Table 1. Figs. 2, 5–6
Barathronus algrahami Nielsen, Pogonovski & Appleyard, 2019 ( type locality: 37°27.30’S, 138°38.28’E).
Barathronus maculatus (not Shcherbachev, 1976): Yeh et al. 2009: 228.
Material examined ( 5 specimens, SL 85–200 mm). Holotype: CSIRO H 1932-01, female, SL 200 mm, west of Cape Martin, South Australia, 37°27.30’S, 138°38.28’E, FRV Soela, field no. SO 01/89/41, demersal trawl, 1300– 1230 m, 30 Jan. 1989. Paratypes: ASIZ P0064071, female, SL 170 mm, off Su-ao, eastern Taiwan, 24°25.43’N, 122°21.40’E, RV Ocean Researcher I, cruise 657, st. CD199, otter trawl, 1134–1188 m, 12 Sep. 2002. ASIZ P0066252 (Gen- Bank Accession KU 943179), female, SL 195 mm, off Su-Ao, eastern Taiwan, 24°23.4’N, 122°14.4’E, RV Ocean Researcher I, st. OCP279, ORE beam trawl, 1224–1270 m, 14 Jun. 2005. ASIZ P0066254 (GenBank Accession KU 943180), female, SL 195 mm, off Su-ao, eastern Taiwan, 24°24.15’N, 122°14.06’E, RV Ocean Researcher I, st. CP281, beam trawl, 1162–1240 m, 15 June 2005. ASIZ P0068057, unripe male, SL 85 mm, Aurora, Philippines, 15°00.47’N, 123°12.60’E, RV Ocean Researcher, st. CC2703, otter trawl, 1191–1262 m, 27 May 2007.
Diagnosis. Barathronus algrahami differs from the other five Barathronus species with dark pigmented peritoneum by the following combination of characters: Dorsal-fin rays 69–78 rays, anal-fin rays 60–67, pectoral-fin rays 21–25, precaudal vertebrae 34–37, total vertebrae 74–81, no bulbs at basis of penis, no ventral flexure of anteriormost vertebrae, anterior gill arch with 27–32 long rakers, 3–5 fangs on vomer and 3–5 on each dentary, predorsal length 47.0–52% SL, eyes not externally visible in adults, pigment laterally on body, dark blue peritoneum and newly caught specimen reddish all over. It reaches 200 mm SL, only surpassed in the genus by B. maculatus that reaches 225 mm SL. Rounded otolith small ( 3 mm long in 200 mm holotype) about twice as long as thick and with a poorly developed centrally placed, undivided sulcus one fourth the length of the otolith ( Fig. 6).
Description. For a detailed description see Nielsen et al. (2019: 561). The principal meristic and morphometric characters are shown in Table 2.
Coloration. Fig. 5A shows the holotype when freshly caught dominated by reddish colors and a very dark peritoneum. After 29 years of preservation ( Fig. 5B) the reddish color has completely gone and the brownish musculature and dark peritoneum is seen through the transparent skin.
Comparisons. Barathronus algrahami seems most similar to B. maculatus, but differs by not having distinct brown pigment laterally and by the small, rounded otolith only half the length of the flat otolith from a B. maculatus of same SL.
Distribution ( Fig. 2). Barathronus algrahami occurs off South Australia, eastern Taiwan and Aurora, Philippines, at bathyal depths ( 1134–1300 m).