Siphonaria caubianensis Jenkins & Köhler, 2024, sp. nov.
Creators: name: Jenkins, Bruce
name: Köhler, Frank
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Siphonariida
Siphonariidae
Siphonaria
Siphonaria caubianensis

description: Siphonaria caubianensis sp. nov.
(Figs 53G–H, 54F–G)
Siphonaria cf laciniosa — Poppe 2010: 440, pl. 911, fig. 4a–c.
S. luzonica — Poppe 2010: 442, pl. 912, figs 4–5 (not S. luzonica Reeve, 1856).
S. subatra — Poppe 2010: 444, pl. 913, figs 5–6 (not S. subatra Pilsbry, 1904).
Material examined. Type material. Holotype, from Caubian Island, 10°17.22’N, 124°10.53’E, Bohol, Philippines (AM C.595933, Fig. 53F). Paratypes. Same data as holotype (AM C.595934 6d, Fig. 53G).
Other, non-type material. Philippines: Caubian Island, Bohol, 10°17.22’N, 124°10.53’E (AM C.595932 20+d, C.595935 p [SK559]); NW Polillo Is, E Quezon, Bolunga District, nr Panukalan, 14°59’N, 121°49’E (WAM S72342 10p, WAM S113803 p [SK557]).
External morphology (preserved). Foot sole and foot wall evenly cream, paler to foot edge; mantle pale, translucent, edge thick and lobed band; irregular widely spaced dark pigmentation spots on foot wall, concentrated over posterior and faintly over cephalic lobes.
Shell (Figs 54F–G; Table S9). Medium sized (max sl mean = 20.6 mm, SD = 2.1 mm, n = 20), circular ovate; height medium; apex offset weakly left and posterior, apical sides convex; protoconch direction homostrophic (n = 3), shell whorl dextral; exterior uneven, dark brown, weak radial colour banding; rib count (mean = 30, SD = 3.1, n = 20), ~14–16 primary ribs, straight to slightly bent towards shell edge, primary ribs white or dark brown, number (0– 14) and position on shell extremely variable, ridges raised, rounded, broaden slightly and increasingly raised to shell edge, variably and strongly protrude beyond shell lip (often> 3 mm) to strongly and unevenly scallop shell edge; 0–4 finer secondary ribs between primary ribs, rib interstices darker; siphonal ridge formed by closely paired, often end flared, primary ribs. Interior shell dark chocolate brown, spatula white to mottled dark brown; white rays on shell margin aligned in furrows under primary ribs, may extend to spatula, siphonal groove prominent, pale white to dark chocolate brown; ADM scar indistinct, darker than margin and shell edge, CMS straight; thickening and whitening of shell lip not observed.
Reproductive system (Fig. 53G; n = 1). Positioned within right side of coelom, against foot wall on foot muscle, under the respiratory cavity; epiphallic parts positioned over BM; GA small, with singular GP through foot wall; AO large, broad, blunt, joined to upper GA; ED long, wide, centrally twisted, joins to side of AO and GA; GA, AO, ED all white muscular fibrous tissue; EG large, soft whitish tissue, folded, joins ED with single long narrow bent flagellum (F1), appears as a narrower extension of ED; BD and CD connect juxtapose into GA / AO, opposing ED join, both ducts long, narrow, slightly bent, whitish, pass closely together through outer side of RAM (smooth featureless BD over wrinkled CD) into soft white folded tissues of MG; MG / AG complex large; CD connecting to ducts, BC embedded in folds close to embedded SV; BD with bursal loop; BC relatively small, elongated, thin whitish translucent test; HD long, broad, coiled, links ducts in soft white folded tissues of AG to granulated HG; outer edge of MG unlobed; AG larger than HG, sides match curvature of inner foot wall.
Spermatophore (Fig. 53H). Thread-like (length = 11.1 mm, 74 % of AL, n = 1); translucent, test thin; head section bluntly rounded, cylindrical, containing a prominent coiled white core, tapers to a thin tip; both sections smooth, featureless. Head section longer wider than flagellum (head length = 9.7 mm, mean ~ 88% of SPM length, head width = 155 μm, flagellum width = 34 μm); 1 SPM tightly folded in BC (WAM S113803).
Comparative remarks. We found this species in sympatry with four congeners on Cebu, Philippines. For comparisons with S. sirius, S. bifurcata, S. alba, and S. sipho refer to comparative remarks under these species. We have not been able to sequence material of this species.
Distribution and habitat. Recorded from Cebu and Bohol Islands, Philippines (Fig. 55). Found on rocky intertidal shores.
Etymology. For the type locality, Caubian Island, Philippines.
description: Published as part of Jenkins, Bruce & Köhler, Frank, 2024, Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda), pp. 1-217 in Megataxa 13 (1) on pages 144-146, DOI: 10.11646/megataxa.13.1.1, http://zenodo.org/record/14984186