The first record of the plexaurid genus Psammogorgia from the shallow waters of Peru is reported here. A new species (Psammogorgia hookeri sp. nov.) is described from Isla San Gallán, Paracas National Reserve. The new species was morphologically analysed using light microscopy and scanning electron microscopy. It is distinguished from the others in the genus by its small size; prominent calyces with wide lips around polyp apertures and without a special type of sclerites, but with a concentration of irregular, thorny spindles and wart-clubs around the calyx rim; coenenchymal sclerites that do not reach more than 0.2 mm long; the occurrence of conspicuous star-like radiates; and the colour of the colony and coenenchymal sclerites, which is coral red. The results increase species richness within a genus that has not been studied for more than a century, and contribute to the establishment of characters for further morphological studies. Additionally, the new species adds value to existing protected areas and to the octocoral biodiversity records for the Peruvian region and the eastern Pacific.

A low-cost and non-invasive survey technique focused on pelagic sharks was evaluated during an ecotourism cruise on two Sudanese reefs, Angarosh and Sha'ab Rumi, in the Southern Red Sea. The research technology was based on a set of small, underwater video recording cameras and a pair of laser pointers. Video footage provided insight into shark biodiversity on the two reefs, detecting five species, Alopias vulpinus, Sphyrna lewini, Triaenodon obesus, Carcharhinus amblyrhynchos and Galeocerdo cuvier, during 15.8 h of video recording. These recordings also provided preliminary information on aggregations of S. lewini. The laser pointers were used to measure the size of sharks, providing seven total length (TL) measurements for S. lewini (N = 2) and C. amblyrhynchos (N = 5), confirming the possibility of easily obtaining size parameters using this tool. These low-cost and user-friendly instruments provide ecotourism divers with an opportunity to become involved in marine research projects.

This paper studies age, growth and hatch date distributions of young of the year striped sea bream Lithognathus mormyrus from Canakkale near shores by using a beach seine during September 2006–December 2007. Using otolith microstructure analysis, a total of 416 specimens ranging from 20 to 103 mm LT were aged and found to be between 30 and 307 days old. Average growth rates were estimated to 0.325 mm d−1. The juvenile instantaneous mortality coefficient was found to be 0.0219, which corresponds to a daily mortality of 2.16%. The hatching period of the striped sea bream was determined to occur between April and January, with relatively higher hatching frequency in August.

Concentrations of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn) and iron (Fe) were measured in three macroalgal species, Codium simulans, Sargassum sinicola and Gracilaria pachydermatica, and in the sea slug Elysia diomedea, living in marine ecosystems dominated by Sargassum species and located near exploited phosphorite deposits. Metal concentrations in macroalgae and sea slugs were significantly different among sites. The highest concentrations of Cd recorded in C. simulans and S. sinicola, as well as in E. diomedea were recorded at the site closest to the phosphorite deposit. In general, Cd and Zn concentrations in E. diomedea were higher than those recorded in specimens of C. simulans, S. sinicola and G. pachydermatica. In contrast, Pb, Cu, and Fe concentrations in E. diomedea were lower than or similar to those in macroalgae from all sampled sites. The information generated contributes to the knowledge about potential mobility and metal bioaccumulation at lower trophic levels in marine eco systems.

The spaces between sand grains are home to a myriad of microscopic marine eukaryotes, including kalyptorhynch rhabdocoels equipped with an eversible proboscis that enables them to capture microscopic prey living in these environments. The structure of the kalyptorhynch proboscis separates the two major subclades within the group: the Schizorhynchia (bifurcated proboscis) and the Eukalyptorhynchia (unbranched proboscis). A survey of meiofaunal metazoans in the Pacific north-west led to the discovery of three new schizorhynch species (Undicola tofinoensis gen. nov., sp. nov., Schizorhinos vancouverensis gen. nov., sp. nov. and Linguabana tulai gen. nov., sp. nov.) and two new eukalyptorhynch species (Thinodactylaina tlaoquiahtensis gen. nov., sp. nov. and Rostracilla nuuchahnulthensis gen. nov., sp. nov.). This survey also recovered the putative cosmopolitan eukalyptorhynch (Polycystididae) Gyratrix hermaphroditus Ehrenberg, 1831. We performed molecular phylogenetic analyses on 18S rDNA sequences from all five novel isolates and from all available kalyptorhynch species in GenBank. The molecular data supported the monophyly of the Eukalyptorhynchia and Schizorhynchia and helped demonstrate the boundaries between different species within the Kalyptorhynchia.

Two new species of free-living nematodes discovered from the sediments in the East China Sea are described: Linhystera breviapophysis sp. nov. and L. longiapophysis sp. nov. Both species possess a dorso-caudally directed gubernacular apophysis, which makes them distinctly different from the two already known species of Linhystera. Linhystera breviapophysis is characterized by a gubernacular apophysis about 3.3 μm long, the presence of a crown of cervical setae and a filiform tail. Linhystera longiapophysis is characterized by a prominent gubernacular apophysis about 10 μm long, sparse cervical setae and a long filiform tail. An emended diagnosis of Linhystera and a pictorial dichotomous key to the species are given.

Preliminary molecular data obtained from one mitochondrial (COI) and one nuclear marker (H3) from the available species of the genus Okenia have revealed a new cryptic species of this genus. The new species (Okenia harastii sp. nov.), from New South Wales (NSW) eastern Australia, has a light brown body with scattered dark brown and white spots of different sizes, and six pairs of translucent mantle processes. Okenia harastii sp. nov. is compared with other Okenia species from NSW and with other morphologically similar species.