Fish assemblage and guild structure in the Ashtamudi Estuary, a tropical Ramsar site in India.

A first hand study on guild structure of fish species (n = 148) in Ashtamudi Estuary, a Ramsar Site of International importance, was carried out from May 2019 to April 2020 based on temporal (monsoon, pre-monsoon and post-monsoon seasons) and spatial (upper, middle and lower zones) data. Guild composition consisted of eight estuarine use guilds (marine estuarine opportunist, marine estuarine dependent, estuarine resident species, anadromous species, freshwater migrants, freshwater stragglers, catadromous and marine stragglers) and eight feeding guilds (zooplanktivore, zoobenthivore, carnivores, herbivores, invertebrate feeders, omnivores, detritus feeders and piscivores). The most dominant estuarine use guilds comprised of marine migrants (marine estuarine opportunist and marine estuarine dependent), whereas carnivore, omnivore and zooplanktivore formed the dominant feeding guilds in Ashtamudi Estuary.