Tegulaplax hululensis (E.A. Smith, 1903 )

Dell’Angelo, Bruno, Gori, Sandro, Baschieri, Leonardo & Bonfitto, Antonio, 2010, Chitons (Mollusca, Polyplacophora) from the Maldive islands, Zootaxa 2673 (1), pp. 1-38 : 14

Tegulaplax hululensis (E.A. Smith, 1903)

( Figures 4J–O , 12D )

Ischnochiton hululensis E.A. Smith 1903: 619 , pl. 36, figs 3–6. Chiton hululensis ; Leloup 1952: 23, 56, fig. 10; pl. 3, fig. 5; Slieker 2000: 48, pl. 12, fig. 17. Chiton (Tegulaplax) hululensis ; Dell’Angelo & Smriglio 1999: 184, pls. 62–63, fig. 112; Anseeuw & Terryn 2004: 9, figs

40–41; Dell’Angelo et al. 2004: 54, pl. 4, figs 12–14; Schwabe 2005: 54, pl. 2, fig. 4; 2006: 101, figs 1B, 2G–L, 5;

Kaas et al. 2006: 240, fig. 97 (bibliography and synonymy); Schwabe et al. 2008: 15, figs 2E–F. Tegulaplax hululensis ; Saito 2000: 19, pl. 9, fig. 3.

Type: NHM 1903.9.17.27.

Type locality: Maldive Archipelago , Kaafu Atoll, Hulule Island (4°10’59” N, 73°31’58” E), 1.8–11 m.

Material examined: M13: 64 valves (9 head, 43 intermediate and 12 tail); M17: 4 valves (1 head, 2 intermediate and 1 tail); M19: 5 valves (1 head, 3 intermediate and 1 tail); M20: 9 valves (2 head, 4 intermediate and 3 tail); M23: 5 valves (1 head, 2 intermediate and 2 tail); M26: 13 valves (1 head, 7 intermediate and 5 tail); M28: 1 spm (length 10.5 mm, Fig. 12D ); M65: 38 valves (5 head, 23 intermediate and 10 tail); MLD01A: 7 valves (1 head, 5 intermediate and 1 tail); MLD02A: 30 valves (3 head, 14 intermediate and 13 tail); MLD03A: 21 valves (4 head, 12 intermediate and 5 tail); MLD04B: 2 valves (1 intermediate and 1 tail); MLD05A: 4 valves (1 head and 3 intermediate); MLD05B: 8 valves (1 head, 6 intermediate and 1 tail); LB01: 2 spm (length 14.5 and 8 mm); LB02A: 1 spm (length 9.2 mm); LB03A: 2 spm (length 17 and 13.8 mm); LB05: 25 valves (6 head, 15 intermediate and 4 tail).

Remarks: A detailed description of this species is given by Kaas et al. (2006).

This well known species is widely but discontinuously distributed throughout the Indo-West Pacific and has numerous synonyms ( Kaas et al. 2006). It is characterized by its sculpture consisting of small, irregular, concentric costae, sinuous in the middle, occurring on head valve, lateral, and postmucronal areas.

Distribution: Tegulaplax hululensis is known from the Tasman Sea trough the Torres Strait, NE Papua New Guinea, S. Vietnam, the Moluccas, the Timor Sea, Japan, Guam, the Fiji Islands, the Maldive Islands, Sri Lanka, Madagascar, Mozambique, Aden, the Red Sea and through the Suez Canal to the Mediterranean coast of Israel.

Figures

FIGURE 4A–C, Callochiton clausadeae Kaas & Van Belle, 1985, tail valve, Maldive, M13. A–B, dorsal and lateral views, respectively. C, detail of the sculpture. D–F, Callochiton sp., S. Nilandu Atoll, Maldive, NHM 1903.4.11.71 (living specimen collected by J.S. Gardiner, not coated). D, detail of the sculpture of an intermediate valve. E, dorsal view of the complete specimen. F, girdle dorsal spicules in situ. G–I, Rhyssoplax maldivensis (E.A. Smith, 1903), Maldive, MLD02A. G, intermediate valve, dorsal view. H–I, tail valve, dorsal and lateral views, respectively. J–O, Tegulaplax hululensis (E.A. Smith, 1903), Maldive, M13. J–L, head valve. J–K, dorsal and lateral views. L, detail of the sculpture. M–O, tail valve. M–N, dorsal and lateral views, respectively. O, detail of the sculpture. Scale bars 1 mm: E, G, J, K, M, N; 500 µm: A, B, D, H, I; 100 µm: C, F, L; 50 µm: O.

FIGURE 12A, Parachiton hylkiae mauricejayi Schwabe, 2002, living specimen, Maldive, LB03B, length 12.8 mm. B, Ischnochiton albinus Thiele, 1911, living specimen, Maldive, M13, length 5.2 mm. C, Ischnochiton feliduensis E.A. Smith, 1903, Maldive, Felidhoo Atoll, Holotype, NHM 1903.9.17.25, length 6 mm. D, Tegulaplax hululensis (E.A. Smith, 1903), living specimen, Maldive, M28, length 10.5 mm. E–F, Callochiton sp., S. Nilandu Atoll, Maldive, NHM 1903.4.11.71 (living specimen collected by J.S. Gardiner), length 6.6 mm. G, Lucilina sp., living specimen, Maldive, M07, length 4 mm. H, Lucilina indica (Leloup, 1981), holotype (MNHN), Madagascar, Tuléar, length 8 mm. I, Acanthopleura miles (Carpenter in Pilsbry, 1893), living specimen, Japan, Okinawa, Sesoko Island, length 29.2 mm. J, Schizochiton incisus (Sowerby, 1841), living specimen, Indonesia: inside lagoon of Woka Island, off South Halmahera, 1°2.02’S, 128°13.97’E (ZSM Mol 20052075), length 40 mm. K, Acanthochitona penicillata (Deshayes, 1863), living specimen, Maldive, MLD04A, length 6.5 mm. L, Craspedochiton cf. laqueatus (Sowerby, 1842), living specimen, Maldive, M59, length 13.5 mm. M–Q, Craspedochiton laqueatus (Sowerby, 1842), NHM type material, Philippines, Mindoro, Calapan. M, lectotype (NHM 1988071/1), length 17.4 mm. N, paralectotype (NHM 1988071/2), length 17.5 mm. O–Q, paralectotypes (NHM 1988071/3-5), length respectively 16, 13.2 and 11.3 mm. R–S, Cryptoplax burrowi (E.A. Smith, 1884), living specimen, Maldive, M07, length ca. 11.7 mm. T, Cryptoplax burrowi (E.A. Smith, 1884), living specimen, Indonesia, ZSM Mol 20033081, length 25.4 mm. U–X, Cryptoplax burrowi (E.A. Smith, 1884), NHM 1992 053, syntypes, H. Cuming colln., Port Adelaide, S. Australia, length respectively 56.4, 38.5, 47 and 45.1 mm.