Omitted spawning in compensatory-growing perch
Abstract:Individual growth trajectories of perch Perca fluviatilis in a Swedish forest lake (sampled in March) revealed growth depression at intermediate sizes, followed by enhanced, compensatory growth at larger sizes. All males of age ≥3+ years had mature, almost ripe testes. The proportion of spawning females was higher at age 3+ years (79%) than at older ages (44%), indicating that older females with non-developing ovaries were resting rather than immature juveniles. Resting females were 175–247 mm in total length (LT), and they were usually in a state of increasing annual growth. Spawning females were of more variable size (123–418 mm), and the larger ones had entered the faster growing state ≥2+ years before catch. Detectable growth costs of spawning indicated that resting females made a trade-off between current and future reproduction, rather than being constrained by poor feeding conditions.
Document Type: Regular Paper
Affiliations: National Board of Fisheries, Institute of Freshwater Research, SE-17893 Drottningholm, Sweden
Publication date: 2003-04-01