number, 82·2% by weight); Todarodes sagittatus (7·3% by number, 6·0% by weight); Galiteuthis sp. (0·9% by number, 0·02% by weight); an oceanic octopod, Haliphron atlanticus (3·6% by number, 0·9% by weight) and one neritic species, Loligoforbesi (0·9% by number and 0·1% by weight). Mantle lengths of the squid were estimated to vary from 126 to 1056 mm.

The generic name Ovulina was proposed by Anderson, Rogerson & Hannah (1996) to apply to the type and only species O. parva Anderson et al., 1996 based on laboratory cultured individuals isolated from sediments in the Firth of Clyde, Scotland and type specimen deposited in the British Museum of Natural History (registration number 1995:10:25:2). The name is a junior homonym and therefore invalid. Ovulina was proposed previously for a foraminiferan by Ehrenberg (1854) and used subsequently by Gruber (1884).

Ovulinata nom. nov. is proposed here as a replacement name for Ovulina Anderson, Rogerson & Hannah, 1996. The name signifies the ovoid shape of the test and the ovulate cell body as described in the original diagnosis and etymology (Anderson et al., 1996).