Barathronus maculatus Shcherbachev, 1976

Nielsen, Jørgen G., 2019, Revision of the circumglobal genus Barathronus (Ophidiiformes, Bythitidae) with a new species from the eastern North Atlantic Ocean, Zootaxa 4679 (2), pp. 231-256 : 244-245

Barathronus maculatus Shcherbachev, 1976

Table 2. Figs. 2 , 15–17

Barathronus maculatus Shcherbachev, 1976: 191 (type locality: 26°41’S, 34°06’E).

Barathronus maculatus: Shcherbachev, 1978: 191 ; Nielsen & Machida 1985; Nielsen et al. 1999: 139; Yeh et al. 2009: 228; Bray et al. 2015; Nielsen et al. 2019: 563 .

Barathronus sp.: Nielsen 1969: 59; Machida 1984: 266.

Material examined ( 22 specimens, SL 115–225 mm): Holotype: ZIL 42298 (SL 157 mm, male), Mozambique Channel, 26°41’S, 34°06’E, RV Fiolent, st. 198, bottom trawl, 1000 m, 27 Sep. 1973. Non-types: USNM 150285 (SL 156 mm, male), off Japan, 35°05’40’’N, 138°29’30’’E, RV Albatross, st. D-5065, bottom trawl, 386–430 m, 15 Oct. 1906. MNHN 1988-1589 (SL 154 mm, male), off Madagascar, 22°20´2.3’’S, 42°58’58.8’’E, RV Vauban, Crosnier coll., trawl 109, 995– 1020 m, 30 Nov. 1973. ZIL 45144 (SL 182 mm, female), off Natal, South Africa, 30°16’S, 31°18’E, RV Fiolent, bottom trawl, 950–1050 m, 26 may 1974. MNHN 1984-371 (SL 144 mm, male), off Madagascar, 13°02’S, 48°02’E, RV Vauban, Crosnier coll., trawl 133, 1000–1525 m, 21 Jan. 1975. BSKU 28689 (SL 137 mm, female), off Ryu-kyu ls., 28°53’N, 127°18’E, RV Yuryo-maru, No. 8 net no. 60, bottom trawl, 820–830 m, 16 Mar. 1978. AMS I 24059-013 (SL 187 mm, female), off New South Wales, 33°29’S, 152°12’E to 33°32’S, 152°09’E, RV Kapala, field no. K 83-09-02, bottom trawl, 942–978 m, 23 Aug. 1983. AMS I 27717-002 (SL 175 mm SL, female), off New South Wales, 33°58’S, 152°12’E, RV Kapala, field no. K 88-04-08, bottom trawl, 1025–1150 m, 24 Mar. 1988. AMS I 27711-001 (SL 163 mm, male), off New South Wales, 33°50’S, 151°57’E to 33°47’S, 151°57’E, RV Kapala, field no. K 88-10-01, bottom trawl, 960–1050 m, 16 May 1988. AMS I 27638- 001 (SL 225 mm, male), off New South Wales, 33°44’S, 152°06’E to 33°42’S, 152°09’E, RV Kapala, field no. K 88-11-01, bottom trawl, 1020–1040 m, 14 June 1988. AMS I 28477-002 (SL 212 mm, male), off Newcastle, New South Wales, 32°57’S, 152°44’E, RV Kapala, field no. K 88-16-04, bottom trawl, 1042–1061 m, 17 Aug. 1988. SAMZ MB-F031499 (SL 116+ mm, male), off Natal, South Africa, 29°43.2’S, 31°43.6’E, RV Benguela, st. G 13534, prawn trawl, 645 m, 23 Aug.1988. ZMUC P771755 (SL 118+ mm, male), off northern Madagascar, 12°28.5’S, 48°09.9’E, RV Vityaz, cr. 17, st. 2601, bottom trawl, 710– 700 m, 12 Nov. 1988. AMS I 29799 -003 (SL 188–215 mm, 2 females), east of Newcastle , New South Wales, 32°57’S, 152°48’E to 32°55’S, 152°45’E, RV Kapala , field no. K 89-06-02, bottom trawl, 1043–1061 m, 10 Apr. 1989. AMS I 29823-008 (SL 188 mm female), off Port Stephens , New South Wales, 32°38’S, 152°57’E to 32°28’S, 153°00’E, RV Kapala , field no. K 89-13-01, bottom trawl, 896–969 m, 29 June 1989. AMS I 29748-002 (SL 195 mm, female), east of Nowra , New South Wales, 34°55’S, 151°14’E to 34°52’S, 151°16’E, RV Kapala , field no. K 89-16-01, bottom trawl, 1024–1061 m, 10 Aug. 1989. CSIRO H 3142-01 (SL 83 mm, male), south-west of Imperieuse Reef , West Australia, 18°00’S, 118°09’E, RV Surefire , prawn trawl, 545 m, 28 Feb. 1992. CSIRO H 3149-01 (SL 85 mm, female), north of Dampier Archipelago , West Australia, 18°50’S, 116°20’E, RV Surefire , prawn trawl, 500 m, 10 Mar. 1992. CSIRO H 3197-05 (SL 96 mm, female), north of Dampier Archipelago , West Australia, 18°46’S, 116°15’E, RV Surefire , prawn trawl, 550 m, 06 Feb. 1992. CSIRO H 4136-02 (SL 91 mm, female), west of Rowley Shoals , West Australia, 18°46’S, 116°17’E RV Surefire , prawn trawl, 555 m, 15 Feb. 1992. BSKU 86066 (SL 115 mm, female), Tosa Bay , Japan, 33°06.5’N, 133°42.5’E to 33°05.5’N, 133°43.0’E, RV Kotaka-maru , otter trawl, 763–803 m, 2 Mar. 1999.

Remarks. Barathronus maculatus is relatively often caught by commercial trawlers as it occurs on the upper continental slope.

Diagnosis. Barathronus maculatus is the largest known species of the genus with a SL of up to 225 mm. It differs from the other five species of the genus with dark-pigmented peritoneum by the distinct, dark brown pigmentation dorsally between head and dorsal fin and on sides of the light brown body in preserved specimens ( Fig. 15B ); in newly caught specimens ( Fig. 15A ) the pigmentation is dark blue like the peritoneum and the body is faintly reddish. Also the following combination of characters is characteristic: dorsal-fin rays 75–83, anal-fin rays 54–66, precaudal vertebrae 32–36, total vertebrae 74–79, long rakers on anterior gill arch 31–32, vomer with up to four and dentary with up to five fangs. Length of penis up to 10% SL ( Fig. 16 ); it is proximally covered by a large dorsal clasper and a smaller ventral clasper protected ventrally by a well-developed fleshy hood. In specimens longer than about 140 mm SL the eyes are not externally visible while the eyes of smaller specimens appear as a narrow, dark ring surrounding lighter tissue. Otolith roundish and three times as long as thick and twice as long as the centrally placed, undivided sulcus ( Fig. 17 ).

Description. For a detailed description see Nielsen & Machida (1985: 1). The principal meristic and morphometric characters are shown in Table 2.

Comparisons. Long preserved specimens of B. maculatus with completely bleached lateral pigmentation may be confused with B. algrahami (described in the present paper), but additional characters separate the two species (see B. algrahami ).

Distribution ( Fig. 2 ). Known from South Africa to Japan and off southeastern Australia at 386–1525 m depth.

Figures

FIGURE 2. Records of Indo-Pacific Barathronus species. Numbers indicate several stations.

FIGURE 15. Barathronus maculatus, AMS I. 24059-013, female, SL 187 mm: A - newly caught (K. Graham photo). B—after 35 years of preservation (M. Krag photo).

FIGURE 16. Barathronus maculatus, ZMUC P771755, male, SL 118+ mm: newly caught (J. Nielsen photo).

FIGURE 17. Right otolith from Barathronus maculatus, AMS I. 27638-001, female, SL 225 mm: A—inner face. B—ventral view.