Zoarder Faruque Ahmed

Condition, length–weight and length–length relationships of the silver hatchet Chela, Chela cachius (Hamilton, 1822) in the Old Brahmaputra River of Bangladesh

The silver hatchet chela, Chela cachius (Hamilton, 1822), is a cyprinid freshwater species, commercially important for both subsistence and artisanal fisheries in Bangladesh. This study describes the length–weight relationship (LWR), length–length relationship (LLR) and the condition of this minnow species from the Old Brahmaputra River in Bangladesh. In this study, 12 monthly samples totalling 2400 specimens (1172 male; 1228 female) collected from November 2004 to October 2005 were used to conduct this study. For each individual, the total length (TL), fork length (FL) and standard length (SL) as well as body weight (BW) were measured. The overall sex ratio showed no significant difference from the expected value of 1:1 and the analysis of covariance (ANCOVA) revealed no significant difference between LWRs of male and female for the pooled data over a year. Parameters of LWRs of combined gender varied monthly with high coefficients of determination (r 2 > 0.751; p < 0.001). All the LLRs (SL vs. FL, FL vs. TL and SL vs. TL) exhibited strong correlations (r 2 > 0.886; p < 0.001) and ANCOVA analyses further indicated that LLRs did not differ between males and females. The relative-condition factors with regard to both months and SLs varied in all gender groups. Females maintained similar mean condition throughout life and showed more plumpness than both males and combined genders in all months. Finally, the results should be useful for the sustainable management of this minnow species in Old Brahmaputra River and adjacent water-bodies.

THREATENED FISHES OF THE WORLD: Eutropiichthys vacha (Hamilton, 1822) (Siluriformes: Schilbeidae)

River catfish Eutropiichthys vacha is one of the foods high in nutritional value in Asian countries. However, natural populations have seriously declined or are on the verge of extinction due to over-exploitation and various ecological changes in its natural habitats, leading to an alarm- ing situation which deserves high conservation attention. This paper suggests conservation measures that should be taken into account to- wards the preservation of the remnant isolated population of E. vacha in Asian countries.

THREATENED FISHES OF THE WORLD: Heteropneustes fossilis (Bloch, 1794) (Siluriformes: Heteropneustidae)

Department of Fisheries, Faculty of Agriculture, University of Rajshahi, Rajshahi 6205, Bangladesh Department of Fisheries Management, Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh Faculty of Fisheries, Kagoshima University, 4-50-20 Shimoarata, Kagoshima 890-0056, Japan Department of Zoology, Anando Mohan College, National University, Gazipur 1704, Bangladesh

THREATENED FISHES OF THE WORLD: Botia dario (Hamilton, 1822) (Cypriniformes: Cobitidae)

Bengal loach Botia dario is a valuable food fish in South Asian countries including Bangladesh, Bhutan, India and Nepal. However, the wild popula- tion is declining due to heavy harvest, habitat loss and its ecological chang- es. This paper suggests actions for the conservation of the lasting isolated populations of B. dario in Asian countries.

Threatened fishes of the world: Wallago attu (Bloch and Schneider, 1801) (Siluriformes: Siluridae)

The Asian Silurid catfish Wallago attu is an endangered species. Populations are declining due to over-exploitation, pollution and environmental degradation. Law enforcement to ban destructive fishing practices should be enhanced for the conservation of the populations.

An overview of the genus Plesionika Bate, 1888 (Decapoda, Caridea, Pandalidae) in Asian waters

The pandalid genus Plesionika Bate, 1888 includes 93 species and has a widespread distribution including mainly subtropical and tropical waters and some temperate waters, but most species can be found in the Indo-West Pacific. The species of this genus are benthic or nektobenthic, feeding on pelagic and benthic resources. Up to the present, the occurrence of 45 species of the genus has been reported from Asian waters. However, studies on these species from this region are mainly concerning their taxonomic report and very less their biology. Herein a key for the 45 Asian Plesionika species, and brief notes on its taxonomy are provided.