FOOD SPECTRUM OF THREE FISH SPECIES FROM THE MUGILIDAE FAMILY IN BRACKISH WATER ALONG THE BULGARIAN BLACK SEA COAST

Abstract

The food spectrum of three fish species from the Mugilidae family in different age groups was studied. The samples were collected in 2019 - 2021 from the river estuaries and the coastal brackish lakes at the Bulgarian Black Sea coast. The research aims to establish the food spectrum of mullets and thus make a connection between food components. The results show that the predominant groups in the stomachs of the three mullet species are detritus, zoobenthos (Rissoa sp. And Trochammina inflate - 64.28%) and macrophytes (Cladophoraceae family - 53.14%). Several potential toxic species were also found: Amphora coffeaeformis, Pseudo-nitzschia delicatissima, Pseudonitzschia seriata, Prorocentrum cordatum, E. pyriformis, P. minimum, Protoperidinium crassipes. For the first time along the Bulgarian Black Sea coast, in the stomachs of mullet fish, the presence of particles (less than 2.5 cm) from the category "Artificial polymers" was observed. The most common in the stomachs of mullet are macrophytes of the family Ulvaceae - 45.5%; family Cladophoraceae - 35.5%; from phytoplankton - Navicula spp (97.09%); of zoobenthos: Nematoda g.sp. - 49.3% and Trochammina inflate - 32.3%.