Three genetic groups of Sepioteuthis spp. was identified in Japan and Taiwan. Sepioteuthis sp. 2 was dominant in Japan, whereas Sepioteuthis sp. 1 was dominant in Taiwan. Variations in life-history traits and statolith shapes of the squid were greater between geographic populations (Japan and Taiwan) than among the taxa. The results provide insights into the population structure and connectivity of Sepioteuthis spp. in the Northwest Pacific.

The age and growth of the Pacific cownose ray, Rhinoptera steindachneri, were examined in the south-western region of the Gulf of California, through edge type and marginal increment analysis of 276 vertebral centra. Individual growth was described using a multi-model approach and inference. Results indicated that R. steindachneri is a batoid species with intermediate growth and a shorter lifespan than for confamilial species and even than species with similar reproductive traits.

Black dogfish off Canada undergoes a multi-year distributional shift, starting in the Laurentian Channel pupping grounds–nursery area, then spreading out along slope waters, with the largest fish being found furthest from the Channel, up to 4000 km away. No other deep demersal species are known to have a dedicated nursing ground–pupping area or to undergo a progressive migration as they grow.

This paper presents information on the distribution, behaviour, ecology and population size of humpback whales observed off the Pacific coast of Nicaragua. Thought to be part of the endangered humpback whale population off the Pacific coast of Central America, little is known about the population characteristics of the whales off Nicaragua. This knowledge will be valuable for scientists and decision makers to help establish effective conservation measures.

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), as an organophosphorus flame retardant, prevails in the marine environment. This study shows that exposure to TDCIPP can adversely affect larval survival, larval growth, fecundity, and embryonic development in marine invertebrates. The results have implications for ecological risk assessment and management of organophosphorus flame retardants.

Vulnerability of elasmobranchs to multiple fisheries was estimated through the productivity and susceptibility analysis (PSA) and rebound potential method. Among sharks and rays, the silky shark, sandbar shark and scalloped hammerhead, and southern stingray and spotted eagle ray had the highest vulnerability and the lowest rebound potential. In addition, significant correlations between rebound potential and the cumulative vulnerability of the approach that averaged susceptibility attributes were estimated, indicating a general pattern in which the species’ rebound potential increases while the vulnerability decreases.

The population dynamics and dietary habits of monkey goby were studied in its native range in a freshwater habitat (Dnieper River). Altogether, 70 taxa of prey organisms composed the diet of this fish, among which the most abundant were chironomid larvae, followed by cladocerans. The opportunistic feeding strategy combined with time-expanded multiple spawnings and relatively fast growth can facilitate the successive invasion and establishment of this species in new environments, and contribute to its wide distribution.