First Record of the Species Pleuroxus trigonellus (O.F. Müller, 1776) (Crustacea: Cladocera: Chydoridae) in the Waters of the Northern Al-Kabir River Dam Lake (Lattakia, Syria).

Abstract

Crustaceans of the order Cladocera are essential components of freshwater ecosystems, serving as a natural food base for fish and their larvae. They occupy a critical intermediate position in aquatic food chains, acting as a vital link between primary producers and higher consumers. This research aims to advance taxonomic studies related to aquatic biodiversity in general, and freshwater diversity in particular, while updating the biodiversity map of the Syrian Arab Republic by documenting new species.

The study was conducted on Cladocera in the Northern Al-Kabir River Dam Lake (Latakia). During this study, the species Pleuroxus trigonellus (Family: Chydoridae) was recorded for the first time in Syrian freshwaters. This species was found inhabiting the lower water layers of the lake on 5m depth. Furthermore, the abundance of this species was monitored throughout the study period, which extended from February 2025 to January 2026. However, Pleuroxus trigonellus occurred exclusively from April (spring) until September (late summer). Its maximum abundance reached 26.8 individual/m³ in June (early summer).