Two new species of Photonectes (Teleostei: Stomiidae) from the Indo-Pacific, and a re-examination of P. achirus Author Flynn, A. J. Author Klepadlo, C. text Memoirs of Museum Victoria 2012 2012-12-31 69 259 267 https://museumsvictoria.com.au/collections-research/journals/memoirs-of-museum-victoria/volume-69-2012/pages-259-267/ journal article 10.24199/j.mmv.2012.69.04 1447-2554 10666120 Photonectes paxtoni new species Figures 3 , 5 ; Table 1 Holotype : AMS I.1970 -243 ( 23.4 mm SL), 05°05'S , 145°56'E , off Madang , Papua New Guinea , 27 October 1969 , 2 m IKMWT , 135 m depth . Paratype : AMS I.19727-023 ( 22.4 mm SL), 05°05'S , 145°54'E , off Madang , Papua New Guinea , 27 October 1969 , 2 m IKMWT , 130 m depth . Diagnosis: Photonectes paxtoni differs from other members of the subgenus Photonectes in the following combination of characters: barbel short, with a very enlarged ovoid terminal bulb lacking terminal appendages; absence of blue luminous tissue; length of gill filaments on first branchial arch reduced, less than arch depth; and VAV photophores 15—16 ( vs. 10—15), AC photophores 13 ( vs. 9—12) and IV photophores 29 ( vs. 30— 46). The bulb is remarkably large and plain (without filaments). The enlarged bulb is similar to P. ovibarba (synonym of P. braueri ). However, P. paxtoni has no pectoral fins ( vs. present, with 2 rays each), IV photophores 29 ( vs. 32—33), AC photophores 13 ( vs. 10—12), and the bulb lacks any terminal appendage ( vs. bearing a small ovoid appendage). Another species with a large bulb, P. fimbria (synonym of P. parvimanus ), can also be eliminated based on the following: IV photophores 43—49 ( vs. P. paxtoni with 29), IP photophores insert near mandibular symphysis or no gap ( vs. insert halfway along the isthmus, or with gap), thick skin over dorsal- and anal-fin rays ( vs. thick skin absent), and bulb with terminal flap increasing with growth ( vs. no flap or terminal appendage; growth change unknown). Description: Body elongate, 22.4—23.4 mm SL; depth about seven times into length. HL 3.5—4.0 mm (15.6—17.1% SL); Sn-V 13.8—14.3 mm (61.1—61.6% SL); V-vent 3.4—3.6 mm (15.2—15.4% SL); vent-C 5.2—5.5 mm (23.2—23.5% SL) (see Table 1 ). Eye 1.0— 1.1 mm (25.0—27.5% HL). Opercle lobate, slightly concave dorsally. Gill filaments on first branchial arch reduced, length less than arch depth; tips of gill filaments unpigmented. Color of body rusty-brown in preservative, assumed black in life. Dorsal-fin rays 16—18; anal-fin rays 18; pelvic-fin rays 7; pectoral fins absent. Dorsal and anal fins not covered with black fleshy skin; fin-rays covered with minute white luminous spots; membranes clear. Pelvic fins inserted closer to caudal fin than to snout tip (38.4—38.9% SL vs . 61.1—61.6% SL); longest ray extending to anal-fin origin. Caudal-fin rays broken; fin assumed forked. Photophores: IV 29 ( IP 8; PV 21); VAV 15—16 (last 2 to 3 over anal-fin base); AC 13; OA 34 ( OV 20; VAL 14, last two photophores over anal-fin base); BR 8. IP series beginning posteriorly about halfway along isthmus length, opposite BR-8; photophores evenly spaced. Anterior end of AC series beginning on same level as last VAV . Secondary photophores scattered over head and body, in clusters along dorsum, tapering ventrally to between each OA photophore, continuing ventrally between each IV photophore, and in clusters along ventral surface; none on any fin rays. Postorbital organ ovoid, elongate, about equal to eye diameter. One PRO and one SO photophore on operculum, and one postorbital photophore. Specimen AMS I.1927 -023 with a pair of white luminous spots on snout between nostrils. Blue luminous tissue and dark markings absent. Teeth caniniform, long and short; premaxillary teeth longest, needle-like. Premaxillary teeth 4; 5—7 maxillary teeth erect and 8 oblique; mandibular teeth 12—15; vomerine teeth one pair; palatine teeth absent; basibranchial teeth 4 (one pair anteriorly and two single teeth midlength). Vomerine teeth long, length equal to longest premaxillary tooth. Barbel short, 1.5—1.8 mm (42.9—45.0% HL), with very large ovoid bulb. Stem short, ~1.0 mm (~25% HL), pigment tapering anteriorly onto base of bulb in a small V-shape; no secondary photophores on stem. Bulb large and simple, with no appendages or terminal filaments; width ~1.0 mm. Color of bulb in life unknown. Distribution: Known only from type locality off Madang , Papua New Guinea ; depth 130— 135 m. Etymology: The name recognises Dr. John Paxton for his many contributions to the study of mesopelagic fishes and for his encouragement to the authors. Remarks: Photonectes paxtoni is currently known from two specimens from shallow collections (depth 130—135 m ). They were located among 46-year-old museum specimens labeled Photonectes sp.