Pseudoscopelus lavenbergi, Melo, Marcelo R. S. & Klepadlo, Cynthia, 2007

Melo, Marcelo R. S. & Klepadlo, Cynthia, 2007, Two new species of Pseudoscopelus (Teleostei: Chiasmodontidae), with a new diagnosis for the genus, Zootaxa 1605, pp. 33-46 : 36-41

Pseudoscopelus lavenbergi , new species

( Figs. 4 , 5 and 6 ; Tables 2 and 3)

Holotype. SIO 71-358 (73.0), eastern Pacific, off Ecuador, 0 1o21.0’N, 0 86o36.0’W, 21-III-1967, R/V Alaminos.

Paratypes. Eastern Pacific: CAS 61407, 1 (63.0), Ecuador, Humboldt Current area, 02°26'S, 88°46'W, 0- 300 m, 27/ 28-V-1966, R/V Anton Bruun; LACM 33335-1, 1 (82.2), south of the Galapagos Islands, 400 m, 1o48’S, 90o19’W, 26-V-1966; LACM 33340-1, 1 (45.3), ca. 180 miles SE of the Galapagos Islands, 2o59’S, 88o11’W, 2300-3000 m, Te Vega Expedition, 25-IX-1968; LACM 30074-8, 1 (102.7), Baja California, 28o48’N, 114o28.48’W, 11-IV-1968, R/V Velero IV; LACM 30379-2, 1 (91.4), Baja California, 49 miles from Punta Abreojos, 26o0.66’N, 114o10’W, 24-VI-1968, R/V Velero IV; LACM 30530-1, 1 (166.6), California, 32o19.75’N, 117o49.11’W, 27-I-1968, R/V Velero IV; LACM 30573-1, 2 (86.3-97.6), Baja California, from Punta Abreojos, 22o30’N, 110o00’W [inferred by authors], 1324-1624 m, 23-VI-1968, R/V Velero IV; LACM 31793-1, 1 (143.9), California, San Clemente Island, 10.5 miles from Pyramid Head, 32o40’N, 118o20’W [inferred by authors], 29-VII-1969, R/V Ve le ro I V; LACM 33336-1, 1 (76.5), Baja California, about 100 miles west of Cabo San Lazaro, 24o55’N, 114o12’W, 29-30-III-1962; SIO 56-109-60A, 1 (30.2), from stomach of Alepisaurus taken by longline, 0 1o57.5’N, 110o39.0’W, M/ V N.B. Scofield; SIO 75-316, 1 (73.0), 0 6o03.1’N, 117o46.0’W, 30-I-1973, R/V David Starr Jordan; SIO 92-9, 1 (54.9), 0 8o05.0’N, 0 95o02.0’W, 21-IX-1967, R/ V Rockaway; SIO 93-22, 1 (67.7), off Mexico, 19o2.5’N, 105o40.5’W, 14-IX-1967, R/V Thomas Washington; SIO 95-83, 1 (70.4), 0 8o36’N, 111o32’W, 5-I-1968, R/V David Starr Jordan; SIO 97-203, 1 (81.6), 20o00’N, 129o00’W, 1000 meters of wire, 27-V-1973, R/V David Starr Jordan. Central Pacific, south of Hawaii: USNM 289000, 1 (47.4), 10o58’N, 150o00’W, 950 m, 14-I-1978, R/V Kana Keori ; USNM 289002, 1 (44.5), 10o10’N, 150o00’W, 710 m, 30-V-1979, R/V Gyre; UW 116439 (former SIO 60-243), 1 (44.7), 10o22.3’N, 147o18.8’W, 0-2100 m, 8-9-VII-1960, Tethys Expedition.

Non-type specimens. Eastern Pacific: LACM 56617-1, 1 (84.8), off Chile, 23o52’S, 71o08’W, 0-200 m, 23-IX-1968, R/V Akademik Kurchatov; LACM 56618-1, 1 (173.6), off Ecuador, 0o0’, 85o00’W, 0-1500 m, 29- VII-1968, R/V Akademik Kurchatov; LACM 30205-29, 1 (133.1), California, San Clemente Island, 32o33.45’N, 118o10.08’W, 1812- 1464m, 26-VII-1968, R/V Velero IV; LACM 33334-1, 1 (39.9), probably off Southern California or Baja California, 13-V-1966; LACM 33337-1, 1 (60.4), Gulf of California; LACM 33339-1, 1 (181.8), California, 0.3 miles 183o T from West End Light, Santa Catalina Island, 27-VIII-1970, R/ V Ve le ro; SIO 95-131, 1 (36.4), 3o11.5’N, 119o21.0’W, 26-X-1967, R/V David Starr Jordan; SIO 69-330, 1 (34.2), 14°46.0’S, 93°32.5’W, 18-III-1969; SIO 63-165, 1 (159.9), 28o53.0’N, 118º08.4’W, 21-IV-1963, 0-750 m, R/V Horizon. Central Pacific, Hawaii: LACM 30042-10, 1 (ca. 80.0) Leward Oahu, 21o20.5’N, 158o20.5’W, 600-650 m, 9-X-1970, R/V El Pescadero II.

Diagnosis. Pseudoscopelus lavenbergi can be distinguished from its congeners by three unique characters: trf in broad band of three or more rows (vs. trf absent on P. scutatus and P. bothrorrhinos ; in single row with widely spaced organs on P. altipinnis ; and in single row with closely spaced organs on remaining species); ptvf short, not reaching anus, and extending anteriorly only halfway to pelvic-fin origin (vs. ptvf elongate, extending close to anus, and extending anteriorly to very close to pelvic-fin origin); mxf completely absent and apf present (vs. both mxf and apf absent on P. scutatus and P. bothrorrhinos ; both apf and mxf present on remaining species).

Description: Meristic data summarized in Table 2, and morphometric data in Table 3. Moderate-sized species of Pseudoscopelus , largest specimen 181.0 mm SL. Body elongate, fusiform, not greatly compressed anteriorly, but progressively more compressed in caudal region. Greatest body depth at origin of first dorsal fin. Scales absent, except for lateral line.

Anterior profile of head round in lateral view. Tip of snout protruding, with abrupt curve dorsally at level of anterior naris. Mouth terminal and large, reaching edge of preopercle. Orbit circular. Nares distinctly separated, anterior naris circular, close to third supraorbital pore; posterior naris C-shaped, close to anterodorsal edge of eye.

Pseudoscopelus lavenbergi Pseudoscopelus bothrorrhinos Character Holotype Range Mode Holotype Range Mode

Fin Rays

First dorsal-fin rays VIII VIII VIII VII VII VII Second dorsal-fin rays ii, 21 ii, 21-23 ii, 21 ii, 21 ii, 20-22 ii, 21 Anal-fin rays iii, 20 iii-iv, 20-22 iii, 21 iii, 21 ii-iii, 20-22 iii, 21 Pectoral-fin rays 12 12-15 13 14 12 -14 14 Pelvic-fin rays I, 5 I, 5 I, 5 I, 5 I, 5 I, 5 Caudal-fin rays i, 7, 8, i i, 7-8, 7-8, i i, 7, 8, i i, 7, 7, i i, 7, 7-8, i i, 7, 8, i Branchiostegal rays 7 7 7 7 7 7

Sensorial Pores

Lateral line 78 77-81 80 76 73-77 76 Temporal 2 2 2 2 2 2 Supratemporal 3 3 3 3 3 3 Otic 2 2 2 2 2 2 Supraorbital 6 6 6 6 6 6 Supranasal pore 2 2-3 2 3 3 3 Epiphyseal branch 3 2-3 3 3 2-3 3 Infraorbital 12 12 12 12 12-13 12 Preopercular 5 5 5 5 5 5 Mandibular 6 6 6 6 6 6 Fifth mandibular pore 2 1-2 2 1 1 1

Gill Rakers and Dentition

Epibranchial 0 0-2 0 0 0 0 Ceratobranchial 9 9-23 12 6 6-9 7 Hypobranchial 6 6- 16 9 2 1-4 2 First basibranchial 13 9-19 14 8 5-11 6 Palatine teeth 7 4-8 5 5 4-8 5

Teeth present on premaxilla, dentary, and palatine. Premaxillary and dentary dentition of P. lavenbergi illustrated in Fig. 5 . Premaxilla wide; premaxillary teeth arranged in three series: lateral, middle and mesial. Lateral series at edge of premaxilla, first tooth curved orally, type 1; remaining teeth at lateral edge curved caudally, type 4. Middle series in irregular rows of one to two straight teeth, needle-like, type 4, size increasing from lateral to mesial. Mesial series in transverse rows of one to four teeth, needle-like, type 4, size increasing from lateral to mesial. Dentary teeth in two rows: lateral and mesial. Lateral series at edge of dentary conical, type 4; mesial row in series of one to three teeth, needle-like, type 4. Palatine teeth conical, type 1, arranged in single row.

Gill arches four; pseudobranch present. Epibranchial of first arch attached to opercle to midline; ceratobranchial, hypobranchial and basibranchial of first arch free. Epibranchials of second, third and fourth arches connected anteriorly to each other and pharyngobranchials; ceratobranchial of second arch free. Hypobranchial and basibranchial of second, third and four arches connected medially. Ceratobranchial of third arch connected anteriorly to fourth arch; ceratobranchial of fourth arch connected medially to body wall at anterior half. Gill rakers short, conical, similar to type 1 tooth; present on first basibranchial, first and second gill arches, and pharyngeals; absent on basihyal, other basibranchials, third and fourth gill arches. Rakers of first basibranchial arranged in V-shaped row.

Pseudoscopelus lavenbergi Pseudoscopelus bothrorrhinos Landmarks Measurements H Range Mean SD H Range Mean SD 1-2 Standard length (mm) 73.0 44.9- 90.9 37.3 45.9 29.61-55.1 39.8 7.7

166.6

1-3 Head length (mm) 24.8 14.8-55.2 29.6 12.4 12.5 8.15-14.8 10.7 2.0

Proportions of HL

1-7 Snout 25.6 23.7-28.4 25.8 1.2 23.5 23.5-27.6 25.5 1.4 1-4 Upper jaw 63.2 60.4-68.5 63.8 2.4 67.8 63.8-70.8 67.1 2.2 5-6 Lower jaw 71.3 67.7-76.3 71.4 2.4 76.1 71.7-78.8 74.8 2.2 7-8 Orbit width 14.9 12.6-18.1 15.4 1.8 15.8 14.7-18.3 16.7 1.2 9-10 Orbit height 12.5 10.6-15.0 12.7 1.3 14.6 13.7-16.6 15.0 1.0 11-7 Anterior nostril to eye 14.4 11.9-14.6 13.5 1.3 17.6 15.9 -18.6 17.6 0.7 12-7 Posterior nostril to eye 7.8 5.1-8.7 6.6 1.0 6.6 5.3-7.8 6.4 0.7 11-12 Distance between nostrils 7.9 5.5-7.9 6.8 0.8 11.1 9.1-12.1 10.8 1.0 13 (left to right) Interorbital distance 24.9 22.4-25.5 23.8 1.1 28.6 28.6-32.1 30.7 1.0 14 (left to right) Head width 34.2 30.9-35.8 33.8 1.9 41.1 38.2 -43.3 41.3 1.5 10-15 Cheek depth 8.3 7.8-10.1 9.0 0.8 9.7 7.4-10.6 8.9 1.0

Proportions of SL

1-3 Head length 33.9 30.5-33.9 32.5 0.9 27.2 25.2-29.2 26.9 1.2 16 (left to right) Body width 9.1 7.7-11.7 8.9 1.2 8.4 7.0-11.6 8.6 1.4 1-16 Insertion of pectoral fin 32.4 32.1-34.7 33.4 0.9 26.6 26.6-29.1 27.3 0.9 1-17 Insertion of pelvic fin 33.0 32.3-34.7 33.5 0.9 27.9 27.9-33.7 30.2 1.9 1-20 Origin of first dorsal fin 35.5 32.8-37.6 35.2 1.2 32.8 31.5-35.5 33.5 1.1 20-21 Base of first dorsal fin 14.0 11.2-16.1 13.8 1.6 11.9 9.3-12.8 11.6 1.2 1-23 Origin of second dorsal fin 52.7 49.7-54.2 52.6 1.2 52.4 51.6-57.9 53.7 1.8 23-24 Base of second dorsal fin 37.4 36.1-40.3 37.6 1.2 39.6 33.9-40.5 37.3 2.0 1-26 Origin of anal fin 52.7 50.2-54.6 52.2 1.5 50.5 47.4-55.6 50.9 2.5 26-27 Base of anal fin 36.1 34.8-39.1 36.9 1.4 38.1 34.2-41.5 37.0 2.1 16-18 Pectoral-fin length 21.3 14.1-24.0 18.6 2.9 16.0 13.2-19.2 16.0 1.5 17-19 Pelvic-fin length 13.1 9.5-14.4 11.9 1.5 10.1 8.6-11.5 9.8 1.0 20-22 First dorsal-fin depth 12.4 11.2-12.5 12.2 0.5 9.3 7.4-12.2 8.9 1.3 23-25 Second dorsal-fin depth 18.5 12.5-22.4 18.8 3.7 19.3 17.6-21.7 19.3 1.2 26-28 Anal-fin depth 19.3 15.5-20.7 18.7 2.0 18.1 14.2-20.5 18.6 1.8 29-30 Peduncle depth 6.1 4.7-6.1 5.6 0.4 6.8 5.2-8.0 6.3 0.8 27-2 Peduncle length 11.5 9.7-12.1 11.3 0.8 12.5 11.1-15.5 12.7 1.5

Pectoral fin elongate, reaching origin of second dorsal and anal fins; pelvic-fin origin slightly posterior to pectoral-fin base; dorsal fins two, first dorsal-fin origin slightly posterior to pelvic-fin insertion, second dorsal-fin origin at level of anal-fin origin. Sensorial system of head as in Fig. 2 ; pore counts listed in Table 2. Lateral line complete, with pores opening between scales; last scale of lateral line separate, on lower lobe of caudal fin, with two pores (included in lateral-line pore count). Total vertebrae 37-39 (mode=38, n=5), precaudal 17-18 (mode=17, n=5).

Color. No freshly collected specimens known, most specimens bleached; two well preserved specimens completely dark brown, including fins. Oral and branchial cavities dark, including gill arches; gill filaments not pigmented.

Luminescent organs. Luminescent organs present as discrete photophores on head and body; pattern of P. lavenbergi illustrated in Fig. 6 . Photophores on head: dnf, info 1-2, mxf, opf, pof absent; vnf as small triangular patch of few organs, slightly posterior to first supraorbital pore; apf triangular, short, restricted to angle between premaxilla and preopercle; amf medial on dentary, elongate, beginning halfway between second and third mandibular pores, extending to midpoint between third and fourth pores; pmf lateral on dentary, elongate, originating slightly posterior to fourth mandibular pore, extending halfway between fifth and sixth pores, in one to two irregular rows. Photophores on body: rtf, spf, svf, and scf absent; pf in single row along ventralmost pectoral-fin ray; paf in triangular patch at pectoral-fin axil; vf short, in single row, restricted to first third of mesial pelvic-fin ray; vaf extending over base of pelvic rays 4-5; if elongate, in two to four rows of photophores; prvf short, 1/3 of if, in one to four rows; ptvf short, from halfway between anus and pelvic fin, to close to anus, in one to three rows; trf in broad band of three or four rows; saf reaching anus, but not extending further anteriorly, in single row except for anterior part, posterior ends not connected; prcf in two rows anteriorly and three to four rows posteriorly, short, extending from posterior part of peduncle and extending over anterior lower procurrent caudal-fin rays.

Distribution. Pseudoscopelus lavenbergi is known from the eastern Pacific, from California to Chile, 32o N to 23o S; extending west to near the Hawaiian Islands, 158o W ( Fig. 10 ).

Etymology. The species is named for Robert J. Lavenberg, in recognition of his contributions to our knowledge of the genus Pseudoscopelus .

Figures

FIGURE 2. Diagram of laterosensory system of the head of Pseudoscopelus. Lateral-line canals: ESC, epiphyseal branch of supraorbital sensory canal; IO, infraorbital canal; MD, mandibular canal; MDP- 5, 5 th mandibular-canal pore; OT, otic canal; PrO, preopercular canal; SN, supranasal pore; SO, supraorbital canal; ST, supratemporal canal; T temporal canal; TR, trunk canal. Osteological abbreviations are as follows: den, dentary; ext, extrascapular; fr, frontal; io 1 - 6, infraorbitals 1 - 6; mx, maxilla; mst, mesethmoid; lls, lateral-line scale; na, nasal; pa, parietal; pmx, premaxilla; pop, preopercle; pto, pterotic; ptt, posttemporal; so, supraoccipital.

FIGURE 4. Pseudoscopelus lavenbergi, new species, SIO 71 - 358, 73.0 mm SL, holotype.

FIGURE 5. Dentition pattern of Pseudoscopelus lavenbergi, based on LACM 30573 - 1, paratype: (A) premaxilla, and (B) dentary; the tooth arrangement is above, and the tooth insertion sites are below, with circles proportional to the toothbase diameter. Scale bar equals 5 mm.

FIGURE 6. Photophore pattern of Pseudoscopelus. lavenbergi, based on CAS 61407, paratype.

FIGURE 10. Map of distribution of Pseudoscopelus lavenbergi (triangles), and P. bothrorrhinos (circles). A symbol may represent more than one locality.