identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03E81D53B32130195EC8FABDFC1EF83D.text	03E81D53B32130195EC8FABDFC1EF83D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Meadia roseni Mok, Lee & Chan 1991	<div><p>Meadia roseni Mok, Lee &amp; Chan, 1991</p><p>Figures 1–4, Table 2</p><p>Rosen’s cutthroat eel</p><p>Meadia roseni Mok, Lee &amp; Chan, 1991: 39 (type locality: Taiwan; holotype: NSYU 2582) — Vo et al. 2021: 187 (Taiwan, description); Ho &amp; Vo 2024: 210 (Vietnam, description).</p><p>Distinctive characters. Preanal distance 4.2–4.6 in TL; head large, 6.3–7.4 in TL; intermaxillary and vomerine teeth blunt-tipped; total number of vertebrae 197–204.</p><p>Material examined: SAIAB 90361, 2 specimens, 368.5 mm TL (tissue sample SPR22-065) and 828.0 mm TL (tissue sample SPR22-029), Tanzania, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=41.583332&amp;materialsCitation.latitude=-10.016666" title="Search Plazi for locations around (long 41.583332/lat -10.016666)">Western Indian Ocean</a>, 10°01’S, 41°35’E, R / V Dr. Fridtjof Nansen, station 354, bottom trawl, 219–224 m depth, 01 July 2023, collected by S. V. Bogorodsky &amp; S.A. Bruck .</p><p>Comparative material: CSIRO H 7398-13 (BW-A12109), 426.0 mm TL, Taiwan, 22°28'N, 120°27'E, 18 March 2012 .</p><p>Description (data for the large specimen given first with data for smaller specimen in parentheses). General appearance shown in Figures 1 and 2. Body robust, body depth at gill opening and at anus subequal, 13.4 (17.9) and 13.1 (17.5) in TL, respectively; body oval in cross section anteriorly, body width at gill opening 18.1 (27.3) in TL; anus much closer to snout tip than to tip of tail, preanal length 4.2 (4.6) in TL; head relatively large, its length 6.3 (7.0) in TL; postorbital distance about 1.5 times in head length; dorsal profile of snout straight, dorsal profile of head convex behind eye; trunk very short, length 11.3 (13.4) in TL; tail much longer than preanal length, 1.3 (1.4) in TL; origin of dorsal fin above middle of pectoral fin, predorsal length 5.6 (6.0) in TL; anal fin begins a short distance behind anus; dorsal fin low, subequal to pupil diameter, anal fin distinctly higher than dorsal fin, its height about 3 times of body depth; pectoral-fin rays 16; pectoral fins short, their length 3.9 (3.7) in HL, pectoral-fin base relatively broad, subequal to width of gill opening; caudal fin with truncate posterior margin.</p><p>......continued on the next page</p><p>Mouth relatively large, rictus about 1.5 (1.0) eye diameter behind eye; eye small, its diameter 12.9 (13.1) in HL, located laterally on head; interorbital width relatively narrow, 5.9 (7.2) in HL; snout somewhat blunt, distinctly longer than eye diameter, its length 4.1 (3.3) in HL; upper jaw slightly longer than lower jaw, 2.2 (2.0) in HL and 2.5 (2.4) in TL, respectively; sides of upper and lower jaws, tip of snout, chin (except tip) covered with numerous small papillae; anterior nostril a short tube on side of snout, above tip of lower jaw; posterior nostril a raised relatively broad rim with a short thin anterior flap, located at ventroanterior margin of eye; gill opening crescentic, oblique, located lateroventrally on body, its width 9.4 (12.5) in HL, dorsal end of gill opening slightly below ventral end of pectoral-fin base; interbranchial width 6.0 (7.3) in HL, less than 1.5 times of width of gill opening.</p><p>Intermaxillary teeth in a round patch of 12 (15) stout blunt-tipped teeth (Fig. 3), patch not exposed when mouth closed; teeth in jaws small, pointed, maxillary teeth in 3–4 irregular rows, mandibular teeth in 3 irregular rows anteriorly, teeth of middle row slightly larger, becoming in 2 rows posteriorly; vomerine teeth stout, somewhat blunt-tipped, arranged in ovate patch in 3 rows, teeth of middle row twice as large as teeth in outer rows, specimen from Taiwan (CSIRO H 7398-13) has similar dentition; smaller Tanzanian specimen has five vomerine teeth in one irregular row, fourth tooth largest; vomerine patch extending nearly to anterior margin of eye (at level of posterior nostril).</p><p>Lateral-line pores small (Fig. 4): 11 (11) pores in lateral line anterior to pectoral fin, 15 (14) pores in lateral line anterior to dorsal-fin origin, and 25 (27) pores in lateral line anterior to anus. Cephalic pores relatively small; 4 supraorbital pores (SO), 3 pores at snout tip and fourth over dorsal margin of eye; 6 infraorbital pores (IO), first pore at posterodorsal edge of anterior nostril, two pores between nostrils, two pores below eye, and last pore above posterior end of rictus; 11 preoperculo-mandibular pores; no supratemporal pores. Vertebrae: predorsal 15 (15), preanal 29 (30), total number 200 (200).</p><p>Coloration of fresh specimens (Figs. 1 &amp; 2). Uniform dark brown, anal fin gray-brown; papillate area on upper and lower jaws mottled with dark brown on a pale background; pectoral fins nearly black; caudal fin black.</p><p>Size. Reaches 845.0 mm TL (Ho &amp; Vo 2024).</p><p>Distribution and habitat (Fig. 5). Previously, the species was known from Taiwan and Vietnam. The two specimens reported here represent the first record from Tanzania as well as the first record for the Indian Ocean. The holotype was collected at a depth of 1020 m; the depth of collection of other six specimens from Taiwan and Vietnam is unknown. The Indian Ocean specimens were trawled at depths of 219–224 m off southern Tanzania over a sandy substrate.</p><p>Phylogenetic analysis (Fig. 6). Phylogenetic analysis of the mitochondrial COI gene revealed a distinct clade formed by the genus Meadia . Within this clade, four species ( M. roseni, M. abyssalis, M. sp. 1 and M. sp. 2) are clearly resolved, with the specimens from Tanzania (EAF008-24 and EAF053-24, this study) clustering closely with M. roseni from Taiwan (FOAN1316-12). This relationship is supported by very low intraspecific pairwise genetic distances within M. roseni (&lt;0.2%), whereas mean interspecific distances between M. roseni and other species and genera ranged from 15.99% (between M. roseni and Meadia sp. 1) to 21.8% (between M. roseni and Ilyophis brunneus) (Table 3).</p><p>Remarks. Since its original description in 1991, Meadia roseni has been subsequently collected only from Taiwan (Vo et al. 2021) and was considered endemic to this region until a single large specimen was reported from a fishing port in Vietnam (Ho &amp; Vo 2024). Consequently, the specimens trawled off Tanzania represent an unexpected and substantial range extension into the Western Indian Ocean.</p><p>The holotype measured 745.0 mm TL, and the specimen from Vietnam, at 845 mm TL, represents the largest known specimen of the species. Accordingly, the larger Tanzanian specimen (828.0 mm TL) is the second-largest known specimen. In general, this specimen closely matches the description of the holotype of M. roseni from Taiwan but differs slightly in some proportions. These differences may reflect geographical variation and/or its slightly larger size, for example a somewhat deeper body (13.4 in TL vs. 15 in TL) (Table 2).</p><p>The assignment of the Tanzanian specimens to M. roseni is supported by phylogenetic analysis, as they are nested with the Taiwanese specimen in the same genetic lineage (Fig. 6), showing very low intraspecific divergence (&lt;0.2%). The identification of the Taiwanese specimen was confirmed by morphological examination. The larger Tanzanian specimen is almost identical in proportions to the large Vietnam specimen, except for a slightly shorter snout (Table 2).</p><p>Among the three valid species of the genus, Meadia abyssalis is the most widespread Indo-West Pacific species. It has been reported from the Western Indian Ocean off Mauritius, Réunion, and Mayotte (Quéro &amp; Saldanha 1985; Eudeline 2023). The phylogenetic analysis also indicates the presence of two putative species from Western Australia (Fig. 6). Specimens of both Australian lineages are currently under study by the last author and J. Pogonoski (CSIRO).</p><p>Meadia abyssalis differs from M. roseni by having a shorter head (8.3–9.7 in TL vs. 6.3–7.4 in TL), a shorter preanal distance (5.5–6.5 in TL vs. 4.2–4.6 in TL), a shorter trunk (15.4–18.9 in TL vs. 10.8–13.3 in TL), fewer prepectoral and predorsal pores (3–4 and 5–6 vs. 9–12 and 14–17, respectively), and paler coloration, including a white margin of the anal and caudal fins. Meadia minor, a medium-sized species known only from Vietnam, differs from both species in the position of the anus, which is located more than head length posterior to the gill opening (vs. less than head length behind gill opening in M. abyssalis and M. roseni). Consequently, M. minor has a greater preanal distance (2.8–3.1 in TL vs. 4.2–4.6 in TL in M. roseni and 5.5–6.5 in TL in M. abyssalis). Furthermore, M. roseni has 197–204 vertebrae and 25–32 preanal pores compared with 174–179 vertebrae and 14–16 preanal pores in M. abyssalis, and 118–122 vertebrae and 35–41 preanal pores in M. minor .</p></div>	https://treatment.plazi.org/id/03E81D53B32130195EC8FABDFC1EF83D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Matiku, Patroba;Bogorodsky, Sergey V.;Samucidine, Kelvin;Matcher, Gwynneth;Bills, Roger;Tighe, Kenneth A.	Matiku, Patroba, Bogorodsky, Sergey V., Samucidine, Kelvin, Matcher, Gwynneth, Bills, Roger, Tighe, Kenneth A. (2026): Unexpected record of Meadia roseni Mok, Lee & Chan, 1991 (Anguilliformes: Synaphobranchidae) from the Western Indian Ocean, with comments on its ontogenetic changes. Zootaxa 5777 (1): 169-183, DOI: 10.11646/zootaxa.5777.1.8, URL: https://doi.org/10.11646/zootaxa.5777.1.8
