Factors determining community structure of metazoan parasites from brown-spotted grouper, Epinephelus chlorostigma (Valenciennes, 1828) in Southern Saudi Arabia

Abstract

Several factors influence the structure of parasite communities, which are important components of the biodiversity of various ecosystems. Some of these factors may be related to the environment and/or to the host. The present study evaluated the influence of host size and season on the structure of the metazoan parasite community of the brown-spotted grouper, Epinephelus chlorostigma. One hundred thirty-two fish were collected between March 2018 to February 2019 from the Red Sea, Saudi coast, Southern Saudi Arabia. Eight parasite species were recorded: one copepod (Sarcotaces sp.), one isopod (Argathona rhinoceros), two monogeneans (Pseudorhabdosynochus epinepheli and Megalocotyloides epinepheli), three digeneans (Prosorhynchus epinepheli, Helicometrina nimia, and Erilepturus hamati), and one nematode (Cucullanus epinepheli). The overall prevalence was 43.2% Digeneans were the most frequent parasite species and represented (50.55%) followed by monogeneans (45.05%), crustacean (3.42%), and nematode (0.98%) of the total individual parasites collected from 57 infected fish. Parasite community structure and species composition varied significantly among host size. Positive associations were found between infection parameters of parasite species and host size. Our results suggest that parasite infection parameters were affected by host size and season. Further long-term research is required to conclude the factors determining the structuring of the parasite community of E. chlorostigma.

Digenea community structure of the Salema, Sarpa salpa (Linnaeus, 1758) (Teleostei, Sparidae), from the Central coast of Algeria

“…The influence of the host's length and weight on the mean abundance and mean intensity of Digenean revealed a negative correlation for W. capitellata and M. brachycoelia. This correlation is also seen in other studies infecting various hosts ( Poulin, 1999 ; Villalba-Vasquez et al , 2018 ; Gharbi et al , 2023 ; Ibrahim & Alghamdi, 2023 ) and it could be related to the host's immune system; larger fish are more likely to have a more efficient immune response than the smaller ones. Furthermore, Kotb et al (2014) and Villalba-Vasquez et al (2018) seem to support this point of view as well.…”

“…However, a positive correlation can also occur, and it is observed in R. fractum , which means the mean abundance or mean intensity of the parasite increases along with the length or weight of the host. Previous studies have noted the same tendency ( Poulin & Rohde, 1997 ; Sasal et al , 1997 ; Poulin, 1999 ; Poulin, 2000 ; Vidal-Martínez & Poulin, 2003 ; Villalba-Vasquez et al , 2018 ; Ibrahim & Alghamdi, 2023 ), and it could be explained by the fact that larger host can harbour more number of parasites than small ones ( Guégan et al , 1992 ; Poulin, 2000 ; Valtonen et al , 2010 ; Timi & Poulin, 2020 ). In fact, several research have indicated that there is a positive correlation between the length of the gut and the total length of the fish ( Ribble & Smith, 1983 ; Karachle & Stergiou, 2010 ; Hafiz et al , 2023 ).…”