Abstract

Diatom pseudonitzchia is a poisonous genus of family Bacillariaceae causing harmful algal bloom in coastal waters in many parts of the world. At the time of bloom, these diatoms produce domoic acid and neurotoxin that cause Amnesic Shellfish Poisoning (ASP) and can change ecosystems equilibrium following mortality of important groups like marine mammals and seabirds. In addition, it can threaten human health via food chains. Several cases of neurological disorder observed in humans 48 hours after consuming shellfishes. During the sampling of coastal waters of Chabahar Bay in February 2019, Pseudonitzchia sp. was observed. In this study, seawater samples were collected for identification and isolation of Pseudonitzchia like phytoplanktons. Then, the single cell diatoms species were isolated and transferred to petri dish including f2 media and maintained in the phycolab at 12L:12D period at 25°C. Morphological observations showed the purified sample was most similar to Pseudonitzchia australia. Due to economic damages of HAB phytoplanktons to the aquaculture industry and threatening health of environment and humans, it is necessary to identify their morphology and phylogeny accurately.

Keywords: Isolation, Phytoplankton, Chabahar Bay, Pseudonitzschia