Spawning and nursery habitat of the wedge sole Dicologlossa cuneata (Moreau, 1881) in the Gulf of Cádiz (SW Spain)

Abstract

Ichthyoplankton samples and hydrological data were obtained in an inshore area, between the mouths of the Rivers Guadalquivir and Guadiana (Gulf of Cádiz, SW Spain) during monthly surveys carried out from March 2002 to March 2003. Horizontal and temporal distributions of wedge sole (Dicologlossa cuneata) egg and larval abundances were analysed during this annual cycle in relation to environmental parameters. This area proved to be an important spawning and nursery ground for the species, which showed a winter-spring reproductive strategy with a long reproductive period lasting from autumn until early summer. Spawning areas were located in the shallowest waters (above 30 m depth) between the mouths of the Rives Guadiana and Tinto-Odiel, and to a lesser extent in the coastal zone between the mouths of the Rivers Tinto- Odiel and Guadalquivir. The spawning habitat was mainly determined by the distribution of the adults, the bathymetry and the temperature, and a preference for shallow and colder waters was observed. The inshore zone between the mouths of the Rivers Tinto-Odiel and Guadalquivir is the main nursery ground, with the greatest larval concentration and productivity in the area, due to the influence of the River Guadalquivir. The presence of recruits in this area may be linked to these favourable conditions for larval growth and survival.