985 resultados para Phylogeny, Conservation, Wet tropics, Bioluminescence, Cave, Troglophile
Resumo:
Two new species of the genus Zospeum Bourguignat, 1856 are described from caves in the Sierra de Aitzgorri (Gipuzkoa) and the Sierra Salvada (Burgos) in Northern Spain. The taxa Z. vasconicum sp. n. and Z. zaldivarae sp. n. have recently, without a formal name, been included in a molecular study of worldwide members of the Carychiidae. In the present paper, the shell morphology and variation of these species is described and illustrated.
Resumo:
The giant freshwater prawn (Macrobrachium rosenbergii) is cultured widely around the world but little is known about the levels and patterns of genetic diversity in either wild or cultured stocks. Studies have suggested that genetic diversity may be relatively low in some cultured stocks due to the history of how they were founded and subsequent exposure to repeated population bottlenecks in hatcheries. In contrast, wild stocks have an extensive distribution that extends from Southern Asia across Southeast (SE) Asia to the Pacific region. Therefore, wild stocks could be an important resource for genetic improvement of culture stocks in the future. Understanding the extent and patterns of genetic diversity in wild giant freshwater prawn stocks will assist decisions about the direction future breeding programs may take. Wild stock genetic diversity was examined using a 472 base-pair segment of the 16S rRNA gene in 18 wild populations collected from across the natural range of the species. Two major clades ("eastern" and "western") were identifi ed either side of Huxley’s line, with a minimum divergence of 6.2 per cent, which implies separation since the Miocene period (5-10 MYA). While divergence estimates within major clades was small (maximum 0.9 per cent), evidence was also found for population structuring at a lower spatial scale. This will be examined more intensively with a faster evolving mtDNA gene in the future.
Resumo:
Conservation and the potential and need for aquaculture of three major fish (Catlocarpio siamensis, Probarbus spp. and Pangasius gigas) of the Mekong River are discussed. Different steps being undertaken by the Cambodian government in doing such activities are highlighted.
Resumo:
This paper summarizes some of the major issues relating to ex-situ conservation of the germplasm of aquatic organisms and gives examples of some current activities and future possibilities.
Resumo:
The highly productive fisheries of Kerala, India, are suffering from overexploitation. Use of unsuitable fishing gears that result in a high level of wasteful bycatch and destruction of egg bearing and juvenile fish should be controlled. This paper makes some suggestions for monitoring and conservation of the fisheries in Kerala.
Resumo:
An endangered fish species in China, Reeves shad (Tenualosa reversii), is finding hope of restoration and conservation in aquaculture and induced breeding efforts spearheaded by the Yangtze River Fisheries Management Commission. The history and sensitive traits of the Reeves shad are described featuring the species' life history, population dynamics and management of the Reeves shad resources.