The European Zoological Journal (Jul 2024)
Diversity pattern of ichthyofaunal assemblage in South-central coastal region of Bangladesh
Abstract
The south-central coastal waters of Bangladesh are recognized as one of the foremost aquatic biodiversity hotspots despite severe anthropogenic and environmental hazards to natural fishery resources. Therefore, this study was undertaken to examine the current status of fish faunal diversity and evaluate the condition and conservation status of fish in the rivers spanning the south-central coastal region of Bangladesh. During the research period, spanning from July 2021 to February 2022, a total of 105 fish faunal species belonging to 84 genera, 50 families, and 14 orders were documented. The order Perciformes (27.62%) was found to be the most diverse fish group, followed by Cypriniformes and Scombriformes (12.38%), Siluriformes and Clupeiformes (11.43%), Synbranchiformes and Pleuronectiformes (3.81%). According to the International Union for Conservation of Nature (IUCN) Red List classification, 52 species recorded from the studied areas were determined to be of Least Concern, while 11 species were Vulnerable, 14 species were classified as Endangered, and 7 species are recognized as Critically Endangered. In order to assess the species diversity, richness, and evenness of the fish assemblage in the sampling areas, four diversity indices, viz. the Shannon-Wiener index (H), Simpson’s dominance index (D), Simpson’s index of diversity (1-D), and Margalef’s index (d), were applied. Their overall values were 3.39–3.59, 0.05–0.07, 0.95–0.94, and 7.67–8.75, respectively. All of the species were more or less evenly distributed throughout the three sites, with Kalapara having the most even distribution. Several anthropogenic and natural attributes that contribute to decline in fish diversity were recorded using a survey questionnaire which revealed that management and conservation measures should be taken with utmost urgency.
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