A New Camallanid Nematode from Hawaii

Abstract

Spirocamallanus istiblenni n. sp. is described from the intestine of Istiblennius zebra, a tidepool fish at Oahu, Hawaii. Female worms average 21.5 mm long, and the adult female:male length ratio is 1.44:1.0. The chief diagnostic characters include a reduced posterior ovary, a male caudal papillae pattern of six preanal and three postanal, a spicule length ratio of 3:2, and an H-shaped arrangement of the anterior excretory canal system. The buccal capsule possesses 13-14 spiral thickenings. The possible evolutionary significance of the posterior ovary is mentioned; a list of other parasites of this host and ecological consideration s are included.