Biodiversity on intertidal oyster reefs in the Hab River mouth: 35 new records from Pakistan

The present study investigated the biodiversity of sessile and motile organisms using intertidal reef habitats constructed by giant oysters Magallana cuttackensis (Newton & Smith, 1912) and backwater oysters Magallana bilineata (Roding, 1798) at the Hab River Delta in Pakistan. A one year (February 2017 to January 2018) field survey was carried out to investigate the species diversity and abundance on the reefs and surrounding area. Monthly samples were taken and the abundance of macro-organisms was observed. Oysters were brought to the laboratory for a detailed examination of shells for the presence of other species. Specimens of 122 species were collected, including 35 new records for Pakistan. The most abundant phylum was Mollusca, represented by 55 species. Overall biodiversity was highest in the pre-monsoon season, declining in monsoon and post-monsoon periods. April was the month with the highest number of species observed. This study constitutes a baseline and an important step to gain a better understanding of oyster reefs and their ecological value as habitat for other species. (C) 2020 Elsevier B.V. All rights reserved.