Repopulation by green sea urchins Strongylocentrotus droebachiensis of a steeply sloping rock bottom was monitored at a wave-exposed headland (Chebucto Head) following a disease outbreak that caused mass mortality in September 1999. Density and size of urchins were sampled in four depth strata: at 8–10 m in an urchin grazing aggregation (front) along the lower margin of a kelp bed, at 12 m and 16 m on a bedrock ramp, and at 24 m on a cobble and boulder field where urchins were unaffected by the disease. Shoreward migration of adults along the ramp from the surviving population at 24 m was the primary means of repopulation, which was augmented by recruitment via planktonic larvae. At 16 m, urchin density stabilized (at ∼50 urchins m−2) within six months of the die-off while repopulation at 12 m took more than eight months. A grazing front of large urchins (40–60 mm, test diameter) had formed along the lower edge of a kelp bed by January 2002, which reached densities of up to 284 urchins m−2. Video surveys at Chebucto Head and two adjacent locations of similar bathymetry revealed an extensive urchin population between 25 and 55 m depth, with a mean density on rocky substrata of 73 urchins m−2.

The first occurrence of a giant squid Architeuthis sp. specimen in Portuguese waters is noted and another reference set of biological and biometrical data provided which may in future be used in conjunction with others to further elucidate important aspects of the identity, biology and ecology of the species. The fact that the specimen is a male is relevant, since males have been much less frequent in the reports in the scientific literature than have females. Additionally, this is the most southerly report of a male known to have occurred in the Atlantic Ocean.

Phytoplankton blooms are known to influence barnacle recruitment and in boreal regions spring blooms work as an important trigger. Close to the west coast of the sub-continent of India, blooms tend to be triggered by breaks in the monsoon and the recurrence of the monsoon after a short break can stress the new recruits. The recruitment of Balanus amphitrite, an acorn barnacle, at Dona Paula Bay at the mouth of Zuari estuary, Goa, India was studied. Observations included variations in recruitment, larval abundance, development and reproduction. Adult conditioning and inter-brood variations were important factors in the larval ecology of this organism. The results indicate that the impulsive release of larvae during breaks between monsoons could be a short-sighted luxury for Balanus amphitrite in these waters. Temporal variations or recruitment failure in such environments can be attributed to inappropriate cue synchronization.

five raja species are displayed in the ‘ray reef’ at dolfinarium harderwijk and, from 1993–2001, 41,772 eggs were laid, of which 39% contained a yolk sac and 3% hatched successfully. different egg-laying periods were distinguished between species. no annual differences in the egg-laying period were observed for raja microocellata, while hatching periods, and thus incubation periods (4.8–7.0 months), differed significantly. no correlation between seawater temperature and incubation time was found.

Previous morphological studies of Illex coindetii from the Mediterranean have shown both juvenile and mature individuals all year round suggesting an homogeneous population pattern, however, seasonal spawning variation seems to exist varying with geographical area. Present work analysed 240 individuals from the northern Tyrrhenian and Atlantic Iberian waters at the four year-round seasons using 33 presumptive enzyme-coding loci to compare geographical and temporal variances. Genetic variability was low (Ho=0·02–0·04). Moderate variation at some loci was found due to both temporal and geographical factors (12% of total genetic variance) and to temporal variance (FST=0·004–0·015). Unweighted pair-group method using arithmetric averages (UPGMA) and Multidimensional scaling–minimum spanning tree (MDS–MST) analyses after Cavalli-Sforza & Edwards (1967) chord genetic distances showed the summer Italian and the spring Atlantic samples as the most divergent among the whole.

Seasonal changes in the diet of the Atlantic mackerel from the north-east Atlantic in ICES Division VIIIc during the period 1988–1999. The diet of juvenile (21–29 cm) and adult mackerel (30–45 cm) in this area in spring (the spawning season) and autumn varied in composition and size of prey. In spring, the average prey weight was 0·009 g and the number of prey was 180 individuals per stomach, with the average stomach content volume being 1·62 g (0·60% BW [body weight]), and 1·50 g (0·51% BW) when considering the empty stomachs. In autumn, the average prey weight was 0·28 g, the average number of prey per stomach was 17, and the average stomach weight that contained food was three times higher than in spring, and 2·3 times when considering the empty stomachs. In spring, the diet of the juveniles consisted of euphausiids, crustacean larvae and other zooplankton, whereas euphausiids formed 90% of the diet in the adults. In addition, during this period mackerel were cannibalistic, feeding on their own eggs. In autumn, the juveniles ate hyperiids and other, mainly gelatinous zooplankton, whereas for the adults blue whiting were clearly important, since they comprised 90% of the stomach weight.

Larval development of the parasitic barnacle Heterosaccus papillosus (Cirripedia: Rhizocephala: Sacculinidae) is described from larvae reared in the laboratory. Lecithotrophic nauplii of H. papillosus reached the cypris stage in 3·5 days, at 22–23°C. The development included five naupliar and the single cypris stage, thus following the typical pattern in the Rhizocephala Kentrogonida. Like the nauplii of all sacculinids, those of H. papillosus had a single pigmented nauplius eye, unsegmented frontolateral horns each with two long spines and a tubercle between the furcal rami, but they lack a flotation collar and have no seta on the antennal basipod. The male larvae are larger than female ones, the mean lengths in the two sexes never overlap. The most interesting feature of this species are the morphological differences between the male and female larvae. In the male nauplii III to V the anterior body margin is noticeably convex, that is not characteristic for female larvae. The male cyprid also has a more acuited anterior region, whereas that of the female is rounded.

Siphonophores (Cnidaria: Hydrozoa) are dominant members of the carnivorous plankton, and they are known for their ability to produce bioluminescence. Here we describe two new calycophoran species (sub-family Prayinae) that are unique in their morphological and optical traits. One species, Gymnopraia lapislazula gen. nov., sp. nov., displays a dramatic form of blue structural coloration, and the other, Lilyopsis fluoracantha, sp. nov., bears an exceptional amount of fluorescence–enough to give a greenish cast during white-light illumination. We also introduce a consistent terminology for siphonophore axes and zooids, discuss characters important for distinguishing the known prayine genera, and suggest that the presence or absence of a disjunct pedicular canal could be of diagnostic value for the group.

The phylogenetic position of Xenoturbella spp. has been uncertain since their discovery in 1949. It has been recently suggested that they could be related to Ambulacraria within Deuterostomia. Ambulacraria is a taxon that has been suggested to consist of Hemichordata and Echinodermata. The hypothesis that X. bocki was related to Ambulacraria as well as the hypothesis of a monophyletic Ambulacraria is primarily based on the analysis of DNA sequence data. We tested both phylogenetic hypotheses using antibodies raised against SALMFamide 1 and 2 (S1, S2), neuropeptides isolated from echinoderms, on X. bocki and the enteropneust Harrimania kupfferi. Both species showed distinct positive immunoreactivity against S1 and S2. This finding supports the Ambulacraria-hypothesis and suggests a close phylogenetic relationship of X. bocki to Ambulacraria. In particular, the presence of immunoreactivity against S2 can be interpreted as a synapomorphy of Enteropneusta, Echinodermata, and Xenoturbella spp.

the body length–water depth distribution of urophycis tenuis white hake (pisces, gadidae) in the southern gulf of st lawrence (1971–1975, 1981–1985, 1991–1995 and 2001–2002) and cabot strait (1994–1997) was examined. contrary to expectation, linear regression analyses indicated 13 of 17 years had negative slopes with larger fish being found in shallower water. length–depth relationships were statistically significant for five of 17 years (negative slopes: 1971, 1972, 1975, 1981; positive slope: 2002). regression slopes generally increased from 1971 to 2002 indicating the length–depth relationship changed from negative in the early 1970s and 1980s, to negative and positive in the early 1990s, and finally to positive in 2001–2002. in the cabot strait, a significant positive relationship was observed for fish length and water depth indicating large u. tenuis generally occurred in deeper water. we propose that slopes of the length–depth relationship became positive in the 1990s and early 2000s due to the loss of large u. tenuis taken in a seasonal fishery in the southern gulf of st lawrence that targeted highly aggregated spawning and post-spawning shoals of fish in shallow water during summer.

The feeding of the most important chaetognath species (Sagitta enflata, Sagitta minima, Sagitta setosa and Sagitta serratodentata) found in a grid of 35 stations in the north Aegean Sea (Strymonikos and Ierissos Gulfs) was investigated through gut content analysis during five sampling periods from June 1997 to May 1998. Sagitta enflata and S. minima were the most abundant species in summer–autumn 1997 and in spring 1998, respectively. Copepods were the main food for all chaetognath species in spring 1998, while cladocerans in summer–autumn 1997 dominated the diet, especially of S. enflata. In September 1997, the juvenile specimens of cladocerans were the most important prey of the immature Stage I specimens of S. enflata, which resulted from the major breeding period in late summer. The estimated impact of chaetognath predation on the copepod and cladoceran communities ranged between 0.02–2.76% and 0.01–1.29% of the copepod and cladoceran standing stock, respectively. Stage I specimens of S. enflata accounted for nearly 90% of the total copepod and cladoceran standing stock consumed per day by the total population of this species in September 1997.

The diet of anglerfish (Lophius piscatorius), based on the analysis of stomach contents, was investigated in the Shetland Islands. Samples were obtained during trawling for sandeel (Ammodytidae species) and demersal trawling when mainly whitefish (gadoids) are targeted. This allowed the diets of samples collected from different areas and at different times to be compared. The diets in different length groups were also compared and niche breadth investigated.

A wide range of prey types, mainly fish, were recorded but the main prey was Norway pout (Trisopterus esmarkii) and lesser sandeel (Ammodytes marinus). Diet composition varied seasonally. In samples collected during whitefish trawling the occurrence of empty stomachs decreased from the first to the third quarters and generally increased with increasing anglerfish size. Empty stomachs occurred less frequently in samples collected from areas where sandeel fishing occurred compared to areas where whitefish trawling occurred.

This updated re-description of the prayine siphonophore Rosacea cymbiformis includes figures of all zooids (except larval nectophores) and is based on material held in the collections of the Natural History Museum (NHM), London. Rosacea cymbiformis was originally described in 1830 under the name Physalia cymbiformis, and subsequently reported many times during the 19th Century. However, during the 20th Century it was confused with the closely related species R. plicata, and the two species are still not clearly differentiated. Previous descriptions are reviewed herein, including conflicting interpretations of nectophore designation in R. plicata, and bract orientation in R. cymbiformis and R. plicata. To identify these siphonophores to species level and separate them from other closely related prayines, it is essential to distinguish the first definitive nectophore from the second, and the right paired bracteal canals from the left canals. This becomes critical when only detached siphonophore zooids are available, as for example, in plankton samples collected with nets. A summary of the differences between R. cymbiformi and the five other currently recognized Rosacea species, R. plicata, R. repanda, R. limbata, R. flaccida and R. arabiana, is presented. The full synonymy of R. cymbiformis is too long for inclusion here and is deferred to a later paper.

The new mangrove barnacle, Fistulobalanus sumbawaensis sp. nov. from Sumbawa Island, Indonesia shares the common morphological characteristics with the subfamily Amphibalaninae in having a shell wall of six, porous compartmental plates; radii solid; alae not cleft; basis calcareous, tubiferous in single layer. This new species belongs to the genus Fistulobalanus mainly in having parietal tubes arranged in two or more rows; primary tubes with transverse septa; subsidiary tubes formed between the primary septum and outer lamina. In particular, the new species is similar to F. patelliformis in the shape of the shell, the transverse section of subsidiary tubes, the tergum and some characteristics of trophi and the cirri. However, this new species is easily distinguishable from all members of the genus Fistulobalanus in having no coloration or striations on the external surface of the shell, subsidiary tubes only appearing inside the ribbed part of the shell, and the scutum having a short adductor ridge.

the strontium (sr) and calcium (ca) concentrations in the otoliths of the skipjack tuna katsuwonus pelamis collected in the western pacific ocean were examined by wavelength dispersive x-ray spectrometry on an electron microprobe. otolith sr:ca ratios of the tunas collected off the marshall islands in the tropical waters were constant over the life history transect of the otolith. in contrast, ratios in most tunas collected off sanriku in the temperate waters in october fluctuated from low to high at 1100–1800 μm from the core. a similar fluctuation of otolith sr:ca ratio from low to high was found in a skipjack tuna that was tagged and released off sanriku, and then recaptured off the palau islands. therefore, at least two life history patterns of the skipjack tunas, of global migration toward northern temperate regions and local residence in tropical spawning grounds, are suggested by specimens collected in the western pacific ocean.

The full developmental sequence from egg to juvenile of Lipophrys trigloides in controlled conditions is described. In addition, some notes on the spawning behaviour of adults are provided. Embryonic development lasted 13–14 days at 21·00–23·00°C, 16–17 days at 17·25–18·50°C and 17–18 days at 14·00–16·50°C. Newly hatched larvae measured 4·8 mm, had the mouth and anus opened, pigmented eyes and almost no yolk. Most larvae settled between day 39 and 42 after hatching at 16·0–17·0 mm total length (TL) and showed full juvenile pigmentation patterns and behaviour 5 to 10 days later (17·0–18·0 mm TL). A summary of the characteristics of the eggs and larvae that may help in the distinction between L. trigloides and Lipophrys pholis, a very close related species, is also provided.

Scales for stomach fullness and colour were developed and calibrated in order to provide an easy and reliable way to determine feeding intensity and food quality in sardines. The categories of the fullness scale reproduce the amount of food intake as indicated by the weight of the stomachs. The levels of the colour scale reflect the type of plankton eaten as shown by concentration of a-type phaeopigments and prey analysis of the stomach contents. Individuals of a wide length range were used in this study, leading us to suggest that these indices can be applied to the entire juvenile and adult sardine population. The use of the colour and fullness scales provides a rapid and efficient means of characterizing sardine feeding. Based on the colour and fullness categories of the stomachs the majority of stomachs were almost empty or at most half-full and the diet was composed of different proportions of phyto- and zooplankton items. As indicated by the prey analyses of the contents the most important constituent of the diet, in volume, were zooplankton prey.

Two reciprocally monophyletic mitochondrial clades of the commercially valuable jellyfish Catostylus mosaicus are endemic to south-eastern Australia. Here, medusae in the two clades are shown to differ also in colour and in the dimensions of their papillae, oral disk, and bell depth. They are referred to two varieties recognized in 1884 by von Lendenfeld. The clade occupying localities adjacent to Bass Strait is redescribed as subspecies C. mosaicus conservativus; the clade from New South Wales and southern Queensland spans the type locality (Port Jackson) of C. mosaicus and is designated C. mosaicus mosaicus. Their ecology and colour, in the context of von Lendenfeld's original descriptions, and the implications for fisheries are discussed.

falkland islands' mullet (eleginops maclovinus) were aged successfully using whole sagittal otoliths from 1403 individuals. marginal increment analysis indicated that one opaque and one translucent zone were laid down annually. unvalidated daily ring counts confirmed what was thought to be the first translucent zone. the translucent zones were found to form earlier in juveniles than in adults. juveniles over winter in the creeks and inlets whereas adults are more common in deeper inshore waters where there is a one month lag in the minimum winter water-temperature. the maximum observed age was found to be 11 years. the calculated von bertalanffy growth model (lt=124.41(1−e−0.14/year(t-0.01years))) showed that e. maclovinus is a fast-growing fish, growing on average 10.2 cm/year for the first six years of its life.

Removal of egg-tending males in a monogamous goby, Amblygobius phalaena, was performed on coral reefs of Okinawa, Japan. All five removal experiments led to shifts of parental care to the paired females, and two of the females continued egg care until just before the eggs hatched. Evolution of the shift of parental care to a non-caregiving parent in this species may be facilitated by the spatial closeness between mates after spawning and no necessity of special structures and organs for guarding care.