Age, growth, and reproduction of perch,Perca fluviatilisL., in Lake Pounui

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Abstract
Ages of 1052 perch (Perca fluviatilis L.) from Lake Pounui, Wairarapa, were calculated from annual bands in the opercular bones. Growth was seasonal, with no significant increase in length occurring between April and October. For these months combined, back‐calculations of length at previous age were generally significantly different from the mean length per age class. Females grew faster than males, and growth in both sexes fitted the von Bertalanffy growth model. Seasonal changes in condition and gonad weight for each sex were studied by calculating mean monthly total and gonad weights for a given length. The reproductive cycle was examined further by recording stages of gonad development and calculating gonadosomatic indices. Fecundity from 66 females ranged from 2657 to 63858. Females dominated all samples, with an overall male:female ratio of 1:4, although seasonal variation was noted; the highest proportion of males, 1:1.7, occurred immediately before spawning.