The first species ofLamellisabella to be described from the Atlantic Ocean has rows of small teeth on the tentacles. It occurs at about 4000 m depth in the Bay of Biscay, and its range probably extends along the continental rise at least as far south as the Gulf of Guinea.

Data are presented on the lipid composition of Balanus balanus spermatozoa.

Lecithin is the major lipid and little plasmalogen is present.

The results are discussed in relation to what is known of other spermatozoa, both vertebrate and invertebrate.

Some data on the inorganic and organic constituents of Balanus balanus seminal plasma have been given by Barnes (1962 a, 1963); lipids were shown to be present in the plasma and are a well-known constituent of the spermatozoa of other animals (Mann, 1964). In view of the relatively small amount of data on the detailed phospholipid composition of invertebrate spermatozoa the opportunity was taken during the investigation reported in the previous paper (Dawson & Barnes, 1966) to examine the spermatozoa of Balanus balanus. The results are, however, best presented and discussed separately. The results are given in Table 1.

Eudendrium moulouyensis is a zooxanthellate hydroid originally described from the Chafarinas Islands (Alboran Sea, south-western Mediterranean) in summer 1991. According to the original description, this species can be identified due to the occurrence of symbiotic zooxanthellae in the entire endodermal layer of the colony (gastrodermis and tentacle endodermis), a unique feature among the Mediterranean Eudendrium species. However, several aspects of its life cycle and the extent of its phenotypical variability are still unknown. Since winter 2004, colonies of E. moulouyensis were recorded throughout the year from 0.5 m to 30 m depth from the southern Adriatic Sea (Otranto Channel) and the Gibraltar Strait (Alboran Sea). Additional specimens were collected from the northern Adriatic (Vis, Croatia), Sicily Channel (Pantelleria and Lampedusa Islands), and western Sardinia (Costa Paradiso). These findings offered the opportunity to describe for the first time the full life cycle and to elucidate several biological aspects related to phenotypical variation of colony morphology, vertical zonation, seasonality, zooxanthellae–polyp relationship, and cnidome morphology and distribution. The number and morphology of male gonophores per reproductive polyp is described here for the first time, providing a useful taxonomic character to easily discriminate Myrionema amboinense from E. moulouyensis. From the available information, the occurrence of M. amboinense in the Mediterranean Sea should be regarded as doubtful, if they are not accompanied by observations of cnidome, male gonophores or distinctly separate tentacles whorls.

The present study is the first record of twinning in Delphinus delphis. The first foetus was a female of 72 cm total length which had a curved caudal area. This animal was located in the left uterine horn, very close to the genital aperture. The second foetus was a male of 46 cm total length and its external morphology was deformed. It was located in the uterus and the nose was shorter than the female foetus. Documented incidences of twinning in cetaceans are rare.

On 30 July 1955 Dr J. H. Fraser, of the Scottish Home Department, Marine Laboratory, Aberdeen, sent to the British Museum for determination two adult females of a penaeid prawn collected at 01.56–02.0 h B.S.T. near the surface (15 fm.) at Rosemary Knoll, to the north-west of the Outer Hebrides, on 22 July 1955. The actual depth at this locality, 59° 12′ N., 10° 09′ W., is 229 fm (419 m). These specimens were identified by one of us (R. W. I.) as Funchalia woodwardi Johnson. Later the senior author confirmed this determination and wrote to Dr Fraser as follows:

Eight species of Yoldiella (Yoldiella biguttata Allen, Sanders & Hannah, 1995; Yoldiella similis Allen, Sanders & Hannah, 1995; Yoldiella extensa Allen, Sanders & Hannah, 1995; Yoldiella aff. jeffreysi (Hidalgo, 1877); Yoldiella sp.1; Yoldiella sp. 2; Yoldiella sp. 3 and Yoldiella sp. 4) from the continental slope off Rio de Janeiro were used to test if quantitative morphometric measurements of shell shape and hinge plate could effectively discriminate among them. Thirty specimens of each species were sampled, and a total of 25 variables were established and utilized as input data to perform a discriminant analysis. The percentage of correctly classified cases was never less than 80%. The hinge plate variables were always relevant, and the most important one was the width of the posterior hinge plate. On the other hand, shell shape variables, when present, were secondary. Considering that the variation in the shell of Yoldiella species is subtle, and also the findings of this study, we can state that the hinge plate morphometry has good potential to improve species discrimination.

We examined habitat, population size-structure, colour dimorphism, reproductive behaviour, arm loss and the relation between arm regeneration to pyloric caeca indices in populations at Whitford Rock (WR) and Port Beach (PB) in January 2009. The sediment was fine sand at WR and a mix of larger particles at PB. Individuals at PB were predominantly orange and more uniform in colour than those at WR, which were predominantly grey. Body size and pyloric caeca index of individuals at WR were greater than those of individuals at PB, indicating the nutritional condition was better at WR. This suggests the quantity or quality of food at WR was better. Organic matter of the pyloric caeca and body wall of intact and regenerating individuals at both sites were similar, indicating loss of an arm did not affect gross proximate composition of the organs. Sea stars with regenerating arms made up 5.4 and 8.4 % of the populations observed. Despite the very small size of the gonads, some individuals were in the pseudocopulatory position, indicating this behaviour occurs even when gametes are not present. In every case observed, the male of the pseudocopulating pair was situated above the female. Given the abundance of this species in nearshore habitats dominated by sediment, it is likely to be ecologically important. However much of the biology and ecology of the species, even its diet, remain unknown. This together with its unusual mode of reproductive behaviour involving pseudocopulation, which is only known from two other species of asteroids, underscore the need for more research on Archaster angulatus.

A new species of Sphaerodoridae (Annelida: Polychaeta), Sphaerodoropsis solis sp. nov., is described from the Challenger Plateau in the Tasman Sea, south-west Pacific. It is the third species of the genus with ventral macrotubercles and is further characterized by the lack of dorsal papillae and the specific arrangement pattern of ventral papillae. A character indicating sexual dimorphism, that has been observed in three morphologically similar species, S. arctowskyensis Hartmann-Schröder & Rosenfeldt, 1988, S. bisphaeroserialis (Hartmann-Schröder, 1974c), and S. garciaalvarezi Moreira, Cacabelos & Troncoso, 2004, is confirmed for S. solis sp. nov. Besides S. solis sp. nov., S. arctowskyensis and S. parva (Ehlers, 1913) are newly recorded from the Challenger Plateau and the East Campbell Plateau in the south-west Pacific. An updated key for the genus Sphaerodoropsis is provided.

The ultrastructure of spermatogenesis, the euspermatozoa and paraspermatozoa, is investigated in Trophon geversianus. Spermatogenesis follows the general developmental pattern of caenogastropods. Paraspermatid development is characterized by elongation of the cell, concurrent with the appearance of a cytoplasmic elongation at the apex of the cell and the breakdown of the nucleus into small round fragments (caryomerites). Euspermatozoa consist of: a tall, conical acrosomal vesicle (with a invagination); a rod-shaped, highly electron-dense nucleus with an internal axoneme; an elongate midpiece consisting of the axoneme sheathed by helical mitochondrial elements; an elongate glycogen piece; and a short free-tail region. Paraspermatozoa of T. geversianus are vermiform. They contain approximately 12–16 axonemes arranged peripherally, numerous oblong dense vesicles, numerous less dense (round) vesicles, and scattered mitochondria. Most of the euspermatozoal features of T. geversianus are also observed in many neogastropods. However, the presence of the axoneme continuously located inside of the nucleus has not been reported before, and may prove to be a diagnostic feature of the Muricidae.

The feeding mechanism of the nudibranch Calma glaucoides (Alder & Hancock) has been described by Evans (1922) and that of the crustacean Nebaliopsis typica (Sars) by Cannon (1931) and myself (1943). Calma is seasonally relatively abundant in the coastal waters of parts of Europe where it is found attached to the eggs of certain fishes. It is known to feed exclusively on these eggs and young embryos. Nebaliopsis is a deep pelagic form from the Antarctic Ocean. It has been obtained only rarely and cannot be observed alive and in its natural environment. Two specimens were available for examination. Thus complete certainty about the diet is impossible. The external features and mouth parts were described by Cannon and the structure of these suggested that Nebaliopsis, like other known Nebaliacea, might be a filter feeder. Examination of the morphology of the gut and its contents indicates that this is very improbable. There is no mechanism for the sorting out of particles of different sizes such as is found in other filter feeders. The food passes into a blind sac and there is no apparent means by which the large quantities of indigestible material taken in when particles are filtered from the water indiscriminately might be evacuated. In addition to this negative evidence the food mass found in the large storage chamber of one specimen was completely homogeneous and structureless, its appearance in section suggesting coagulated yolk. It has therefore been suggested that Nebaliopsis feeds on fish eggs found floating in the deeper water layers.

A male of the new species Stygiopontius senckenbergi belonging to the family Dirivultidae Humes & Dojiri, 1980 (Copepoda: Siphonostomatoida) and endemic to deep-sea hydrothermal vents, is described from a raised fault block structure south of Edison seamount of the New Ireland Fore-Arc system (Papua New Guinea). The copepods were collected in by box-corer during cruise SO-133 of the RV ‘Sonne’ at a depth of 1610–1625 m, 3°19′S 152°35′E. The new species belongs to a group of eight species that are separate from 21 congeners on the basis of setation of legs 1 and 4: the coxa of leg 1 has an inner seta (absent on the others) and the third exopodal segment of leg 4 has three outer spines (instead of two spines). The new species shares with S. pectinatus Humes, 1987 a pectinate maxilliped but differs from it in lacking two pectinate, terminal claw-like setae on the endopod of the antenna.

1. Photo-electric cells of the rectifier type are useful for approximate measurements of light intensity, in air or under water, using a lowresistance galvanometer, the current through which may be reduced by a special shunt keeping the circuit resistance constant.

2. Such an arrangement has proved serviceable for shore work, a light gun-metal photometer, housing a cuprous oxide cell, having been carried about by a diver.

3. These rectifier cells can also be used at sea, but instead of the current, the E.M.F. is determined by means of the potentiometer outfit as used at sea in previous years.

Krapp-Schickel (1975) described three closely related species of Leucothoe Leach, which together make up a Leucothoe lilljeborgi species complex (L. lilljeborgi Boeck, L. incisa Robertson, L. occulta Krapp-Schickel) in European waters. Of these, the two species L. lilljeborgi and L. incisa have caused considerable problems to taxonomists. As pointed out by Lincoln (1979), ‘There has been a lot of confusion over the identification of lilljeborgi and incisa and it would be advisable to treat earlier records with caution.’ Despite Lincoln's (1979) work, however, the problem persists, several workers (P. G. Moore & J. M. C. Holmes, personal communications) having noted forms apparently intermediate between these two species.

In order to clarify the situation, we have examined material from localities in Ireland and Britain. It is clear that the existence of apparent ‘intermediates’ is due to unfortunate choice of key characters by Lincoln, one of which requires phase contrast microscopy for correct determination. In his key to species of Leucothoe (1979, p. 172) he separates the two species by the anterodistal margin of coxa 4 being either angular (lilljeborgi) or rounded (incisa) and by the inner margin of the gnathopod 1 carpal process being either toothed (incisa) or smooth (lilljeborgi) (although in the description of L. lilljeborgi (p. 176) this process is described as weakly crenulate). Thus specimens with toothed gnathopod 1 carpal process and angular coxa 4 anterodistal margin, appear to be intermediate. It is apparent from our studies, that both L. lilljeborgi and L. incisa have a toothed gnathopod 1 carpal process, but that the structure of the teeth is quite different as revealed by phase contrast microscopy.

The effects of nutrient additions and zooplankton excretion products upon carbon fixation rates in the phytoplankton present at Station L 4 in the English Channel during the summer and autumn of 1979 have been studied. Nitrate, ammonium, urea, phosphate, glucose-6-phosphate and the excretion products when added individually all caused photosynthesis to be stimulated, and the result of the simultaneous addition of nitrate and phosphate indicated that their effects were additive. Germanic acid, which inhibits photosynthesis mainly in diatoms, removed the stimulatory effect of the nitrogen supplements, indicating that they were utilized mostly by the diatoms; the higher fixation rates caused by the phosphate enrichments were, however, decreased by the same proportion as the unenriched controls when germanic acid was present, suggesting that the whole of the phytoplankton population was phosphorus-limited. This was supported by the finding that glucose-6-phosphate stimulated carbon fixation in all of the phytoplankton.

The excretion products, even at concentrations likely to be produced in the sea, stimulated carbon fixation, and it has been calculated that zooplankton-regenerated nitrogen and phosphorus compounds could supply the amounts needed to maintain primary production during the summer period.

Nutrient additions and zooplankton excretion products had little effect upon carbon fixation in the autumn samples, presumably because the higher nutrient levels then present in the water exceeded the requirements of the phytoplankton.

It has been concluded that the predominance of the sub-10 μ microflagellates in the summertime is probably due to their ability to utilize more efficiently than the other types of phytoplankton the low levels of nutrients which become available due to regeneration.

Many pinnipeds travel long distances between breeding and feeding grounds in some cases showing remarkable homing abilities (James & Dykes, 1978). Very little is known about the methods they use to plot their course but if they were aware of their rate of movement, this ability could conceivably assist them. The following procedure which was undertaken with a captive male harbour seal (Phoca vitulina Linnaeus) demonstrated that the animal was able to determine his swimming speed.

The seal was first trained to swim at any speed through ten hoops 48 cm in diameter submerged at equal intervals around the periphery of an 8 m oval tank filled with sea water to a depth of 1.2 m. Each trial consisted of one circuit of the tank, and always began at the same hoop. A screen preventing the seal from going through this start hoop was removed to indicate the onset of each trial. The seal was then trained to swim the 17 m course maintaining a speed of 6 km/h. The experimenter observed from a bridge suspended over the tank, and measured the animal's speed by listening to a series of tones. These tones were audible only to the experimenter and were timed such that if the seal were swimming at 6 km/h, he would reach each hoop at the same moment the experimenter heard the tone. A buzzer was sounded whenever the animal swam at less than the required speed, and a whistle was blown if he were moving too quickly.

This study aimed to assess the population biology and reproduction of the fiddler crab Uca chlorophthalmus at its limit of geographical distribution, Saco da Inhaca mangrove, southern Mozambique. Monthly samples were conducted at low tide periods between January and December 2003. The size distributions showed uni- and bimodal patterns, with males reaching larger sizes than ovigerous and non-ovigerous females. Females were slightly more abundant than males, but the overall sex ratio (1:1.01) did not differ significantly from 1:1. Uca chlorophthalmus displays continuous reproductive patterns with peaks of breeding in March and December. Moreover, linear correlations revealed that breeding in this crab is controlled by both temperature and rainfall. Similarly, juvenile recruitment was constant, but was more intense in winter (May–July). Brood size was positively associated with female size. Timing of the observed breeding pattern in the study area may enhance reproductive output and recruitment of the species.

The crab whose habits I now describe has not previously been recorded as an inhabitant of British seas. I found two specimens, both male, imbedded in a patch of coarse shell sand on the south side of Drake's Island at low water, spring tides: one on August 11th, 1896, and the other on the following day.

Anadara demiri (Piani, 1981) is an alien species in the Mediterranean Sea extending its range from Turkey westernly to the Adriatic Sea, where it is locally abundant. The species was first identified as Arca amygdalum Philippi, 1847 in the 1970s. The locus typicus of A. amygdalum is China. This first identification has never been discussed and the species has been thought to be of Indo-Pacific origin to date. However, in the Indo-Pacific province no Anadara shows any similarity with A. demiri. Morphological and molecular data suggest A. demiri is closely related to Anadara transversa (Say, 1822), a common species of the eastern coasts of North America. Anadara demiri is hence considered a junior synonym of A. transversa and the origin of this immigration has to be searched in the southern range of this species, maybe the Gulf of Mexico coasts of Florida.

Temporal variations over short and medium time scales play an important role in fish assemblage dynamics, but have been poorly investigated in tropical estuaries. This study evaluates the hypothesis that fishes co-occurring on a tidal mudflat have different patterns of temporal segregation at short- and medium-term scales that optimize resource use and habitat partitioning. A total of 6222 individuals and 66 fish species were caught during different hours covering the entire 24 h cycle, tidal regimes and the wet and dry seasons. Biomass and species richness, and to a lesser extent CPUE and evenness, showed statistically significant interactions across short- and medium-term scales. Biomass was higher during the dry season and its oscillation along tidal cycles revealed distinct patterns over the photoperiod in each season. A similar complex pattern was also observed for species richness, which showed distinct temporal patterns between high and low tides over the photoperiod in each season. Overall, shorter-term variations on fish assemblage attributes were correlated mainly with photoperiod and, to a lesser extent, tidal regime. Medium-term variations in fish abundance and species richness, in contrast, could result from seasonality in recruitment patterns and higher availability of allochthonous food resources during the wet period.

As many Arctic fish species are intermediate hosts of anisakids, they are present in the diet of the ringed seal, Pusa hispida, and the bearded seal, Erignathus barbatus. Parasitic nematodes from the stomachs of 66 seals caught in the Nunavut region (Canada) from two communities (Arviat and Sanikiluaq) from October 2007 to January 2008 have been examined in order to identify the epidemiological risk for Inuit communities who consume traditional food. In Arviat 2428 anisakids were observed in 37 seals, while in Sanikiluaq 316 Anisakidae were isolated from 29 seals. The worms were treated with a host tissue, washed in deionized water and stored until analysis in 70% ethanol. The parasites were divided into three parts. The anterior and posterior parts were stored in 70% ethanol containing 5% glycerol and were examined using a light microscope by evaporation of the ethanol/glycerin mixture. The central parts were prepared for molecular identification by fixing in 70% ethanol. Using the polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) method, the following members of the family Anisakidae were identified: Contracaecum osculatum A and C and Pseudoterranova bulbosa. In the studied material, more adult worms were noted than larval stages. The most numerous nematodes were P. bulbosa, and mixed infection was observed. The mean prevalence of anisakids infection was 43.2% in the Arviat and 37.9% in the Sanikiluaq communities.