Thiara cancellata, (RODING, 1798)

Strong, Ellen E., 2011, More than a gut feeling: utility of midgut anatomy in phylogeny of the Cerithioidea (Mollusca: Caenogastropoda), Zoological Journal of the Linnean Society 162 (3), pp. 585-630 : 614

THIARA CANCELLATA (RÖDING, 1798)

Material examined

Philippines: Bohol Island, Abatan River , 9°45.0′N, 123°55.9′E ( USNM 1143358 ) .

Description

Marginal fold S-shaped ( Fig. 17D ), terminating at posterior tip of sorting area; oesophageal aperture at tip of marginal fold recurved segment; sorting area rectangular, with broadly rounded posterior margin; left margin of sorting area with slight bulge; accessory marginal fold extending from oesophageal aperture, around posterior margin of sorting area, with slight posterior median depression, intersecting short, slightly curving fold posteriorly at left; small, rounded sorting area pad present at left posterior end of sorting area; anterior flap and crescentic pads lacking; glandular pad flattened, flaring posteriorly, with broadly rounded posterior end; broad, paired digestive gland ducts opening at left of glandular pad to deep pocket; crescentic ridge long, emerging from oesophageal aperture, forming short transverse segment above digestive gland duct pocket, turning posteriorly, curving around end of glandular pad; crescentic ridge distal tip curving deeply into caecum, forming broad half loop under pad; caecum extending past midline of pad; paired, textured caecal folds present at right of glandular pad, opposite caecum; very large, triangular, textured accessory pad present at anterior end of glandular pad; U-shaped fold present below style sac aperture at left; typhlosoles fused along entire length.

Figures

Figure 17. Midgut anatomy of Thiaridae. A, Melanoides tuberculata (AM C.337978). B, Stenomelania denisoniensis (USNM 1083388). C, Tarebia granifera (USNM 1143357). D, Thiara cancellata (USNM 1143358). Scale bars: 1.0 mm; refer to the text for a list of anatomical abbreviations.