Recent studies of the large cheilostome bryozoan genus Scrupocellaria have shown a greater degree of taxonomically informative morphological variation in zooids, opesia, and polymorphic structures than previously recognized. Only one subgenus has been named within the genus, Retiscrupocellaria d'Hondt, 1988, erected for Scrupocellaria jolloisii. In this work we further analyse S. jolloisii and its related species, resurrecting an earlier genus name, Licornia van Beneden, 1850 for Licornia jolloisii, and nine relatives, L. annectens, L. cervicornis, L. cyclostoma, L. diadema, L. ferox, L. gaspari, L. longispinosa, L. macropora, and L. prolata. Licornia jolloisii was originally described from the Red Sea, and most species of the genus occur in the Indo-Pacific region. The species, however, has now been found in the Western Atlantic, in the Florida Keys, US, and in Bahia de Todos Santos, Brazil.

Sea urchins can have important ecological effects on benthic communities through their aggregation and feeding behaviour. Urchin movement has been demonstrated to be negatively affected by wave action, but the impact of unidirectional tidal currents on urchin movement has not been investigated. This study examines the effect of unidirectional water velocity on the direction of displacement and movement rate of the green sea urchin, Strongylocentrotus droebachiensis. In laboratory flume experiments there was a clear effect of water currents on the displacement of sea urchins. At speeds ≤30 cm s−1 urchins moved across the current in a downstream direction, but at speeds of ≥36 cm s−1 the urchins switched directions by more than 90° and moved across the current in an upstream direction. There was a significant effect of flow speed on urchin movement speed, with urchin movement speed decreasing as water current speed increased.

Seventeen chondrichthyan species were caught in the Cantabrian Sea (southern Bay of Biscay) during a multidisciplinary survey carried out in the Avilés canyon system in May 2011. This survey provided the first records of three species (Galeus murinus, Neoraja iberica, and Neoraja caerulea) in these waters, and a further record of Rajella kukujevi. To confirm the identity of these species, the cytochrome c oxidase subunit I (COI) of the specimens was sequenced. Genetic analyses revealed that the DNA sequences of the two Neoraja species were identical in all the specimens analysed. Morphometric analyses, based on 40 characters, showed 3.66% dissimilarity between the two species. The morphometric character that contributed most to this discrepancy was disc width.

This study presents new information on the population biology, growth and maturation schedules of Galeus melastomus, Centroselachus crepidater and Apristurus aphyodes sampled from the Rockall Trough, a region where deep sea fishing activity has been prevalent for the past 40 years and where shark by-catch is considerable. Both G. melastomus and C. crepidater showed significant sexual size dimorphism with females attaining a greater length and mass. The size (L50) at first maturity was estimated to be 55.6 cm total length (TL) for males and 59.7 cm TL for females in G. melastomus, 57.2 cm TL for males and 75.4 cm TL for females in C. crepidater and 49.0 cm TL for males and 56.9 cm TL for females in A. aphyodes. This represents the first TL50 analysis for Apristurus aphyodes globally. Sharks were aged using a technique which employed cobalt (II) nitrate to stain growth bands in vertebra centra. Band pairs were successfully viewed in G. melastomus and pair counts ranged from 0 to 5 in males and 2 to 7 in females. A higher asymptotic length was deduced from the von Bertalanffy growth equation for females than males (females: L∞ = 69.3 cm; males: L∞ = 60.8 cm) in G. melastomus. Staining was unsuccessful in C. crepidater and A. aphyodes and age could not be determined using this technique.

The pollack, Pollachius pollachius, is an important commercial species for the Spanish artisanal fleet in Atlantic Iberian waters. This study provides information on the reproductive biology of the species, including length at maturity, reproductive cycle and gamete development pattern based on histological methods. A collection of 622 individuals were sampled from fish markets along the western coast of Galicia (NW Spain), between November 2009 and October 2010. Histological examination of the gonads revealed an asynchronous development of secondary growth follicles. Testicular tissue was of lobular type. The reproductive season extended from January to April for females and from January to May for males, with a peak of reproductive activity in February for both sexes. The hepatosomatic index was related to the reproductive cycle, with a mean maximum value during the developing reproductive phase. Length at 50% maturity was significantly different between females (47.1 cm) and males (36.1 cm).

Information on the ontogeny of complement system might help us better understand the anti-infection mechanism in the early fish life. The ontogenic expression of the representative complement genes and their response to lipopolysaccharides (LPS) challenge in zebrafish larvae are reported here. The expression of C1r/s, C3, C4, C6 and MBL steadily increased before 21 days post-fertilization (dpf) and a decrease was detected thereafter. MASP expression elevated and peaked on 14 dpf and a decline followed. Bf expression fluctuated during the experimental period. Moreover, Bf (involved in alternative pathway, AP) expressed at higher levels than C1r/s (involved in classical pathway, CP), MASP (involved in lectin pathway, LP) and C4 (involved in both CP and LP) in the normal adult fish and larvae, suggesting the more significance of AP than CP and LP during the development of zebrafish. LPS challenge induced up-regulation of all the genes at 12 h in the adult fish. For the larvae, Bf, C3 (key complement component) and C6 (involved in lytic pathway) responded to LPS challenge at earlier stages than the other complement genes, with the up-regulation detected since 14, 14 and 7 dpf, respectively. In the larvae at 28 dpf, all the above three genes responded to LPS challenge by up-regulating their expression in a fashion similar to that of the adult fish, hinting that complement operating via AP develops earlier and plays a key role in protecting the larvae; it showed effective responses to LPS challenge from 14 dpf and might mature before 28 dpf.

The biocrystallization process and the prescence of manganese in sagitta otoliths is described for the first time via electron paramagnetic spectroscopy. Spectra of Mn2+ are applied to verify inter-species differences in 12 Sciaenidae species and geographic variations among three stocks of banded croaker Paralonchurus brasiliensis and rake stardrum Stellifer rastrifer. Similar spectra shape and zero-field splitting D (22.4 mT) indicated that the biocrystallization process is the same for all fish species, at any stage of development and under different environmental conditions, corresponding to Mn2+ in the aragonite (CaCO3). Inter-species differences in Mn2+ concentration were detected regarding the otolith shape. Elongated otoliths have higher manganese concentrations compared to rounded otoliths. Geographic variations among stocks of P. brasiliensis and S. rastrifer could be detected. Fish stocks under riverine influence have less Mn2+ concentration than ones under marine influence. Manganese detection via electron paramagnetic spectroscopy is a non-destructive approach that can be useful in fish stocks studies.

The snailfish Liparis tanakae is an annual fish, growing up to >300 mm in total length. This species is known as a predator of 0-year-old Japanese flounder Paralichthys olivaceus. To reveal when and where the predation occurs, monthly collections of both species at various depths were conducted off Fukushima, Japan. The snailfish inhabited shallow areas ≤50 m deep until June. Thereafter, they shifted their main habitat to offshore areas ≥100 m deep from July to September. The snailfish migrated to inshore areas with depths of ≤50 m again around October–December, during which time the habitat overlap between snailfish and 0-year-old Japanese flounder was observed. In that period, >40% of 0-year-old Japanese flounder were vulnerable to the snailfish. Larger snailfish showed stronger piscivory, and some flatfish were found in their stomachs. These results suggest that by not releasing hatchery-reared Japanese flounder until September can forestall predation by the snailfish.

A total of 209 strandings of sea turtles (152 loggerhead turtles Caretta caretta, 42 green turtles Chelonia mydas, 15 unidentified) were recorded during the period 1984–2011 along the coasts of Rhodes (Aegean Sea, Greece). The proportion of dead to live individuals was different in the two species. Stranded Caretta caretta were larger than Chelonia mydas. The size range of stranded green turtles, usually juveniles, appeared to increase since 2000, including the largest specimens ever observed in Greek waters. For both species, a tendency to strand more frequently on the west coast of the island, along fishing ground areas, was noted. The higher incidence of loggerhead turtle strandings was observed in summer, while more green turtle strandings were documented in winter. Factors involved in the increased trend of stranding records of both species, along with the acceleration of this phenomenon in the last decade, are discussed. Data from Rhodes provide evidence that human activities detrimentally affect mainly larger-sized loggerhead turtles living in shallow waters.