Caecum cf. corrugulatum Carpenter, 1857

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 cf. corrugulatum Carpenter, 1857

Caecum corrugulatum Carpenter, 1857: 327, pl. 37, figs 375, 1547. Type locality: Mazatlán, 1 sp. off Chama [Mexico].

Material examined.

Panama • 1 (Fig. 5F, G ); Achotines; 7.6207, -80.0013; depth 12 m; 29 Feb 2016; USNM Achotines2016 exped.; Stat. PA14; DNA voucher; GenBank: MT727069, MT731722; USNM 1618861.

Shell morphology.

Shell color whitish translucent. Tube regularly curved, shape equal in width but bears prominent edge at transition to septum (Fig. 5F ). Septum round and blistered lacking a mucro. Aperture equally wide as tube with straight edge. Sculpture appears completely smooth but shows fine concentric ribs at higher magnification (Fig. 5G ).

Remarks.

We assigned the specimen collected in the Pacific coast of Panama to C. corrugulatum based on the description of Carpenter (1858-1859) who already highlighted its similarity with another inconspicuous species ( C. glabriforme ). Both species are described from the same geographic area ( Mazatlán, Pacific coast of Mexico) and resemble the C. glabrum -like type: translucent, blistered septum without mucro, smooth, however slightly bigger than the eponymous C. glabrum from European waters. Caecum corrugulatum , can be distinguished by microsculptural concentric wrinkles, which could be observed with higher magnification in our specimen. So far, only C. glabriforme was recorded in Pacific Panama ( Lightfoot 1993b) and recollection at the type locality is needed to 1) confirm the validity of both co-occurring species and reject conspecificity and 2) to confirm their putative distribution range from Mexico to Panama and exclude the possibility of further cryptic species among C. glabriforme and C. corrugulatum species along the Pacific Coast of Central America (as discovered herein for the Atlantic Coast, see below).

Figures

Figure 5. A-D Meioceras nitidum, specimen MNHN-IM- 2013 - 72087 A light microscopic picture B SEM scan C SEM close-up of mucro and D microsculpture E M. cubitatum, specimen USNM 1618851 F, G C. cf. corrugulatum, specimen USNM 1618861 F light microscopic picture G light microscopic close-up of microstructure H MOTU II, specimen USNM 1618853 I-L MOTU I, specimen ZSM-Mol- 20200039 I light microscopic picture J SEM scan K SEM close-up of mucro and L microsculpture M C. glabrum, specimen ZSM-Mol- 20200096 N C. glabellum auctt. non Adams, specimen ZSM-Mol- 20200074 O-R C. invisibile sp. nov., holotype ZSM-Mol- 20100320 O light microscopic picture P SEM scan Q SEM close-up of mucro and R microsculpture. Scale bars: 10 µm (R); 20 µm (C, K, L, Q); 50 µm (D, E) 100 µm (I, J, O, P); 200 µm (A, B, M, N).