Morphological analysis of Caligus elongatus von Nordmann, 1832 (Copepoda: Caligidae) from the rosy goatfish Parupeneus rubescens (Mullidae)

Abstract

Copepods are a common component of ectoparasite assemblages of all kinds of fish, from all environments and ecosystems. In the present investigation, a total of 80 specimens of the rosy goatfish Parupeneus rubescens were randomly collected from the Arabian Gulf, and then transported to the laboratory in order to be dissected and examined for the presence of copepodid infections. Copepod parasites were recovered from the gills of the infected fish. One copepod species within the Caligidae family was identified and labeled as Caligus elongates von Nordmann, 1832. This copepod species examined using light and scanning electron microscopy to observe the most characteristic generic features. Morphological and morphometric characterizations revealed differences between the identified species and other related copepodid species. Therefore, the present study showed that the rosy goatfish is a new host for this Caligus species and added a new locality record for this infection.

Systematic Status of Copepods Infecting the Rosy Goatfish (Parupeneus rubescens)

“…Caligus is the largest genus of parasitic copepods, containing more than 250 species (Ho and Lin, 2004;Abdel-Gaber et al, 2020b). So far, 43 species of this genus have been reported from the fishes of the Far East, but only eight of them are known from Taiwan.…”

“…The morphological feature of Caligus species, distinguishing them from the closely related Lepeophtheirus species, is the presence of a pair of lunules on the anterior margin of the adult parasites (Kabata, 1979). The main differences between the Caligus species are the relative sizes of the body parts, the armature and structure of the fourth leg, particularly the shape and size of the genital complex and the length and segmentation of the abdomen (Öktener and Trilles, 2009;Agusti-Ridaura et al, 2018;Abdel-Gaber et al, 2020b). The sea louse Caligus elongatus has been found on many hosts.…”

A Monogenean Gill Parasite within the Genus Haliotrema (Ancyrocephalidae) Infecting Argyrops filamentosus Fish: Morphology and Molecular Studies

“…Marine fish are the most common and widely distributed type of fish worldwide. [ 1 ]. The sparid fish fauna in the Red Sea includes 16 species from 9 different genera [ 2 ].…”