Antropora commandorica sp. nov. is described from the Commander Islands (Bering Sea). This species is unique within the bryozoan genus Antropora in its sub-Arctic distribution; all other known species are distributed in tropical and sub-tropical waters. This species is also most often found as an epibiont of gastropod shells, some with an associated pagurid crab. Whilst this is not unknown in other species of the genus Antropora, A. commandorica appears to use these substrata almost exclusively.

The capture of a single specimen of Kyphosus sectator (Osteichthyes: Kyphosidae) is reported from the island of Mallorca. It represents the first record of this species in the Balearic Sea (western Mediterranean). Some aspects relative to its distribution and ecology are also given.

On 16 September 1996, a single specimen of Bermuda sea chub, Kyphosus sectator (Linnaeus, 1766) (Osteichthyes: Kyphosidae), was caught with a surrounding purse seine by an artisanal fishing vessel involved in the dolphin-fish (Coryphaena hippurus Linnaeus, 1758) fishery carried out in Mallorcan waters (western Mediterranean) (Massutí & Morales-Nin, 1995). The set was made around drifting wooden flotsam, in waters approximately 600 m deep, and 9 nautical miles from the eastern coast of Mallorca (Figure 1). The surface temperature was approximately 23°C throughout the thermocline, down to a depth of 40 m (S. Devdero, unpublished data).

In the programme of work for the summer of 1906, it was decided by the Director that a series of cruises should be carried out by the Association's steamer Oithona to investigate the fauna of the deeper waters of the English Channel. The bearing S.W. ½ S., Magnetic, = S. 23° W., True,* from the Eddystone Lighthouse was chosen as a baseline, and the work was to be carried out with special reference to points at 10-mile intervals along this bearing. The fauna was to be investigated as fully as possible, and bottom-deposits, particularly stones, were at the same time to be carefully recorded and collected. In all, eight cruises were made, the work being extended nearly as fer as the 50-mile point.

A total of 104 Semirossia patagonica were collected all over the Patagonian shelf between the depths of 47 and 295 m. Mature female size varied from 10 to 35 mm ML, mature male size was 16–32 mm. Potential fecundity ranged between 527–766 eggs in pre-spawning females, ripe egg size was 3.4–5.0 mm. The oviduct capacity probably was no more than 30 eggs. The maximum number of spermatophores in males was 229. Males transfer 2–19 spermatophores to females during copulation. The ovulation pattern is asynchronous, individual spawning is continuous. Reproduction occurs all year round. Semirossia patagonica is a south-west Atlantic ecological sibling of north-east Atlantic bobtail squids Sepiola spp. and Sepietta spp.

Morphological variations of Tunisian Lithognathus mormyrus populations were investigated using 41 morphometric measurements (27 truss elements and 14 traditional measurements) and eight meristic characters collected from ten marine and lagoon samples. Statistical analyses (e.g. discriminant function analysis (DFA)) performed separately to truss and traditional data revealed a significant degree of morphological dissimilarity of lagoon samples (Bizerta, Ghar El Melh and El Biban lagoons). For these three lagoon environments the overall assignment of individuals into their original sample (percentage classification success) by DFA was 94% for truss elements and 98% for traditional measurements. This morphological discrimination among lagoon samples, revealed with traditional measurements, seems to be associated only with the anterior part of the body (especially with the pre-orbit and snout length). However, for truss analyses, it was explained by both anterior and posterior parts (peduncle region). Statistical analyses for only marine samples showed partial overlapping with significant morphometric variation of the Chebba and Gabès samples mainly related to the anterior part of the body, for the first sample, but also to the posterior region, for the second one. These morphometric variations are often due to environmental conditions and mainly to the exploitation of different ecological niches that are particularly limited by the availability, type and size of prey. Thus, truss and traditional approaches are complementary and provide more accurate explanations of such a morphological discrimination. Meristic character analyses showed homogeneity of striped seabream samples, except for the Ghar El Melh lagoon sample which quietly differed from the others. This distinction was mainly explained by the number of soft anal rays.

Pterobranchs are small marine filter feeders in the phylum Hemichordata. Their phylogenetic position and anatomical structure has resulted in pterobranchs featuring in many scenarios concerning the evolution of chordates. Despite this interest, the basic reproductive biology of pterobranchs is still poorly known. To address this issue, the reproductive season of Rhabdopleura compacta was investigated by collecting specimens in 2004–2007 from a population growing on disarticulated bivalve shells off the south coast of Devon, UK. I analysed reproductive status by categorizing shells according to the condition of the colonies growing on them. The frequency of shells having mature females was almost constant from spring to autumn among shells with active colonies. However, it was apparent that: (a) shells having mature females were more likely to be incubating embryos or larvae in June and July than other months; and (b) the production of embryos was high in June, and then decreased by July. Thus, despite the previous speculation that the species is capable of successful sexual reproduction throughout the year, the present study shows seasonality in reproduction of R. compacta, with at least a peak season during summer.

Polyplacophoran molluscs (chitons) are phylogenetically ancient and morphologically constrained, yet multiple living species are often found co-occurring within widely overlapping ecological niches. This study used two sets of experiments to compare interspecific variation among co-occurring species in the North Atlantic (Ireland) and separately in the North Pacific (British Columbia, Canada) chiton faunas. A complementary review of historical literature on polyplacophoran physiology provides an overview of the high level of metabolic variability in this group of ‘living fossils’. Species examined in de novo experiments showed significant variation in oxygen consumption both under air-saturated water conditions (normoxia), and in response to decreasing oxygen availability (hypoxia). Some species demonstrate an ability to maintain constant oxygen uptake rates despite hypoxia (oxyregulators), while others oxyconform, with uptake rate dependent on ambient oxygen tension. These organisms are often amalgamated in studies of benthic communities, yet show obvious physiological difference that may impact their response or tolerance to environmental change.

Phorbas is a common genus with cosmopolitan distribution. A new species of sponge, Phorbas megasigma sp. nov. (Porifera: Poecilosclerida: Hymedesmiidae) is described from material collected during the third Spanish expedition on the study of the Antarctic benthos, ‘Bentart 03’. Phorbas megasigma is closely related to P. nexus but differs in the possession of arcuate chelae and very big sigmata as microscleres.

The gill-parasitic polyopisthocotylean monogenean, Hexabothrium appendiculatum and the skin-parasitic microbothriid monogenean, Leptocotyle minor share the same host, the common dogfish Scyliorhinus canicula. The larvae of these parasites are stimulated to hatch by host skin secretions and the behaviour patterns of these larvae have been found to be remarkably similar. The freshly hatched oncomiracidia of both parasites rarely remain swimming (in the presence of hatching stimulants) for more than 30 min; there is a strong tendency for the larvae to attach themselves temporarily or permanently by either the anterior or posterior ends to glass or Perspex surfaces. Other important features of the behaviour of these oncomiracidia are their erratic mode of swimming and their apparent lack of response to environmental stimuli such as light, shadows, mechanical disturbance or water currents. There is some evidence that the swimming oncomiracidia of both parasites may be negatively geotactic after hatching but this response is weak and of short duration. The erratic swimming pattern, the lack of response to environmental factors and the readiness to attach to available surfaces seem likely to be particularly favourable for the establishment of larvae on the surfaces of dogfishes foraging at the sea bottom and providing the hatching stimulus for drifting eggs.

A new thecideide brachiopod species, Thecidellina meyeri, is described from the southern Lesser Antilles (Aruba, Bonaire, Curaçao), Caribbean Sea, with unique morphological characters which clearly separate it from all other described species of Thecidellina in the region. A virtually complete series of ontogenetic stages is recorded, providing insight into the plasticity of shell development during growth in thecideide brachiopods and offering a well-defined standard for comparison with fossil material. Study of the soft tissue suggests that T. meyeri is dioecious, which contradicts the idea of Thecidellina to be hermaphroditic. The limited distribution and the unexpectedly high species diversity within the genus Thecidellina in the Caribbean region support the idea of allopatric speciation due to limited dispersal ability.

Epixanthus dentatus (Crustacea: Brachyura: Eriphiidae) is a predator crab, commonly inhabiting East African mangroves, whose nocturnal and elusive behaviour usually prevents analysis of its natural diet and prey selection. The present study was carried out on a population inhabiting a peculiar mangrove habitat in which E. dentatus produces heaps of non-ingested parts of its prey. Fifty-nine of these accumulations of prey remains were examined and 17 species were identified as part of the diet of E. dentatus. Relative prey consumption was then analysed with respect to the relative abundance of prey species within the local faunal community. This methodology provided important information about prey selection by E. dentatus; in particular, gastropods were always strongly under-represented, while there was an active selection among the different crab species. Uca species were under-represented, while swimming crabs were also part of the E. dentatus diet, which shows that the latter is able to prey both at low and high tide.

For the first time the meiofauna of the rocky walls of a submarine cave was studied. The cave, known as il Ciolo (Strait of Otranto, south-east Italy) is a closed tunnel about 125 m long, with a maximum depth of 6 m below sea level. The meiofauna was collected from artificial panels and natural rocky walls. This double approach enabled: (1) the description of the community's initial organization (on artificial substrata), and (2), especially for Harpacticoida, its mature composition (on rocky walls), which also helped to establish spatial differences. The collected samples yielded 70 taxa in total. Harpacticoida represented the most important group of organisms in terms of both abundance and identified taxa. The meiofauna assemblage appeared not to be affected by community age, with the exception of the very early stage. The meiofauna of the cave showed assemblage differences from the entrance to the innermost positions, but not as evident as in the case of the macrobenthos. The similarity of community composition at different ages (6, 12 and 24 months) and at different positions along the cave could be the consequence of the specimens’ vagility.

In the family Pyuridae the larval and post-larval stages are known only in Halocynthia pyriformis (Rathke) and Boltenia echinata (L.). Berrill (1948) has pointed out that this is the least specialized family of the Pleurogona and that its larvae are therefore of particular interest.

On 1 August 1950 specimens of Pyura squamulosa (Alder), up to 36 by 30 mm., were collected from boulders at low-water level in the Sound of Kerrera, Argyll. They were taken on the following day to the Marine Station, Millport, and there kept in running sea water until 4 August, when artificial fertilizations were carried out.

A new marine tardigrade of the genus Tanarctus is described from Japan. Tanarctus diplocerus sp. nov. was collected from Shimabara Bay, Kumamoto and Tanabe Bay, Wakayama. It is characterized by simple leg IV appendages, the lack of the internal–external relation in the dorsal and ventral cirri and the lack of the club-shaped secondary clavae. The secondary sexual dimorphism of the primary clavae and probable two-digit juveniles of the new species are reported. The problematic terminology of the so-called ‘internal’ and ‘external’ cirri is also discussed. A taxonomic key for the species of Tanarctus is provided.

The occurrence, meristic, length frequency, condition factor, length–weight relationship and day/night differences in catch are reported for a population of cuskeel Ophidionrochei at Duće-Glava (43°26′N 16°41′E, Croatian coast, eastern middle Adriatic) from April 2000 to March 2001. The highest catches in shallow water occurred in June, with a second peak in September and October, and were always at night, indicating this species as nocturnal predator.

A new species of Gastrophanella, G. cavernicola sp. nov. (Demospongiae: Siphonidiidae), is described from submarine caves in Fernando de Noronha Island (north-east Brazil), Carrie Bow Cay and Columbus Cay, Belize (central Western Atlantic), at depths of 5-30 m. It differs from all other species of the genus by its lobate shape with thin superficial canals and centrotylote tylostrongyles. Gastrophanella cavernicola sp. nov. is the second record of the genus Gastrophanella from both Brazil and the Caribbean. It is the sixth ‘lithistid’ sponge reported from the Brazilian coast, whereas at least 32 other desma-bearing sponges are known from the Caribbean. The genus now includes five valid species, G. implexa Schmidt from the West Indies (type species), G. mammilliformis Burton from South Africa, G. primore Gómez from the Pacific Coast of Mexico, G. stylifera Mothes & Silva from south Brazil, and G. cavernicola sp. nov. from north-east Brazil and Belize. Aciculites oxytylota Lévi & Lévi from New Caledonia is transferred to Siphonidium Schmidt. The family Siphonidiidae Lendenfeld, which is probably related to order Hadromerida, is redefined to contain only Siphonidium and Gastrophanella, both with fused rhizoclone desmas associated to microspined exotyles.

Mechanized dredging impact on discards was assessed along the northern Alboran Sea (W Mediterranean Sea). Data from 101 dredging operations were analysed for contrasting spatial and seasonal variability of damage, with the use of a three-level damage scale. 4.5% of discarded individuals displayed intermediate damage, whereas 11.3% displayed severe damage. Echinoderms displayed the highest level of damage (~75% of total collected individuals) and Echinocardium cf. mediterraneum was the most susceptible discarded species (85% with severe damage), followed by bivalves (7.3%) and crustaceans (3.3%). The target Chamelea gallina showed a low proportion of damaged individuals, probably due to their thick protective shell, which promotes the survival of discarded undersized target individuals. Spatial differences in damage level on discards were linked to some gear characteristics, to the higher amount of gravels and to longer tow durations, whereas damage was generally higher in cold months and partly related to higher quantities of hard shelled molluscs, in both cases increasing the abrasion and damage to retained organisms. Data suggest that dredges with a lower number of narrower iron teeth and towed for a shorter time could decrease the damage rate in discards of this fishery. A spatial management plan based on the type of grounds would be useful in order to improve efficiency of these fisheries and minimize their impact to soft bottoms with different commercial catches and biological communities.

A new species of pleustid amphipod of the genus Pleusymtes is described from the west coast of Ireland. It was found to be common in association with an Acanthogorgia sp. gorgonian at 725 and 900 m depth on coral habitats in the continental shelf-break areas of the Porcupine Seabight and Porcupine Bank. It is assumed to be a commensal due to its modified pereopod dactyls.

The species range of Calanus sinicus along the Chinese coast extends from the Bohai Sea and the Yellow Sea in the north to the northern part of the South China Sea in the south. The subtropical seas along the southern coast of China mark the southern edge of the range of C. sinicus. In coastal seas off eastern Hong Kong, C. sinicus appears first in December, but densities comparable to those in the Yellow Sea and the East China Sea are reached only in January and February when temperature is <15°C. Density decreases in March as temperature increases. No individuals remain after May when temperature is >25°C. The average prosome length of females collected in February is comparable to that of females from the Yellow Sea, but females collected after mid-March are smaller than the smallest females from the Yellow Sea. Reproduction occurred mainly between January and March. Rapid decline of the population in April and the absence of a summer population suggest that the local population is derived from individuals advected from the north by ocean currents. Eggs produced locally probably did not hatch or develop into adults.

In investigating the parasites of adult thick-lipped grey mullets Chelon labrosus (Risso, 1826) at Plymouth these fishes were found to be infected exclusively with an ancyrocephaline gill monogenean identified as Ligophorus angustus Euzet & Suriano, 1977. When, at a later date, some juvenile C. labrosus were examined ancyrocephalines were again collected; however, quite unexpectedly, these parasites were not juvenile L. angustus but belonged exclusively to a new species of ancyrocephaline subsequently reported as Ergenstrema labrosi Anderson, 1981.

It seemed then that there might be a situation of considerable biological interest in which young fishes were characterized by one host-specific monogenean and older mullets by another. Although a change in the species composition of the total parasite fauna of mullets with age has been reported previously by Reshetnikova (1955) for golden grey mullet Liza aurata of the Black Sea, a change of monogenean species has never previously been recorded.

From an examination of the literature (e.g. Hickling, 1970) on the life history of the British thick-lipped grey mullet it was inferred that the situation described above might be associated with the migratory habits of the fish and in particular the different environments inhabited by young and old mullets; while there may be many factors (e.g. oxygen, temperature, pH, etc.) which differ between the open sea and tidal pools, inhabited by old and young fishes respectively, the most obvious one is that of salinity. Hence, in addition to establishing the identity and frequency of the ancyrocephaline infections with host age, it was decided to make investigations on the salinity tolerances of L. angustus and E. labrosi.