Siphonaria campestra, B. W. Jenkins & Köhler, 2024

Siphonaria campestra View in CoL sp. nov.

( Figs 53C–D View FIGURE 53 , 54A–C, M–N View FIGURE 54 )

Material examined. Type material. Holotype, from Dolokoan Beach 8°31.424’S, 125°37.091’E, N of Dili, Timor-Leste; coll. B.W. Jenkins, TL01-1, 14 July 2019 ( AM C.584823 [M447, SK230 (RS)], Fig. 54A View FIGURE 54 ). GoogleMaps Three paratypes, same data as holotype ( AM C.585353 p [SK265], AM C.585354 p [SK266], Fig. 54B View FIGURE 54 ; AM C.585355 p [SK267], Fig. 54C View FIGURE 54 ). GoogleMaps

External morphology ( Fig. 54N View FIGURE 54 ). Foot sole evenly grey; foot edge and cephalic folds cream, slightly lobed; foot wall, mantle and pneumostomal lobe evenly shaded dark grey, lighter to foot edge; mantle narrower than foot wall, translucent, elongated at anterior, edge thickened, lobed with grey/black banding (over mantle width) aligning with rib interstices and interstice width; pneumostome elongated.

Shell ( Figs 54A–C View FIGURE 54 ; Table S9). Small sized (max sl mean = 8.1 mm, SD = 0.6 mm, n = 4), ovate; height low to medium; apex offset to posterior and slightly left; apical sides convex, concave and elongated to posterior; protoconch direction homostrophic (n = 1), shell whorl dextral; growth striae prominent uneven, shell thickness thin; shell edge uneven; rib count (mean = 28.3, SD = 2.3, n = 4), exterior with dual shaded bands, paler apical (white ribs and pale brown interstices) and darker shell edge (white ribs and black/dark brown interstices); primary ribs white, crooked, broaden to shell lip, weakly protrude beyond shell lip to unevenly scallop and corrugate the edge, 0–1 interspersed pale white finer secondary ribs; loosely paired primary ribs form siphonal ridge, no more prominent than other primary ribs; interior shell margin very dark brown to black, white rays on shell margin to lip align under primary/secondary ribs, siphonal groove indistinct, spatula very dark chocolate to black with some underlying white; ADM scar distinct, CMS straight; thickening of shell lip not apparent.

Reproductive system ( Fig. 53C; n View FIGURE 53 = 2). Positioned within entire right side of coelom, against foot wall on foot muscle, under the respiratory cavity occupying large proportion of animal body volume; epiphallic parts positioned over BM. GA small, with singular GP through foot wall; AO very small, narrow, bluntly pointed, joined to lower ED and upper GA; ED very short, very broad, centrally bent, joins to side of GA; GA, AO, ED all white muscular fibrous tissue; EG very large, soft whitish tissue, slightly folded, joins ED; extension joins in parallel to single very broad flagellum (F1), similar width to ED, appears as an extension of ED; BD and CD connect side-by-side into GA between ED join and GP, both ducts short, slightly bent, smooth, thickened, whitish, featureless, pass closely together inside outer RAM ( BD over CD) into soft white folded tissues of MG; MG / AG complex medium; CD connecting to ducts, BC embedded in folds close to embedded purplish SV; BD without distal loop and MA, with loop immediately prior to BC; BC relatively large, spherical, thin whitish translucent test; HD short, narrow, coiled, links ducts in soft white folded tissues of AG to yellowish granulated HG; outer edge of MG lobbed; AG larger than HG, outer sides match curvature of inner foot wall.

Spermatophore ( Fig. 53D View FIGURE 53 ). Broad head with short flagellum (length = 2.38 mm, n = 1); head section cylindrical, bulbous, centrally twisted, rounded tip; test thin, smooth, featureless, translucent encasing a white opaque central core; short tapering section merges head to filamentous flagellum; head shorter, wider than translucent flagellum (head length = 0.95 mm, ~ 40% of SPM length, head width = 103 μm; flagellum width = 17 μm, n = 1); 1 SPM found coiled in two BCs ( Fig. 53D View FIGURE 53 ).

Comparative remarks. Siphonaria campestra sp. nov. ( normalis group, unit 82) is most closely related to S. normalis , S. madangensis , S. fuliginata , and S. costellata , with which it forms a sub-clade in the normalis group ( Figs 1 View FIGURE 1 , 4 View FIGURE 4 ). However, it is well-differentiated from other species by COI distances of ≥ 18% (Table S2). This species has been found in sympatry with five congeners in TL: For comparisons with S. alba , S. javanica , and S. viridis refer to comparative remarks under these species. Siphonaria forticosta sp. nov. has a larger, darker shell with a more distinct siphonal ridge, a larger BC and narrower ED. Siphonaria planucosta sp. nov. has a larger shell with more raised ribbing, a less prominent siphonal ridge, a narrower AO, BD with distal loop, and a larger BC.

Distribution and habitat. Recorded from Dolokoan Beach, Timor-Leste ( Fig. 51 View FIGURE 51 ). In this study, found in sheltered positions (mainly crevices) on moderately exposed rocky shores, upper and lower littoral levels ( Fig. 54M View FIGURE 54 ).

Etymology. From ‘campestris’ (Latin = level, even), referring to the level or even primary ribs on the shell.