Mode of attachment and histopathological effects of Macrogyrodactylus clarii, a monogenean gill parasite of the catfish Clarias gariepinus, with a report on host response

Abstract

A detailed account is given about the mode of attachment and histopathological effects of Macrogyrodactylus clarii Gussev, 1961, a viviparous monogenean from the gills of the catfish Clarias gariepinus. Most parasites attach their haptors to the proximal region of the gill filament (primary gill lamellae), while few specimens were seen attached to the distal region. Attachment of the haptor was achieved mainly by the blade of the hamuli, but no evidence was found indicating the participation of marginal hooklets in the attachment. The hamuli of M. clarii penetrate into the interlamellar epithelium of the gill tissue. Some evidences were found to indicate that M. clarii may also utilize suction force during haptoral attachment. The pathological effects of M. clarii are manifested by breakdown of the coating epithelium, necrosis of the epithelial cells, vacuolations inside and outside the host cells, fusion of the gill lamellae, rupture of blood capillaries, infiltration of erythrocytes and degeneration and fibrosis of the interlamellar epithelium. The host response includes the appearance of lymphocytes, mucoid secretions and hyperplasia of the tissue at the site of attachment.

Monogenean parasites from fishes of the Vaal Dam, Gauteng Province, South Africa. I. Winter survey versus summer survey comparison from Labeo capensis (Smith, 1841) and Labeo umbratus (Smith, 1841) hosts

“…Macroscopic pathology/abnormal conditions resulting from monogenean infection may include sporadic haemorrhages (Martins et al 2000) and pale gills with excessive mucous secretion (Buchmann and Bresciani 1998, Buchmann 1999, Arafa et al 2009). None of the afore-mentioned conditions were observed macroscopically during handling and processing of fish.…”

“…The interaction between parasitism, water contamination and condition factor is complex, being influenced by various biotic and abiotic factors (Escher et al 1999, Thomas et al 2000, Lamková et al 2007, Pervin and Mortuza 2008, Tavares-Dias et al 2008, Arafa et al 2009). None the less water quality (with particular reference to pollutants such as heavy metals) has been shown to negatively affect monogenean parasite numbers and distribution (Dušek et al 1998, Galli et al 2001, Marcogliese 2004, Blanar et al 2009).…”

Scanning and transmission electron microscopy of the histopathological impact of Macrogyrodactylus clarii (Monogenea: Gyrodactylidae) on the gills of catfish, Clarias gariepinus

“…The morphology of uninfected gills of the catfish Clarias gariepinus resembles that described for other teleost fish species (Wilson and Laurent 2002, Kearn 2004, Arafa et al 2009, Senger et al 2011, Elsheikh 2013. Each gill consists of a gill arch from which arise two rows of primary gill lamellae (gill filaments).…”

“…Previously, Arafa et al (2009) recorded breakdown of the gill epithelium, epithelial cell necrosis, host cell vacuolation, fusion of the gill lamellae, ruptured blood capillaries, infiltration of erythrocytes and degeneration and fibrosis of the inter-lamellar epithelium of catfish infected with M. clarii. In the present study, SEM and TEM revealed surface damage of the host gill tissues, compressed and widely spaced host cells, desquamated surface epithelia adjacent to the lateral flaps of the parasite, vacuolated cells, necrotic tissue and damaged cells with pyknotic nuclei.…”

Histochemical demonstration of five enzymes\' activities in Macrogyrodactylus clarii (Monogenea: Gyrodactylidae) from the catfish Clarias gariepinus

“…Clarias lazera) in Egypt by El-Naggar and serag (1987). since that date the biology of this parasite has been widely studied (see for example, El-Naggar 1993, Hagras et al 1999, El-Abbassy 2001, El-Naggar et al 2001a, b, 2004, El-Naggar and cable 2007, Arafa et al 2009). like other gyrodactylids, M. clarii is a viviparous monogenean; its uterus may contain up to four developing embryos one inside the other.…”