Histophatology and ultrastructure of Henneguya caudalongula sp. n. infecting Prochilodus lineatus (Pisces: Prochilodontidae) cultivated in the state of São Paulo, Brazil

Abstract

Prochilodus lineatus (Valenciennes, 1836) is a detritivorous teleost popularly known as curimba or curimbatá, is widely distributed in South American rivers and attains a relatively large size, with some specimens measuring 75 cm in length and weighing 8.2 kg (Godoy 1975). It has a high reproductive capacity, rapid growth, good acceptance on the market and is one of the most consumed fish species in Brazil. Its consumption has led to increased interest in its cultivation in fish farms throughout the country.Until recently, Myxobolus porofilus Adriano, Aranas, Ceccarelli et Cordeiro, 2002 was the only myxosporean species reported to parasitize P. lineatus. However, during a survey of myxosporean parasites of fish species cultivated in Brazil, we found a new species of Henneguya parasitizing the gills of P. lineatus. This species is described based on light microscopy, scanning electron microscopy, transmission electron microscopy, and on the histopathological effects produced in the host. MATERIALS AND METHODSFour-month old specimens of P. lineatus (curimbatá), Piaractus mesopotamicus (Holmberg, 1887) (pacu), Brycon cephalus (Günther, 1869) (matrinxã) and Leporinus macrocephalus Garavello et Britski, 1988 (piauçu) obtained from artificial reproduction programs were released in a pond at the Center for the Research and Management of Continental Fishing Resources (Cepta/Ibama) located in the municipality of Pirassununga, state of São Paulo, Brazil. Each month, five specimens of each fish species were examined for the presence of myxozoan parasites from March 2000 to February 2002. Immediately after collection, the fish were transported alive to the laboratory where they were killed by transection of the spinal cord, before being measured and necropsied. Of 120 curimbatá examined, 20 were 7-15 cm long, 78 were 15.1-25 cm long and 22 were 25.1-30.5 cm long.The parasite was identified according to Lom and Arthur (1989). Measurements from 40 fresh mature spores were obtained using a ocular micrometer and are givem in micrometres (mm) as the mean ± standard deviation (SD). Smears containing free spores were stained with a Giemsa solution and mounted in low-viscosity mounting medium (Cytoseal) as permanent preparations. For histological analysis, the gills were fixed in 10% buffered formalin for 24 h, embedded in paraffin, cut into sections 4 µm thick and stained with sirius red (Adriano et al. 2002), haematoxylin and eosin, and PAS. For scanning electron microscopy, free spores were deposited on a coverslip coated with poly-L-lysine and fixed for 2 h at room temperature with glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.2). After washing in the same buffer, the preparations were dehydrated in ethanol, critical point dried by CO 2 , coated with metallic gold and examined in JEOL JSM 35 microscope operated at 15 kV. For transmission electron microscopy, fragments of gills containing plasmodia were fixed in 2.5% glutaraldeyde in cacodylate buffer (2 h), dehydrated in increasing concentrations of acetone and embe...

Fine structure of Henneguya hemiodopsis sp. n. (Myxozoa), a parasite of the gills of the Brazilian teleostean fish Hemiodopsis microlepes (Hemiodontidae)

“…n. the spores were surrounded by a thin anastomosed network of microfibrils, in Henneguya theca, Henneguya adherens, Henneguya testicularis, Henneguya rhamdia and H. rondoni, the spores were surrounded by a hyaline homogenous structure and in Henneguya malabarica and Henneguya striolata, the sheath was constituted by granulo-fibrilar structures organised into a complex ramified network. This inflammatory reaction seems to be of the same type as that observed and described in other Brazilian fishes (Martins et al 1988, Adriano et al 2005). …”

“…Thirty-six species have been described from Brazilian fauna based on light microscopy micrographs and diagrammatic illustrations (Jakowska & Nigrelli 1953, Kent & Hoffman 1984, Gioia et al 1986, Martins et al 1988, Gioia & Cordeiro 1996, Martins & Souza 1997, Barassa et al 2003a, b, Eiras et al 2004a, b, 2008, 2009, Martins & Onaka 2006, Abdallah et al 2007). Recently, ultrastructural studies of developmental stages and mature spores supported the classification of some new species of the genus Henneguya (Rocha et al 1992, Azevedo & Matos 1995, Casal et al 1997, Vita et al 2003, Adriano et al 2005, Matos et al 2005.…”

Infection by Henneguya sp. (Myxozoa) in the bone tissue of the gill filaments of the Amazonian catfish Hypophthalmus marginatus (Siluriformes)

“…infection are fairly common (ADRIANO et al, 2005;FEIJÓ et al, 2008), the present study found inflammatory infiltrates in the vicinity of the cysts. Furthermore, the special Ziehl-Neelsen staining techniques (LUNA, 1968) made it possible to mark the presence of Henneguya cysts in bone tissue and spore isolates in the gill tissue structure.…”

“…The gill filaments parasitized by this myxosporeans had become crooked and deformed, such that the cartilaginous parts had withered due to pressure caused by the development of plasmodium (Figure 7 and 8). Deformities in the gill filaments brought about by parasites of the genus Henneguya have often been described in the literature (ADRIANO et al, 2005;NALDONI et al, 2009;CAMPOS et al, 2011;YE et al, 2012;AZEVEDO et al, 2014). El-Mansy & Bashtar (2002) obtained findings similar to those described in the present study, through studying parasitism by Henneguya suprabranchiae.…”

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.…”