Rev. Biol. Trop. 49 Supl. 1: 21-27, 2001 Notes on Galápagos grenadiers (Pisces, Gadiformes, Macrou r i d a e ) , with the description of a new species of Co ry p h a e n o i d e s Tomio Iwamoto and John E. McCosker California Academy of Sciences, Golden Gate Park, San Francisco, CA94118 USA[fax 1-415-750-7148; email: [email protected]] Received: 16-VIII-2000 Corrected: 23-XI-2000 Accepted: 8-XII-2000 Abstract: Two unusual specimens of the grenadier genus Coryphaenoides were collected by the deep-submersible vehicle Johnson Sea-Link off the Galápagos. Unlike any other member of the genus, the snout in these specimens was rounded, non-protruding, naked anteriorly and ventrally, with no tubercular scales marking the terminal and lateral angles. They are herein described as Coryphaenoides gypsochilus. Additional specimens of grenadiers were procured by the Johnson Sea- Link, including the second and third specimens of Nezumia ventralis and the first record of Caelorinchus canus from these waters. Three species and one subspecies of Galápagos grenadiers are endemic. Key words: Grenadier, Macrouridae, Coryphaenoides, Galápagos, deep-submersible research vehicle Two individuals of an unusual unde- other member of C o ry p h a e n o i d e s and is scribed species of grenadier were captured in somewhat suggestive of the snout shape in the Galápagos during recent California Acad- H a p l o m a c ro u ru s and K u ro n e z u m i a, emy of Sciences expeditions using the Harbor grenadiers possessing seven branchiostegal Branch Oceanographic Institution’s Johnson rays. The new species may be endemic to the Sea-Link deep-submersible manned research Galápagos, where it was observed and cap- vehicle. The presence of six branchiostegal tured along steep, rocky slopes at depths of rays, serrations along the leading edge of the 630-900 m. spinous second ray of the first dorsal fin, anus located immediately in front of the anal fin MATERIALAND METHODS with no enlarged periproct region and no sign of a ventral light organ, and a fairly typical All specimens are deposited in the squamation, mouth, and head structure sug- ichthyological collections of the California gest a relationship closest to the genus Academy of Sciences. Coryphaenoides. The peculiar snout of the Methods for making measurements and fish—low, rounded, and naked at its anterior counts follow general procedures described end, lacking spinous tubercles at tip and lat- in Iwamoto (1970) and Iwamoto & Sazonov eral angles, and scarcely protruding beyond (1988). All measurements are point-to-point. the mouth—is, however, unlike that of any The internasal, interorbital, and suborbital 22 R E V I S TA DE BIOLOGIA T R O P I C A L measurements are least bony widths. A small, over snout, then straightening from snout to splint-like ray closely adhered to the base of front of nape; from there the profile ascends the uppermost developed ray in the pectoral over nape in a high arch before descending fin is noted in the fin ray count with a small gently posteriorly to end of trunk, then grad- “i.” Transverse scale row counts are to, but ually leveling off to end of long, tapered tail. do not include, the lateral line scale. Lateral- Snout rounded, essentially non-protruding line scales are counted from the anterior ori- beyond mouth, naked anterior to lateral tips gin over a distance that is equal to that from of nasal bones and below suborbital shelf the snout tip to the origin of the first dorsal posteriorly about to area below nostrils; this fin. pattern of naked areas somewhat reminiscent of that seen in species of Kumba. Anterior Coryphaenoides gypsochilus new species portion of lower jaw also naked. Sensory Figs. 1-3 pores of head fairly prominent along dorsal and ventral margins of occipital region and Type specimens. over preopercle, but not along snout, subor- Holotype: CAS 86530 (77.2 mm HL, 390 mm TL); bital, or lower jaw. Lips thick and papilla- Galápagos, Isla Fernandina (=Narborough), Bolivar Channel, 00°14.64’S, 91°6.54’W, 732 m; Johnson Sea- ceous. Chin barbel short, stout near base, Link dive 3958; collector J.E. McCosker et al., 17 Nov. gradually tapering to fine distal tip. Opercu- 1995. Paratype: CAS 209223 (91.5 mm HL, 437 mm lar opening broad, extending from upper end TL); Galápagos, Is. Fernandina, off Cabo Douglas, of opercle to level of posterior angle of lower 00°17.4’S, 91°38.8’W, 631 m; Johnson Sea-Link dive 3088; collectors J.E. McCosker & C.C. Baldwin, 23 June jaw; a narrow free fold of gill membrane 1998. across isthmus. Gular and branchiostegal membranes naked. Gill rakers finely spinu- D i a g n o s i s . Branchiostegal rays six. lated, mostly tubercular but somewhat plate- Anus immediately before anal fin origin, like on ventralmost part of arch and on epi- small periproct lacking light organ. Head lat- branchial arm. Twelve pre-caudal vertebrae erally compressed; snout rounded, without were counted in the holotype (and paratype); prominent tubercular scale at tip or lateral there were seven anal pterygiophores before angles, scarcely protruding beyond larg e the first haemal spine. mouth, naked over anterior end and ventrally Holotype a male with a pair of well- below suborbital ridge to about vertical developed testes and 13 long, slender pyloric through posterior nostril. Opercular opening caeca. (Paratype a male with 16 pyloric wide, extending ventrally forward to below caeca, each about 20 mm long. Swimbladder angle of lower jaw. Suborbital region almost large, with two drumming muscles along vertical, lacking prominent angular ridge and anterolateral wall, and four small gas glands. coarsely modified scale rows. Base of pec- Intestines multiply looped, in a pattern simi- toral fin broad, i22-i24 rays; pelvic rays 10 or lar to that of C. anguliceps in figure 8a of 11. Iwamoto & Sazonov (1988), except for an Description of holotype (paratype char- additional short loop at oral end.) acters in parentheses). Fresh specimens have Teeth short, conical, in broad bands in a thick mucous coating over entire fish, both jaws, with outer premaxillary series including fins, but that coating is easily spaced and slightly enlarged. sloughed off with handling. Head and body Spinulation on body and head scales compressed laterally, width of head across essentially all similar, consisting of 1-5 short opercles about 1.7 times into greatest body rows of small, tightly imbricate, greatly depth; head about five times in total length. reclined, conical spinules aligned in parallel Profile of body relatively flat ventrally, but or slightly divergent rows. Height of spinule rising from mouth in a steep, rounded curve rows on each scale increasing posteriorly on I N T E R N AT I O N A L J O U R N A L OF T R O P I C A L B I O L O G Y AND CONSERVAT I O N 23 Fig. 1. Coryphaenoides gypsochilus new species, holotype, CAS 86530 (390 mm TL), Galápagos, Isla Fernandina, 732 m. Scale bar equals 25 mm. Drawn by Alison E. Schroeer. exposed field, the last spinule in each row Color. Soon after its capture, McCosker extending beyond scale margin. Spinules photographed and made color notes of the much reduced posteriorly on tail; spinules paratype. He noted: “body gray. Dorsal-most absent on scales posteriorly from about two pectoral, first pelvic, and first dorsal rays head lengths (about 2.4 head lengths in chalky-white. All other rays gray/black. paratype) behind opercular margin. A l l Anal and tail (fins) black. Opercular and sub- scales on head except those on gill cover opercular membranous margins black. Pec- small; those over suborbital region somewhat toral base black. Lips and chin barbel white.” similar to those in species of Mesobius, viz., Color of holotype preserved in 70% ethyl short, conical, closely adjacent spinules alcohol: ground color brown; lips pale; nar- aligned in a single row, but some scales hav- row black eye ring; chin barbel pale; mouth ing two or three divergent rows. Alignment dark; gill cavity black, gill filaments, arches of spinule rows give a somewhat striated pat- and rakers pale; outer margin of branchioste- tern to surface. gal rays black. Fins mostly black, although Fins well developed and typical of distal membranes (but not rays) of first dor- macrourines. First spinous ray of first dorsal sal, pectoral, and pelvic fins clear, and spin- fin minute, scarcely noticeable; second spin- ous ray of first dorsal, uppermost ray of pec- ous ray long, well-developed, the leading toral, and outer ray of pelvic fins pale. edge beset with numerous short, weak, non- (Paratype much darker, more swarthy over- overlapping serrations. Pectoral fin broad- based, its origin slightly above midlateral axis all.) of trunk, its length about equal to postorbital Counts and measurements: H o l o t y p e length of head. Pelvic fin relatively broad- first (paratype between parentheses if differ- based, short, outer ray slightly prolonged into ent). First dorsal fin rays II,10; pectoral fin a filamentous distal tip extending to base of rays [left/right] i23/i22 (i24/i23); pelvic fin 4th to 7th anal ray; most of fin extending to or rays 11 / 11 (10/11); gill rakers first arch beyond anus. (In paratype most of rays fall [outer/inner] 8/2+11 (7/3+10), second arch short of anus.) 1+11/2+11 (1+10/2+11); scales below first 24 R E V I S TA DE BIOLOGIA T R O P I C A L Fig 2.