Occurrence of thelohanellosis caused by Thelohanellus wuhanensis (Myxosporea) in juvenile allogynogenetic silver crucian carp, Carassius auratus gibelio (Bloch), with an observation on the efficacy of fumagillin as a therapeutant

A Review: Gaps in Our Knowledge on Myxozoan Parasites of Fishes

“…Since the mid-1980s, many researchers have reported successful oral treatments with the fungal anti biotic, fumagillin (Molnar et al, 1987;Hedrick et al, 1988;Szekely et al, 1988;Wishkovsky et al, 1990;Yokoyama et al, 1990;El-Matbouli and Hoffmann, 1991 b; Sitja-Bobadilla and Alvarez-Pellitero, 1992; Rhee et al, 1993;Yokoyama et al, 1999;Wang et al, 2001) and its analog TNP-470 (Higgins and Kent, 1998) against many myxozoan diseases (Table 1), except for ceratomyxosis (Izbarra et al, 1990;Whipple et al, 2002). However, the toxicities of these drugs have lim ited their practical application for farmed fish (Wishkovsky et al, 1990).…”

Thelohanellus wangi n. sp. (Myxozoa, Myxosporea), a new gill parasite of allogynogenetic gibel carp (Carassius auratus gibelio Bloch) in China, causing severe gill myxosporidiosis

“…Meanwhile, accompanied with the rapid development of allogynogenetic gibel carp aquaculture industry, more and more pathogenic organisms have been reported to cause morbidity, mortality, and severe economic losses (Luo et al 2013). Among them, myxozoans represent an important parasitic group (Wang et al 2001;Zhang et al 2010a, b;Xi et al 2011). Furthermore, frequent transregional trade of seedlings and marketable fish under the condition of lacking strict quarantine further accelerated the transmission of these agents in China, and some wild fish in the epizootic were found to be infected by myxosporean spilled from cultured allogynogenetic gibel carp (authors' unpublished data).…”

“…Some of them show high bias of infection to fish size. For instance, Thelohanellus wuhanensis exclusively infects the fry of nursery stage, but Myxobolus turpisrotundus, Myxobolus honghuensis, and Myxobolus ampullicapsulatus are obligate parasites of the fattening fish (Wang et al 2001;Zhang et al 2010b;Xi et al 2011;Liu et al 2012).…”

Synopsis of the species of Thelohanellus Kudo, 1933 (Myxozoa: Myxosporea: Bivalvulida)

“…Most of the species of Thelohanellus have been reported to be less pathogenic to their hosts. However, T. wuhanensis Xiao & Chen, 1993, T. hovorkai Akhmerov, 1960, T. nikolskii Akhmerov, 1955, T. kitauei Egusa & Nakajima, 1981 wangi Zhang 2013 were shown to cause severe morbidity and mortality of infected fish (Wang et al, 2001;Liyanage et al, 2003;Molnár, 1982;Shin et al, 2011;authors' unpublished data). Until now, the life-cycles of three species of the genus have been elucidated, i.e.…”