Species composition and inshore migration of the tropical eels Anguilla spp. recruiting to the estuary of the Poigar River, Sulawesi Island

In order to determine the species composition and inshore migration of the tropical eels Anguilla spp. migrating to an Indonesian river, we collected 21 633 glass eels at the mouth of the Poigar River, north Sulawesi Island, throughout 1997, and subjected these samples to both morphological examinat ion and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Three species, Anguilla celebesensis, A. marmorata and A. bicolor pacifica, were found throughout the season in fluctuating abund ance, while the previously recorded A. borneensis was not recognized in the study. A. celebesensis constituted a dominant 88.3% of all glass eels migr ating to the Poigar River in 1997, and was seen throughout most of the year , with a peak in May and June. A. marmorata (11.3%) was also seen throughou t most of the year, with peak occurrence in June. A, bicolor pacifica (0.4% ) occurred only in January, March, April, October and December.