A Freshwater Bryozoan, Hyalinella vaihiriae Hastings (1929), from Hawaiian Prawn Ponds

Abstract

The occurrence of Hyalinella vaihiriae Hastings (1929) in ponds for culturing freshwater prawns at Kekaha, Kauai, represents a new record to the Hawaiian fauna and the second record of a phylactolaemate bryozoan from the islands. This represents the fourth record of this species which was first described from a lake at 427 m elevation on Tahiti. The known distribution also includes E. Australia and Utah, United States. The bryozoan was found growing in a broad band to a depth of 60 cm attached to vegetation around the banks of the ponds. Specimens collected in both May and August 1982 contained statoblasts, but they were much more numerous in the August material. In the laboratory adult prawns were observed to feed on the bryozoan which grew more luxuriantly in ponds holding a reduced standing crop of prawns. The prawn ponds at Kekaha, Kauai, are no longer operational so the exact status of this species in Hawaii is not known.