Sciadonus pedicellaris Garman, 1899

Nielsen, Jørgen G., 2018, Revision of the cosmopolitan deep-sea genus Sciadonus (Teleostei, Bythitidae) with two new species, Cybium 42 (2), pp. 177-187 : 183-184

Sciadonus pedicellaris Garman, 1899

( Tab. I, Figs 1 , 8-13 )

Sciadonus pedicellaris Garman, 1899: 172 (type locality

Gulf of Panama).

Sciadonus kullenbergi Nybelin, 1957: 310 (type locality off the Azores).

Leucochlamys galatheae Nielsen, 1969: 75 (Kermadec

Trench, South West Pacific).

Leucochlamys galatheae : Rannou et al., 1975: 1253.

Leucochlamys sp. : Nielsen et al., 1968: 247.

Sciadonus galatheae : Nielsen and Eagle, 1974: 1071;

Nielsen, 1986: 1171; Haedrich and Merrett, 1988: 1336; Nielsen et al., 1999: 142; Nielsen and Møller, 2008: 43; Nielsen and Møller, 2015: 738.

Sciadonus kullenbergi : Munk, 1966: 27.

Sciadonus pedicellaris : Marshall, 1954: 232; Grey, 1956:

221; Nielsen, 1969: 63.

Sciadonus sp. : Nielsen and Eagle, 1974: 1071.

Unknown brotulid fish: Bruun, 1953: 187 (drawing). Holotype of Leucochlamys galatheae Nielsen, 1969 .

Material examined (19 specimens, SL 44-126 mm)

MCZ 28628 (holotype of Sciadonus pedicellaris ), SL 70 mm, female, Gulf of Panama, 5°31’N, 86°31’W , R / V

Albatross, st. 3365, Agassiz trawl, 1847 m, 27 Feb. 1891. NHMG Pi. ex.1744 (holotype of Sciadonus kullenbergi ), SL 102 mm, female, off Azores , 40°32’N, 35°24’W- 40°34’N, 35°52’W, Swedish Deep-Sea Exped., st. 387, trawl, 4540- 4600 m, 7 Sep. 1948 . ZMUC P77456 (holotype of Leucochlamys galatheae ), SL 84 mm, female, Kermadec Trench, Southeast Pacific, 36°31’S, 178°38’W , R / V Galathea , st.663, herring otter trawl, 4410 m, 24 Feb. 1952 . ZMUC P77457 (paratype of Leucochlamys galatheae ), SL 61 mm, male – same data as for ZMUC P77456 . IOM no cat.no., SL 80 mm, female, off northern Chile, 23°30’S, 71°19’W , R / V Akademik Kurchatov , st. 238-A, Galathea trawl, 4880 m, 27-28 Sep. 1968 . OS 11637 , SL 118 mm, female, Northeast Pacific , 44°38.2’N, 132°10.6’W , R / V Yaquina , st. TP-2, beam trawl, 3655 m, 31 May 1970 . ZMUC P77537 , SL 126 mm, female, Northeast Pacific, 44°41.1’N, 133°24.1’W , R / V Yaquina , st. TP-3, beam trawl, 3784 m, 3 Jun. 1970 . OS 11636 , SL 116 mm, male, Northeast Pacific , 45°20.9’N, 126°39.7’W , R / V Yaquina , st. CP-2-c, beam trawl, 2750 m, 18 Feb. 1971 . MNHN 1973-33, SL 93 mm, female, off Brittany , 47°38’N, 8°56’W , R / V Jean Charcot , st. 251, trawl, 3360-3600 m, 17 Nov. 1971 . OS 11641 , SL 75 mm, female, Northeast Pacific , 44°04.3’N, 133°10.9’W , R / V Yaquina , cruise Y7210A, st. TP-7, beam trawl, 3700 m, 7 Oct. 1972 . OS 11643 , SL 93 mm, female, Northeast Pacific, most sta- tion data missing, 2 Aug. 1974 . BMNH 2017.3 .17.7, SL 75 mm, female, southwest of Ireland, 49°30.1’N, 13°19.9’W , R / V Challenger , st. 17-8/79 , OTSB 14 , 1750 m, 7 Jun. 1979 . NMNZ P.034545, SL 85 mm, female, Bellona Trough , New Zealand, 41°22.7’S, 166°44.4’E , NZOI R / V Tangaroa , st. NZOI P0940 , trawl, depth 2092 m, 3 Apr. 1980 . NMNZ P.025244, SL 44 mm, female, Hikurangi Trough , New Zealand, 41°11.9’S, 177°19.6’E , NZOI R / V Tangaroa , st. NZOI P0971 A, trawl, 2200-2328 m, 8 Jun. 1980 . BMNH 2017.3 .17.6, SL 77 mm, male, southwest of Ireland, 49°37’N, 13°48’W , R / V Challenger , st. CH 51803 , OTSB 14 , 3990- 3920 m, 26 Sep. 1983 . BMNH 2017.3 .17.5, SL 78 mm, male, southwest of Madeira , 31°07’N, 25°5’12’’W , R / V Discovery , st. 11261#44 , OTSB 14 , 5440 m, 1 Jul. 1985 . BMNH 2017.3 .17.4, SL 65 mm, female, southwest of Ireland, 49°02’42’’N, 16°00’34’’W , R / V Discovery , st. 52403#14 , OTSB14 , 4860- 4850 m, Dec. 1986 . MNHN 2002-3876, SL 98 mm, male, Solomon Sea , 9°S, 159°49’E, Solomon 1 cruise, st. CP1754, beam trawl, 1169-1203 m, 26 Sep. 2001 . ZMUC P771588 , SL 58 mm, male, Solomon Sea, 13°45’S, 156°41’E , R / V Galathea 3, st. 061219-05, otter trawl, 2255-2283 m, 19 Dec. 2006 .

Diagnosis

Sciadonus pedicellaris is long, slender and compressed with protruding lower jaw and differs from all other Sciadonus species by the following combination of characters: no black pigmentation on body, dorsal fin rays 90-107, precaudal vertebrae 43-49, origin of anal fin below dorsal fin rays nos. 44-56 and below vertebrae nos. 44-49. Tissue flaps anteriorly on lower jaw well developed on most specimens.

Description

The principal meristic and morphometric characters are shown in table I. Body slender and compressed with scaleless, loose skin. Skin and peritoneum transparent showing the inner organs. Mouth horizontal with protruding lower jaw. Most specimens with a pair of distinct tissue flaps anteriorly on lower jaw (cf. Fig. 7 ). Small deep-set black eyes placed above posterior third of upper jaw. Opercular spine absent. Sagittal otolith ( Fig. 10 ) small, half as thick as long; sulcus undivided reaching to about middle of inner face and with wide opening at anterior rim. Origin of dorsal fin at about tip of pectoral fin; anal fin origin well behind midpoint of fish. Vertical fins joined. Pectoral peduncle about three times as long as high. Pelvic fin rays very thin and short, when present; lacking in about half of the specimens. Anterior gill arch ( Fig. 11 ) with 12-15 small, knob-formed rakers each provided with 2-6 short spines and with gill filaments equal in size to rakers. Filaments on second and third gill arch twice the length of those on anterior arch. Pseudobranchial filaments not observed. Females with a pair of well-developed claspers ( Fig. 12 ). Penis partly covered ventrally by the urogenital hood that ends in two small wing-like prolongations on each side of penis and a pair of probably vestigial claspers placed at each side at base of hood ( Fig. 13 ). A thorough description of the holotype and paratype of the now synonymized Leucochlamys galatheae is given in Nielsen (1969: 75-78).

Figures

Figure 1. – Records of Sciadonus species.

Figure 7. – Sciadonus longiventralis: Ventral view of head. MNV A 5672, holotype, male, SL 70 mm. a: tissue flaps, b: ventral fins.

Figure 8. – Sciadonus pedicellaris: MCZ 28628, holotype, female, SL 70 mm (from Garman, 1899).

Figure 9. – Sciadonus pedicellaris: ZMUC P77456, female, SL 84 mm (from Nielsen, 1969).

Figure 10. – Sciadonus pedicellaris: Right otolith of ZMUC P771588, male, SL 58 mm. A: Inner face; B: Dorsal view; C: Anterior view.

Figure 11. – Sciadonus pedicellaris: Anterior, right gill arch of NHMG Pi. ex. 1744, female, SL 102 mm (from Nielsen, 1969).

Figure 12. – Sciadonus pedicellaris: Female claspers of ZMUC P77456. a: anus (from Nielsen, 1969).

Figure 13. – Sciadonus pedicellaris: Urogenital hood and penis of ZMUC P77457. a: anus, b: vestigial clasper, c: wing-like prolongations (from Nielsen, 1969).