Dactylogyrids (Monogenoidea) Parasitizing the Gills of Astyanax Spp. (Characidae) From Panama and Southeast Mexico, a New Species of Diaphorocleidus and a Proposal for Characithecium N. Gen

Abstract

Diaphorocleidus orthodusus n. sp. and Diaphorocleidus kabatai (Molnar, Hanek and Fernando, 1974) Jogunoori, Kritsky, and Venkatanarasaiah, 2004 are detailed from Astyanax orthodus and Astyanax aeneus, respectively. Palombitrema heteroancistrium (Price and Bussing, 1968) is described from specimens collected from A. aeneus, and Urocleidoides strombicirrus (Price and Bussing, 1967) is reported for the first time from A. aeneus and Astyanax fasciatus in Panama. Characithecium costaricensis (Price and Bussing, 1967) n. comb. is detailed based on specimens from A. aeneus. Characithecium costaricensis is characterized by having overlapping gonads, a medioventral vaginal aperture, a copulatory complex consisting of single counterclockwise coil of the copulatory organ that is articulated to the accessory piece, and a haptor having 2 pairs of anchors, dorsal and ventral bars, and 14 hooks. Measurements of body size varied substantially among individual worms, both within and across different host species and locations. However, the morphological differences were insufficient to separate species of Characithecium. This result suggests limited parasite speciation across sympatric species of Astyanax in Mexico and Panama.Urocleidoides Mizelle and Price, 1964, was erected for a species that infected Poecilia reticulata (Poeciliidae) in a California aquarium. Mizelle et al. (1968) emended it by adding gonads overlapping or tandem, male copulatory organ coiled with a single or multiple rings, 1 or 2 prostatic reservoirs, and vaginal pore on the left side of the body or absent. Urocleidoides included species from fishes in 5 orders (Atheriniformes, Characiformes, Gymnotiformes, Perciformes, and Siluriformes) until Kritsky et al. (1986) (2007). Additional specimens were mounted unstained in Gray and Wess's medium to examine the sclerotized structures. Measurements, all in micrometers (m), represent straight-line distances between extreme points and are expressed as the mean followed by the range and number (n) of structures measured in parentheses; body length includes the haptor. Numbering of hook pairs follows Mizelle (1936) and Mizelle and Price (1963).

Helminth parasites of freshwater fishes, Nazas River basin, northern Mexico

“…and Gyrodactylus spp (see Hoffman 1999), needs to be determined with more survey work in northern regions of Mexico. Although, recent studies by monogenean taxonomists have demonstrated that the species richness of this parasitic group in freshwater fishes of Mexico is increasing very rapidly (see Kritsky and Mendoza-Franco 2003;Mendoza-Palmero and Aguilar-Aguilar 2008;Mendoza-Franco et al 2009;Mendoza-Palmero et al 2009). From a biogeographical perspective, it is also possible that the Nearctic freshwater fish host a larger proportion of adult helminth parasites than larval forms.…”

Taxonomic Distinctness and Richness of Helminth Parasite Assemblages of Freshwater Fishes in Mexican Hydrological Basins

“…3). In the same way, the continuous description of new species, named and described based on morphological taxonomy [47], [48], [49], [50] points out that even in the best studied drainage basins and fish families, the inventories are far from complete. Particularly, the study of Mexican monogeneans of freshwater fishes remains a challenge for taxonomists.…”

Helminth fauna of Astyanax fasciatus Cuvier, 1819, in two distinct sites of the Taquari River, São Paulo State, Brazil

“…These monogeneans were first described parasitizing the gills of Astyanax spp. (Mendoza-Franco et al, 2009), and there is only one report of D. kabatai parasitizing A. altiparanae Garutti andBritsky, 2000 (Almeida andCohen, 2011). Thus, this study corroborates the literature and strongly suggests the specificity of these monogeneans with the genus Astyanax.…”