Present status and distribution of the family Syngnathidae at the Hooghly-Matlah estuarine system with some conservation aspects

Abstract

The Syngnathidae family, comprising of pipefishes, seahorses, and seadragons, frequently occurs in marine, estuarine, and occasionally in freshwater environments. The Hooghly-Matlah estuary in West Bengal, India, is characterised by tidal dynamics, a salinity gradient, and rich biodiversity, making it an ideal habitat for many fish species, including multiple syngnathid species adapted to brackish water environment. Sampling in the Hooghly-Matlah estuary system was carried out between 2021 and 2023, which encountered altogether three syngnathid species. Pipefishes are designated as Least Concern, while seahorses are listed as Vulnerable (VU) in the IUCN Red List. Syngnathids are largely used in trade, and because of their rapidly declining populations, several countries have prohibited their exports. Among the three species (Hippichthys spicifer, Hippocampus trimaculatus, and Microphis cuncalus), only one species (Microphis cuncalus) was barcoded, and the sequence is submitted to the GenBank with accession number OP090589.1. Even though some syngnathids live only in marine habitats, the Hooghly-Matlah estuary supports a few of these species; consequently, proper conservation plans and management measures should be implemented to ensure their long-term sustainability.