Investigation of Endoparasites in tow lessepsian fish species Parupeneus forsskali and Sphyraena chrysotaenia in the Syrian Marine waters

Abstract

This study aims to investigate the presence of the endoparasite Hysterothylacium aduncum in two Lessepsian migratory fish species from the Red Sea, namely the Blackspot Goatfish (Parupeneus forsskali) and the Yellowstripe Barracuda (Sphyraena chrysotaenia), in Syrian marine waters. The study highlights the seasonal environmental factors influencing infection rates and underscores the parasite's significance as a biological indicator for environmental pollution monitoring.

A total of 150 specimens of P. forsskali and 100 specimens of S. chrysotaenia were collected from three fishing sites along the Latakia coast between June 2022 and May 2024. The study employed laboratory methodologies including isolating the parasites, preserving them in a 70% alcohol solution, and staining them with Carmine dye for species identification and classification using global taxonomic keys. Infection prevalence and intensity rates were calculated using specialized formulas.

The results showed that the prevalence of the parasite was 30.6% in P. forsskali and 44% in S. chrysotaenia, with an infection intensity of 1.9 worms per fish for both species. Higher infection rates and intensities were observed during the spring and summer seasons, suggesting that seasonal changes significantly influence the parasite's spread. No apparent effects of the parasite on fish health were observed; however, it poses a health risk to humans when consuming raw or undercooked fish.

The study concluded that Hysterothylacium aduncum is valuable as a biological indicator for monitoring environmental pollution. It recommended further studies to update the parasite database in the region and to understand the impact of environmental factors on its distribution, with a focus on migratory species and their ecological and health implications.