Pseudo-Nitzschia sp(Bacillariophyceae), seasonal distribution in the lagoon of Nador (Morroco)

Ouassila Riouchi,Mustapha Akodad,Faid El Madani,Ghizlane Azizi,Abdelmajid Moumen,Hanane Ait Hmeid,Mourad Baghour,Alí Skalli ,Éric Abadie

doi:10.1051/e3sconf/202131401003

Abstract

The goal of this study is to look into the dominance of diatoms, specifically the genus “Pseudo-Nitzschia Sp” at the Nador lagoon level and how it relates to the physicochemical parameters of the environment. From the four sampling stations and for two seasons (spring and summer 2018). This diatom of the genus “Pseudo-Nitzschia Sp” includes toxic species capable of producing domoic acid (DA), a neurotoxin responsible for amnesic intoxication syndrome in humans. During sampling, the species “PseudoNitzschia Sp” showed variable cell densities between stations and seasons. The dominate microalgae were observed during the spring period with a maximum concentration of (4000 Cells / l). And a low viscosity during the summer seasons (140 Cells / l).

Highlights

Diatoms (Bacillariophyceae) are the unicellular algae which constitute the most diverse group of eukaryotic phytoplankton, estimated at 12,000 species [1], they produce 40% of the total marine photosynthetic activity and Responsible for about 20 25% of marine primary production [2,3]
The photosynthetic apparatus of diatoms consists of two main parts: the collecting antenna that absorbs light energy and the reaction centre (RC) that transforms this light energy into chemical energy
The minimum cell density of “PseudoNitzschia Sp” at station C, which corresponds to Kariat Arakman, is of the order of 240 cells/l

Summary

Introduction

Diatoms (Bacillariophyceae) are the unicellular algae which constitute the most diverse group of eukaryotic phytoplankton, estimated at 12,000 species [1], they produce 40% of the total marine photosynthetic activity and Responsible for about 20 25% of marine primary production [2,3]. The photosynthetic apparatus of diatoms consists of two main parts: the collecting antenna that absorbs light energy and the reaction centre (RC) that transforms this light energy into chemical energy. This photosynthetic activity is similar to other eukaryotic algae and all types of plants. Perag 1900 belongs to the order of pennate diatoms and is represented by cells, of elongated shape This genus includes 52 species of which 26 produce a neurotoxin called domoic acid (DA), responsible for the contamination of shellfish with amnesic toxins [7,8,9,10,11]. 15 species of potentially toxic Pseudo-Nitzschia have been reported in the Mediterranean Sea [19], of which at least nine have been identified in the Adriatic [20,21]

Study area

Results and discussions

St B