Scaeochlamys squamea Dijkstra & Maestrati, 2009
DIJKSTRA, H. H. & P. MAESTRATI. 2009. New bathyal species and records of Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from Taiwan. Bulletin of Malacology, Taiwan, 33: 37-54, pls. 1-4. [p. 45, pl. 4, figs. 32-36]
2009 Scaeochlamys squamea Dijkstra & Maestrati, 2009
H. H. Dijkstra & P. Maestrati, 2009, plate 4.
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«Remarks
The present specimen from Taiwan is identical to the type material. Scaeochlamys squamea n. sp. (PI. 4, figs 32-36) Chlamys lemniscata (Reeve). – Abbott & Dance, 1982: 312, fig.; Rombouts, 1991: 15, pI. 6, fig. 2; Xu & Zhang, 2008: 81, fig. 225 (not Pecten lemniscatus Reeve, 1853). Chlamys (Azumapecten) squamata (Gmelin).– Springsteen & Leobrera, 1986: 328, pI. 93, fig. 11 (not Ostrea squamata Gmelin, 1791). Chlamys (Laevichlamys) lemniscata (Reeve). – Okutani, 2000: 899, pI. 447, fig. 9 (not Pecten lemniscatus Reeve, 1853). Coralichlamys lemniscata (Reeve). – Wang, 2002: 183, pI. 5, fig. 5 (not Pecten lemniscatus Reeve, 1853). Scaeochlamys livida (Lamarck). – Raines & Poppe, 2006: 230 [partly], pI. 179, fig. 1 (not Pecten lividus Lamarck, 1819). Type locality Taiwan, 24°57'N, 122°02'E, 115-170 m, beamtrawl, TAIWAN 2001 stn CP 76, leg. Bouchet, Richer & Chan, 07.05.2001. Material examined Taiwan. TAIWAN 2000: Stn DW 7, 22°20'N, 119°13'E, 260 m, 6 v; stn DW 8, 22°19'N, 119°15'E, 266 m, 1 v; stn DW 34, 22°02'N, 1200 36'E, 246 Ill, 3 v; stn DW 35, 22°02'N, 120°27'E, 246 m, 1 v; stn DW 36, 21·55'N, 120°36'E, 305 m, 5 v. TAIWAN 2001: Stn CP 74, 24°51 'N, 121°59'E, 220 m, 4 v; stn CP 76, 24°57'N, 122°02'E, 115-170 m, alive, 1 pr (holotype, NMNS-5904-001), 1 v (paratype, NMNS-5904-013); stn CP 78, 24°54'N, 121°57'E, 100-118 m, 5 v; stn CP 83, 24°51 'N, 121°57'E, 75-110 m, 22 v (paratypes, 20 MNHN 21268, 2 ZMA Moll. 4.09.007); stn CP 88, 24°51 'N, 122·03'E, 650 m, 1 v; stn CP 94, 24°53'N, 121°58'E, 153 m, 2 v; stn DW 118, 24°56'N, 122°02'E, 128-136 m, 1 v. TAIWAN 2004: Stn DW 255, 24°58'N, 122°02'E, 120-128 m, 3 v. Description Shell up to ca. 60 mm high, commonly smaller than 40 mm, weakly inflated, nearly equally convex to opisthogyrate, elongate (somewhat posteriorly oblique), inequivalve, inequilateral, auricles strongly unequal in shape and size, umbonal angle ca. 85-90°, colour strongly variable, nearly all gradiations and patterns of white, orange, red, yellow, pink, purple and brown. Left valve sculptured with ca. 24-30 irregularly spaced scaly radial ribs, strongly different of development, of which 8-9 more prominent, commencing with ca. 8 at 1 mm shell height, increasing intercostally and extending to the ventral margin. Intercalate reticulate or shagreen microsculpture in early growth stage and antimarginal microsculpture in early radial stage and posteriorly. Anterior auricle much larger in shape and size than posterior, with 6-10 weak squamous radial riblets and reticulate or shagreen microsculpture, posterior auricle nearly smooth. Right valve with ca. 30-36 irregularly spaced scaly radial ribs, less different of prominence than of left valve. Anterior auricle with 4 weak radial ribs and overrunning commarginal lamellae, prominent dorsally. Posterior auricle nearly smooth. Byssal notch deep, byssal fasciole rather broad. Functional ctenolium well-developed with 5-7 teeth. Distribution Southern Japan (Okutani, 2000: 899, 30-300 m), East China Sea and South China Sea (Xu & Zhang, 2008: 81), Philippines (Springsteen & Leobrera, 1986: 328), southwards to the tropical waters of Australia (unpubl. data, AMS, WAM). Comparison Specimens from the western Pacific are by previous authors often attributed to Pecten lemniscatus Reeve, 1853, placed in Laevichlamys (see Waller, 1993: 204), occuring in the south-western Indian Ocean, or to Ostrea squamata Gmelin, 1791, placed in Scaeochlamys, commonly occuring in Japan, and to Pecten lividus Lamarck, 1819, also placed in Scaeochlamys, occuring in the temperate waters of Australia. L. lemniscata is closest to the present species and could be distinguished by the following characters: S. squamea has a coarser radial macro sculpture on the right valve with less radial riblets (30-36) than S. lemniscata (up to 50) and lacks an antimarginal microsculpture on the right valve. Moreover, S. squamea has a persistant reticulate or shagreen microsculpture on the left valve, which is lacking in typical S. lemniscata.
A closely resembling congeneric species is Scaeochlamys squamata (Gmelin, 1791), known from the western Pacific, which differs from S. squamea in having less prominent radial ribs (5-6) on the left valve (S. squamea 8-9), in having weaker early radial sculpture on the right valve and a few more radial ribs (6-7) on the anterior auricle of the right valve (S. squamea 4) and a reticulate microsculpture throughout on both valves (S. squamea only on the left valve in early ontogeny). Other characters like an opisthogyrate form and antimarginal microsculpture are identical.
Etymology Shell with squamous texture (Lat. squameus, adj. = squamous).» HENK H. DIJKSTRA & PHILIPPE MAESTRATI, 2009
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«Habitat. Scaeochlamys squamea lives in shallow water from the subtidal zone down to the continental shelf, and is often deformed, as a result of its coral-dwelling niche.
Distribution. Japan southwards to Western and northern Australia. Taiwan, 75–170 m (Dijkstra & Maestrati, 2009: 45–46); Philippines, 5–50 m (as Scaeochlamys squamata and Scaeochlamys livida; Raines, 2010: 628; Dijkstra, 2013: 77). Maximum depth range of live-taken specimens is 5–170 m. Present specimens from Australia alive at 3–73 m.
Remarks. This species was identified as Pecten lemniscatus Reeve, 1853 by Abbott & Dance (1982: 312), but P. lemniscatus is known only from the south-western Indian Ocean and is currently placed in Laevichlamys (Waller, 1993, p. 204). The two species can be distinguished by the following characters: Scaeochlamys squamea has coarser radial macrosculpture on the right valve with fewer radial riblets (30–36) than Laevichlamys lemniscata (up to 50) and lacks antimarginal microsculpture on the right valve. Moreover, Scaeochlamys squamea has persistant shagreen microsculpture on the left valve, but shagreen microsculpture is lacking in all species of Laevichlamys. Table 5 lists the characters distinguishing these two species.
A closely similar congeneric species is Scaeochlamys squamata (Gmelin, 1791), known from Japanese waters. Scaeochlamys squamata differs from S. squamea in having fewer prominent radial plicae (5–6) on the left valve (S. squamea has 8–9), in having weaker early radial sculpture on the right valve, and a few more radial costae (6–7) on the anterior auricle of the right valve (S. squamea has 4) and shagreen microsculpture throughout on both valves (S. squamea only on the left valve early in ontogeny). Other characters such as the opisthogyrate form and antimarginal microsculpture are identical. Scaeochlamys squamea is a new record for Australia.» DIJKSTRA, H. H. & A. G. BEU. 2018. Living scallops of Australia and adjacent waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae). Records of the Australian Museum, 70 (2): 113-330, figs. 1-102. [p. 122, 124]
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Scaeochlamys squamea Dijkstra & Maestrati; H. H. Dijkstra & A. G. Beu, 2018, Living scallops of australia and adjacent waters, figures 76F, 76H, 78E, 78F.
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«Description. — Shell up to c. 60 mm high, most specimens under 40 mm, weakly inflated, almost equally convex to prosogyrate, elongate, inequivalve, inequilateral, auricles highly unequal in shape and size, umbonal angle c. 85-90˚; colour highly variable, in almost all intergradations and patterns of white, orange, red, yellow, pink, purple and brown. Left valve sculptured with c. 24-30 unevenly spaced, scaly radial costae, varying strongly in prominence; 8-9 costae more prominent than others, commencing with c. 8 at 1 mm shell height, increasing by intercostal intercalation and
extending to ventral margin. Shagreen microsculpture present in radial interspaces in early growth stage; antimarginal microsculpture present in early radial stage and on posterior area of disc. Anterior auricle much larger and longer than posterior, bearing 6-10 weak, squamous radial riblets and shagreen microsculpture, posterior auricle almost smooth. Right valve with c. 30-36 unevenly spaced scaly radial costae, varying less in prominence than on left valve. Anterior auricle with 4 weak radial costae, with commarginal lamellae continuous over costae, lamellae prominent dorsally. Posterior auricle almost smooth. Byssal notch deep, byssal fasciole rather broad. Functional ctenolium well-developed, with 5-7 teeth. Hinge with moderately weak resilial and dorsal teeth. Interior somewhat plicate. Distribution. — Tropical Indo-West Pacific from southern Japan southwards to northern Australia (ZMA, unpubl. data). Bathymetric range of live-taken specimens in 5-50 m (ZMA, unpubl. data). Specimens are often deformed, caused by its coral dwelling niches. Remarks. — This species was attributed to Pecten lemniscatus Reeve, 1853 (in 1852-53), by Abbott & Dance (1982: 312), but P. lemniscatus is known only from the south-western Indian Ocean and is currently placed in Laevichlamys (Waller, 1993: 204). The two species can be distinguished by the following characters: S. squamea has coarser radial macrosculpture on the right valve with fewer radial riblets (30-36) than L. lemniscata (up to 50) and lacks antimarginal microsculpture on the right valve. Moreover, S. squamea has persistant shagreen microsculpture on the left valve, but shagreen microsculpture is lacking in L. lemniscata, as in all other species of Laevichlamys. A closely similar congeneric species is Scaeochlamys squamata (Gmelin, 1791), known from the western Pacific. Scaeochlamys squamata differs from S. squamea in having fewer prominent radial costae (5-6) on the left valve (S. squamea has 8-9), in having weaker early radial sculpture on the right valve, and a few more radial costae (6-7) on the anterior auricle of the right valve (S. squamea has 4) and shagreen microsculpture throughout on both valves (S. squamea only on the left valve early in ontogeny). Other characters such as the opisthogyrate form and antimarginal microsculpture are identical.» DIJKSTRA, H. H. 2013. Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from the Panglao region, Philippine Islands. Vita Malacologica, 10: 1-108, pls. 1-32. [p. 77]
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Scaeochlamys squamea Dijkstra & Maestrati, 2009; H. H. Dijkstra, 2013, Pectinoidea from the Panglao region, Philippine Islands, plate 17, figures 5a, 5b (juvenile); plate 20, figures 1a-1d.
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