Ophichthus lithinus (Jordan & Richardson, 1908)

Psomadakis, Peter N., 2018, Snake eels of the genus Ophichthus (Anguilliformes: Ophichthidae) from Myanmar (Indian Ocean) with the description of two new species, Zootaxa 4526 (1), pp. 71-83 : 79-80

Ophichthus lithinus ( Jordan & Richardson, 1908)

Fig. 8

Leiuranus lithinus Jordan & Richardson, 1908: 238 (Cuyo, Philippines).

Ophichthus evermanni Jordan & Richardson, 1909: 172, Pl. 67 (from Takao, Taiwan).

Ophichthus lithinus ( Jordan & Richardson, 1908): Böhlke 1953:49; McCosker et al. 2006:272; Ho & Shao 2011:23; McCosker et al. 2012:7; Larson et al. 2013:27; McCosker 2014:339; Ho et al. 2015:8; McCosker & Ho 2015:72; Ho et al. 2015:172.

English name: Marbled snake eel (En)

Material examined. Myanmar: USNM 438266 , 642 mm TL, female, off Ayeyarwady Delta (15 o 15.64 N, 94 o 96.46 E), collected by R/V Dr. Fridtjof, Sta. 64, bottom trawl, 53.5 m depth, 9 May 2015. Australia: NTM 10651, 620 + mm, Darwin; NTM 13782, 585 mm, Beagle Gulf . Philippine islands: CAS-SU 20211 , 296 mm, holotype of Leiuranus lithinus, Cuyo ; USNM 1354141 , 8 (340 – 470), Cebu ; CAS-SU 26 829, 585 mm, Manila ; CAS 27124, 425 mm, Cebu ; CAS 48867, 530 mm, Lingayen Gulf . Taiwan: FMNH 52118 , 426 mm, holotype of Ophichthus evermanni, Takao ; CAS-SU 21 260, 548 mm, paratype of O. evermanni , from Takao ; CAS 237405 , 528 mm, Tashi . Thailand: NSMTP 104758 , 795 mm, Phuket .

Diagnosis. Body elongate, cylindrical, tapering and laterally compressed posteriorly; snout and tail tip pointed; body depth behind gill openings 32 – 37 in TL; anus at midbody; HL 9.7 – 11.7 in TL; tip of lower does not reach the posterior margin of the anterior nostril bases; dorsal fin arises ahead of gill opening by length of upper jaw; pectoral fin blade-like, rounded, 3.5 – 4.0 in HL; a notable barbel beneath mid-snout; posterior nostril along edge of lip, covered by a minute flap, and opens into mouth; eye ends above corner of jaw; teeth pointed, uniserial, medium-sized and retrorse; 3 rd preopercular pore present; color of head and body brownish yellow, overlain dorsally by irregular brown saddles and mottling; fins pale, median fins darkened ca. 1 HL before tail tip; vertebral formula 12-67-152, total vertebrae 147 – 157.

Size. To 148 cm TL.

Distribution. Known from Taiwan, Philippines, northern Australia, India, and Myanmar. Occupies shallow sand and mud bottoms.

Remarks. This specimen from Myanmar is a female with minute developing ova. Excellent black and white illustrations accompany the original descriptions of O. lithinus and its junior synonym O. evermanni , however to our knowledge, no adequate color photograph or illustration of a live or freshly captured specimen has been published. Our color photograph ( Figure 8 ) demonstrates the dorsally mottled coloration which might provide camouflage when it is out of the substrate. The yellow coloration of the throat, axillary spot, and ventral surface is stunning; it may relate to the condition of this specimen’s developing ova, however we currently have no other explanation of its significance. Previously known only from the Western Pacific, specimens from the Bay of Bengal, India, were reported by Ray et al. (2015). The O. lithinus specimen collected in Myanmar extends its geographical distribution in the Eastern Indian Ocean.

Figures

FIGURE 8. Ophichthus lithinus Jordan & Richardson 1908, USNM 438266, 642 mm TL, female. Photographed soon after capture and before preservation by O. Alvheim. Arrows indicate the origins of the dorsal fin (left) and the anal fin (right).