Caecum donmoorei Mitchell-Tapping, 1979

Egger, Christina, Neusser, Timea P., Norenburg, Jon, Leasi, Francesca, Buge, Barbara, Vannozzi, Angelo, Cunha, Regina L., Cox, Cymon J. & Joerger, Katharina M., 2020, Uncovering the shell game with barcodes: diversity of meiofaunal Caecidae snails (Truncatelloidea, Caenogastropoda) from Central America, ZooKeys 968, pp. 1-42 : 1

Caecum donmoorei Mitchell-Tapping, 1979

Caecum donmoorei Mitchell-Tapping, 1979: 104, 105, figs 21, 22, 31, 32 Type locality: In 5 m of water in Sprat Baz, Water Island, USVI.

Material examined.

Panama • 1, juv.; Bocas del Toro; 9.2141, -81.9318; depth 8.5 m; 5 Jun 2010; USNM BRS 2010 exped.; Stat. BRS108; DNA voucher; GenBank: MT704265, MT731691; USNM 1618857. • 1; same collection data as for preceding; DNA voucher; GenBank: MT704266, MT731692; USNM 1618858. Belize • 1 (Fig. 7G ); Carrie Bow Cay; 16.8015, -88.0790; depth 10 m; 14 Jan 2010; USNM Belize2010 exped.; Stat. CBC1b; DNA voucher; GenBank: MT704274, MT731703; USNM 1618844.

Shell morphology.

Shell opaque white and solid. Size large> 2.0 mm. Tube moderately curved and curvature stronger towards aperture (Fig. 7G ). Septum blistered with pointed, sharp mucro (Fig. 7G ). Aperture surrounded by three narrow thick rings. Sculpture consists of 25 distinct squarish ribs with wide, deep interspaces. No microsculpture available.

Remarks.

The collected specimen USNM 1618844 closely resembles the description of C. donmoorei from the Virgin Islands ( Mitchell-Tapping 1979), however microsculptural data for comparison is missing. Our molecular data suggests the species identity among specimens with less separated, strongly flattened rings and almost vanishing interspaces (e.g., in juvenile USNM 1618857). The same has been observed for the confusingly similar species C. quadratum , Carpenter (1855-1857: 322, pl. 34, fig. 370). It can also exhibit a considerable variety of shell morphologies ( Lightfoot 1993a), however it origins from the Eastern Pacific. And a second highly similar species, C. regulare (see above) is clearly distinguished herein based on molecular data.

Figures

Figure 7. A-F Caecum pulchellum A, C, E, F specimen ZSM-Mol- 20090485 B, D juvenile specimen ZSM-Mol- 20200118 A, B light microscopic pictures C, D SEM scans E close-up of mucro and F microsculpture H-K C. donmoorei, specimen USNM 1618844 H-K C. regulare, specimen ZSM-Mol- 20100321, juvenile H light microscopic picture I SEM scans J close-up of mucro and K microsculpture L-T C. cf. teres and C. cf. strangulatum L specimen ZSM-Mol- 20200033, juvenile specimen with larval shell still attached M, N, Q, S specimen ZSM-Mol- 20200032, juvenile M light microscopic picture N SEM scan Q close-up of mucro and S microsculpture O, P, R, T C. cf. strangulatum, specimen ZSM-Mol- 20200038, juvenile O light microscopic picture P SEM scan R close-up of mucro and T microsculpture U-X C. cf. semilaeve, specimen ZSM-Mol- 20200034 U Light microscopic picture V SEM scan W close-up of mucro and X microsculpture. Scale bars: 10 µm (F, S, T, W, X); 20 µm (J, K, Q, R); 50 µm (E); 100 µm (H, I, L-P, U, V); 200 µm (A-D).