Review of the Fishes of the Genus Kuhlia (Perciformes: Kuhliidae) of the Central Pacific

Abstract

Ten species of fishes of the genus Kuhlia are recognized from Palau to Hawai'i in the North Pacific and from Fiji to Easter Island in the South Pacific: K. malo (Valenciennes) from fresh water in the Society Islands; K. marginata (Cuvier) from fresh water in the western Pacific, east to Kosrae, Caroline Islands, and Fiji; K. mugil (Forster) (K. taeniura is a synonym) from most of the Indo-Pacific (not the Hawaiian Islands) and the tropical eastern Pacific; K. munda (De Vis) from fresh and brackish water in Fiji, Vanuatu, New Caledonia, and Queensland (K. proxima Kendall & Goldsborough and K. bilunulata Herre are synonyms); K. nutabunda Kendall & Radcliffe from Easter Island; K. petiti Schultz from the Phoenix Islands, Malden Island, and the Marquesas Islands (Dules taeniurus marquesensis Fowler is a synonym); K. sandvicensis (Steindachner) from the Hawaiian Islands and other islands of the central Pacific; K. rupestris (Lacépède) from fresh water from East Africa to Samoa (K. caerulescens Regan from the Solomon Islands is a new synonym); K. salelea Schultz from fresh water in the Samoa Islands; and K. xenura (Jordan & Gilbert) from the Hawaiian Islands, with a mistaken type locality of El Salvador, Central America. The name K. sandvicensis has long been used for the common endemic species in the Hawaiian Islands; however, the original description leaves little doubt that it should apply to the species widely distributed in the central Pacific and only recently discovered in Hawai'i; it has usually been misidentified as K. marginata. The endemic Hawaiian species therefore takes the only available name, K. xenura (Jordan & Gilbert). Kuhlia sandvicensis differs from K. xenura in having a smaller eye (3.0-3.45 in head length, compared with 2.55-2.95 for K. xenura), straight dorsal profile of the head of adults (concave in xenura); usually 14 pectoral-fin rays (usually 15 in xenura), usually 50 lateral-line scales (usually 49 in xenura), gill rakers 38-43 (35-39 for xenura), and a dark reticular pattern dorsally on the head in life.

The fishes of the family Kuhliidae are moderately deep-bodied and compressed, with two opercular spines, a deeply notched dorsal fin of 10 spines and 9-13 rays, and a scaly sheath at the base of the dorsal and anal fins. They have large eyes and are primarily nocturnal, at least as adults, feethng principally on planktonic crustaceans. These fishes are generally silvery, often with dark markings on the caudal fin, the basis for the common name flagtails. The Hawaiian name āholehole is also sometimes used beyond Hawai'i. The family consists of a single genus, Kuhlia, the species of which occur in tropical and subtropical waters of the Indo-Pacific region, and one is also found in the tropical eastern Pacific. Only one species exceeds 320 mm in total length. Some species occur mainly in fresh water, whereas others are primarily marine. The latter tend to form schools by day and are typically found inshore; the young may be common in tide pools. At least some of the marine species are able to live in fresh water, and the freshwater species often occur in brackish environments.

In total 40 nominal species and subspecies of Kuhlia have been described (Eschmeyer 1998:2343), 18 of these in the genus Dules, now determined as a genus of Serranidae. Kuhlia was revised by Regan (1913), who recognized 12 species, three of which he described as new. Six species and subspecies of the genus have been described since 1913.

A second species of Kuhlia was recently discovered in the Hawaiian Islands. It is the fish currently identified as Kuhlia marginata (Cuvier), described from Java and presumed to be wide-ranging throughout much of Oceania, including Johnston Island. We examined the holotype of Dules marginatus in the Muséum National d'Histoire Naturelle in Paris (MNHN 9002, 93 mm SL, not the "syntypes" listed by Eschmeyer [1998:1019]; Cuvier described the species from a single specimen). The holotype has 13 pectoral rays, 41 lateral-line scales, and 7 + 17 gill...