HELICOLENUS

Population structure and reproductive ecology of Helicolenus dactylopterus dactylopterus in the Iberian platform

  

The bluemouth, Helicolenus dactylopterus dactylopterus (De la Roche, 1809), is a benthic species widely distributed on the Atlantic Ocean and on the Mediterranean Sea. Our research group has been doing exhaustive studies about the reproductive biology of this species. The bluemouth is an oviparous zygoparous species with variable period of gestation, a long period of sperm storage inside the females’ ovaries, and with fecundity higher than the expected one for an internal fertilization species; at least in samples coming from exploited areas.

Besides, early analysis on the population structure of this species at trawling depths of peninsular and insular coasts, together with our research with samples from the Catalan coast, confirm that within the fishing areas only appear recruits and young specimens. On the contrary, for non-fishing areas, our data seem to indicate that stocks may have size and age composition significantly different, although there is no comparative study.

The aim of this project is to analyse the population structure of this species in five well-differentiated sectors of the Iberian coast (Asturias,Galicia, Alborán, Alicante and Tramontana) with particular environmental and exploitation characteristics and to describe the reproductive ecology of stocks for every sector. These results shall be compared and interpreted according to these characteristics in order to determine the existence of different stocks and if there is a relation between the fishing exploitation and the observed changes in the population structure and if some plasticity in the reproductive strategy could carry with this pressure.

In addition, the analysis and biological interpretation of historical data of MEDITS and Demersales campaigns, together with the analysis of the morphometric and genetic distances between the mentioned areas, as well as the degree of genetic differentiation among populations will allow us to assess the importance of flow between possible stocks. Besides, these results will show us if there is some closeness between Atlantic and Mediterranean populations, and if the less exploited Mediterranean populations can work as specimens’ reservoir for the areas subjected to a higher fishing pressure. All our research has the purpose of provide useful information for the management of this species.

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