Upstream migration and altitudinal distribution patterns of 'Nereina punctulata' (Gastropoda: Neritidae) in Dominica, West Indies

Villeneuve, A.R, Thornhill, I and Eales, J (2019) 'Upstream migration and altitudinal distribution patterns of 'Nereina punctulata' (Gastropoda: Neritidae) in Dominica, West Indies.' Aquatic Ecology. ISSN 1573-5125

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Official URL: https://doi.org/10.1007/s10452-019-09683-7

Abstract

The snail Nereina punctulata has been observed performing amphidromous migrations (salt to freshwater migration, post-larval settlement) in the Caribbean, small and medium sized snails achieving maximum survival fitness at mid and high altitudes, but they may be restricted by energy stores. Large snails show no difference in fitness across altitude, but their previous migration history dictates their high-altitude placement in watersheds. The factors determining the rate of migration have not yet been studied. In this study, we sought to understand how migration rate changes with shell size and altitude. We used mark-recapture to track individual snails across seven sites of varying altitude in a single watershed on Dominica and measured the shell length of randomly collected snails at sites. Volunteers assisted with data collection in both cases. Shell length was positively correlated with distance from river mouth, although smaller snails were more frequently found at high altitude, high flow sites. Snails closer to the river mouth had faster upstream migration rates than those at mid-altitude. While we found large snails at higher altitude sites, there was no significant relationship between migration rate and shell size. Our findings suggest that large snails do not migrate at maximal rates allowed by energy stores. We also observed erosion of the outer shell periostracum and calcium carbonate underneath, which was seen significantly more often on larger shells. We hypothesize that this erosion is a product of exposure of the structural calcium carbonate to low alkalinity in Dominican streams, following an initial chipping of the periostracum.

Item Type: Article
Keywords: amphidromy, citizen science, Dominica, gastropod, Neritidae, upstream migration
Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
Divisions: College of Liberal Arts
Date Deposited: 11 Mar 2019 10:09
Last Modified: 26 Apr 2019 11:21
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