MINCARONE & MCCOSKER: REDESCRIPTION OF EPTATRETUSLUZONICUS 
347 
the ventral aorta, and parts of the intestine, whieh has been dissected along its entire length. The 
third gill pouch on the left side is missing and the gonads cannot be found. The liver and several 
unidentified small pieces of muscle tissue are detached from the body. Fortunately, the teeth are in 
good condition making an accurate tooth count possible. The slime pores can be easily counted, 
except those of the trunk, which are difficult to observe due to dissections and poor preservation. 
We are unable to say with certainty whether the poor condition of the specimen resulted from inap¬ 
propriate preservation and/or multiple dissections after collection. All material collected by the 
Albatross Philippine Expedition was preserved directly in ethyl alcohol as formalin was not used 
at that time (Smith and Williams 1999). 
In their original description of Eptatretus fernholmi, McMillan and Wisner (2004) briefly com¬ 
pared this species with some western Pacific hagfishes, including Eptatretus strahani McMillan 
and Wisner, 1984 (Philippines), Eptatretus chinensis Kuo and Mok, 1994 (South China Sea), and 
Eptatretus okinoseanus (Dean, 1904) (Japan and Taiwan). McMillan and Wisner (2004) stated that 
Eptatretus fernholmi had no eyespots and a vestigial ventral finfold, and therefore differed from 
E. okinoseanus, which has prominent eyespots and a well-developed ventral finfold. This statement 
was based on Bo Femholm’s notes taken from the holotype, which was already in poor condition 
when he examined it in 1976 (Bo Fernholm pers. comm., Febmary 17, 2012). The badly damaged 
skin of the holotype makes it impossible to check its eyespot and ventral finfold conditions. The 
examination of additional specimens, however, revealed that E. fernholmi (= E. luzonicus) has very 
conspicuous eyespots (Fig. 3) and a ventral finfold that ranges from 1 mm (in a 404-mm specimen) 
to 7 mm high (in a 563-mm specimen). Therefore, E. luzonicus cannot be distinguished from 
E. okinoseanus based on the diagnosis proposed by McMillan and Wisner (2004). 
The presence of eight pairs of gill pouches and 3-cusp multicusps on the anterior sets and 
2-cusp multicusps on the posterior sets of cusps distinguishes Eptatretus luzonicus from all con¬ 
geners except five: Eptatretus gomoni Mincarone and Fernholm, 2010 from Western Australia, 
Eptatretus indrambaryai Wongratana, 1983 from Thailand, Eptatretus octatrema (Barnard, 1923) 
from South Africa, Eptatretus okinoseanus (Dean, 1904) from Japan and Taiwan, and Eptatretus 
wisneri McMillan, 1999 from the Galapagos Islands. Eptatretus luzonicus differs from these five 
in having: 47-51 total cusps (vs. 40 in E. octatrema, 44 in E. wisneri)', 13-15 prebranchial pores 
(vs. 23 in E. octatrema, 9-10 in E. wisneri); 49-55 trunk pores (vs. 57-58 in E, gomoni, 65 in 
E. octatrema, 54-61 in E. okinoseanus, 43^5 in E. wisneri); and 84-88 total pores (vs. 91-93 in 
E. gomoni, 77-82 in E. indrambaiyai, 109 in E. octatrema, 87-97 in E. okinoseanus, 73-75 in 
E. wisneri). In addition, E. luzonicus has a single nasal-sinus papilla in the middorsal surface of the 
nasal sinus, while no nasal-sinus papilla was observed in all these eight-gilled congeners. Another 
Eptatj^etus species, E. mccoskeri McMillan, 1999 from the Galapagos Islands also has eight pairs 
of gill pouches, but it differs from all other eight-gilled congeners in having 3-cusp multicusps on 
the anterior and posterior sets of cusps and two bilaterally symmetrical nasal-sinus papillae in the 
dorsal surface of the nasal sinus. 
Another species of Eptatretus has been recorded from the Philippines. Eptatretus strahani 
McMillan and Wisner, 1984 was originally described from five specimens trapped at M^OO'N, 
120°18.2'E (near Liibang Island) at 189 m depth on 21-22 March 1976 (McMillan and Wisner 
1984). It has also been recently reported off Western Australia, based on two specimens collected 
at two locations: 16°54'S, 120°22'E, at 405 m, and 17°32'S, 118°48'E, at 430 m (Mincarone and 
Fernholm 2010). Eptatretus luzonicus can be easily distinguished from E. strahani by its number 
of gill pouches (8 vs. 7) and its multicusp pattern (3/2 vs. 3/3). 
Also collected during the Hearst Expedition to the Philippines was a single specimen (CAS 
233680, 393 mm TL) of the genus Myxine, which was trapped at 587-604 m in the same station 
