Meadia roseni Mok, Lee & Chan, 1991

Vo, Van Quang, Ho, Hsuan-Ching, Dao, Ha Viet & Tran, Hoa Hong Thi, 2021, A new arrowtooth eel of genus Meadia (Synaphobranchidae: Ilyophinae) from Vietnam, South China Sea, Zootaxa 4952 (1), pp. 181-191 : 187-189

Meadia roseni Mok, Lee & Chan, 1991

Figs. 3B , 4B , 5B ; Table 1

Meadia roseni Mok, Lee & Chan, 1991:39 , figs. 1–3 (type locality: off Tongkang [Dong-gang], southwestern Taiwan, 22°21'05"N, 120°12'46"E, depth 1020 m). Ho & Shao, 2011:22 . Ho et al., 2015b:179 . Ho et al., 2015c:8 .

Description. Head with a clear hump behind eye. Dorsal-fin origin slightly behind pectoral-fin base. Anal-fin origin about 0.6–0.7 HL behind head. Middle of eye through posterior third of upper jaw. Posterior nostril with low rim and its margin bearing many fringes. Numerous cirri or papillae on snout and chin, gradually becoming scattered on posterior portion of head. Gill opening against lower end of pectoral-fin base ( Figs. 3B , 4B ).

Head pores: SO 1 (ethmoid) + 3, 3 at tip of snout and the fourth above upper margin of eye; IO 6, 1 (adnasal) at posterodorsal corner of anterior nostril, 2 between nostrils and 2 below eye, the sixth above posterior end of rictus; F 0; POM 10 or 11 (mainly 11), the penultimate pore 0.5–1 eye diameter behind rictus and the last 1.5–2 eye diameter behind rictus. ST 0. Lateral-line pores: head 9 or 10; PDLL 14 or 15; PAL 30–32. Numbers of dorsal-fin rays before anal-fin origin 37–46.

Vertebrae: PDV 15–16, PAV 31–35, PCV 62–65, TV 200–204, and MVF 16-32-202.

Tooth pattern: an oval patch of 14–20 moderately large, stout teeth on intermaxillary; followed by a long patch of various-sized teeth on vomer, which has about 11–15 enlarged and stout teeth, most teeth with a cutting edge, followed by 4–7 much smaller stout teeth posteriorly. Maxilla with a long band of about 4 rows of pointed teeth, those on outer row smallest, those on inner rows gradually larger. Lower jaw with about 4 rows of stout teeth anteriorly, gradually becoming 2 rows posteriorly, those on outer row smallest, those on inner row gradually becoming larger, most teeth with a cutting edge at tip.

Coloration. In both fresh and preserved specimen, body uniformly grayish brown to dark brown, generally darker than that of M abyssalis . Anterior portion of dorsal and anal fin (about half of the fin) grayish brown with broad pale margin, gradually becoming darker and the margins becoming narrower, darkened at about one head length from posterior end; caudal fin black ( Figs. 3B , 4B , 5B ). Peritoneum pale with black pepper dots, stomach and intestines pale.

Remarks. The lateral-line pores are more numerous and are rather close to each other in M. roseni compared to the two other congeners. In general, M. roseni has more teeth on jaws, intermaxillary, and vomer and a darker body color compared to M. abyssalis .

Figures

FIGURE 3. A. Meadia abyssalis, NMMB-P24798, 575 mm TL, photo by H.-C. Ho. B. Meadia roseni, NMMB-P29943, 723 mm TL, photo by K. Koeda.

FIGURE 4. Close-up of head and trunk region. A. Meadia abyssalis, NMMB-P26380, 256 mm TL, left-right reversed. B. Meadia roseni, NMMB-P25976, 429 mm TL. C. Meadia minor sp. nov., from holotype. Arrows point to dorsal-fin origin (D), anal-fin origin (A) and gill opening (GO). Not to scale.

FIGURE 5. Posterior portion of tail showing the coloration of fins. A. Meadia abyssalis, NMMB-P15513, 336 mm SL, leftright reversed. B. Meadia roseni, NMMB-P25976, 429 mm TL. C. Meadia minor sp. nov., from holotype. Not to scale.Anterior to left.