18 June 1991 PROC. BIOL. SOC. WASH. 104(2), 1991, pp. 328-334 PARMOPS CORUSCANS, A NEW GENUS AND SPECIES OF FLASHLIGHT FISH (BERYCIFORMES: ANOMALOPIDAE) FROM THE SOUTH PACIFIC
Richard H. Rosenblatt and G. David Johnson
Abstract.— Parmops coruscans, new genus, new species, is described from a single specimen taken in 350 m at Tahiti. It is distinguished from other anom- alopids 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 cir- specimen indicates that it represents a clade cumtropical group of nocturnal neritic be- between Anomalops and Phthanophaneron ryciform fishes. The most conspicuous de- within the phylogeny proposed by Johnson fining character of the group is the presence & Rosenblatt (1988, fig. 10), and thus should of a luminous organ beneath the eye in which be placed in a new genus. symbiotic luminous bacteria are cultured Whether the new species is restricted to (Harvey 1922). The bacteria glow contin- deep water or, like Kryptophanaron alfredi uously, and the light organ is occluded me- and Anomalops katoptron, has a broad depth chanically, either by rotation of its luminous distribution, remains to be determined, face downward or by the erection of a black along with all other aspects of its biology. elastic membrane upward over it (Johnson The purpose of this paper is to describe the & Rosenblatt 1988). new species and discuss its relationships The family was reviewed recently by within the Anomalopidae. Methods and ter- McCosker & Rosenblatt (1987), who rec- minology are those of Rosenblatt & Mont- ognized five species in three genera and el- gomery (1976) and Johnson & Rosenblatt evated the subspecies Photoblepharon pal- (1988) for external and light organ occlusion pebratum steinitzi to specific rank. Those morphology, respectively. authors noted the presence of two forms in the Indo-Australian area, P. palpebratum Parmops, new genus and Anomalops katoptron. Subsequently, Figs. 1-3, Tables 1, 2 Johnson & Rosenblatt (1988) described the Diagnosis.— An anomalopid with the mechanisms of light organ occlusion, dis- dorsolateral margins of the first four infra- cussed the evolution of these mechanisms orbital bones expanded to form a medially in light of an hypothesized generic phytog- sloping shelf that protrudes laterally well eny, and erected a new genus, Phthanophan- beyond the perimeter of the orbit, a spinous eron, for the eastern Pacific Kryptophanaron dorsal fin, two anal-fin spines, a pelvic-fin harveyi. spine, a row of enlarged scutes on the belly, The fish collection of the Bernice P. Bish- a fully rotatable light organ and an elastic op Museum (BPBM) contains a single shutter that lies flat on the floor of the orbit anomalopid specimen collected in deep wa- when relaxed. ter at Tahiti that cannot be assigned to any Type species.—Parmops coruscans, new known species. Our examination of that species. VOLUME 104, NUMBER 2 329
Etymology. — From the Greek parme, a illae with uniformly small teeth, dentaries small shield, and ops, eye, in reference to with anterior patches of enlarged teeth that the expanded infraorbitals. Gender mas- extend outside mouth. Vomer toothless, culine. palatines with bands of teeth similar to smaller jaw teeth. Bones of head and shoulder girdle strong- Parmops coruscans, new species ly sculptured, with numerous spine-bearing Figs. 1, 2, Tables 1, 2 ridges. Cleithrum broadly exposed, dorsal Holotype.-BPBM 30885. A 48.2 mm SL expansion with serrate posterior margin. immature individual taken 11 Aug 1985 Supracleithrum exposed, its posterior mar- outside the reef at Punnauia, Tahiti, Society gin weakly denticulate. Infraorbitals 1 -4 en- Islands, from the stomach of a grouper, Sa- larged and laterally flared to form medially loptia powelli, caught at 350 m by "Fuller sloping shelf effectively deepening subocu- and Faty." lar pocket that accommodates light organ. Description. —Counts and measure- Laterosensory canals of head developed as ments, in mm, of the holotype: Dorsal-fin broad troughs with bony bridges. Lacrimal rays V—1,16; anal-fin rays II, 12; pectoral-fin with three pores anteriorly followed by two rays iil4i; pelvic-fin rays 1,5; caudal-fin rays larger cavities covered with smooth black 10, 10 + 9, 10; branchiostegals 8; gill rakers membrane without papillae or pores. Post- 8+22; pored lateral-line scales 30; scale rows orbital canal with two bony bridges delin- above lateral line 8; abdominal scutes 9; eating three membrane-roofed spaces. vertebrae 14+ 16. Head length 18.8; pre- Preopercular canal with two bony bridges dorsal length 21.4; prepelvic length 18.6; near angle. Mandibular canal with two pores body depth 19.1; caudal-peduncle depth through bone anteriorly, followed posteri- 10.1; caudal-peduncle length 13.9; snout orly by long trough with two bony bridges length 17.7; eye 9.0; orbit 9.4; light-organ near junction with preopercular canal. Ca- length 6.7; light organ depth 2.6; pectoral- nals of cranium covered by skin that ap- fin length 12.5; pelvic-fin length 9.2; first pears smooth and entire, except for two lat- dorsal-spine length 2.9; fifth dorsal-spine eral and one medial frontal pores above length 4.4. orbit, two small pores on supraorbital canal, Body compressed, width 3.2 in depth. and small temporal pore on right side. Eye Back somewhat elevated, body depth 1.5 in prominent, its diameter about equal to post- length without head. Snout blunt, profile orbital head length. Much of cornea black, sloping forward without much curvature with subspherical clear window 6.0 mm long from occiput to before eye, then descending by 5.0 mm high. Pupil 4.0 mm in diameter. convexly to rostrum. Nostrils just before Single fleshy tubercle on posterior margin eye, anterior with thickened posterior rim. of eye on level with lower margin of pupil. Mouth oblique, tip of lower jaw about Vi of Ovoid luminous organ below eye, free ex- eye height above lower margin of eyeball, cept at anterior end, rotatable so that lu- upper jaw slightly included. Maxilla ex- minous face can be rotated downward into tending posteriorly to about middle of eye. pocket formed by flared infraorbitals. Outer Posterior supramaxilla ovoid with an an- margin of adpressed organ well below in- terior process, covering all but posteroven- fraorbital rim. Black elastic shutter mem- tral corner of maxilla. Anterior supramax- brane attached along lateral margin of sub- illa substantially smaller with no anteriorly orbital pocket, lying flat on floor of pocket directed process. Premaxillae with pro- when relaxed, with free margin directed me- nounced notch at symphysis into which dially. lower jaw fits. Jaw teeth in bands, premax- Scales strongly ctenoid (ct' of Johnson 330 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
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Fig. 1. Holotype of Parmops cornscans, BPBM 30885. A. Whole specimen in lateral view, light organ occluded. B. Head in dorsolateral view, light organ exposed.
1984), small, and difficult to enumerate be- Gill rakers on first arch well developed, cause of irregular arrangement, approxi- lath-like; length of first raker below angle mately 100 lateral body rows. Head scale- about Vi eye diameter; rakers becoming less except for a few irregular scales at shorter on succeeding arches, those on last anterodorsal corner of opercle, along pre- arch nubbins. Pseudobranch well devel- opercle and on cheek. Gular isthmus naked, oped, with about 18 filaments, longest with transverse fleshy ridges. No cycloid slightly longer than filaments of first gill arch. scales on body. Scale sheaths well-devel- Spinous dorsal fin relatively low, first oped at bases of dorsal and anal fins. Mid- spine about half length of succeeding four, ventral row of 9 enlarged keeled scales which are subequal. Dorsal and anal soft (scutes) along abdomen. rays mostly broken. First anal spine about VOLUME 104, NUMBER 2 331
Fig. 2. Holotype of Parmops coruscans. Head, light organ occluded, with outline of frontal view to left and light organ and associated structures, removed, below: LD, Ligament of Diogenes; LO, light organ; M, stalk muscle; SN, rudiment of shutter knob; ST, stalk. equal in length to first dorsal spine. Second with no attenuation at the commissure. Pos- anal-fin ray a spine in transition, segmented teriorly the stalk articulates loosely with the at tip. Caudal-fin rays broken. supporting fibrocartilage cup of the organ Pectoral fin angulate, length about 1.5 in and is attached to it by two short ligaments. head, third through sixth rays subequal and The antero ventral comer of the cup extends longest. Pelvic fin shorter than pectoral, ex- forward as a short process that is connected tending to within 0.4 eye diameter of anal- directly by one of the short ligaments to the fin origin. Color black, fins and lower part posteroventral comer of the stalk, which of head darkest. Lateral line conspicuously bears no ventral hook. There is no discrete paler than rest of body. shutter knob, but there is a slight thickening Etymology. — From the Latin coruscans, at the anterodorsal comer of the shutter. sparkling, in reference to the subocular light The cup is a crescentic structure that em- organ. braces the anterior end of the light organ Occlusion mechanism. —The light organ, and extends posteriorly along about two- stalk and supporting cup are shown in Fig. thirds of its ventral surface. Anteriorly, the 2. The light organ is borne on a fibrocarti- cup is expanded as a medially projecting lage stalk that is continuous across the snout shelf. The stalk muscle is relatively small, 332 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Table 1. —States of characters not associated with Table 2.—Light-organ associated character states in light-organ complex in Parmops. (Characters num- Parmops. (Characters numbered as in Johnson & Ro- bered as in Johnson & Rosenblatt 1988). senblatt 1988).
1 Epipleural ribs 2 I Attachment of LD on cup Lateral 2 Branchiostegals Spiny II Attachment of LD anteriorly Maxilla 3 Openings in pars jugularis ? III Cup with medial shelf Moderate 4 Parasphenoid flanges ? IV Insertion of stalk muscle dor- Ligament 5 Swimbladder stay - sally to cup 6 Postorbital papillae 1 V Stalk with inward flexure at — 7 Cephalic sensory canal covering Smooth** cup articulation 8 Lateral-line tubes Closed VI Rotation pad — 9 Midventral scutes Continuous VII Postocular skin flap — Dorsal Fin V-I, 16 Villa Erectile shutter + * 10 Predorsals 0/0/1 + 1/ VIHb Shutter knob — 11 Supramaxillae 2* IX Stalk hook - 12 Transverse ridges on gular isth- + * X Stalk continuous across snout + * mus XIa EM with groove + * 13 Lateral dentary tooth patch Large "V"* Xlb EM with medial swelling - 14 Body scale rows ca. 100* XII Hook and shutter knob inti- NA 15 Reflective or transparent lateral + * mately associated line scales XIII Cup process attached to stalk NA 16 Pelvic spine + hook by ligament 17 Anal spines II XIV Organ rotatable + 18 Vertebrae 14+16 19 Comer of maxilla Smooth Derived states, all shared with Phthanophaneron, Kyptophtanaron, and Photoblepharon. * Derived states shared with Phthanophaneron (lacks 15), Kryptophanaron, and Photoblepharon. Derived state shared as a homoplasy with Kryp- sertion on the maxilla, giving rise to a tophanaron. broader but thinner segment that passes ventrally to insert on the palatine. with little differentiation between the dorsal Relationships. —In physiognomy, Par- portion, which inserts on the dorsal liga- mops most closely resembles Phthanophan- ment that connects the cup and stalk, and eron, and this similarity is reflected in the the ventral portion, which inserts on the primitive nature of the light occlusion articular termination of the stalk. The Lig- mechanism as well. Table 1 lists characters ament of Diogenes attaches to the antero- not associated with the light organ mecha- medial comer of the cup shelf and runs an- nism and Table 2 lists those that are. Our terodorsally, passes over a slight groove in hypothesis of relationships based on these the ethmomaxillary ligament at its forward characters is presented in Fig. 3. Among the flexure, and inserts on the lateral face of the characters not associated with the light or- rostral cartilage. The ethmomaxillary liga- gan mechanism, Parmops shares five de- ment originates dorsally on the mesethmoid rived states with the Phthanophaneron- and extends ventrally, flexes anteroventral- Kryptophanaron-Photoblepharon (hereafter ly at the groove, and then passes around the P.-K.-P.) clade and none with Anomalops. cartilaginous tip of the palatine to insert on For one of those five apomorphies, the pres- the ventrolateral margin of the maxilla just ence of reflective or transparent lateral-line ventral to its head. The groove in the eth- scales (character 15), there is an alternative momaxillary ligament is weakly developed interpretation equally parsimonious to the and there is no notable swelling on the me- topology shown on the cladogram, i.e., in- dial surface of the latter. The ethmomaxil- dependent acquisition in Parmops and at lary ligament branches just dorsal to its in- the K.-P. node rather than reversal in VOLUME 104, NUMBER 2 333
XII - XV
X, Xla
Fig. 3. Cladogram of anomalopid genera. Characters as in Tables 1 and 2. Parentheses and brackets respec- tively denote hypothesized independent acquisitions and reversals.
Phthanophaneron. Of the light-organ asso- Museum, made it available to us for study. ciated characters, Parmops shares three, an W. D. Anderson, R. Birdsong, J. E. Mc- erectile shutter, a continuous stalk, and a Cosker and R. Vari critically read the manu- groove in the ethmomaxillary ligament, with script. The drawings were executed by P. the P. -K. -P. clade. Parmopsis primitive with Hollingsworth. respect to members of that clade in two states, absence of a stalk hook and shutter knob. Parmops is thus placed at the base of Literature Cited the shutter-mechanism lineage, as the sister Harvey, E. N. 1922. The production of light by the group of the P.-K.-P. clade. These four gen- fishes, Photoblepharon and Anomalops. — Pub- era ostensively provide a rare illustration of lications of the Carnegie Institution, Washing- the gradual evolutionary elaboration of a ton 312:45-61. functional complex, in which each genus ex- Johnson, G. D. 1984. Percoidei: development and relationships. Pp. 464-498 in H. G. Moser, W. hibits a slightly more intricate and inte- J. Richards, D. M. Cohen, M. P. Fahay, A. W. grated linkage system to effect shutter erec- Kendall, Jr., and S. L. Richardson, eds., Ontog- tion. eny and systematics of fishes. American Society of Ichthyologists and Herpetologists Special Acknowledgments Publication No. 1. , & R. H. Rosenblatt. 1988. Mechanisms of We wish to thank J. E. McCosker for ser- light organ occlusion in flashlight fishes, family endipitously bringing the present specimen Anomalopidae (Teleostei: Beryciformes), and the evolution of the group.—Zoological Journal to our attention. L. Wrobel obtained the of the Linnean Society 94:65-96. specimen, recognized its interest, and pre- McCosker, J. E, & R. H. Rosenblatt. 1987. Notes served it. J. E. Randall, Bernice P. Bishop on the biology, taxonomy, and distribution of 334 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
anomalopid fishes (Anomalopidae: Beryci- (RHR) Scripps Institution of Oceanog- formes).-Japanese Journal of Ichthyology 34: . . ,^T\T\ 157 164 rapny, La Jolla, California 92093; (GDJ) Rosenblatt^. H.,&W.L.Montgomery. 1976. Kryp- ••• »f ^shes, •£T* SS„f toM^^^arv^anewanomalopidnshfrom Natural History, Smithsonian Institution, the eastern tropical Pacific, and the evolution Washington, DC. 20560. of the Anomalopidae.—Copeia 1976:510-515.
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