Gill infection of Leporinus macrocephalus Garavello & Britski, 1988 (Osteichthyes: Anostomidae) by Henneguya leporinicola n. sp. (Myxozoa: Myxobolidae). Description, histopathology and treatment

Abstract

Piauçus (Leporinus macrocephalus), were raised in 300 m² ponds (density of 10 fish/m²) presenting asphyxia signals and daily mortality of 27 fishes. Specimens with 8-cm total body length, were collected for necropsy. Mucus of body surface and pieces of organs were collected and examined microscopically, in wet mounts, stained or in histological sections. The smears examination showed the presence of several spores in the secondary lamellae of the gill filaments, identified as Henneguya leporinicola n.sp (Myxozoa: Myxobolidae). Histopatological study showed epithelial hyperplasia and fulfilling of the spaces between the secondary lamellae, congestion and teleangiectasia sinusoidal. It was also observed hyperplasia of the goblet cells and several cysts of parasite with 70.3mum diameter. Such cysts were situated among the secondary lamellae, covered or not by the hyperplasic epithelium. With this diagnostic, three applications of formalin solution 10 ml/m³ were carried out. Fifteen days after that, fish were examined again to ascertain whether the treatment was efficient on disease caused by the protozoa. The tissue alterations present in the gills after the treatment were just a moderate sinusoidal congestion and a slight epithelial hyperplasia on the base of the secondary lamellae.

A new species of Henneguya, a gill parasite of Astyanax altiparanae (Pisces: Characidae) from Brazil, with comments on histopathology and seasonality

“…In other works, Kalavati and Narasimhamurti (1985), who studied Channa punctatus infected by H. waltairensis, Martins and Souza (1997), who studied the gills of Piaractus mesopotamicus parasitized by Henneguya sp., and Martins et al (1999b), who studied the gills of Leporinus macrocephalus infected by H. leporinocola, hemorrhage and/or inflammatory foci were observed, neither of which was seen here.…”

An ultrastructural and histopathological study ofHenneguya pellucidan. sp. (Myxosporea: Myxobolidae) infectingPiaractus mesopotamicus(Characidae) cultivated in Brazil

“…Of the 32 Henneguya species recorded so far in the continent, only Henneguya lutzi (Cunha & Fonseca, 1918) cies described in other South American fish, Henneguya santae (Guimarães & Bergamin, 1934) found in Tetragnopterus santae and Henneguya leporinicola (Martins et al, 1999) found in Leporinus macrocephalus share some morphological similarities with H. pellucida, although the first has a smaller caudal process (11.8 µm) and the latter a smaller body spore (7.6 µm) than H. pellucida (body spore length: 11.4 ± 0.3 µm; caudal process length: 24.1 ± 1.5 µm). In Henneguya travassosi (Guimarães & Bergamin, 1933) described in Leporinus copelandi, the spores are approximately equal in size to those of H. pellucida, but are oval in shape, with white plasmodia occurring in the muscles.…”

“…C ultivated and wild fishes are infected by numerous myxosporean species of the genus Henneguya Thelohan, 1892, some of which are important pathological agents (Kalavati & Narasimhamurti 1985;Lom & Dyková 1995;Martins et al, 1999). Eiras (2002) listed a total of 146 Henneguya species that…”

“…In South America, 32 Henneguya species have been reported in freshwater fishes (Barassa et al, 2003), and are the most common myxosporean parasites of the fish, with the gills being the organ most frequently infected (Gioia & Cordeiro, 1996). A few histological (Martins et al, 1999;Adriano et al, 2002;Barassa et al, 2003) and ultrastructural (Rocha et al, 1992;Azevedo et al, 1997;Azevedo & Matos, 1989, 1996, 2002Vita et al, 2003) studies have been done on Henneguya, using Brazilian fish. The present study is part of an investigation into the ultrastructural and histopathological characteristics of myxosporean parasites of freshwater fish cultivated in Brazil.…”

Myxobolus marajoensis sp. n. (Myxosporea: Myxobolidae), parasite of the freshwater catfish Rhamdia quelen from the Brazilian Amazon region

“…The results of the present study provide important insights into the myxosporidean infections found in R. quelen, which may cause significant tissue damage (MARTINS et al, 1999;ADRIANO et al, 2005aADRIANO et al, , b, 2006FEIST & LONGSHAW, 2006) or even death (MARTINS et al, 1999;FEIST & LONGSHAW, 2006). A better understanding of this freshwater microparasite fauna will be essential for the prevention and control of diseases in both wild and farmed stocks.…”