Siphonaria sipho

(Figs 8 – 10, 12 A – F, L – M)

Sumber: Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda)

External morphology (Figs 8 T – U, 12 L – M). Foot sole dark grey, foot edge pale yellow, unpigmented; foot wall, pneumostome and cephalic lobes pale greyish yellow, covered in irregular blotches of black pigmentation; mantle thin, translucent, pale yellowish grey, edge thickened, lobed, with black pigmentation edge bands aligning with underside of rib interstices. Shell (Figs 8, 12 A – F; Table S 9). Highly variable, medium sized (max sl mean = 16.8 mm, SD = 2.9 mm, n = 9), circular ovate, low to commonly tall; thick, apex offset central sightly to posterior and left, apical sides straight to convex, sometimes strongly convex (Figs 8 G – H, J); protoconch homostrophic (n = 2; Figs 8 V), shell whorl dextral; shell exterior and edge usually uneven; growth striae prominent in bands; rib count (mean = 37, SD = 5; n = 9), 10 – 12 fairly evenly spread primary ribs, pale white, raised rounded ridges, widen to shell edge, protrude beyond shell lip to unevenly scallop and corrugate the edge, ends of primary ribs may be flared creating uneven roughness on rib ridges, between primary ribs brown flecks / bands with two to six finer whitish secondary ribs (sometimes none), rib interstices narrow, darker; paired primary ribs on siphonal ridge, no more prominent than other primary ribs. Interior shell margin white to cream, dark brown markings on shell edge align under rib interstices may extend over shell margin (as in Sowerby’s original figure), white rays align on shell margin under primary / secondary ribs, ADM distinct, varies from tan to dark brown; siphonal groove distinct, same colour as shell edge; spatula golden tan with central white to dark chocolate brown; ADM scar distinct, brown to white as spatula; cephalic muscle weakly convex; thickening and whitening of shell lip common, translucent, infills and reduces lip scalloping, spatula becomes whitened. Neotype (Fig. 8 A). Shell (sl = 18.7, sw = 14.4, sh = 6.3 mm) circular ovate, medium; thick, apex offset weakly to posterior and left, ~ 14 primary ribs, with 1 – 3 in between finer secondary ribs; siphonal ridge formed by adjacent dual primary ribs. Interior shell lip and margin white under ribs, dark brown rays on shell lip aligning under rib interstices; taller and slightly darker interior shell form of S. sipho. RS (Fig. 9 A). Reproductive system (Figs 9 – 10; n = 15). Positioned to the right side of coelom, against foot wall, on foot muscle and under the respiratory cavity; epiphallic parts positioned over BM and between RAM; GA very small, with singular GP through foot wall; AO large, base wide, elongated, tip bluntly pointed and solidly embedded in MG, joined to lower ED and upper GA; ED as long as AO, narrow, centrally bent, joins to outer side of GA; GA, AO, ED all white muscular fibrous tissue; EG soft whitish tissue, slightly folded, medium in size, joins end of ED; single flagellum (F 1), short, often looped, appears as an extension of broader ED; BD and CD connect closely but in opposing directions into GA between ED join and GP, BD narrower and longer, both smooth, whitish, featureless, pass closely together through outer side of RAM (BD over CD) into soft white folded tissues of MG; MG / AG complex may be large; CD connecting to ducts; BD with large distal loop often looping behind ED, MA often present; BC small, embedded in top of AG, spherical, thin whitish translucent test; HD short, small, folded, links ducts in soft white folded tissues of AG to yellowish granulated HG; AG similar size to HG, sides match curvature of inner foot wall. Spermatophore (Figs 9 C, G, 10 B). Thread-like (mean total length = 3.63 mm, SD = 1.06 mm, n = 2), translucent, test thin; head section, tip bluntly rounded, evenly cylindrical, elongate, containing a white gelatinous mass; taper region into the filamentous transparent flagellum is short; both sections smooth, featureless. Head shorter and thicker than flagellum (mean head length = 1.46 mm, SD = 0.11 mm, n = 2; mean of SPM length ~ 41 %, SD = 9 %; mean head width = 120 μm, SD = 20 μm, n = 2; mean flagellum width = 13 μm, n = 2, SD = 15 μm). Seven SPM tightly coiled in one bursa found in [SK 078]. Radula and jaw. Dentition formula 40: 1: 40 (Hubendick 1946: 47, misidentified as S. laciniosa).

Sumber: Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda)

Distribution and habitat. Philippines (Bohol, Balicasag, Bandian, Negros, Olango, Siquijor, Mactan, Isla Verde, Cebu, Mangsee Is), Taiwan, Japan (Okinawa, Boso Peninsula, Honshu), Indonesia (Riau and Anambas Islands) (Fig. 11). Commonly found in sheltered locations, such as hollows and crevices, across upper and mid littoral levels, on bare, exposed rocks. Home scars prominent.

Sumber: Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda)