Clenchiella minutissima

Ponder, Winston F., Fukuda, Hiroshi & Hallan, Anders, 2014, A review of the family Clenchiellidae (Mollusca: Caenogastropoda: Truncatelloidea), Zootaxa 3872 (2), pp. 101-153 : 150

Biogeography of Clenchiella minutissima

Clenchiella minutissima is by far the most recorded clenchiellid species, and appears to have a widespread distribution throughout the Indo-Pacific ( Fig. 14 ). Among the Australian individuals sequenced (four from Qld, one from NT, one from WA), there is negligible branch length throughout the east coast localities, with identical sequences obtained for three of the four Queensland individuals. The Darwin sequence differs marginally from those from Queensland, while the Port Hedland sequence exhibits the highest divergence within the minutissima clade. These preliminary results suggest that the highest degree of gene flow occurs along the Queensland coast, possibly attributed to the continuity of suitable habitat, in which the planktotrophic larvae of Cl. minutissima (as indicated by the protoconch) may be readily dispersed between estuarine systems. Conversely, as the Darwin locality is roughly equidistant to the WA and Queensland localities respectively, the greater sequence divergence and thus comparatively reduced gene flow between WA and NT are possibly due to the discontinuity of mangrove habitats along sections of the WA coast, notably along the Eighty Mile Beach situated between Broome and Port Hedland. However, based on the similarity in shell characters as well as the moderate topology and sequence divergence indicated by the molecular analysis, the conservative approach herein is to view these populations as conspecific.

Figures

FIGURE 14. Type localities of Clenchiella victoriae, Cl. bicingulata, Cl. varicosa, Cl. iriomotensis, and all recorded localities of Cl. minutissima (type locality Vietnam).