The contrasting hatching patterns and larval growth of two sympatric clingfishes inferred by otolith microstructure analysis

Larval abundance, age, growth and hatching patterns of two sympatric clingfishes, Gobiesox marmoratus and Sicyases sanguineus (Pisces, Gobiesocidae), were estimated by using otolith microstructure analysis and compared on the basis of collections performed during the austral spring in 2010 off the coast of central Chile. G. marmoratus larvae were more abundant than S. sanguineus larvae during the study period. For both species, the sagittae deposited micro-increments during embryonic development (before hatching) and a hatch mark was observable in all examined otoliths. The sagittae otoliths of G. marmoratus grew in radius, perimeter and area faster than did the otoliths of S. sanguineus. Both species showed significant (P<0.05) differences in larval growth and lunar periodicity of the hatching events. G. marmoratus hatched at smaller sizes (2.6mm) mainly during the first-quarter moon and the larvae grew at rates of 0.24±0.01mmday^-1. S. sanguineus hatched as larger larvae (>3mm) during the first-quarter and full moons and grew at slower rates (0.14±0.01mmday^-1) during the initial 25 days. The high abundance of larval clingfish in near-shore waters, temporal decoupling among the hatching events, and the different growth rates may be tactics to increase self-recruitment in coastal waters.