The Chatham Islands endemic galaxiid: A Neochanna mudfish (Teleostei: Galaxiidae)

Abstract

Re‐examination of specimens of the endemic galaxiid from Lake Tuku a Taupo, Chatham Islands, and of specimens recently collected from the nearby Lake Rakeinui, and including much larger specimens from the latter lake (to 175 mm TL), suggests that fish from the two lakes are conspecific, and that they belong in the mudfish genus Neochanna. This conclusion is based firstly on the general form of large Rakeinui specimens, including: elongate body form and anguilliform swimming behaviour; apparent oral breathing at the surface when oxygen stressed; small eye; long, tubular, anterior nostrils; strongly developed flanges on caudal peduncle; and secondly on osteology, especially with regard to pectoral girdle and fin. As in the pectoral girdle in other Neochanna species, the coracoid does not participate in the median ventral pectoral symphysis anteriorly, and the bone is small and triangular, having no close association with either the scapula more dorsally, or the pectoral radials more posteriorly. © 2004 Journal of the Royal Society of New Zealand.