Rare data on a rocky shore fish reproductive biology: sex ratio, length of first maturation and spawning period of abudefduf saxatilis (Linnaeus, 1758) with notes on stegastes variabilis spawning period (perciformes: pomacentridae) in São Paulo, Brazil - Bessa, Eduardo; Dias, June Ferraz; Souza, Ana Maria de (Brazilian Journal of Oceanography, 2007)