Brooding behaviour and reproductive success in two species of free-living simultaneous hermaphrodites |
| |
Authors: | Emma L Johnston Ka-Man Lee |
| |
Institution: | (1) Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia;(2) Present address: School of Environment, Griffith University, Gold Coast, QLD, 4222, Australia |
| |
Abstract: | Although polyclads are amongst the most structurally simple of the triploblastic metazoans, they adopt a wide range of reproductive
strategies. Parental care behaviour in this group is yet to be quantified for any species. We assessed the significance of
brooding behaviour to the reproductive success of two free-living marine flatworms. Echinoplana celerrima and Stylochus pygmaeus were collected from the field and placed in pairs in containers of filtered seawater where they laid batches of eggs. Both
parents were then removed from half of the containers and the brooding behaviour and hatching success of eggs were quantified.
There were interspecific differences in brooding behaviour. Egg masses were covered by one E. celerrima parent for 12 ± 2% of time, whereas egg masses of S. pygmaeus were covered by one or both parents simultaneously for 85 ± 8% of time. Egg batches were abandoned by both species immediately
prior to the onset of hatching (10–12 days). Hatching success was generally high (~90%) and brooding did not enhance the hatching
success of eggs. We assessed the significance of parental care to hatching success of E. celerrima egg masses in the presence of three potential egg predators; in the presence of other organisms. E. celerrima devoted less time to brooding; however, hatching success was not affected. The amount of time spent brooding eggs differed
greatly between the two polyclad species but was not essential to their reproductive success under benign conditions. Parental
care may be of adaptive value under more stressful environmental conditions commonly experienced in estuarine environments
such as lowered salinity, increased hypoxia or turbidity. Covering egg batches may play an additional role of advertising
sexual status and a willingness to care for eggs. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|