Siriya Seneewongse Na Ayudthaya. Effects of TBT on tissues of various organ systems in littoraria melanostoma (Gray, 1839) . Master's Degree(Environmental Biology). Mahidol University. : Mahidol University, 2006.
Effects of TBT on tissues of various organ systems in littoraria melanostoma (Gray, 1839)
Abstract:
The objectives of this research were to study the effects of tributyltin (TBT) on
the survivorship and tissues of digestive and reproductive systems of Littoraria
melanostoma. The sex ratio, female : male, of Littoraria melanostoma from noncontaminated
(Tumbon Klongkone, Samut Songkram Province) and contaminated
(Phra Chunlachomklao Fort, Samut Prakarn Province) areas were observed from
February 2003 to 2004. The sediments were analysed for the texture. The
concentrations of TBT (5, 10, and 20 ng/l as Sn) and the exposure periods (30 days)
were designed for the study of histopathological changes in tissues.
The sex ratios of L. melanostoma at non-contaminated and contaminated areas
were 0.85 to 1.82 and 0.78 to 1.78, respectively. L. melanostoma in the contaminated
area had smaller size than those in the non-contaminated area. The sediment texture
of non-contaminated area was considered as clay while the sediment texture of
contaminated area was loam. The median lethal concentrations (LC50) of TBT on L.
melanostoma at the exposure time of 24, 48, 72, and 96 hours were 0, 13.142, 13.5,
and 12.575 ng/l as Sn, respectively. For histophatological effects, vacuoles in
epithelial cells of digestive and reproductive organs were increased in size and
number when increasing TBT concentrations and the exposure time. Moreover, cell
lysis was obviously seen at 5 and 10 TBT ng/l as Sn for 30 and 20 days, respectively.
This research showed that TBT was highly toxic to the snail. Therefore,
Littoraria melanostoma could be considered as a good bio-indicator in the TBT
contaminated area.