A REVIEW OF THE OPHIDIOID FISH GENUS. DESCRIPTION OF A NEW SPECIES FROM THE vvtestern NORTH ATLANTIC

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1 A REVIEW OF THE OPHIDIOID FISH GENUS LUCIOBROTULil WITH THE DESCRIPTION OF A NEW SPECIES FROM THE vvtestern NORTH ATLANTIC DANIEL M. COHEN Bureau of Commercial Fisheries, Ichthyological Laboratory, Washington, D. C. ABSTRACT Luciobrotula has heretofore been known from the Philippines, Japan and the Gulf of Aden. The genus is redefined and Volcanus, from Hawaii, is relegated to the synonymy of Luciohrotula. A new species from the Gulf of Mexico, Caribbean, and tropical western Atlantic is described. INTRODUCTION The species described as new in this paper was trawled by the Bureau of Commercial Fisheries exploratory fishing vessel OREGON. I am much indebted to Harvey R. Bullis, Jr., for placing specimens at my disposal. While studying the western Atlantic material reported upon herein it became apparent that it was most closely related to the recently described Hawaiian genus Volcanus Gosline, Further study revealed that Vo/canus and Luciobrotu/a Smith & Radcliffe, 1913, are congeneric and this genus is diagnosed and considered to contain three species. All of the previously unreported specimens described in this paper are distorted. They share in common with the holotype of V o/canus lineatus the fact that their heads are thrown back and their branchial membranes and opercles are flared out. For this reason, measurements are not as precise as might be desired. Counts of rays in the dorsal, caudal and anal fins, and numbers of vertebrae were taken from X-ray photographs. Definitions of most of the counts and measurements are given in Cohen (in press). One additional measurement is preventral, distance from the tip of the lower jaw to the base of the ventral fin. 1 am indebted to Bruce B. Collette of the Bureau of Commercial Fisheries, Walter R. Courtenay, Jr., of Duke University and William A. Gosline of the University of Hawaii for their kindness in reviewing the manuscript. Genus Luciobrotula Smith & Radcliffe, 1913 Luciohrotula Smith & Radcliffe, ] 913, in Radcliffe, ] 913, p. ] 70 (type species by original designation, Luciobrotula bartschi Smith & Radcliffe). Volcanus Gosline, 1954, p. 78 (type species by original designation, Vo/canus lineatus Gosline). External intromittent organs absent, species probably oviparous. Body elongate, but the tail not greatly elongated and tapering. Barbels absent;

2 388 Bulletin of Marine Science of the Gulf and Caribbean [14(3) shaft of maxillary sheathed beneath the eye; however, posterior margin of maxillary greatly expanded and free. Small, granular teeth present on premaxillaries, dentaries, vomer and palatines; gill rakers three; tongue small, with a sharp anterior extension. Branchiostegal rays eight; a weak spine buried in the flesh near the upper angle of the operc1e; posterior margin of preoperc1e free, lacking spines. Body completely covered with small cycloid scales, as are the bases of the pectoral and vertical fins; snout naked, bearing a series of fleshy flaps and ridges, pores and pit organs; a single, incomplete lateral line tube extending along the side of the body over the scales and dorsal to the midline. Tubular anterior nostril about midway between posterior nostril and tip of snout, not on upper lip. Eye small, with horizontal diameter greater than vertical. Vertical fins confluent but caudal fin exserted. Each ventral fin with two rays; ventral fin originating behind the symphysis of the c1eithra by a distance equal to at least the vertical diameter of the eye and at or behind the level of the posterior margin of the preoperc1e. The two ventral fins closely adjacent, not separated by an interspace. Pectoral fin broadly rounded, supported on a fan-like, fleshy, scale-covered base, lacking any free or elongated rays. Neural spine on first centrum shorter than subsequent spines; neural spines on abdominal vertebrae depressed, the posterior ones with more or less truncate tips. Ribs present on first two centra. Anterior ribs serving as swimbladder support. First three ribs with thickened leading edges and thin, blade-like posterior expansions. Pyloric caecae absent. Lining of body cavity dark; lining of mouth and branchial cavity pale. Discussion-Gosline (1954) related Volcanus to Luciobrotula. I have examined the holotype and one other, previously unreported specimen of L. bartschi, the single species described in the genus, and I can find no generic differences distinguishing Volcanus from Luciobrotula. Gosline stated that Volcanus differed from Luciobrotula in lacking a lower opercular spine; in having an incomplete, tubular lateral line; in having flaps and lines (i.e., ridges) on the snout and in having scales on the upper part of the suborbital area and on the area between the posterior nostril and the eye. I will discuss each of these characters. 1. Opercular spine. Virtually all ophidioids have an inverted, L-shaped process on the operde. It is skin-covered with only the posterio-dorsal point, which is the so-called opercular spine, protruding in most species. The holotype of L. bartschi was apparently initially preserved in alcohol causing the skin to shrink against the body. In addition, the skin has partially cleared so that the end of the ventral arm of the inverted, L-shaped opercular process is visible. This is the "lower spine" mentioned

3 1964] Cohen: Review of Luciobrotula 389 by Smith & Radcliffe (in Radcliffe, 1913) in their original description of L. bartschi. Volcanus possesses an identical structure beneath the skin of the opercle. One difference between the two nominal genera, however, is that in Volcanus the tip of the upper opercular spine is rather flattened in cross section, and blunt, while in Luciobrotula the spine is round in cross section and sharp. 2. Lateral line. Interpretation of this character was also affected by poor preservation. Careful observation of the holotype of L. bartschi leads me to believe that the lateral line in Luciobrotula is similar to that in Volcanus. I find no trace of the posterior section of the lateral line illustrated by Radcliffe (1913). There are, however, some darkly pigmented remnants of what appears to have been a lateral line tube running parallel to the dorsal profile intermediate between the midline of the body and the dorsal profile and disappearing close to the level of the vent. This interpretation is confirmed by the lateral line on the second specimen of L. bartschi at hand. 3. Flaps and ridges on the snout. Although Smith & Radcliffe (in Radcliffe, 1913) do not mention it in their description, the snout of the holotype of L. bartschi does indeed bear flaps. There is a prominent fleshy mound at the tip of the snout bearing six fleshy flaps. Structures which may have been ridges prior to preservation are also present. My second specimen of L. bartschi has definite ridges and flaps on the snout. 4. Squamation on the upper part of the suborbital and between the posterior nostril and the eye. On the basis of Smith & Radcliffe's original description and illustration Gosline assumed that these areas lacked scales in Luciobrotula. This is actually not the case. Close observation shows the remnants of scale pockets and even a few scales in these areas. Relationships.-Gosline (1954) postulated the existence of a group of oviparous brotulid genera which are morphologically intermediate between the oviparous genera and the viviparous genera designated by Norman (1939). Of Hawaiian deep-water brotulids, Gosline (1954) assigned Pycnocraspedum and V olcanus to this group and by inference also included Luciobrotula. I quite agree with his suggestions and would go a step farther and place Petrotyx (including Pseudobythites; see Bohlke, 1955) in this assemblage as well. I defer comment, however, on Gosline's mention of Brotula and its similarities to this group. For the present Luciobrotula can be distinguished within this nameless group of genera by the following combination of characters; body elongate; posterior margin of maxillary free, not sheathed; posterior margin of preopercle free, not buried in flesh on the cheek; caudal fin exserted; flaps, ridges and papillae present on head; however, snout, lips and ventral

4 390 Bulletin of Marine Science of the Gulf and Caribbean [14(3) surface of head not densely covered with prominent papillae; pleural ribs reduced, not prominent elongate structures. Luciobrotula resembles this group in the following ways; external intromittent organs absent, species probably oviparous; barbels absent; small granular teeth present on premaxillaries, dentaries, vomer and palatines; gill rakers 3; tongue small with a pointed anterior extension; branchiostegal rays 8; body completely covered with small cycloid scales; tip of snout lacking scales; a single lateral line running above the midline of the body; anterior nostril not directly over upper lip but located midway between posterior nostril and tip of snout; vertical fins confluent; each ventral fin with two rays; pectoral fin broadly rounded, supported on a fleshy, fan-shaped, scale-covered base, lacking any free or elongated rays; anterior ribs serve as swimbladder support. I have examined the following material in preparing the foregoing sections: The holotype and a previously unreported specimen (USNM , Philippines, ALBATROSS station D 5445, 383 fms.) of Luciobrotula bartschi, and the holotypes of Pycnocraspedum armatum and Volcanus lineatus in the U.S. National Museum; specimens of Petrotyx hopkinsi and P. sanguine us in the U.S. National Museum and Academy of Natural Sciences of Philadelphia; the type material of the new species described below. I am indebted to the curators in Philadelphia and Washington for the opportunity to examine specimens in their collections. Species.- Three species may be assigned to Luciobrotula as defined above. L. bartschi, known from two specimens (one the type) from the Philippines; one specimen from the Gulf of Aden (Norman, 1939); and two specimens from Province Tosa, Japan (Kamohara, 1954). L. lineata, known from a single specimen taken off Hawaii. L. corethromycter, herein described as new, from the Gulf of Mexico, Caribbean, and tropical western Atlantic. These species may be distinguished by use of the following key. la. Lateral line terminating at about level of origin of dorsal fin; gill rakers stubby, shorter than the vertical diameter of eye; eye 7.0 times in head; ventral fin 1.5 times in head L. lineata (Gosline) 1b. Lateral line terminating at about level of origin of anal fin; gill rakers elongate, longer than vertical diameter of eye; eye 7.9 to 10.9 times in head; ventral fin 1.9 to 3.5 times in head 2. 2a. Dorsal fin rays 87-89; preventral distance 16.4 to 16.7 per cent of standard length; ventral fin 1.9 to 2.2 times in head; pectoral fin rays 25-26, vertebrae 52 L. bartschi Smith & Radcliffe 2b. Dorsal fin rays ; preventral distance 18.5 to 21.7 per cent of standard length; ventral fin 2.3 to 3.5 times in head; pectoral fin rays 27-29; vertebrae L. corethromycter, new species

5 1964] Cohen: Review of Luciobrotula 391 Luciobrotula corethromycter, Figs. 1-5 new species Material Studied.-HOLOT PE: USNM , off north coast of Panama: OREGON sta.3586, 9 c 20'N, 81 24'W, fms., 25 May 1962 (534 mm. SL). PARAT PES.-Gulf of Mexico: USMN , OREGON sta. 3655, 29 1O.5'N 'W, fms., 26 July 1962 (295 mm. SL).- USNM , OREGON sta. 4145, 24 25'N, 83 29'W, 300 fms., 14 Dec (310 mm. SL).-CNHM 66454, OREGON sta. 4571, 23 04'N, 86 37'W, 400 fms., 7 Dec (435 mm. SL).-MCZ 42930, OREGON sta. 4558, 24 25'N, 83 30'W, 300 fms., 2 Dec (277 mm. SL).- Panama: USNM , OREGON sta. 3601, 9 07'N, 81 10'W, 400 fms., 31 May 1962 (390 mm. SL).-Guiana: USNM , OREGON sta. 4296, 7 55'N, 53 55'W, 500 fms., 22 March 1963 (500 mm. SL).- USNM , OREGON sta. 4293, 7 14'N, 52 55'W, 400 fms., 21 March 1963 (414 mm. SL).-UMML 13664, OREGON sta. 4300, 7 44'N, 54 19'W, 300 fms. 23 March ]963 (440 mm. SL). Measurements and Counts.-Given in per cent of standard length, the average first followed by range in parentheses. Preanal 53.2 ( ); predorsal 32.1 ( ); preventral 20.3 ( ); head length 23.7 ( ); depth of body at vent ]5.] (13.8-]6.9); snout 6.0 TABLE 1. COUNTS OF THREE SPECIES OF LUCIOBROTULA Dorsal fin rays L. bartschi 1 - I L. lilleata L. corethromycter L. bartschi L. lilleata L. corethromycter L. hartschi L. lineata L. corethromycter Anal fin rays 6R ] Caudal fin rays Pectoral fin rays Vertebrae

6 392 Bulletin of Marine Science of the Gulf and Caribbean [14(3) E E

7 19641 Cohen: Review of Luciobrotula 393 ( ); length of upper jaw 12.6 ( ); width of expanded posterior portion of maxillary 4.5 ( ); pectoral fin length 11.8 ( ); ventral fin length 8.2 ( ); horizontal diameter of orbit 2.4 ( ). Lateral scale rows difficult to count, ranging from about 125 to about 145; other counts given in Table 1. Description.-Body long, depth at vent 5.9 to 7.2 in standard length but tail not greatly elongated and whiplike. Several specimens have their bellies greatly distended with food or ripe gonads. In all of the specimens examined the head is deflected up and back, and the opercles and branchial membranes are expanded making it difficult to discern the shape of the head. It seems probable, however, that the anterior part of the head is depressed. Dorsal fin originating well behind the nape, over the posterior half or third of the pectoral fin; proximal three-fourths or more of the dorsal and anal fins covered with thick, fleshy, scale-covered skin. The scales on the skin covering the dorsal and anal fins are smaller and kss regularly arranged than the scales along the sides of the body. Rays of the caudal fin notably longer than adjacent dorsal and anal fin rays. Pectoral fin short, 1.7 to 2.3 in head, broad and paddle-shaped with a fleshy scale-covered lobed base. Scales extend out about one-half the length of the fin. Each ventral fin with two rays which are united at their bases, outer ray one-half to two-thirds the length of the inner ray; middle rays relatively short, extending only slightly beyond the level of the origin of the pectoral fin. Ventral fin originating well behind the anterior tip of the symphysis of the cleithra, a distance equal to at least the vertical diameter of the orbit. Body completely covered with small cycloid scales, which extend out onto the distal three-fourths or more of the bases of the dorsal and anal fins and onto the caudal fin. The scales along the body are arranged in regular rows, the scales on the fins are smaller and irregularly arranged. The head also bears small scales; however, the anterio-ventral part of the suborbital and the anterior part of the snout are naked (Fig. 2). Scales are present on the expanded, posterior portion of the maxillary along the rami of the lower jaw and on the branchiostegal membranes between the upper four or five branchiostegal rays. A single lateral line along the side of the body, originating at the upper angle of the opercle and extending posteriorly in a straight line placed about midway between the midline and the dorsal profile of the body. This lateral line extends posteriorly to approximately the level of the vent where it terminates, although a few interrupted segments may be present posteriorly. The lateral line is a fleshy tube which actually overlays the scales (Fig. 3) as Gosline (1954) has described for L. lineata. About two dozen pores are present at the ends of the very short branches which are given off both above and below the lateral line. The latera1is

8 394 Bulletin of Marine Science of the Gulf and Caribbean [14(3) FIGURE 2. Luciobrotu/a corethromycter, holotype, USN M , 534 mm standard length. Dorsal view of head showing squamation, ridges and flaps. Drawn by Mildred H. Carrington. system also continues onto the head. The lateral canal has a single pore located on a papilla above the gill opening. The supraorbital canal has three pores (two in one specimen); one is located between the fleshy flaps on the upper lip and is difficult to distinguish from a series of deep pits containing pit organs, which are also located between the nose flaps. The other two pores of this series are located along the fleshy ridges on the top of the snout. The infraorbital series most commonly has five pores, with two as elongate slits in the skin of the upper lip beneath the nostrils and the other three along the lower edge of the suborbital. In two specimens there are several additional pores which appear to belong in this series, located lateral to the posterior two pores in the supraorbital series. The preoperculomandibular series has seven or eight pores. Two are located near the tip of the lower jaw, the second is partly fused to its mate on the other side; three, four and five are located along the ramus of the lower jaw; six is located a short distance posterior to the hind margin of the maxillary; seven and eight (sometimes only seven) are located along the hind margin of the preopercle. There are several FIGURE 3. Luciobrotula corethromycter, paratype, USNM Section of lateral line. Drawn by Mildred H. Carrington.

9 J 964] Cohen: Review of Lllciobrotula 395 series of pit organs on the head; however, they will not be further de;" scribed in this paper..' Snout depressed, the anterior two-thirds to three-fourths lacking scales. The tip of the snout (Fig. 2) bears a series of broad, fleshy flaps which are overlain by two broad fleshy lappets, one on either side of the snout; the bases of the flaps and the lappet are interspersed with deep pit organs and one of the pores of the supraorbital series. The snout also bears a series of prominent, fleshy ridges which are illustrated in Figure 2. The opercular spine near the upper angle of the operc1e is a broad, flattened structure with a rather blunt tip which protrudes through the skin in a few specimens but is buried beneath the skin in the others. The eye is small; the horizontal diameter, which is greater than the vertical, is 9.1 to 10.3 in the head. The iris is greatly reduced in proportion to the lens. The posterior nostril is a large, circular opening located at about FIGURE 4. Luciobrotula corethromycter, holotype, USNM Diagram of looth-bearing (stippled) areas in the jaws. Drawn by Mildred H. Carrington.

10 396 Bulletin of Marine Science of the Gulf and Caribbean [14(3) the midlength of the snout. The tubular anterior nostril is closer to the tip of the snout than to the posterior nostril; it is located at about the level of the posterior nostril, well above the upper lip. The jaws are large, extending at least an eye diameter beyond the eye. The suborbital sheaths the shaft of the maxillary; however, the broadly expanded posterior end of the bone is free. All teeth (Fig. 4) are small and granular. Wide bands are present on the dentaries, premaxillaries and palatines; the vomerine tooth patch has two widely flaring wings. There are five basibranchial tooth patches; the most anterior and largest is unpaired; it begins at the base of the first gill arch and extends posteriorly almost to the base of the third gill arch. Paired ooth patches are present at the bases of the third gill arches, at the posterior end of the elongate median patch; these two patches and the median patches are very close to each other, separated by only a narrow line of flesh. Another pair of tooth patches is present posterior to the bases of the fourth gill arch. Three pairs of suprabranchial tooth patches are present. The anterior gill arch (Fig. 5) bears three prominent rakers, one at the angle and two on the lower arm. The arch is paved with patches of granular teeth similar to those on the jaw bones. Each of the three gill rakers also bears granular teeth along its inner surface. The gill filaments are relatively short; filaments opposite the angle of the first gill arch are equal to about three-fourths the diameter of the eye; the filaments on subsequent arches are somewhat longer, being equal to or longer than the vertical diameter of the eye. The pseudobranch is reduced to one or two filaments or is completely absent. The branchiostegal membranes are free from the isthmus and connected to each other for a short distance at their anterior extremes. There is no evidence of external s('xual dimorphism. The gonads are paired in the male. In the female the ovaries are fused medially into a single, bilohed structure. Each lobe is pat:ked with many slender tubes, each of which is packed with eggs. Each tube is flattened distally into a flat membranous plate which is apparently closely appressed to the ovarian membrane. The anterior three ribs serve as a swimbladder support. Walter R. Courtenay made some observations on the ribs of a female (USNM ) which he has allowed me to summarize. The first rib has a strong, thickened leading edge and a flattened tip which is connected with a lateral extension of the tunica externa of the swimbladder. The second rib has an extensive, thin, blade-like area behind the thickened leading edge; the medial part of the distal end of this blade-like area supports the swimbladder. The third rib is smaller but similar in structure and function and has a lesser blade-like area. The third rib is the first one to bear an epipleural.

11 1964] Cohen: Review of Luciobrotula 397 FIGURE5. Luciobrotu/a corethromycter, paratype, USNM First gill arch of left side; top figure is lateral view, bottom picture is medial view. Drawn by Mildred H. Carrington. The anterior projections of the cleithra are loosely held together. The pelvic girdle is joined to the cleithra by a ligament. The head and most of the body is brown; the belly is darker, as are the extremities of all but the ventral fin. One specimen, USNM , is very pale, and appears to have been dead long before it was preserved. This species has been taken singly at nine different localities, two off the north coast of Panama, one off Campeche, one off the mouth of the Mississippi, two west of the Florida keys, and three off the Guianas. Depths range from 300 to 500 fathoms. All specimens were taken from a mud bottom. The specimen from OREGONstation no contained a partially digested example of the caridean shrimp Glyphocrangon longleyi (identified

12 :398 Bulletin of Marine Science of the Gulf and Caribbean [14(3) through the kindness of Dr. Raymond Manning of the U.S. National Museum). The name corethromycter is from the Greek korethron (broom) and mykter (nose) and alludes to the tuft on the end of the nose. SUMARIO UNA REVISION DEL GENERO DE PECES Luciobrotula CON LA DESCRIPCION DE UNA NUEVA ESPECIE DEL ATLANTICa NOR-OCCIDENTAL El genero Luciobrotula ha sido conocido previamente por una sola especie de las Filipinas, el Japon y el Golfo de Aden. EI genero Volcanus, de Hawaii, es considerado como sin6nimo de Luciobrotula. Se diagnostica Luciobrotula y sus relaciones con Pycnocraspedum y se discute Petrotyx. Estos tres generos comprenden un pequeno grupo de especies probablemente ovfparas, que morfologicamente son intermedias entre un gran grupo de formas oviparas, y un gran grupo de formas viviparas. Se da una descripci6n nueva de Luciobrotula de la regi6n tropical del Athlntico Occidental. Se tomaron ejemplares de fondos fangosos a profundidades de 300 a 500 brazas en localidades del Golfo de Mexico, del Caribe, en el area de Panama y de las Guayanas. REFERENCES BOHLKE, JAMES The brotulid fish genus Petrotyx from the Great Bahama Bank. Notula Naturae, Acad. Nat. Sci. Philadelphia, 273: 1-6. COHEN, DANIEL M. In press. A review of the ophidioid fish genus Oligopus with the description of a new species from West Africa. Proc. U. S. nat. Mus. GOSLINE, WILLIAM A Fishes killed by the 1950 eruption of Mauna Loa. IL Brotulidae. Pacific Sci., 8( I ): 68-R3. KAMOHARA, TOSHIJI A review of the family Brotulidae found in the waters of Provo Tosa, Japan. Rep. Usa Mar. BioI. Stat., 1(2): NORMAN, J. R Fishes. Sci. Reps., John Murray Exped., 7( I): RADCLIFFE, LEWIS Descriptions of seven new genera and thirty-one new species of fishes of the families Brotulidae and Carapidae from the Philippine Islands and the Dutch East Indies. Proc. U.S. nat. Mus., 44: , pis