A key challenge in biodiversity is: How many species are there on earth? This issue is especially acute in poorly surveyed regions with high diversity, particularly Southeast Asia that also experiences many limitations such as lack of funds, documents and experts. To help meet this challenge, I have developed a five-tiered approach for diversity measurement of freshwater fish for use in Thailand. This is: (1) the creation of a newly updated species inventory that uses existing data; (2) exploration of the patterns of species richness, endemism, and uniqueness; (3) estimation of the total species richness; (4) investigation of patterns of rarity; and (5) integration of this knowledge into conservation practice. The system should be applicable to other regions and other taxa where a similar challenge exists. My work shows that eight hundred and seventy-two species in 17 orders, 55 families and 255 genera of freshwater fishes, accounting for roughly 10% of the world's freshwater fish diversity, have been reported for Thailand to date. This number was derived from information in the museum collections, literature and all other available sources, including reports written in Thai as well as in English. During this work I uncovered many gaps in biodiversity information, in terms of taxonomic and spatial records, though some families and basins are better represented than others. Taxonomic uncertainty also continues to be a challenge for taxonomists and users. The high diversity of freshwater fishes in Thailand is the result of both high alpha (α) diversity (diversity within a particular locality) and beta (β) diversity (diversity differences between localities). I concluded that the substantial beta diversity I detected is associated with the geographical separation of the six river basins in Thailand. For example, the species composition of freshwater fishes in the Salween Basin dramatically differs from all other basins of Thailand. In contrast, the Chao Phraya Basin and the Mekong Basin contain the greatest number of shared species. Approximately 55% of species have a wide distribution range (being reported from more than two basins), whereas 45% are highly restricted within a single basin. Analyses using species richness estimators suggest that the figure of 872 species is an underestimate and that there may be between 1000 and 1300 fish species in Thailand, in other words an increase of between 14.7% and 49.1% over the list I compiled (which is itself an increase of 52.2% over the last report in 1997). Freshwater fish have become increasingly vulnerable to anthropogenic activities. Of the 872 Thai fish species, 6.8% and 15.1% are globally and nationally threatened, respectively. Nonetheless, a striking feature of the database is that the conservation status of the vast majority of species has not so far been assessed, either globally or nationally. Scientists and policy makers will find these results useful in appreciating the magnitude of the tasks involved in surveying, describing and conserving the country's freshwater fish biota. My work highlights localities and taxa where conservation is a priority and is thus an important resource for policy makers and conservation planners concerned with the management of freshwater fish in Thailand.

M.Sc. / The Kruger National Park is internationally one of the best known conservation areas. The perennial rivers draining eastward towards and through the park are of great importance in maintaining a healthy ecosystem. The Olifants River catchment is the largest of all the rivers flowing through the Kruger National Park. Although this river has ceased flow for three days in 1968, problems experienced in the Olifants River are of a qualitative rather than a quantitative nature. Several factors contribute to the deteriorating water quality of the Olifants River. Urbanization, agricultural, industrial and mining activities in the Phalaborwa area pose a threat to the lower parts of the Olifants River. Pollution has on several occasions lead to mortalities of populations of fish in these parts...

M.Sc. (Zoology) / This study was undertaken to determine the osmotic regulation of Labeo capensis and to investigate the effectiveness of the addition of salt to water in which the fish are transported. The blood of L. capensis in tap water has a lower pH value than that of the same species acclimatized to salt water. It seems that the pH of fish transported in salt water is not altered immediately as in the case of fish transported in fresh water. In both groups the lowest pH values were reached two days after the fish had been transported ...

Freshwater vertebrates were sampled in different waters of the Upper Parramatta River catchment to determine their patterns of distribution with respect to water quality. A total of 730 animals (831 captures)were caught between November 1997 and December 1998. Data was collected on three freshwater turtle species, and four fish species.The abundance of aquatic vertebrates was correlated with physiochemical water quality parameters. The large aquatic vertebrates studied did not correlate with the commonly used parameters for aquatic health. The assumption ANZEEC water quality parameters are the definitive determinant of aquatic health for vertebrates is, therefore, erroneous. / Master of Science (Hons)

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No description available.

Glaciated areas offer a unique opportunity to study the dispersal of animals. During glaciation the fauna of glaciated areas was either destroyed or forced into unglaciated refugia. When the icesheets retreated the glaciated regions were open to reinvasion. [...]

Thesis (Ph.D.)--University of Western Australia, 2006.

Thesis (M.S.)--Michigan State University, Fisheries and Wildlife, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 95-106). Also issued in print.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 176-194). Also available on the World Wide Web.