Pacific Science (1982), vol. 36, no. 2 © 1982 by the University of Hawaii Press. All rights reserved Cantherhines longicaudus, A New Filefish from Oceania, with a Review of the Species of the C.fronticinctus Complex· J. BARRY HUTCHINS 2 and JOHN E. RANDALL3 THE MONACANTHID FISH GENUS Cantherhines Caldwell and Randall (1967) to be a junior Swainson was reviewed by Randall (1964), synonym of rapanui De Buen]; these three who distinguished it from the monotypic filefishes lack caudal peduncular spines, are Amanses Gray and recognized 11 species in small to moderate in size, and have a relatively the genus from the tropical and subtropical long caudal fin. In the present paper we will Indian, Pacific, and Atlantic oceans. Hutchins review the fishes ofthis third group, which we (1977) removed one of these, longipinnis shall term the "fronticinctus complex," and (Fraser-Brunner), to his new genus Canthes­ add to it a new species, C. longicaudus, from chenia and placed melanoides (Ogilby), known the Society Islands and Cook Islands. from only the small holotype from Queens­ land, in the synonymy of Cantherhines par­ dalis (Ruppell). Recent studies (Hutchins) METHODS have shown that still another species, C. multi­ lineatus (Tanaka), should be shifted from Counts and measurements were made fol­ Cantherhines to Thamnaconus Smith. lowing Hutchins (1977). However, the termi­ The remaining eight species ofCantherhines nology used here differs with reference to the form three natural groups. The first, which structure representing the rudimentary pelvic consists ofthe western Atlantic macrocerus fin located at or near the end of the pelvis in (Hollard) and the Indo-Pacific dumerilii most monacanthids. The "pelvic bony struc­ (Hollard), is characterized by two pairs of ture" of Hutchins is replaced by "pelvic fin spines on the side of the caudal peduncle and rudiment." The length recorded for specimens relatively large size (more than 300 mm SL). is standard length (SL). The second group includes sandwichiensis Thefollowing abbreviations for institutions (Quoy and Gaimard) from the Hawaiian are used: AMS, Australian Museum, Sydney; Islands, pardalis (Ruppell) from the Indo­ BC, University of British Columbia, Van­ Pacific except Hawaii, and pullus (Ranzani) couver; BPBM, Bernice P. Bishop Museum, from the Atlantic; these three species lack Honolulu; LACM, Natural History Museum spines on the caudal peduncle, are smaller in of Los Angeles County, Los Angeles; RUSI, size, and possess a short caudal fin. The third J. L. B. Smith Institute of Ichthyology, group includes the Indo-West Pacific fronti­ Rhodes University, Grahamstown; UH, De­ cinctus (Gunther), the Hawaiian verecundus partment of Zoology, University of Hawaii, E. K. Jordan, and the Easter Island rapanui Honolulu; USNM, U.S. National Museum of (De Buen) [c. tiki Randall was shown by Natural History, Washington, D.C.; WAM, Western Australian Museum, Perth. Counts of the soft dorsal and anal fin rays 1 Fish collecting by the junior author at Easter Island are given in Table 1. These include the counts and French Polynesia was supported by funds from the from Randall (1964) and the specimens listed National Geographic Society. Manuscript accepted 16 herein for each species. December 1981. In the description ofthe new species, data in 2 Western Australian Museum, Francis Street, Perth, Western Australia 6000, Australia. parentheses refer to the paratype. Propor­ 3 Bernice P. Bishop Museum, P.O. Box 19000-A, tional measurements of the two type speci­ Honolulu, Hawaii 96819. mens are given in Table 2. 175 176 PACIFIC SCIENCE, Volume 36, Apri11982 TABLE 1 FIN-RAy COUNTS OF SPECIES OF THE Cantherhinesfronticinctus COMPLEX SOFT DORSAL RAYS ANAL RAYS PECTORAL RAYS * 33 34 35 36 37 30 31 32 33 34 11 12 13 14 fronticinctus 3 3 9 2 8 9 4 12 longicaudus 1 1 1 2 verecundus 2 13 11 9 16 18 10 25 rapanui 6 9 3 3 7 7 15 2 • Counts do not include the rudimenlary upper ray. KEY TO THE FILEFISHES OF THE Cantherhines fronticinctus COMPLEX 1. a. First dorsal spine relatively long, 1.1-1.4 in head length; a patch offine bristles on side of caudal peduncleinadulUnales; interorbital space usually crossed by two prominent dark- brown bands (East Africa to western Pacific) Cantherhines fronticinctus b. First dorsal spine shorter, 1.5-2.3 in head length; no bristles on side ofcaudal peduncle; interorbital space crossed by two faint-brown bands, never prominent. .......... .. 2 2. a. Caudal fin long, 0.9-1.1 in head length; fresh ground color generally dull yellow (Society Islands and Cook Islands) ...................... .. Cantherhines longicaudus n. sp. b. Caudal fin shorter, 1.1-1.3 in head length; fresh ground color generally gray or greenish brown 3 3. a. First dorsal spine of medium length, 1.5-1.7 in head length; maximum size of known specimens 114 mm SL; fresh ground color gray (Hawaiian Islands) . ................................................... .. Cantherhines verecundus b. First dorsal spine relatively short, 1.8-2.3 in head length; maximum size of known specimens 158 mm SL; fresh ground color usually brown to greenish brown (Easter Island) ... ............................................ .. Cantherhines rapanui Cantherhines fronticinctus Gunther along each posterolateral edge; second dorsal and anal fins not elevated anteriorly, about Figures 1,2 equal in height; longest soft dorsal ray (fifth to Monacanthus fronticinctus Playfair and eighth) 2.7-3.3 in head length; caudal fin re­ Gunther, 1867, p. 136, pI. 19 (type lo­ latively long, its length 1.3-1.6 in head length, cality, Zanzibar). the posterior border rounded; pelvic fin rudi­ DIAGNOSIS: A species of Cantherhines sep­ ment small, 3.2-4.1 in orbit diameter, consist­ arable from all other monacanthids by the ing of three pairs of incasing scales fused to following combination of characters: soft rear end of pelvis; scales on body small, each dorsal fin rays 33-36; anal fin rays 31-32; with rows of minute slender spinules which pectoral fin rays 12-14 (usually 13); gill rakers give the skin a velvety texture; an elongate 29-37; vertebrae 7 + 12; head length 2.7-3.2 patch of fine bristles on each side of caudal in SL; snout length 3.3-3.7 in SL; first dorsal peduncle of adult males. spine relatively long, its length 1.1-1.4in head Color when fresh (based on color trans­ length, originating over anterior half of eye, parencies of specimens from Western Aus­ and folding into a moderately deep groove in tralia, Seychelles, Philippines, and Okinawa): back when depressed; dorsal spine covered by yellowish brown, usually with five darker small asperities and a row ofvery small barbs body stripes, each enclosing a row of dark- C. longicaudus, A New Filefish from Oceania-HuTcHINS AND RANDALL 177 FIGURE I. Cantherhinesfronticinctus; 77 mm SL; BPBM 22322; Okinawa, Ryukyu Islands. brown spots; a brown blotch somewhat larger mens short irregular blue lines and spots than eye near tip of pectoral fin; bases of soft extend onto ventral surface ofpelvic flap); first dorsal and anal fins each with three brown dorsal spine yellowish brown with four or five saddles, the posteriormost darkest; a pale ring darker cross bands (bands sometimes indis­ encircling anterior half of caudal peduncle, tinct); soft dorsal, anal, and pectoral fin rays the posterior half either dark brown or with pale brown, membranes hyaline; caudal fin short continuations of the three body stripes; yellowish with two broad curved cross bands, a broad dark-brown band joining anterior the posterior one on distal third offin usually margin of each eye across interorbital, a very dark to almost black, the anterior one second narrower band crossing posterior inter­ faint, usually restricted to dark blotches on orbital space at base of first dorsal spine; a upper and lower fin margins. dark-brown spot behind eye (first of series of In life, Cantherhines fronticinctus is similar dark-brown spots of second brown stripe of to the fresh coloration as given above, with the body); a dark-brown blotch below eye; an following exceptions: the ground color may iridescent blue line nearly surrounding eye, vary from dark brown through yellowish the discontinuity below nbstrils where the two brown to greenish; the pale band encircling ends ofthe circle form a short acute projection anterior part of caudal peduncle is white to passing ventroanteriorly from eye; a patch of yellowish green (the most conspicuous mark­ blue wavy lines or short irregular spots in a ing underwater); a large triangular dark­ broad region anterior to gill opening which brown blotch encloses both pectoral fin base continues toward lower jaw (on some speci- and gill opening, its apex just touching the 178 PACIFIC SCIENCE, Volume 36, April 1982 FIGURE 2. Cantherhines fronticinctus; 172 mm SL; BPBM 22111; Cebu, Philippine Islands. blotch below eye; the blue markings on cheek Ryukyu Islands. It is not a common species. and pelvic flap may be absent; the anterior Smith (1949) stated that it lives mainly in shal­ dark cross band on the caudal fin may be low water among weeds. We have found it prominent or indistinct. most often on reefs. It has been taken by Preserved specimens are grayish brown to spear, rotenone, and gill nets in depths rang­ brown, many of the markings mentioned ing from the intertidal to 43 m. above still visible. The interorbital bands are Playfair and Gunther (1867) described particularly distinct. MonacanthusJronticinctusfrom two skins col­ lected at Zanzibar off the east coast ofAfrica. REMARKS: Cantherhines Jronticinctus is It was subsequently reported by Gunther found throughout the tropical and subtrop­ (1870:231) that these skins represented two ical Indian Ocean and in the western Pacific as species. He designated the skin from which the far north as the Ryukyu Islands. It has been illustration accompanying the type descrip­ reported from East Africa (Durban to Zan­ tion was made as "type." The second skin zibar), Seychelles, Indonesia, and the Philip­ was relegated (p.