Observations on some aspects of the biology of Sudanonautes aubryi (H. Milne Edward,1886) (Crustacea: brachyura: potamoidea: potamonautidae) in Orogodo River, Niger Delta, Nigeria

  • JA Meye Department of Fisheries Technology, Delta State Polytechnic, PMB 5, Ozoro, Nigeria
  • FO Arimoro Department of Zoology, Delta State University, PMB 1, Abraka, Nigeria
  • CA Edokpayi Department of Zoology, University of Lagos, Lagos, Nigeria

Abstract

Investigation into some aspects of the ecology of the amphibious freshwater crab, Sudanonautes aubryi (H. Milne Edwards, 1886) in Orogodo River at Abavo, Southern-Nigeria was carried out between March and August, 1995. The study revealed that the crab species is wide spread and abundant in the river. There was a seasonal trend in the level of abundance both in number and biomass. The crab showed more abundance at the peak of the rainy season (August). Both adults and juveniles showed a progressive increase from late dry season to mid-rainy season (August). The male–female ratio was 1:1.2. The fluctuation in the number and percentage of gravid females indicated that the crab spawned during the mid-rainy season (June–August). The crab attained a maximum total length and weight of 8.4cm and 89.09g respectively. Its growth pattern was isometric. The mean monthly condition factor (k) ranged from 17.15 to 23.52 and generally showed a monthly fluctuation with a peak in April.

Keywords: sudanonautes aubryi, biomass, gravid, Orogodo River, condition factor

Tropical Freshwater Biology 2003/2004 Vol. 12/13: 105-118
Published
2006-02-28
Section
Articles

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eISSN: 0795-0101