Histopathological and ultrastructural studies of a Henneguya species (Myxozoa: Myxosporea) infesting the intestine of Clarias gariepinus from Benin (West Africa)

Abstract

Fish culture is the best alternative to fill the gap between natural fish catches and estimated needs of populations in animal protein consumption. In West Africa, this goal required to have suitable fishes for aquaculture which are Clariidae and Tilapia. Clarias gariepinus (Clariidae) fetches a higher price than tilapias as it can be sold alive at the market but a high infestation by Henneguya leads to decrease this commercial value. Those reasons lead us to perform studies on seasonal variations, histopathological aspects and life cycle of Henneguya sp. infecting the intestine of C. gariepinus using light and electron microscope. From November 2011 to December 2012, 339 specimens were collected from Ouémé River (Benin) and examined. An overall prevalence of 7.37 % was recorded for plasmodia of Henneguya sp. Parasite occurrence did not vary significantly between seasons (χ(2) = 12.235; df = 3; p > 0.05), nor sexes (χ(2) = 2.992; df = 7; p > 0.05) while differences were significant between classes of weight (χ(2) = 39.929; df = 5; p < 0.05). The highest prevalence was recorded in host ranging from 300 to 374 g. Histopathological analysis showed that the mass continuous development of the plasmodium produced thickening of the intestine wall and compressed neighboring tissues and destroyed villi and smooth muscle layers. The stages of the parasite development including sporogenesis, capsulogenesis, and valvogenesis were asynchronous. Investigations are still running by molecular approaches in order to identify accurately this species.

Some pathophysiological insights into ovarian infestation by Myxobolus sp. (Myxozoa: Myxosporea) in Clarias gariepinus (Clariids: Silurids) from Bénin (West Africa)

“…The prevalence of the present myxozoan species has a maximum in long dry season and minimum during long wet season. This is in agreement with the report of Tossavi et al (2015) who revealed a high prevalence of Henneguya sp. in long dry season.…”

“…Only pH was correlated with the prevalence of Myxobolus sp. although previous reports indicated that there is no sensibility to parasites of fish hosts linking with physicochemical parameters (Gbankoto et al 2001a;Tossavi et al 2015). It is noteworthy that studies of Myxosporean infestation was not currently very frequent in fish gonads; that makes this observation more interesting.…”

“…Oocyte infection is however higher than intestinal one by Henneguya sp. recorded on C. gariepinus during the same period (Tossavi et al 2015). The high overall prevalence of Myxosporidian infection in fish was recorded from Sarotherodon melanotheron melanotheron (n=391) with 55 % (Gbankoto et al 2003).…”

Assessing the Diversity of Metazoan Parasites of Sarotherodon melanotheron (Cichlidae) from Inlands Waters in Southern Benin (West Africa)

“…Fish in their several specifities, could serve as host of parasites that are harmful to human and animals. In Benin, some parasitological investigations were made on Cichlids [1][2][3][4][5][6]; Silurids [2][3][4][5][6][7][8] and Channids [2,9,10]. Concerning the Cichlids, the main research focused on the genus Oreochromis [11][12][13][14][15] within the continent.…”

Morphological, ultrastructural, and molecular description of Unicapsula fatimae n. sp. (Myxosporea: Trilosporidae) of whitespotted rabbitfish (Siganus canaliculatus) in Omani waters

“…Myxosporea are a class of fascinating, microscopic, metazoan aquatic parasites belonging to phylum Cnidaria (Kent et al 2001 ; Lom and Dykova 2006 ). Since their discovery, they have attracted much attention because of their mysterious and complex life cycles (Anderson et al 2000 ; Marton and Eszterbauer 2011 ), enigmatic phylogeny (Whipps et al 2004 ; Fiala 2006 ; Evans et al 2010 ), and negative impact and pathogenicity on wild (Yokoyama and Itoh, 2005 ; Burger et al 2008 ; Dykova et al 2011 ; Buchmann et al 2012 ) and cultured (Katharios et al 2014 ; Tossavi et al 2015 ; Yuan et al 2015 ) fish stocks. Although extensively investigated among various marine and fresh water fish hosts, there are few valid records of myxosporean parasites infecting wild and reared siganids worldwide.…”