Study of the diet and growth of sand sole (Pegusa lascaris) and brill (Scophthalmus rhombus) on the beaches of the Cadiz coast.

Resumen

Sand sole (Pegusa lascaris) and brill (Scophthalmus rhombus) are two flatfish species whose fisheries are of great commercial interest, although little information is available on aspects of the biology of both species. The main objective of this work, still in a preliminary phase, is to study the diet and growth of these species from the specimens captured by beach seine netting during sampling on five beaches along the coast of Cádiz. A total of 149 individuals of juvenile sand sole and 107 individuals of brill were analyzed. Stomach contents were studied to identify preferences of prey consumed and otolith growth rings were studied to determine age classes. Both species presented a varied diet where it was observed that sand sole fed mainly on cumaceans (52.09 %), bivalves (33.29 %) and crabs (6.24 %) while in brill digestives, mysidaceans (90.06 %), teleosts (4.52 %) and amphipods (3.28 %) were identified. The growth equation parameters of the Von Bertalanffy model for sand sole were L∞= 36.29 cm, k= 0.24 years-1, t0= -0.91 years and for juvenile brill, L∞= 80.06 cm, k= 0.14 years-1, t0= -0.09 years. With this type of study it is expected to increase the knowledge about the biology of both species in the area.