ABSTRACT
Strigeids have a cup-shaped fore body, containing a holdfast organ with two lobes and hind body. The species diversity of strigeids remains incomplete, especially in the Indian sub-continent. Here, we described six Tetracotyle type metacercariae (T. muscularis, T. fausti, T. lucknowensis, T. xenentodoni, T. mathuraensis and T. glossogobii) from five fresh water fish, collected at Lucknow (India). Next, we characterized these metacercariae using ribosomal (18S, 28S, ITS2) and mitochondrial DNA (COI) to determine their systematic and phylogenetic position. Molecular identification using inter-specific variation range for all four molecular markers revealed 1.9-4.9% (18S); 3.3-8.8% (28S); 6.8-12.9% (ITS2), and 3.5-9.4% (COI) among six Tetracotyle type metacercariae. In phylogenetic analysis, constructed by neighbour-joining (NJ) and maximum likelihood (ML) methods, T. fausti, T. glossogobii, T. xenentodoni, T. lucknowensis and T. mathuraenis nested as sister groups with the member of strigeids for all four markers used; T. muscularis, however, formed a basal clade. Furthermore, phylogenetic placement states the monophyly of the Tetracotyle type of metacercariae in all the markers (18S, 28S, COI), except ITS2.
Subject(s)
DNA, Mitochondrial/genetics , DNA, Ribosomal/genetics , Fishes/parasitology , Metacercariae/genetics , Trematoda/classification , Animals , DNA, Helminth/genetics , Fish Diseases/parasitology , Genetic Variation , India , Phylogeny , RNA, Ribosomal, 28S/genetics , Rivers/parasitology , Sequence Analysis, DNAABSTRACT
Diplostomid digeneans are important parasites whose larval stages infect freshwater snails and fish as first and second intermediate hosts respectively. Diplostomid digeneans as adults are parasitic in many fish-eating birds and mammals. Our understanding of the species diversity of diplostomid digeneans remains incomplete, especially in the Indian sub-continent. Here, we describe three Neascus-type metacercariae (N. hanumanthai, N. gussevi, and N. xenentodoni) from freshwater fish specimens of Channa punctata (Bloch 1793), Trichogaster fasciata (Bloch and Schneider 1801) and Xenentodon cancila (Hamilton, 1822) respectively, collected in India. Next, we characterised these metacecariae using nuclear (28S and ITS1) and mitochondrial DNA (cox1) to determine their systematic and phylogenetic position. Molecular identification using interspecific variation for all three molecular markers revealed a closer relationship between N. hanumanthai and N. gussevi (1.9%-2.4%) than either of N. hanumanthai and N. gussevi to N. xenentodoni (3.1%-3.7% and 4.4%-4.0% respectively). In phylogenetic analyses, estimated by neighbour-joining (NJ) and maximum likelihood (ML) methods, N. gussevi and N. hanumanthai nested as sister groups of Posthodiplostomum Dubois, 1936 for all three markers used; N. xenentodoni, however, nested as a sister taxa of all other diplostomes when using 28S and ITS1 and nested as a sister taxa of Bolbophorus, Alaria and Neodiplostomum using cox1. These findings suggest that N. hanumanthai and N. gussevi are members of Posthodiplostomum, but that N. xenentodoni belongs to a separate and unknown genus. Similarly, by proteomics, we found that the cox1 protein sequences and structures were similar between N. hanumanthai and N. gussevi but distinct for N. xenentodoni.
Subject(s)
Fish Diseases/parasitology , Fishes/parasitology , Trematoda/anatomy & histology , Trematoda/genetics , Trematode Infections/veterinary , Animals , Computer Simulation , DNA, Mitochondrial/genetics , DNA, Ribosomal Spacer/genetics , Fish Diseases/epidemiology , India/epidemiology , Larva/genetics , Metacercariae/anatomy & histology , Metacercariae/genetics , Metacercariae/ultrastructure , Microscopy, Phase-Contrast , Phylogeny , Proteomics , RNA, Ribosomal, 28S/genetics , Sequence Analysis, DNA , Snails/parasitology , Trematoda/ultrastructure , Trematode Infections/epidemiology , Trematode Infections/parasitologyABSTRACT
Urocleidus behuri [Agrawal N., Singh H.S., On a known and three unknown monogenetic Urocleidus Mueller, 1934. Pranikee 1982; 3: 22-34], described from Nandus nandus in India, is reassigned to Sundanonchus Lim & Furtado [ Lim L.H., Furtado J.I., Sundanonchus g.n. (Monogenea, Tetraonchoididae) from two Malaysian freshwater fishes. Fol Parasitol 1985; 32: 11-19]. Sundanonchus triradicatus Lim & Furtado [Lim L.H., Furtado J.I., Sundanonchus g.n. (Monogenea, Tetraonchoididae) from two Malaysian freshwater fishes. Fol Parasitol 1985; 32: 11-19] is determined to be a junior subjective synonym of U. behuri and a new nomenclatural combination, Sundanonchus behuri is proposed. This article provides a redescription of this new combination, S. behuri [ Agrawal N., Singh H.S., On a known and three unknown monogenetic Urocleidus Mueller, 1934. Pranikee 1982; 3: 22-34], including the previously undescribed egg morphology, based on newly collected specimens from N. nandus in India-a new geographical record.
