Gymnothorax pseudoherrei Böhlke, 2000

Smith, David G., Bogorodsky, Sergey V., Dandar, James & Zajonz, Uwe, 2024, A new species of short unpatterned moray eel (Anguilliformes: Muraenidae) from the northwestern Indian Ocean, including the Socotra Archipelago, with a redescription of Gymnothorax pseudoherrei Böhlke, Zootaxa 5477 (4), pp. 465-474 : 471-473

Gymnothorax pseudoherrei Böhlke, 2000

( Figure 4 , Table 1 )

Gymnothorax pseudoherrei Böhlke, 2000: 408 (part), Figs. 2F , 3D , 7. Type locality Philippines, Mindanao. Holotype, USNM 357430 .

Material examined (including those from Böhlke 2000). Maldive Islands: CAS 35657 (5, 66–141 mm), Male Atoll, east side of Hulele Island , on outer reef, 04°11’ N, 73°31’ E, 08 November 1964 ; CAS 52094 (1, 102 mm), Male Atoll, 04°11’ N, 73°31’ E, 08 November 1964 ; FMNH 75523 (1, 123 mm), Miladumadulu Atoll, SW shore Kendikolu Island , 05°56’ N, 73°24’ E, 27 March 1964 ; FMNH 75540 (4, 123–134 mm), Tiladummati Atoll, Filadu Island , 31 March 1964 . Sri Lanka: ANSP 138609 (2, 46–122 mm), Trincomalee , south side of bay north of harbor, 10–22 m, 04 April 1970; ANSP 138701 (1, 111 mm), Hikkaduwa , 1 mile N of rest house, 15 m, 13 February 1970 ; MCZ 46958 (2, 140–166 mm), Trincomalee Bay , 03 April 1970 ; USNM 357433 (3, 116–155 mm), southeast side of bay at Galle , coral heads, 6–9 m, 16 February 1970 ; USNM 451459 (1, ~200 mm, corresponding to GenBank OR785803; alive in aquarium at the present time) . Philippines: ANSP 144451 (7, 102–148 mm), Palawan, 09°48’ N, 118°44’ E, 7–13 m, 03 July 1979; ANSP 164646 (1, 152 mm), Mindanao, 08°51’ N, 123°24’ E, 0–4.6 m, 04 May 1979 ; ANSP 177712 (7, 115–152 mm), Mindanao, Zamboanga del Norte, west side of Solino Island , 08°51’ N, 123°24’ E, 0–4.6 m, 03 May 1979 ; ANSP 177769 (1, 174 mm), same as ANSP 177712 ; ANSP 177775 (2, 151–156 mm), collected with holotype ; CAS 52575 (1, 130 mm), Sulu Prov., Siluag Island , 23 June 1948 ; CAS-SU 26801 (1, 118 mm), Negros Oriental, Dumaguete, June–August 1931 ; USNM 357430 (holotype, female, 147 mm), Mindanao, Zamboanga del Norte, W side of Solino Island , 08°51’ N, 123°24’ E, 0–4.6 m, 03 May 1979 ; USNM 357432 (2, 115– 124 mm), Palawan Prov., Sulu Sea, Puerto Princesa Bay, Pagnagtaran Point, 09°44’ N, 118°45’ E, 7–13 m, 02 July 1979 ; USNM 435956 (1, 186 mm, corresponding to PHILV090-15 ), Puerto Galera, Boquete Island [Paniquian Island], 13°51’ N, 120°94’ E, 1–3 m, 30 March 2015 (specimen cannot be found) . Indonesia: ANSP 131300 (4, 93–126 mm), Mentawei Island off Pulu Siburu, 02°00’ S, 99°35’ E, 1–2 m, 30 November 1963 ; ANSP 138523 (1, 125 mm), Pulo Jarak, 03°59’ N, 100°06’E, 0–4 m, 30 October 1963 ; USNM 210269 (1, 148 mm), Moluccas, northeast side of Ambon Island., ca. 2 km east of Sawa Telu , 0–8 m, 03 January 1973 ; USNM 274957 (1, 103 mm), Sulawesi, Buton Island , 05°41’ S, 122°62’ E, 1–8 m, 25 March 1974 . Thailand: ANSP 131179 (10, 73–163 mm), Goh Huyong, Similan Islands , coral heads, 08°29’ N, 97°39’E, 2.5 m, 03 November 1963 . Australia (Queensland): ANSP 144601 (2, 145– 182 mm), Endeavour Reef, ca. 15°46′ S, 145°35′ E, middle of north side of eastern half, 1–2 m, 13 January 1969 . Papua New Guinea: ANSP 145110 (1, 109 mm), Trobriand Islands, Kiriwana Island , west side of Boli anchorage, 08°31’ S, 150°59’ E, 16 June 1979 ; USNM 357431 (2, 127– 156 mm), Louisade Archipelago, southwest shore of Panapompom Island , 10°47’ S, 152°24’ E, 0–6 m, 15 June 1979 . New Britain: ANSP 131136 (11, 74–134 mm), Rabaul, Dawapia Rocks, near entrance to Simpson Harbor, 14°14’ S, 152°10’ E, 27 February 1965 . Palau: CAS 208442 (3, 118– 154 mm), lagoon edge of barrier reef 8 miles northwest of Korror Island , 07°24’30” N, 134°21’20” E, 1–2 m, 19 July 1955 . Solomon Islands: ANSP 138525 (5, 90–134 mm), Tautsina Island, east of Kieta Peninsula , coral head, 1–8 m, 11 March 1965 .

Diagnosis. Small size, to about 200 mm TL; dorsal-fin origin before gill opening; maxillary teeth biserial; two branchial pores; total vertebrae 111–116; plain brown in color, without dark grooves on throat and posterior part of head.

Description. In TL: preanal length 2.1–2.4, predorsal length 8.1–9.6, head length 6.1–8.7, depth at gill opening 15–24, depth at anus 16–25. In HL: snout 5.3–7.8, eye diameter 8.7–10.6, upper jaw length 2.8–5.1. Predorsal vertebrae 5–8, preanal vertebrae 45–49, total vertebrae 111–116.

A small eel, maximum size about 200 mm TL, moderately stout. Anus slightly before midlength. Dorsal-fin origin before gill opening ( Fig. 4A ). Snout relatively short and tapering, upper and lower jaws equal in length. Eye moderate, over middle of upper jaw. Anterior nostril tubular, barely reaching edge of lip when depressed. Posterior nostril broadly oval, with a low, dark-edged rim, above anterior margin of eye.

Lateral line with two small pores at anterior end of canal, before level of gill opening and near level of dorsal-fin origin ( Fig. 4A ). Supraorbital canal with three pores; the first on upper lip, before and below base of anterior nostril; the second lateral to and slightly above base of anterior nostril; the third on top of snout, closer to level of anterior nostril than to eye. Infraorbital canal with three pores; the first slightly behind and below base of anterior nostril; the second on upper lip about midway between level of eye and anterior nostril; the third below anterior margin of eye; the fourth below mideye. Preoperculo-mandibular canal with six pores; the first and smallest at edge of lower lip near anterior end; the second below first infraorbital pore; the third below second infraorbital pore; the fourth below third infraorbital pore; the fifth very slightly before posterior edge of eye; the sixth slightly behind level of rictus.

Maxillary teeth biserial, rows subequal; teeth of the outer row about twice as large as teeth of the inner row. Intermaxillary teeth with a single outer series of about 5–6 triangular and pointed teeth on each side, increasing in size from anterior to posterior; two median teeth, conical and pointed, the posterior one larger. Vomerine teeth small, uniserial, about 13. Mandibular teeth biserial in juveniles, teeth of the outer row smaller and more numerous, triangular, pointed, becoming smaller posteriorly, about 25 in number; mandibular teeth generally uniserial in adults, with about two larger teeth anteriorly on each side, the posterior one larger.

Color ( Fig. 4B ): medium brown, head somewhat lighter; a narrow dark ring at anterior margin of eye, some dark pigment at posterior margin of eye; no dark throat grooves, and no obvious markings on body.

Size and development. This is a small species, distinctly smaller than Gymnothorax arabicus ; the largest of 84 specimens reported by Böhlke (2000) was only 182 mm TL. The living individual from Sri Lanka (USNM 451459) measures approximately 200 mm, it has not grown beyond this size in four years. Indeed, this is one of the smallest known species of Muraenidae . Böhlke (2000: 410) reported a ripe female as small as 123 mm TL. A specimen of 148 mm TL examined here (USNM 210269) was noticeably swollen and contained large eggs.

Distribution and habitat. This species is known from the Maldive Islands and Sri Lanka in the central Indian Ocean eastward to Thailand, Indonesia, northern Australia, the Philippines, Papua New Guinea, New Britain, Palau, and the Solomon Islands. It occurs in shallow water; the deepest collection site was 22 m.

Etymology. Named for its superficial resemblance to and confusion with Gymnothorax herrei Beebe & Tee-Van (1933) .

Remarks. As explained above, Gymnothorax pseudoherrei is one of four species among the group of 12 short brown Gymnothorax species (sensu Böhlke 2000) whose vertebral counts and most of the proportions overlap those of Gymnothorax arabicus . It differs from 11 of these by lacking any conspicuous markings. It differs from G. herrei and G. pindae in the same characters as G. arabicus does (see above). It differs from G. arabicus primarily in its smaller size (not exceeding 200 mm TL vs. up to about 300 mm TL), the lack of dark throat and head grooves, and slightly fewer total vertebrae (111–116 vs. 114–120). In addition, it differs genetically from G. arabicus ( Fig. 1 ).

Allen & Erdmann (2012) included the species in their book and reproduced a photograph of it with the locality given as Indonesia. However, they used a photograph taken by J.E. Randall from Jana Island in the Arabian Gulf, and the specimen in fact is G. arabicus . A photograph of the true Gymnothorax pseudoherrei has never been published until now.

Figures

FIGURE 1. Neighbor-joining phenetic tree of COI mtDNA sequences of Gymnothorax arabicus and G. pseudoherrei following the Kimura two-parameter model (K2P) generated by BOLD (Barcode of Life Database, http://www. boldsystems.org); the scale bar represents a 2% sequence difference.

FIGURE 2. Dentition pattern on upper jaw and lower jaw of Gymnothorax arabicus sp. nov. (SMF 34701, paratype). Drawing by U. Zajonz.

FIGURE 3. Gymnothorax arabicus sp. nov., freshly collected specimen, SMF 34700 (sample tissue SOC18-087), holotype, 205 mm TL, Di Hamri, Socotra Island, Socotra Archipelago. A: whole moray; B: head close-up. Photos by S.V. Bogorodsky.

FIGURE 4. Gymnothorax pseudoherrei, live aquarium specimen, ca. 200 mm TL, Sri Lanka. A: negative color photograph shows the presence and position of the two branchial pores (two black arrows), and the dorsal-fin origin (red arrow); B: photograph shows typical coloration. Photo by J. Dandar.