Biology (growth and reproduction) of the Mediterranean deep-water rose shrimp (Parapenaeus longirostris (Lucas, 1846), Crustacea, Decapoda) from the Alicante Gulf (s.e. Spain).

The deep-water rose shrimp (Parapenaeus longirostris) is a demersal species and an important resource for the trawl fishery in the Alicante Gulf (S.E. Spain). This paper describes, for first time in this area, certain biometric relationships, as well as growth parameters and reproductive patterns of the species. The results showed a sexual size dimorphism, with a negative allometry of relative growth and high rates of absolute growth, both particularly in males. However, females dominated in the catch proportion. The spawning period occurred throughout the year, but especially in June-July and in October-November and the maturation stage for females takes place within the second year of life

Age of spent Octopus vulgaris and stress mark analysis using beaks of wild individuals

Age estimation of the cephalopod Octopus vulgaris by using beaks has improved in recent years, but maximum age and longevity in the wild have not been confirmed due to the low availability of senescent wild octopuses. In this study, a beak analysis of lateral wall surfaces (LWS) from 20 spent specimens confirmed the one-year lifecycle of the species in Central East Atlantic waters. Stress marks (checks) were clearly located in the daily increment sequence of rostrum sagittal sections (RSS). The highest daily variations in sea surface temperature (ΔT) that occurred during the last months of their lifetimes coincided with the locations of the marks on the beak, enabling confirmation of O. vulgaris beaks as life recorders for the first time. It also supports the daily deposition of RSS beak increments in the wild. Individuals were grouped into two main zones, at 20ºN and 18ºN respectively. Both groups showed different thermal check patterns, in accordance with the oceanographic differences. Two other checks (not coinciding with high values of ΔT) were observed in RSS at averages of 15 and 28 days before death, respectively, which were interpreted as responding to senescent-related events.Instituto Espanol de Oceanografi

Actualizacion de parametros poblacionales de Sardina pilchardus (Walbaum, 1792) procedente de aguas mauritanas (Clupeidae, Clupeiformes)

Publicado

Reproductive aspects of Octopus vulgaris, Cuvier 1797, caught by the industrial Spanish fleet off Mauritania (NW Africa)

PosterBetween January 2010 and September 2011, a total of 4044 defrosted O. vulgaris (2554 males and 1490 females) caught by Spanish freezing trawlers targeted to cephalopods off Mauritania were analyzed. Length-Weight relationships, sex ratio, spawning season and size at maturity were determined.DCF-E