Morphometric relationships and reproductive maturation of the mudskipper, Periophthalmus barbarus from subsistence catches in the mangrove swamps of IMO estuary, Nigeria

From April 1992 and March 1993, morphometric characteristics and reproductive maturation were studied in Periophthalmus barbarus from subsistence catches in the mangrove swamps of Imo estuary. Morphometric equations for males and females at different stages of ovarian maturation are presented. Generally males were significantly heavier in weight than females, but the latter were heavier than the former of the same body length. Females with developing and mature ovaries were generally heavier than immature females of the same length. Analyses of the gonadosomatic index and percentage of mature males and females indicate all year-round breeding such that: February-May was spawning, June-October postspawning and November to January recovery period. Fecundity varied between 900 and 23933 eggs per spawn and increased with fish size.