Biological Characteristics and Length-Weight Relationships of landed Thornback Ray (Raja clavata, Linnaeus 1758) in the Fishing Port of Durres, Albania

¹Departament of Aquaculture and Fisheries, Faculty of Agriculture and Environment, Agricultural University of Tirana, Koder- Kamez, Tirane, Albania

²Degional Administrate of Protected Areas Lezhe, Agency of Protected Areas, Lezhe, Albania

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Abstract

Elasmobranchs, mainly represented by sharks and rays, account for 0.8% of bottom trawl total landings in the South Adriatic Sea. The thornback ray (Raja clavata, Linnaeus, 1758) represents one of the most important species in terms of landing in the Mediterranean basin. Several studies have shown that k-selected species, like elasmobranchs, with low intrinsic population regeneration potential are the most impacted by harvesting. The thornback ray has been listed as near threatened by the International Union for Conservation of Nature (IUCN) (Ellis et al., 2016), which imply the need for sustainable management of this species population. In order to develop management plans for cartilaginous species (including thorback ray), it requires basic knowledge about life history traits, such as growth rate, maturity, and fecundity. Several male and female individuals of thornback ray fished in the marine area close to the fishing port of Durres were analysed in order to evaluate some biological characteristics of this species in Albanian marine waters. Our allometric measurements results suggested that the environment conditions of marine waters close to the fishing port of Durres didn’t satisfy the physiological requirements of this highly migratory species, though in other studies conducted with speciemens fished in the Souther Adriatic Sea, the thornback ray growth was charachterised by positive allometry.

Keywords: Elasmobranchs, thornback ray; South Adriatic Sea; Mediterranean Sea.