Pacific Science (1998), vol. 52, no. 4: 322-333 © 1998 by University of Hawai'i Press. All rights reserved Balistes polylepis and Xanthichthys caeruleolineatus, Two Large Triggerfishes (Tetraodontiformes: Balistidae) from the Hawaiian Islands, with a Key to Hawaiian Species1 2 JOHN E. RANDALL AND BRUCE C. M UNDy3 ABSTRACT: The large triggerfish Balistes polylepis Steindachner, the most common species of the family in the eastern Pacific, was previously reported from Hawai'i as Pseudobalistes juscus (Bloch & Schneider) or questionably as B. polylepis; the identification as B. polylepis is here confirmed. Because of its rare occurrence in Hawai'i, it was believed to be a waif; however, an under­ water photograph of one guarding a nest indicates that spawning has occurred in Hawai'i. A second large balistid, Xanthichthys caeruleolineatus Randall, Matsuura & Zama, wide ranging from the western Indian Ocean to Cocos Island, Costa Rica, is recorded from the Hawaiian Islands, where it is known from 46 to 165 m. A key is presented to the 11 Hawaiian species of the Balis­ tidae. An enigmatic specimen of Canthidermis reportedly collected in Hawaiian waters is also discussed. JORDAN AND EVERMANN (1905) recorded 11 later identified as a species of Xanthichthys species of the triggerfish family Balistidae by Berry and Baldwin (1966). He referred from the Hawaiian Islands. None of the spe­ B. juscolineatus Seale to the synonymy of cies they listed is recorded by the same bi­ Melichthys buniva (Lacepede), itself a syn­ nomial name today, although four of the onym of M. niger (Bloch) (Randall and specific names are correct. Klausewitz 1973). Fowler included B. juscus Jordan and Jordan (1922) listed the same Bloch & Schneider in the Hawaiian fauna. 11 balistid species from the Hawaiian Islands, However, as discussed below, his Hawaiian but they shifted five of them from the genus specimens are B. polylepis Steindachner. The Balistes to the genus Sufflamen. They illus­ true B. juscus is a wide-ranging Indo-Pacific trated one of two species of Canthidermis, C. species now placed in the genus Pseudoba­ angulosus (Quoy & Gaimard), as plate 4, fig. listes; it remains unknown from the Hawaiian 3, clearly an adult of C. maculatus (Bloch). Islands. Fowler (1928) reported Hawaiian localities Clark (1949) included 11 species of balis­ for 11 balistid fishes. He identified specimens tids in her key to the species of Hawaiian of two species of Canthidermis as C. mac­ plectognaths based on names mentioned in ulatus (Bloch) and C. rotundatus (proce). He earlier publications. Among these, Balistapus regarded earlier Hawaiian records of Balistes undulatus has never been collected in Hawai'i. aureolus (non Richardson) as Canthidermis She mentioned Melichthys radula in her text rotundatus, but listed B. aureolus Richardson but referred to this species as M. buniva in as a junior synonym of B. ringens Linnaeus, her key and figure caption. Clark concluded that the five nominal species of Canthidermis reported from the archipelago are synonyms 1 Manuscript accepted 2 February 1998. of C. maculatus. 2Bishop Museum, 1525 Bernice St., Honolulu, Gosline and Brock (1960) recorded the Hawai'i 96817-0916. same balistids from the Hawaiian Islands as 3 Honolulu Laboratory, Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Fowler except no mention was made of Can­ 2570 Dole St., Honolulu, Hawai'i 96822-2396. thidermis rotundatus. They correctly classified 322 Triggerfishes from the Hawaiian Islands-RANDALL AND MUNDY 323 the species aculeatus and rectangulus in the Schneider) in the genus Sufflamen, but he genus Rhinecanthus. continued to use the invalid name S. cap­ Berry and Baldwin (1966) reviewed the istratus (Shaw). He also included Batistes eastern Pacific species of Balistidae. They fuscus Bloch & Schneider as a valid Hawai­ included Canthidermis rotundatus among the ian species, although he added that it is "very long list of synonyms of C. maculatus (Bloch) closely related to Batistes polylepis Stein­ and classified the Indo-Pacific Batistes frae­ dachner, 1876, a large triggerfish from the natus (Latreille) in the genus Sufflamen Jor­ eastern Pacific." dan, noting that it is a senior synonym of S. Springer (1982) stated that Batistes is capistratus (Shaw). Jordan and Evermann known in the Indo-Pacific only from Hawai­ (1905), Fowler (1928), and Gosline and ian records of "the common eastern Pacific Brock (1960) all used the name capistratus species Batistes polylepis, which has usually for this species in Hawai'i. The description been misidentified as B. fuscus in Hawaiian of S. fraenatus (Latreille) was published in references." He cited a personal communi­ March 1804, and that of S. capistratus cation from J.E.R. as the source of this (Shaw) in November 1804 (F. H. Berry, pers. information. comm., 1966). Berry and Baldwin examined In a book on shore fishes of the Hawaiian three Hawaiian specimens that had been Islands, Randall (1996) provided color pho­ identified as Batistes fuscus and concluded tographs and brief species accounts of nine that they are B. polylepis. They added, "This triggerfishes, including Batistes polylepis. He species in Hawaiian waters is generally in­ mentioned the pelagic Canthidermis mac­ adequately known or unrecognized. It may ulatus as also occurring in the Islands and also occur in other Indo-Pacific areas, and added, "the Hawaiian record of Xanthichthys these uncertainties restrict our analysis of the caeruleotineatus will be reported by the au­ zoogeography and relationships of the spe­ thor and Bruce C. Mundy." cies of Batistes." In their synopsis, however, In this paper, we show that Batistes poly­ they wrote, "Batistes polylepis, obviously re­ lepis is the correct identification for the large lated to the Atlantic B. capriscus, is more triggerfish in Hawai'i that was first identified closely related to specimens we have seen as B. fuscus. Its distribution is not known from Hawaii." to extend to other Indo-Pacific localities. We Randall (1971) showed that Batistes nyc­ also formally record the large triggerfish teris (Jordan & Evermann), a nominal Ha­ Xanthichthys caeruleotineatus Randall, Mat­ waiian species regarded as valid by Fowler suura & Zama from the Hawaiian Islands. (1928) and Gosline and Brock (1960), is the Diagnoses are presented for these two spe­ pelagic juvenile stage of Metichthys vidua cies, based on Hawaiian material, and dis­ (Solander). cussion is provided of the one extant speci­ In a paper on food habits of Hawaiian reef men identified as Canthidermis rotundatus fishes, Hobson (1974) included data on four (Proce) by Fowler (1928). A key to the Ha­ species of triggerfishes, one of which he iden­ waiian species of Balistidae is presented. tified as Xanthichthys ringens. His illustration of this species, however, is the female of X auromarginatus (Bennett), previously unre­ corded from the Hawaiian Islands. His mis­ MATERIALS AND METHODS identification was corrected by Randall et al. Hawaiian specimens of Batistes polylepis (1978), who noted that X ringens is confined and Xanthichthys caeruleotineatus are de­ to the western Atlantic. Randall et al. (1978) posited at the Bernice P. Bishop Museum, illustrated the female and male of X auro­ Honolulu (BPBM). Eastern Pacific specimens marginatus in color. of B. polylepis were examined at the Califor­ Tinker (1978) recorded and illustrated nia Academy of Sciences, San Francisco nine triggerfishes from the Hawaiian Islands. (CAS), and obtained on loan from the Scripps He correctly placed Baliste~ bursa (Bloch & Institution of Oceanography, La Jolla (SIO). 324 PACIFIC SCIENCE, Volume 52, October 1998 A loan was received of the Hawaiian speci­ Batistes polylepis Steindachner men identified as Canthidermis rotundatus by Fowler (1928) from the Academy of Natural Figures 1-3 Sciences of Philadelphia (ANSP). Balistes polylepis Steindachner, 1877: 69 Specimen lengths are recorded as standard (type locality: Magdalena Bay, Baja Cali­ length (SL), the straight-line distance from fornia, Mexico). the front of the upper lip or median upper Balistes fuscus (non Bloch & Schneider) teeth (whichever is most anterior) to the base Fowler, 1928: 451, pI. 45, fig. C (Honolulu); of the caudal fin; body depth is measured Gosline and Brock, 1960: 295; Tinker, vertically from the origin of the anal fin to 1978 :472, fig. on p. 436. the base of the dorsal fin (excluding the scaly Batistes polylepis: Berry and Baldwin, sheath at the dorsal-fin base). This measure­ 1966: 436, figs. 1, 2 A, and 4 of Mexican ment is preferred with balistid fishes because specimens. maximum depth may vary greatly depending on the degree which the pelvic flap is ex­ DIAGNOSIS: Dorsal rays III + 26-28; anal tended. Head length is taken from the front rays 25-26; pectoral rays 15; gill rakers 31 of the upper lip to the upper end of the gill (3ll-mrn specimen only); longitudinal scale opening, and snout length from the same an­ series 70-75; head scales 33-40. terior point to the fleshy edge of the orbit. Body very deep, depth at origin of anal fin Caudal-peduncle depth is the least depth. 2.0-2.05 in SL; head length 2.75-2.9 in SL; Orbit diameter is the greatest diameter be­ dorsal profile of head nearly straight; snout tween the fleshy edges of the orbit. Measure­ length 1.25-1.3 in head; a deep oblique ments of the longest dorsal and anal soft rays groove on snout extending anteriorly from exclude the basal scaly sheath. Caudal con­ eye and passing below nostrils; no prominent cavity is the horizontal distance between ver­ longitudinal oblique grooves on lower side of ticals at the tips of the longest and shortest head; orbit diameter 5.8-6.6 in head; gill caudal rays. Pectoral-ray counts include the opening 2.95-3.1 in head; caudal-peduncle rudimentary uppermost ray. Longitudinal depth 3.9-4.0 in head; pelvic flap not well scale series is the number of oblique to near­ developed; no longitudinal ridges posteriorly vertical scale rows from the upper end of the on side of body; first dorsal spine 1.65-1.9 in gill opening to the mid-base of the caudal fin.