Nutritional stress changes sex-specific reproductive allocation in the simultaneously hermaphroditic land snail Arianta arbustorum
Article first published online: 23 SEP 2002
Volume 16, Issue 5, pages 623–632, October 2002
How to Cite
Locher, R. and Baur, B. (2002), Nutritional stress changes sex-specific reproductive allocation in the simultaneously hermaphroditic land snail Arianta arbustorum. Functional Ecology, 16: 623–632. doi: 10.1046/j.1365-2435.2002.00657.x
- Issue published online: 23 SEP 2002
- Article first published online: 23 SEP 2002
- Received 23 October 2001; revised 20 February 2002; accepted 13 March 2002
- reproductive output;
- sex allocation;
- sperm competition
- 1Sex allocation theory predicts that when resources are limited in simultaneous hermaphrodites, the allocation to one sexual function will automatically reduce the resources available to the other function. This study examines the effect of nutritional stress on mating behaviour and male and female reproductive output (dry mass and nitrogen contents of spermatophores, sperm delivered and eggs deposited) in individuals of the simultaneously hermaphroditic land snail Arianta arbustorum kept under three different food regimes: ample (100%), restricted (50%) and extremely restricted (25%) food supply.
- 2Independent of the extent of nutritional stress, 10–12% of the resources taken up were invested in reproductive output (both gender functions together) and 88–90% in maintenance (including faeces and excretion).
- 3Courtship and copulation behaviour was affected by nutritional stress. Snails with an extremely restricted food supply did not mate, except one pair. Individuals with restricted food supply tended to court longer, and copulated for a shorter period, than individuals with ample food supply.
- 4Nutritional stress did not affect the number of sperm delivered. However, snails with a restricted food supply produced fewer eggs. Thus, snails kept under nutritional stress invested relatively more resources in the male function than in the female function. Nevertheless, the absolute reproductive output remained highly female biased (>95% in all experimental groups).
- 5At the individual level, the existence of a trade-off between resources invested in the male vs the female function could not be confirmed. However, there was a trade-off between nitrogen allocated to reproductive function and maintenance in snails with a restricted food supply.