Paraphyonus rassi ( Nielsen, 1975 )

Nielsen, Jørgen G., Pogonoski, John J. & Appleyard, Sharon A., 2019, Aphyonid-clade species of Australia (Teleostei, Bythitidae) with four species new to Australian waters and a new species of Barathronus, Zootaxa 4564 (2), pp. 554-572 : 567-568

Paraphyonus rassi ( Nielsen, 1975)

Table 1, Figs. 1 , 12

Aphyonus rassi Nielsen, 1975: 350 (type locality 12°59’N, 62°59’W).

Paraphyonus rassi: Nielsen 2015: 339 .

Material examined. (4 specimens, 85–109 mm SL) NMV A 31819-003, male, 103 mm SL, off Newcastle, NSW, 33°26.10’S, 152°39.90’E, RV Investigator , st. IN2017_VO3/065, beam trawl, 4173–4280 m, 30 May 2017. CSIRO H 8125-02 (GenBank Accession MH491989 ), female, 109 mm SL, Hunter Commonwealth Marine Reserve, NSW, 32°08.28’S, 153°31.62’E, RV Investigator , st. IN2017_ V03 /078, beam trawl, 3980–4029 m, 4 June 2017. CSIRO H 8132-01, 2 males, 85–101 mm SL (GenBank Accessions MH491992 and MH491993 , respectively), east of

Moreton Bay, Qld, 27°00.47’S, 154°13.39’E, RV Investigator , st. IN2017_ V03 /102, beam trawl, 4274– 4264 m, 10 June 2017.

Diagnosis. Paraphyonus rassi differs from the other species of the genus by the black pigmentation laterally in the roof of the mouth distinctly visible externally and only 3–4 developed rakers on the anterior gill arch.

Size. Largest known specimen (109 mm SL) is a ripe female with eggs ca. 1 mm in diameter.

Distribution ( Fig. 1 ). Known from four specimens in the West Atlantic (2610–4400 m), from two in the East Atlantic (4415 m) and now from four specimens off NSW and southern Qld (3980–4280 m).

Remarks. The comparison in Table 1 between the present four specimens and the six earlier known specimens all from the Atlantic Ocean (Nielsen 2015) shows close agreement between the specimens from the two areas. One of the six specimens was originally tentatively identified as P. rassi due to differences in number of rays in dorsal and anal fins, number of vertebrae and length between base of pelvic fins and anal fin. However, the present material levels out the differences in number of fin rays and vertebrae. Consequently, there seems no longer any reason for considering the specimen tentatively identified.

Figures

FIGURE 1. Records of aphyonid-clade species in Australian waters including the non-Australian paratypes of Barathronus algrahami n. sp. Some symbols represent more than one specimen (Image © NASA, TerraMetrics, Google Earth).

FIGURE 12. Paraphyonus rassi, NMV A 31819-003, 103 mm SL (Image: CSIRO Australian National Fish Collection).