Boring sponges excavate calcium carbonate substrates by chemical and mechanical methods. The chemical phase of excavation is accomplished at the cellular level by a localized secretion (possibly an acid or an enzyme) at the cell-substrate interface (Cotte, 1902; Nassonow, 1883, 1924; Warburton, 1958; Rützler & Rieger, 1973; Cobb, 1969, 1971, 1975). Chemical etching detaches a chip of calcium carbonate (about 40–60 µm diameter) which is then mechanically removed from the substrate through the sponge tissue and out through the excurrent canal system. Only 2–3% of the substrate is dissolved by the etching cells (Rützler & Rieger, 1973), while the rest is removed as characteristically shaped chips. Recent studies of the mechanism of sponge boring have denned (using light microscopy) the spatial relationships sponge cells establish with the substrate (Cobb, 1971), identified (using transmission electron microscopy) the cell type (etching cell) responsible for chemical etching (Rützler & Rieger, 1973), and described (using scanning electron microscopy) the architectural nature of substrate destruction by sponges (Cobb, 1969, 1971, 1975; Rützler & Rieger, 1973; Pomponi, 1976, 1977, Ph.D. Thesis, University of Miami).

Continuous monitoring by scientists and volunteers of the Biological Working Group of the Dutch SubAqua Union and the ‘Anemoon’ Foundation over the past four years, yielded a surprising six new records of sponges for Dutch coastal waters. Oscarella lobularis, Celtodoryx girardae, Suberites virgultosus, Haliclona (Haliclona) simulans, Halisarca aff. dujardini, and a species identified as Leucosolenia somesii were unknown from Dutch coastal waters before 2000. The latter is a giant calcareous sponge, seemingly belonging to the common Leucosolenia variabilis, but here assumed to be an invader as well, as it has spicular characters well outside the variation found in the majority of Dutch L. variabilis specimens. It is likely a member of a ‘forgotten’ species, L. somesii. Habit photographs, SEM images of the spicules, and for O. lobularis and H. aff. dujardini, photographs of histological sections are provided to substantiate these new records. With the exception of C. girardae, most of the species resemble previously described widespread north-east Atlantic species, occurring in the area to the south and west of the Netherlands, so it is assumed pending future genetic research that at least several of the invaders comprise range extensions related to rising winter temperatures. Possibly, recent shellfish imports may be an additional causal agent. We also report the occurrence of unprecedented spicular deviations observed in three sponge species commonly occurring in Dutch waters, Halichondria (Halichondria) panicea, Hymeniacidon perlevis and Haliclona (Soestella) xena, which grew in small inland water bodies. Possibly, the limited space in these inland waters with possible stress factors for sponges such as reduced water exchange, and deviating chemistry, have caused the sponges to form stunted growth in spicules varying from rhabds with rounded endings to silica spheroids. We provide an updated list of sponges found in Dutch waters and a list of suspected or proven invaders of Dutch waters.

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.

Solen dactylus is a razor clam distributed throughout the coast of the northern Persian Gulf. Study on biology of razor clams in this area is important for an essential management where these clams are overfished without any control. This study provides the first estimate of growth rate and an interpretation of the reproductive cycle of S. dactylus on the coast of the Persian Gulf (Bandar Abbas). In this study, 945 razor clams were collected from April 2007 to March 2008 along two transects of Golshahr coast in Bandar Abbas. Von Bertalanffy growth parameters for transects 1 and 2 ranged from 101–108 mm for asymptotic length (L∞), 0.27–0.28 year−1 for growth constant (k), and −0.99–0.94 for age at length zero (t0), respectively. Gonads were stained with haematoxylin and eosin and gametogenic stages were based on seven stages: (Stage 0) sexual rest; (Stage I) proliferation of gonad and start of gametogenesis; (Stage II) advanced gametogenesis; (Stage IIIA) ripeness; (Stage IIIB) start of spawning; (Stage IIIC) restoration; and (Stage IV) emission. The result showed that S. dactylus is a gonochoric clam and both males and females demonstrated synchronism in gonadal development. The gametogenic cycle began in late August and ended in late February. After several minor spawnings, plus a major one in January, the razor clams entered to the sexual rest stage in March.

Adult female mysids do not moult while carrying young in the marsupium. Successive larval stages can be recognized in the marsupium and this allows examination of the body length of the parents at different points in the inter-moult period. The body length of 13 species of mysids was found to have increased during the course of the inter-moult period; the average increase in length of the body is 7%. An examination of the ratio of abdomen length to carapace length at different points in the inter-moult period shows that this growth in length is accommodated in the abdomen.

Four Benthoctopus species are recognized in the waters of the Falkland Islands: B. eureka, B. magellanicus, Benthoctopus sp. A, and Benthoctopus sp. B. Initial oocyte reserve of B. eureka is 250–535 eggs, the actual fecundity is 75–234 eggs while the rest of the oocytes degenerate at maturation. Larger females have higher fecundity. Gonad maturation of Benthoctopus sp. A and Benthoctopus sp. B follows a similar pattern. The Benthoctopus egg masses contained 170–190 eggs. The hatchlings possess arms that are much longer than mantle length with a large number of suckers, and do not have discernible chromatophores.

Several species of bivalves belonging to families which are typically associated with reducing conditions, like those observed at methane seep sites, have been obtained in recent explorations of the Caribbean Sea margin off the coast of Colombia. The material has been collected at depths of around 500 m west of the Magdalena and Sinú deltas, located in the Sinú–San Jacinto fold belt. These bivalves correspond to the families Vesicomyidae (Calyptogena ponderosa, Vesicomya caribbea and Ectenagena modioliforma), Lucinidae (Graecina colombiensis and three unidentified species of Lucinoma), Solemyidae (Acharax caribbaea) and Thyasiridae (Conchocele bisecta). In addition, for the first time off Colombia empty tubes of vestimentiferan polychaetes, belonging to the family Siboglinidae, were collected. At some of these sites the presence of authigenic carbonates has been observed together with the biological material. Although the obligate seep fauna generally contains relatively few and endemic species, a large suite of accompanying heterotrophic species (here we report only the molluscs) has been found at the seep sites. The occurrence of carbonates, the geological characteristics of the area and the new biological evidence confirms the presence of methane seep ecosystems in the Caribbean Sea off Colombia.

Community structure and vertical distribution of oncaeid copepods were investigated at an offshore site in Tosa Bay, southern Japan. Samples were collected with a 0.063 mm closing type net from eight discrete layers between the surface and 500 m depth in August and November 2005. A total of 45 species and three form variants belonging to the genera Triconia, Oncaea, Spinoncaea, Conaea and Epicalymma were identified. The greatest number of species was consistently found in the lower epipelagic zone, at 50–100 m. The vertical distribution patterns of oncaeid copepods were similar between August and November, with the highest abundances in the upper epipelagic zone above the thermocline. The oncaeid maxima corresponded with the depth where appendicularians occurred in high numbers. Dominant species in the water column (0–500 m) were O. venusta small form, O. media, O. scottodicarloi, O. waldemari, O. zernovi, O. tregoubovi, S. ivlevi, S. tenuis and T. conifera. The vertical succession of species composition was almost the same between August and November, although several species showed a downward shift of their depth-range to some extent in November. The oncaeid copepod community could be differentiated into three distinct groups according to the depth layers, each corresponding to different hydrographic conditions in the water column.

The general biology of Leptomysis gracilis (G. O. Sars) and L. lingvura (G. O. Sars) is described. There are three main generations of L. gracilis, spring, summer and autumn ones, produced during the year, although breeding is continuous in the population between the most productive periods. Females carry as many as sixty young in the spring and summer but usually less than twenty in the winter months.

The relationship between shell growth rate and striae deposition was investigated in a field study in which groups of juvenile scallops, Pecten maximus, (Pectinidae: Bivalvia) were deployed for monthly periods over a year in the Menai Strait (North Wales). The number of striae deposited per day, inter-striae width (the increment of shell deposited between successive striae) and striae abundance (the number of striae deposited per mm of shell height) all correlated well with measured shell growth rates. During the winter months, when seawater temperatures were minimal (6°C), inter-striae width declined, whilst striae abundance increased, whereas during the summer when seawater temperatures were maximal (18°C), shell growth was rapid with maximum inter-striae width, resulting in a seasonal pattern of narrowly grouped, then widely spaced striae. This seasonal pattern in inter-striae width variation provides an accurate and reliable method for estimating the number of growth cycles and hence the age of P. maximus.

Experimental removals of the dominant canopy-forming kelp Ecklonia radiata were conducted at two sites on rocky walls in New Zealand and monitored for approximately 1.5 years. We hypothesized that the removal of the E. radiata canopy would affect the structure of subcanopy assemblages, such that there would be a reduction in sponge species richness and abundance. Furthermore, we investigated the biological and physical (predictor) variables that best explained variability in sponge assemblages after canopy removal. Canopy removal led to a community dominated by turf algae, which corresponded with a decrease in sponge abundance and richness. Our results suggest that the Ecklonia canopy may positively influence the presence of sponge species such as Crella incrustans; we propose that the canopy may allow its coexistence with turf algae underneath the canopy by altering the light regime and other environmental factors, which may be detrimental for some species. Our results highlight how any loss of canopy-forming species might have negative effects on sponge assemblages, which could affect the energy flow and the overall biodiversity found in these habitats.

A phylogenetic analysis of the polychaete clade Terebelliformia (Terebellida) was undertaken in order to test monophyly of families and subfamilies and to determine their affinities. Parsimony analyses of 41 terebelliform species with outgroup Owenia fusiformis and 46 morphological characters yielded 106–144 most parsimonious trees with length 250, consistency index=0·432, retention index=0·659 and rescaled consistency index=0·285. Monophyly was indicated for Alvinellidae, Ampharetidae, Terebellidae and Trichobranchidae and the terebellid subfamily Polycirrinae. Monophyly of Terebellidae is supported by the presence of a ridge-like tentacular membrane. Monophyly of Polycirrinae is supported by the loss of branchiae, trilobed upper lip, pinnate secondary notochaetae and ventro-lateral pads. Recognition of Polycirrinae renders taxa in the other terebellid subfamilies—Terebellinae and Thelepodinae—paraphyletic. Our results do not support previous classifications that placed Trichobranchidae as a subfamily of Terebellidae; rather it should be considered equal in rank with Alvinellidae, Ampharetidae, Terebellidae and Pectinariidae. The following relationships were obtained: (Trichobranchidae ((Alvinellidae, Ampharetidae) (Pectinariidae, Terebellidae))). This is the first time a Pectinariidae–Terebellidae sister group relationship has been found; it is supported by the synapomorphic presence of ventral glandular shields.

The secretion of mucus has been most intensively studied in goblet cells and mucous salivary gland cells from mammals, particularly laboratory rodents. It was therefore thought desirable to characterize mucous cells from the gut of Ciona intestinalis (L.), in which mucus has an important role in food capture, the formation of a food chain, the protection of the gut lining from physical and chemical abrasion and the formation of faeces. The alimentary canal of Ciona is composed of five regions: (I) a perforated pharynx, (II) a short tapering oesophagus, (III) an ovoid ridged stomach, (IV) an intestine and (V) a rectum. Previous authors (Roule, 1884; Yonge, 1925; Van Weel, 1940; Millar, 1953; Fouque, 1954) have described the preponderance of mucus-secreting cells which occur in the oesophagus, intestine and rectum. It is these three regions that have now been studied in more detail, with the use of histochemical and electron-microscopic techniques.

Actinia equina var. mesembryanthemum, the beadlet anemone (Stephenson, 1935), is a very common and widely distributed littoral anthozoan, whose sexual reproduction shows several interesting characteristics. Adult sea anemones of both sexes brood planulae and more advanced developmental stages within the gastrovascular cavity, although earlier embryonic stages are rarely found brooded in this way. Chia & Rostron (1970) suggest that embryos are expelled from the parent female anemone at an early stage and pass through a free-living phase before re-entering anemones of either sex for brooding. However, recent work (Cain, 1974) suggests that juvenile anemones are genetically related to the adult anemones in which they are brooded, and also the distribution of genetic material during sexual reproduction appears to be abnormal (Carter & Thorp, 1979). In an attempt to achieve a better understanding of the unusual sexual reproduction of this species, an ultrastructural investigation of gametogenesis was undertaken. This paper describes the fine structure of the spermatozoon within the testis.

Previous records of Blackfordia virginica, from river estuaries and marineconnected lagoonal systems, show the species to be euryhaline and eurythermal. The collection of the medusa in the estuary of the River Mira provides not only a second record for the eastern North Atlantic but also further evidence of the medusa's requirement for such conditions. It is known to tolerate salinities of 3–35‰ (distribution). Measurements of salinity in the Mira Estuary in April and November 1984, when the medusae were collected, were 15 and 32.5‰ respectively (J. Paula, personal communication).

The abundance and latitudinal and vertical (0-100 m) distribution of planktonic Foraminifera was investigated on the basis of 38 samples collected in November 1994 in the southwestern Atlantic Ocean (34-60°S, along 51-56°W). Mean foraminiferal densities were 1.5 ind. l−1 (range: 0.15.9 ind. l−1), with highest concentrations in subsurface waters (20-50 m). Couplings between the distribution of chlorophyll a and foraminiferal abundances were very loose. Distribution patterns of the 15 species recorded allowed 6 distinct areas to be defined along the transect surveyed. From north to south these are: Subtropical (dominated by Globigerinoides ruber and G. trilobus), Cold intrusion (Globigerinita uvula), Transitional-Subtropical and Transitional (Globigerina bulloides, Globigerina quinqueloba), Subantarctic (G. quinqueloba), and Antarctic (Neogloboquadrina pachyderma, left coiling). Close comparisons with the yields of a similar data set collected in November 1993 show very good agreement. Foraminiferal thermic régimes were also similar in 1993 and in 1994, but for some species significant differences with previous data were detected. While the southwards extensions of the ranges of warm water species are fairly well circumscribed by the Brazil current-influenced waters, several foraminifers widely used as indicators and palaeoindicators of cool waters (in particular Globigerina bulloides, Globigerina quinqueloba and Globigerinita uvula) were recorded in very significant numbers at temperatures as high as 20-24°C. The implication of these findings for hydrological, ecological, and palaeoecological interpretations is discussed.

In Carcinus maenas haemolymph, zinc is almost entirely bound to the respiratory pigment, which is the copper-protein haemocyanin (Hc). Zinc ions are loosely bound, as indicated by the low value of the association constant (k = 1.7 × 105 M-1 at pH = 8.0). The number of binding sites N is equal to 4 per minimal functional subunit (75000 Dalton). No co-operativity has been found between the different metal sites. Data reported in this paper support the hypothesis that haemocyanin can act as metal carrier in the haemolymph of C. maenas.

The pattern of paragnaths in Nereis diversicolor differs markedly between 17 populations from eastern and south-west England. There is a substantial heritable component to these differences, and there is no evidence that sediment type during development has any influence on them. Comparisons with previous studies reveal no consistent relationships of paragnath pattern with either sediment type or salinity. Evidence from scanning electron micrographs and correlations between different groups indicates that the anterior and posterior bands of paragnaths have rather different roles in feeding and suggest that the inter-population differences may be adaptations to different diets. The orientation of the jaws confirms that they play an important role only during predation and the handling of large particles, but not during the more usual browsing of the sediment surface.

When beginning research into the cultivation of marine shrimps and prawns, it is usually the most worth while of the local species that is chosen for study. From this it follows that in tropical regions the penaeids tend to be favoured, especially following the pioneering work of Hudinaga (1942) with Penaeus japonicus (Bate), whereas in the temperate regions of Europe and Canada it is the carideans that are receiving most attention, particularly the palaemonids. One notable exception is the advanced study of the Asiatic Giant Prawn Macrobrachium rosenbergii (de Man), which was initiated in Malaysia and subsequently taken up in Hawaii and Great Britain (Ling, 1962).

Doubtless each chosen species has its merits, but overriding importance must be attached to ease of mating, for this imposes an immediate limit on the reliability of the whole process and holds the key to the selective breeding of improved strains. Indeed, it has been pointed out that reliance on wild-spawned animals is a major obstacle to commercial development (Tabb et al., 1969) and such vagaries in the supply of young shrimps has already limited some research (Cook & Murphy, 1969).

Under captive conditions it has proved a great deal easier to mate carideans than penaeids, but the continuing part played by caridean females in incubating the eggs over a contracted period is a disadvantage. Relieving the ovigerous females of this task would allow the eggs to be incubated at greatly increased densities in conditions no longer dictated by the females. Further, it would lead to the more effective use of the female during the period she would otherwise be incubating.

The effects of surface roughness and microsolubility on fouling levels are examined using glass and acrylic samples. It is found that both of these, often overlooked, physical characteristics have a noticeable effect on the rate of fouling. The microsolubility of acrylic results in lower fouling than found on glass despite the higher hydrophobicity of acrylic and the resultant increase in initial attraction for fouling organisms. Fouling levels were found to increase with increasing surface roughness and therefore studies on the fouling susceptibility of different materials should report the roughness values of the samples examined.