Marine flatworms are important mobile predators on hard substrate, however little is known about their life history. I recorded seven species of flatworms in Botany Bay and described a new species of flatworm Imogine lateotentare sp. nov. It is distinguished from other species in the same genus by having small, transparent and inconspicuous tentacles and continuous bands of numerous frontal and cerebral eyes. This new flatworm species was found closely associated with the barnacle Balanus variegatus (Darwin, 1854) on which it fed. Marine flatworms provide elaborate parental care to their offspring but its significance has not been experimentally confirmed. I provided quantitative measurements of the significance of parental care behaviour in Echinoplana celerrima and Stylochus pygmaeus under controlled laboratory conditions. I also examined the changes in reproductive behaviour of E. celerrima and the hatching success of their eggs when exposed to three putative flatworm egg predators. Brooding behaviour of neither species of flatworm enhanced the hatching success of their eggs and exposure of E. celerrima to the potential egg predators did not affect the timing of hatching or hatching success of its eggs. However, E. celerrima spent more time guarding their eggs when exposed to the potential egg predators. Brooding may be an innate behaviour in marine flatworms but it is not essential to their reproductive success. Marine flatworms are closely associated with sessile organisms and these assemblages are common in bays and estuaries which are subject to anthropogenic inputs from various sources. Impacts of pollutants are known for many flatworm prey species but little is known about the effects on the flatworm themselves. I examined the influence of sublethal concentrations of copper ranging from 0 to 50 ??g L-1 on the predatory and reproductive behaviour of Stylochus pygmaeus. These worms were more sensitive to low levels of copper pollution than their barnacle preys. Response of flatworms to physical stimulation, number of egg batches laid and hatching success were greatly reduced at higher copper concentrations. In areas polluted by heavy metals, flatworm populations will be affected at lower concentrations than their barnacle prey and which may alter sessile invertebrate community structure.
| Identifer | oai:union.ndltd.org:ADTP/258880 |
| Date | January 2006 |
| Creators | Lee, Ka-Man, School of Biological, Earth & Environmental Sciences, UNSW |
| Publisher | Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Ka-Man Lee, http://unsworks.unsw.edu.au/copyright |
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