Composición estacional de larvas de peces frente a Baja California Sur (primavera y otoño de 2003)

The southern oceanic region off the Baja California Peninsula has been poorly studied, although the influence of the California Current in this area has been recognized. To test this influence we analized the ichthyoplankton collected in two oceanographic cruises made on the Pacific coast from Bahía Magdalena to Cabo San Lucas, Mexico, during spring and winter 2003. Samples were collected using single oblique tows, temperature and salinity being recorded with a CTD device. Temperature during spring was low (15–22 °C) with coastal-ocean and north-south gradients, whereas during autumn temperature was higher (26–29 °C). Salinity ranged from 33.7–34.7 in both cruises. Mean larval abundance during autumn (189 larvae/10 m2) was three times higher than in spring (58 larvae/10 m2). During spring Diogenichthys laternatus, Vinciguerria lucetia, and Triphoturus mexicanus represented ~91% of the total larval abundance, whereas in autumn seven taxa contributed ~90% of the larval abundance. During both seasons, more than 85% of the taxa were of tropical affinity. The differences recorded show an ichthyoplanktonic community with significant seasonal changes and an important tropical affinity component, quite different to those in northern regions more influenced by the California Current.