During the final stage of courtship, the garden snail Helix aspersa attempts to stab its mating partner with a mucus-coated calcareous "love dart." I present evidence supporting two predictions of the most promising hypothesis for the adaptive significance of this behavior: that the dart serves to increase the reproductive success of the shooter by increasing the numerical representation of its sperm in the recipient's storage organ (the sperm loading hypothesis). First, I demonstrate that once-mated snails store more of the sperm transferred by successful shooters than by unsuccessful shooters. Second, I demonstrate that this biased storage results in higher paternity scores for successful shooters relative to unsuccessful shooters in the clutches of multiply mated recipients. Moreover, I present evidence that body size and mating order influence the outcome of sperm competition in snails. Finally, I propose a novel mechanism to explain the observed pattern of sperm utilization in H. aspersa based on the motility of stored allosperm.
Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.33833 |
Date | January 2001 |
Creators | Rogers, David W. |
Contributors | Chase, Ronald (advisor) |
Publisher | McGill University |
Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
Language | English |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Format | application/pdf |
Coverage | Master of Science (Department of Biology.) |
Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
Relation | alephsysno: 001874535, proquestno: MQ78950, Theses scanned by UMI/ProQuest. |
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