ABSTRACT
Pygidiopsis macrostomum and Ascocotyle (Phagicola) pindoramensis (Digenea: Heterophyidae) parasitize guppies as intermediate hosts and, respectively, fish-eating mammals or birds as definitive hosts. Heterophyids have zoonotic potential, and molecular studies associated with morphological and ecological aspects have helped to clarify their taxonomy and phylogeny. Poecilia vivipara naturally parasitized by metacercariae of both species (100% prevalence) exhibit no external signs of parasitism. In this work, four new sequences of P. macrostomum (18S rDNA, 28S rDNA and ITS2 rDNA) and one new sequence of A. (P.) pindoramensis (mtDNA cox-1) are presented. Phylogeny reconstructions linked P. macrostomum to other heterophyids, but the separation of the Heterophyidae and Opisthorchiidae remains unclear. Additionally, we used indirect immunocytochemistry and the phalloidin-fluorescence techniques allied with confocal laser scanning microscopy to describe muscular and neuronal structures of P. macrostomum. A complex arrangement of muscular fibres is associated with the tegument, suckers, gut and reproductive system. Radial fibres around the ventral sucker are thick, branched and extend to the body wall. High-resolution confocal imaging revealed a typical digenean muscular arrangement and important heterophyid morphological traits. These data will support future control measures to reduce the parasitism in guppies reared in fish farming systems, especially for aquarium and experimental purposes.
Subject(s)
DNA, Helminth/genetics , DNA, Ribosomal/genetics , Fish Diseases/epidemiology , Heterophyidae/physiology , Poecilia , Trematode Infections/veterinary , Animals , Brazil/epidemiology , Female , Fish Diseases/parasitology , Heterophyidae/anatomy & histology , Heterophyidae/genetics , Male , Microscopy, Confocal/veterinary , Phylogeny , Prevalence , Sequence Analysis, DNA/veterinary , Trematode Infections/epidemiology , Trematode Infections/parasitologyABSTRACT
Morphological and genetic data on the larvae of Anisakidae parasitizing the sandperches Pseudopercis numida and Pinguipes brasilianus were recorded from Cabo Frio, State of Rio de Janeiro, Brazil (23°S, 42°W). Twenty-five specimens of P. numida and 25 specimens of P. brasilianus were necropsied. The 352 larvae collected included 1 Anisakis sp., 344 Hysterothylacium sp., and 7 Raphidascaris sp. We present mtDNA sequence data for Anisakis sp. and Hysterothylacium sp., and we sequenced the ITS ribosomal DNA (rDNA) of Hysterothylacium sp. and Raphidascaris sp. The morphological and genetic profiles confirmed the identification of Anisakis typica (Diesing, 1860). Hysterothylacium sp. and Raphidascaris sp. were not identified to the species level due to the absence of similar sequences for adult parasites. The mtDNA sequence of Hysterothylacium sp. from P. numida showed a high similarity to the sequence of Hysterothylacium deardorffoverstreetorum. However, a phylogenetic analysis demonstrated the presence of different clades under the same name as the larval H. deardorffoverstreetorum. Pseudopercis numida is a new host record for A. typica.
Subject(s)
Ascaridida Infections/veterinary , Ascaridoidea/classification , Fish Diseases/parasitology , Perches/parasitology , Animals , Ascaridida Infections/parasitology , Ascaridoidea/anatomy & histology , Ascaridoidea/genetics , Base Sequence , Brazil , DNA, Helminth/chemistry , DNA, Mitochondrial/chemistry , DNA, Ribosomal/chemistry , Likelihood Functions , Molecular Sequence DataABSTRACT
A redescription of the aspidogastrean trematode Lobatostoma kemostoma (MacCallum & MacCallum, 1913) is provided based on examination of type material, voucher specimens available at institutional collections and newly collected specimens from the type host, Trachinotus carolinus (Linnaeus, 1766), off the Angra dos Reis, Brazil. Partial sequence of its 28S rDNA is given. Lobatostoma kemostoma can be distinguished from the other eight species of the genus by: (1) the hindbody being longer than the ventral disc; and (2) the cephalic lobes having the same shape and size. Features observed for the first time include the number and detailed arrangement of alveoli on the ventral disc, the terminal genitalia and the ovarian complex. New illustrations and morphometric data are given. In the present survey the host specificity in the genus, the validity of some morphological features and the occurrence of an Indian species of Lobatostoma from off the Brazilian coast are discussed. A lectotype of L. kemostoma from the type series deposited at United States National Parasite Collection is also designated.
