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Reproductive biology of the East African lungfish (Protopterus aethiopicus) in Mwanza Gulf, Lake Victoria
Author(s) -
MOSILLE OLIVA I. I. W.,
MMNOYA J. R.
Publication year - 1988
Publication title -
african journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.499
H-Index - 54
eISSN - 1365-2028
pISSN - 0141-6707
DOI - 10.1111/j.1365-2028.1988.tb00965.x
Subject(s) - gonadosomatic index , biology , lungfish , fecundity , population , sex ratio , zoology , actinopterygii , reproductive biology , fishery , fish <actinopterygii> , embryogenesis , embryo , demography , sociology
Summary The population of lungfish ( Protopterus aethiopicus (Heckel)) was sampled by bottom trawling for 12 months from June 1984 to May 1985. A total of 576 lungfish were investigated. The sex ratio in the population was 1 male : 1 ‐98 females. Average size at maturity was found to be 960cm total length (TL) but the smallest matured male measured 72‐9 cm and the female 840 cm TL. It was not possible to establish spawning times and reproductive activity trends either from the variation in relative condition factor ‘kn’ or from gonadosomatic index (GSI). Whereas male lungfish seem to show no further increase in GSI after gonadal maturity stage III, females exhibit GSI values that vary directly with oocyte maturation and ovarian weights. Fat deposited along the gonads was found to be a better basis for assessing maturation and spawning in lungfish. The potential spawning period was found to be from September to May. Absence of lungfish with spent gonads over the 12‐month period and the presence of different egg sizes in ovaries, suggest that the fish is a multiple spawner. Fecundity was found to range from 705 eggs (in 84‐cm TL fish) to 14,922 eggs (in 130‐cm TL Fish).