Scanning electron microscopy study of Strabax monstrosus von Nordmann, 1864 (Copepoda: Chondracanthidae) from Tunisian waters and histopathological study of its effects on host.

Strabax monstrosus von Nordmann, 1864 (Copepoda: Chondracanthidae) is an ectoparasite and it was recently recorded from small red scorpionfish, Scorpaena notata Rafinesque, and red scorpionfish, Scorpaena scrofa L., collected from Tunisian coastal waters. Copepod females were found deeply embedded in the branchial cavity reaching the cardiac region with their mouth-parts. Observations of females and males using scanning electron microscopy showed a number of morphological features that have been previously overlooked or incompletely presented. In this study, we report for the first time the fine structures of appendages, mouthparts, external genital organs (nuptial organs), and other structures of male and female Strabax monstrosus. Histopathological study showed lesions in the cardiac region of the host fish which is the target site of the parasite. The presently reported finding is the first record of Strabax monstrosus from Scorpaena notata and Scorpaena scrofa collected from Tunisian waters.