Bathycongrus, Ogilby, 1898

Karmovskaya, Emma S. & Smith, David G., 2008, Bathycongrus trimaculatus, a new congrid eel (Teleostei: Anguilliformes) from the southwestern Pacific, with a redescription of Bathycongrus bleekeri Fowler, Zootaxa 1943, pp. 26-36 : 34

Key to the species of Bathycongrus in the Indo-West Pacific

1 Two conspicuous dark spots in dorsal fin and one in anal fin (southwestern Pacific) ......... B. trimaculatus

- Dorsal and anal fins without conspicuous spots...........................................................................................2

2 Vomerine teeth in an elongate, oval patch, extending posteriorly to level of posterior nostril, the central teeth not markedly enlarged; eye large, 16–28% head, nearly equal to or greater than snout; preanal lateral-line pores ca. 25–26 ( Philippines) ......................................................................................... B. bleekeri

- Vomerine teeth in a short patch with one or two enlarged median teeth, flanked by a row of smaller teeth or with two somewhat smaller teeth behind on each side of midline; eye smaller, 13–18% head, distinctly shorter than snout; preanal lateral-line pores 29–43....................................................................................3

3 Dorsal-fin origin above or slightly before anteriormost insertion of pectoral fin........................................4

- Dorsal-fin origin slightly behind anteriormost insertion of pectoral fin to above middle of appressed fin 5

4 Head 53–56% of preanal, preanal LL pores 29–32, vertebrae 149–152 (northern Indian Ocean) ................ ....................................................................................................................................................... B. nasicus

- Head less than 50% of preanal, preanal LL pores c. 37, vertebrae 157–161 (northern Indian Ocean) ......... ............................................................................................................................................... B. macrocercus

5 Central vomerine teeth conspicuously enlarged, with just two to three smaller teeth behind ( Japan, Philippines, Indonesia, western Indian Ocean) ...................................................................................... B. wallacei

- Central vomerine teeth only a little to moderately enlarged, flanked by a curved row of smaller teeth on each side.......................................................................................................................................................6

6 Total vertebrae fewer than 150; preanal LL pores 31–36 ( Japan, Philippines) ....................... B. retrotinctus

- Total vertebrae more than 150; preanal LL pores 32–43..............................................................................7

7 Total vertebrae 174–180; preanal LL pores 39–43 (Hawaii) ..................................................... B. aequoreus

- Total vertebrae 157–166; preanal LL pores 32–38.......................................................................................8

8 Lining of branchial and buccal cavities dark to black ( Philippines, Indonesia, southwestern Pacific, northeastern and western Indian Ocean)..................................................................................... B. odontostomus

- Lining of branchial and buccal cavities without obvious black pigmentation (Indo-West Pacific from Hawaii to southwestern Pacific, Indonesia, northeastern and western Indian Ocean) ............. B. guttulatus