Parmops Coruscans, a New Genus and Species of Flashlight Fish (beryciformes: Anomalopidae) from the South Pacific

— Parmops coruscans, new genus, new species, is described from a single specimen taken in 350 m at Tahiti. It is distinguished from other anomalopids by having the first four infraorbital bones expanded laterally to form a shelf beneath the eye. The light organ of P. coruscans is rotatable, and there is an erectile shutter. The shutter mechanism in Parmops is the least developed of all anomalopids. The family Anomalopidae is a small circumtropical group of nocturnal neritic beryciform fishes. The most conspicuous defining character of the group is the presence of a luminous organ beneath the eye in which symbiotic luminous bacteria are cultured (Harvey 1922). The bacteria glow continuously, and the light organ is occluded mechanically, either by rotation of its luminous face downward or by the erection of a black elastic membrane upward over it (Johnson & Rosenblatt 1988). The family was reviewed recently by McCosker & Rosenblatt (1987), who recognized five species in three genera and elevated the subspecies Photoblepharon palpebratum steinitzi to specific rank. Those authors noted the presence of two forms in the Indo-Australian area, P. palpebratum and Anomalops katoptron. Subsequently, Johnson & Rosenblatt (1988) described the mechanisms of light organ occlusion, discussed the evolution of these mechanisms in light of an hypothesized generic phytogeny, and erected a new genus, Phthanophaneron, for the eastern Pacific Kryptophanaron harveyi. The fish collection of the Bernice P. Bishop Museum (BPBM) contains a single anomalopid specimen collected in deep water at Tahiti that cannot be assigned to any known species. Our examination of that specimen indicates that it represents a clade between Anomalops and Phthanophaneron within the phylogeny proposed by Johnson & Rosenblatt (1988, fig. 10), and thus should be placed in a new genus. Whether the new species is restricted to deep water or, like Kryptophanaron alfredi and Anomalops katoptron, has a broad depth distribution, remains to be determined, along with all other aspects of its biology. The purpose of this paper is to describe the new species and discuss its relationships within the Anomalopidae. Methods and terminology are those of Rosenblatt & Montgomery (1976) and Johnson & Rosenblatt (1988) for external and light organ occlusion morphology, respectively. Parmops, new genus Figs. 1-3, Tables 1, 2 Diagnosis.— An anomalopid with the dorsolateral margins of the first four infraorbital bones expanded to form a medially sloping shelf that protrudes laterally well beyond the perimeter of the orbit, a spinous dorsal fin, two anal-fin spines, a pelvic-fin spine, a row of enlarged scutes on the belly, a fully rotatable light organ and an elastic shutter that lies flat on the floor of the orbit when relaxed. Type species.—Parmops coruscans, new species. VOLUME 104, NUMBER 2 329 Etymology. — From the Greek parme, a small shield, and ops, eye, in reference to the expanded infraorbitals. Gender masculine. Parmops coruscans, new species Figs. 1, 2, Tables 1, 2 Holotype.-BPBM 30885. A 48.2 mm SL immature individual taken 11 Aug 1985 outside the reef at Punnauia, Tahiti, Society Islands, from the stomach of a grouper, Saloptia powelli, caught at 350 m by "Fuller and Faty." Description. —Counts and measurements, in mm, of the holotype: Dorsal-fin rays V—1,16; anal-fin rays II, 12; pectoral-fin rays iil4i; pelvic-fin rays 1,5; caudal-fin rays 10, 10 + 9, 10; branchiostegals 8; gill rakers 8+22; pored lateral-line scales 30; scale rows above lateral line 8; abdominal scutes 9; vertebrae 14+ 16. Head length 18.8; predorsal length 21.4; prepelvic length 18.6; body depth 19.1; caudal-peduncle depth 10.1; caudal-peduncle length 13.9; snout length 17.7; eye 9.0; orbit 9.4; light-organ length 6.7; light organ depth 2.6; pectoralfin length 12.5; pelvic-fin length 9.2; first dorsal-spine length 2.9; fifth dorsal-spine length 4.4. Body compressed, width 3.2 in depth. Back somewhat elevated, body depth 1.5 in length without head. Snout blunt, profile sloping forward without much curvature from occiput to before eye, then descending convexly to rostrum. Nostrils just before eye, anterior with thickened posterior rim. Mouth oblique, tip of lower jaw about Vi of eye height above lower margin of eyeball, upper jaw slightly included. Maxilla extending posteriorly to about middle of eye. Posterior supramaxilla ovoid with an anterior process, covering all but posteroventral corner of maxilla. Anterior supramaxilla substantially smaller with no anteriorly directed process. Premaxillae with pronounced notch at symphysis into which lower jaw fits. Jaw teeth in bands, premaxillae with uniformly small teeth, dentaries with anterior patches of enlarged teeth that extend outside mouth. Vomer toothless, palatines with bands of teeth similar to smaller jaw teeth. Bones of head and shoulder girdle strongly sculptured, with numerous spine-bearing ridges. Cleithrum broadly exposed, dorsal expansion with serrate posterior margin. Supracleithrum exposed, its posterior margin weakly denticulate. Infraorbitals 1 -4 enlarged and laterally flared to form medially sloping shelf effectively deepening subocular pocket that accommodates light organ. Laterosensory canals of head developed as broad troughs with bony bridges. Lacrimal with three pores anteriorly followed by two larger cavities covered with smooth black membrane without papillae or pores. Postorbital canal with two bony bridges delineating three membrane-roofed spaces. Preopercular canal with two bony bridges near angle. Mandibular canal with two pores through bone anteriorly, followed posteriorly by long trough with two bony bridges near junction with preopercular canal. Canals of cranium covered by skin that appears smooth and entire, except for two lateral and one medial frontal pores above orbit, two small pores on supraorbital canal, and small temporal pore on right side. Eye prominent, its diameter about equal to postorbital head length. Much of cornea black, with subspherical clear window 6.0 mm long by 5.0 mm high. Pupil 4.0 mm in diameter. Single fleshy tubercle on posterior margin of eye on level with lower margin of pupil. Ovoid luminous organ below eye, free except at anterior end, rotatable so that luminous face can be rotated downward into pocket formed by flared infraorbitals. Outer margin of adpressed organ well below infraorbital rim. Black elastic shutter membrane attached along lateral margin of suborbital pocket, lying flat on floor of pocket when relaxed, with free margin directed medially. Scales strongly ctenoid (ct' of Johnson 330 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON