Muraenichthys velinasalis, Hibino, Yusuke & Kimura, Seishi, 2015

Hibino, Yusuke & Kimura, Seishi, 2015, A new species of Muraenichthys (Anguilliformes: Ophichthidae) from the Indo- Pacific, with revised generic diagnosis, Zootaxa 4060 (1) : -

Muraenichthys velinasalis sp. nov.

New English name: Curtain-nose Worm Eel Figs. 2 b, 3f, 4, 5a, b, c; Tables 1, 2

Holotype. USNM 313976, 281.0 mm TL, sex female, Bay between Ken-Ting and Ta-Yuan Shan, Taiwan, 21°55'30"N, 120°48'00"E, depth 5–8 m, 1 Mar. 1968, coll. V. G. Springer et al.

Paratypes. Four specimens, 97.9–158.3 mm TL. AMS I.17472-073, 97.9 mm TL, Malapoa Peninsula, Efate Island, Vanuatu, 17°44'S, 168°17'E, depth 10 m, 22 Jun. 1973, coll. G. R. Allen; AMS I.20463-060, 158.3 mm TL, Tree Island, Queensland, Australia, 23°30'S, 152°05'E, pool face of reef, depth 1 m, 5 Oct. 1972, coll. AMS Party; ANSP 124398, 139.5 mm TL, Korali Pattu; Kalkudah Bay, Sri Lanka, rock outcrop with some coral growth, surrounded by sand, 9 June 1970, coll. T. Iwamoto; USNM 396145, 123.8 mm TL, Coron Island, Calamian Islands, Philippines, 11°48'58"N, 120°15'11"E, outer reef drop off with rock and coral wall to sand and rubble at base, depth 15–31 m, 7 Mar. 2003, coll. J. T. Williams et al.

Diagnosis. A species of Muraenichthys with the following combination of characters: head 12–14% TL, tail 57–61% TL; dorsal-fin origin slightly posterior to a vertical through mid-anus, horizontal distance from the vertical to the origin1.0–19% HL; posterior nostril opening above lip but concealed by a large flap; teeth relatively robust, their tips weakly pointed; teeth on jaws irregularly two rows anteriorly and one row posteriorly, vomer two rows; predorsal vertebrae 44–53, preanal 44–51 and total 136–139; MVF 48-47-138.

Description. Counts and measurements are shown in Table 2 . Body elongate, subcylindrical, tapered and laterally compressed posteriorly; head relatively large, preanal length shorter than tail ( Fig. 4 ). Snout relatively blunt, length more than twice eye diameter; mouth inferior, distance between tip of snout and tip of lower jaw almost equal to eye diameter; no median groove ventrally on snout; anterior nostril tubular, its length slightly shorter than eye diameter, its opening with a very small flap; inner hole of posterior nostril above upper lip, covered by a broad dermal flap with a prominent projected flap anteriorly; eyes large, covered by a transparent skin, located anterior to mid-jaw; lips smooth, without additional grooves or papillae; mouth large, corner of rictus well behind posterior margin of eye; teeth subconical, robust, their tips weakly pointed ( Fig. 3 f); maxillary teeth irregular ly biserial anteriorly but uniserial posteriorly ( Fig. 5 b); vomerine teeth biserially; intermaxillary teeth usually continuous with vomerine teeth, arranged semicircular; mandible teeth biserial anteriorly and uniserial posteriorly ( Fig. 5 c); arrangement of sensory pores on head as follows ( Fig. 5 a): one + four supraorbital, three + two infraorbital (one between anterior and posterior nostrils), six + three preoperculomandibular, and two supratemporal; a single interorbital and median supratemporal pores; lateral line behind a level of anus but not reaching to mid-tail; interorbital region flat without a distinct groove; gill opening located ventrolateral, constricted. Dorsal and anal fins low, their height less than half of eye diameter, confluent with caudal; dorsal-fin origin located slightly posterior to a level of anus; caudal fin rounded and extremely short; pectoral fins absent.

Color in preserved condition. Head and body pale brown to dark brown. Fins pale brown ( Fig. 4 ).

Distribution and ecological note. Known from Sri Lanka, Taiwan, Philippines, northeastern Australia and Vanuatu; estimated tow idespread in the Indo-Pacific Ocean. A shallow water species (1–31 m depth), found in tidepools or around coral reefs.

Etymology. The scientific name is derived from the Latin meaning “veiled nostril”, in reference to the posterior nostril concealed by a large flap.

Remarks. Although the shape of posterior nostril in M. velinasalis sp. nov. is unique, being one of the diagnostic characters, the location of an inner hole and the presence of a short projected flap on the anterior corner of the posterior nostril are shared with other congeners ( Fig. 2 a, b).The new species possesses the above-mentioned diagnostic characters of the genus Muraenichthys . Muraenichthys velinasalis resembles M. philippinensis and Muraenichthys schultzei Bleeker 1857 in the position of its dorsal-fin origin which is behind a vertical through mid-anus (all other congeners have the origin anterior to a vertical through mid-anus). However, the former species can be easily distinguished from the latter two species by the shape of its posterior nostril, as mentioned above, and by the shape of teeth on the innermost row of the upper jaw (relatively robust and slightly pointed vs. slender and pointed), as the arrangement of upper-jaw teeth (irregularly biserial anteriorly and uniserial posteriorly vs. completely uniserial in M. philippinensis , biserialor triserial in M. schultzei ), and its more numerous or fewer preanaland total vertebrae (44–51 vs. 59–60 in M. philippinensis , 42–47 in M. schultzei ; 136–139 vs. 128–130 in M. philippinensis , 119–128 in M.schultzei ).

Comparative materials. Glenoglossa wassi McCosker 1982 : CAS 47049 (holotype), 150.0 mm TL, Tutuila Island, American Samoa. Muraenichthys gymnopterus : RMNH. PISC. 7165 (holotype), 223.0 mm TL, Java, Indonesia; BMNH 1867.11.28.301 (Bleeker specimen), 325.0 mm TL,?Java. Indonesia; USNM 243005, 222.0 mm TL, Batanta Island, Indonesia. Muraenichthys hattae : SU 6473 (holotype), 331.0 mm TL, Wakaura, Wakayama Prefecture, Japan; FRLM 34541, 303.9+ mm, Owase, Mie Prefecture, Japan (cleared and stained); OMNH-P 38345, 329 mm TL, Osaka Bay, Osaka Prefecture, Japan. Muraenichthys philippinensis : USNM 134951 (holotype), 89.0 mm TL, Badian Island, Philippines; USNM 134952 (paratype), 115 mm TL, Luzon Island, Philippines. Muraenichthys schultzei : BMNH 1867.11.28.331 (holotype), 94.0 mm TL, Batavia, Java Island, Indonesia; SU 26840, two specimens, 97.7–103.8 mm TL, Dumaguete, Negros Island, Philippines; SU 26841, three specimens, 54.8–128.0 mm TL, Dumaguete, Negros Island, Philippines; SU 29750, 115 mm TL, Dumaguete, Negros Island, Philippines; SU 33650, two specimens, 42.8–51.5 mm TL, Nasugbu, Luzon Island, Philippines; SU 38865, 149.0 mm TL, Dumaguete, Negros Island, Philippines; USNM 343393, two specimens, 98.5–110.8 mm TL, Guimaras, Philippines; USNM 343989, 80.3 mm TL, Iloilo, Panay Island, Philippines; USNM 378716, Buyallao Island, southeastern Mindoro Island, Philippines, 99.8 mm TL. Muraenichthys sibogae : ZMA. PISC.112.669 (one of four syntypes), 107.0 mm TL, Timor Island, Indonesia. Muraenichthys thompsoni Jordan & Richardson 1908: SU 20201 (holotype), 96.0 mm TL, Luzon Island, Philippines; NMMB-P 17508, 174.8 mm TL, Dong-gang, Taiwan; HUMZ 198661, 179.5 mm TL, Panay Island, Philippines. Schultzidia johnstonensis ( Schultz & Woods 1949) : USNM 141268 (holotype), 141.2 mm TL, Johnston Island. Scolecenchelys aoki ( Jordan & Snyder 1901): FRLM 45698, 318.0 mm TL, Shima, Mie Prefecture, Japan. Scolecenchelys laticaudata ( Ogilby 1897) : AMS I.20463-033, one of three, 349.5 mm TL, One Tree Island, Queensland, Australia. Skythrenchelys macrostoma : BMNH 1867.11.28.313 (holotype), 223.0 mm TL, Ambon Island, Indonesia; BPBM 29320 (holotype of Skythrenchelys lentiginosa Castle & McCosker 1999 ), 163.1 mm TL, the Red Sea, Port Sudan Harbor. Skythrenchelys zabra Castle & McCosker 1999 : BPBM 38404 (paratype), 185.0 mm TL, Cobourg Peninsula, Northern Territory, Australia; CAS 51992, 136.5 mm TL, Negros Island, Philippines.

Figures

FIGURE 2. Shape of posterior nostril of Muraenichthys schulzei, USNM 378716, 99.8 mm TL (a), Muraenichthys velinasalis sp. nov., USNM 313976, holotype, 281.0 mm TL (b), and Scolecenchelys aoki, FRLM 45698, 318.0 mm TL (c). AN, anterior nostril; IH, inner hole of posterior nostril; PF, projected flap on anterior corner of posterior nostril. Arrows indicate outer hole of posterior nostril; broken circles indicate inner hole; and broken lines indicate inner edge of upper lips.

FIGURE 3. Shape of vomerine teeth (a, b, c) and upper-jaw teeth (d, e, f) in Muraenichthys. a M. gymnopterus, USNM 243005, 222.0 mm TL; b M. philippinensis, USNM 134951, holotype, 89.0 mm TL; c M. thompsoni, NMMB-P 17508, 174.8 mm TL; outer-row tooth (d) and inner-row tooth (e) of M. schultzei, BMNH 1867.11. 28.331, holotype, 94.0 mm SL; f M. velinasalis sp. nov., AMS I. 20463 - 0 60, 158.3 mm TL. Arrows indicate tips of each tooth.

FIGURE 4. Preserved condition of Muraenichthys velinasalis sp. nov., USNM 313976, holotype, 281 mm TL. A, position of anus; D, origin of dorsal fin.

FIGURE 5. Sensory pores on head (a), dentition on upper jaw and palatal area (b) and mandible (c) of Muraenichthys velinasalis sp. nov. a USNM 313976, holotype, 281.0 mm TL; b, c AMS I. 17472 - 073, paratype, 97.9 mm TL. IMT, intermaxillary teeth; IO, infraorbital pores; LL, lateral-line pores; POM, preoperculomandibular pores; SO, supraorbital pores; ST, supratemporal pores; UJT, upper-jaw teeth; VT, vomerine teeth. Arrows indicate interorbital and median supratemporal pores and broken circles indicate toothless holes.

Tables

TABLE 2. Counts and measurements of Bleeker specimens of Muraenichthys gymnopterus and Muraenichthys velinasalis sp. nov. Figures in parentheses indicate mean values.

	Muraenichthys gymnopterus	Muraenichthys velinasalis
	Holotype Bleeker specimen (not of types)	Holotype Paratypes (n=4)
Total length (mm) Counts Lateral-line pores before anus	RMNH.PISC. RMNH.PISC. BMNH 7165 36265 1867.11.28.301 223.0 257.0 325.0 44 43 45	USNM 313976 281.0 97.9–158.3 (129.9) 49 44–47 (46.0)
Predorsal vertebrae	30 30 30	50 44–53 (48.0)
Preanal vertebrae	43 41 44	47 44–51 (47.0)
Total vertebrae	130 129 130	137 136–139 (137.8)
Measurements As % of total length Head length Trunk length	15 14 13 24 24 24	12 13–14 (13.3) 30 25–31 (28.0)
Tail length	61 61 62	58 57–61 (59.3)
Body depth at gill opening	2.8 3.4 3.5	4 2.6–4.4 (3.6)
Body depth at mid-anus Body width at gill opening	2.8 3.7 3.5 1.6 2.8 2.7	4.3 2.5–3.8 (3.0) 2.4 1.6–2.0 (1.8)
Body width at mid-anus	2.3 3.1 3.2	2.6 1.8–2.0 (1.9)
As % of head length Anus to origin of dorsal fin	73 77 87	19 1.0–6.4 (3.6)
Upper-jaw length Length of mouth gape	32 34 39 24 25 27	36 37–40 (38.3) 31 27–29 (28.0)
Snout length	10 13 13	16 13–15 (14.0)
Eye diameter	4.1 3.2 5.5	6 4.8–6.9 (6.3)
Interorbital width Gill-opening length	7.4 7.8 11 5.1 5.4 8.2	10 5.2–7.8 (6.8) 6.9 3.2–6.3 (4.1)
Body depth at gill opening	19 25 27	33 21–32 (27.0)
Body depth at mid-anus	19 27 27	36 20–28 (22.8)