Myxobolus ictiobus n. sp. and Myxobolus minutus n. sp. (Cnidaria: Myxobolidae) from the gills of the smallmouth buffalo Ictiobus bubalus Rafinesque (Cypriniformes: Catostomidae)

Abstract

The smallmouth buffalo Ictiobus bubalus Rafinesque (Catostomidae) is native to North American waterways and occasionally grown in pond aquaculture. Species of Myxobolus Bütschli, 1882 have been reported from the gills, integument, and intestinal tract of buffalo fish, although there is ambiguity in some host records. In the summer of 2013, thirteen adult smallmouth buffalo were seined from a 0.1-acre (0.04-hectare) experimental research pond at the Thad Cochran National Warmwater Aquaculture Center in Stoneville, Mississippi, USA, and examined for the presence of parasitic infection. Two previously unknown species of Myxobolus were observed parasitising the gills. Plasmodia of the two species differed from each other in both size and shape. Morphologically the two species were distinct from one another and from other Myxobolus spp. previously reported from buffalo fish. Myxospores of Myxobolus ictiobus n. sp. were spherical and measured 12.7-14.5 (13.9 ± 0.4) µm in length and 10.7-13.6 (12.5 ± 0.7) µm in width with a thickness of 10.3-14.8 (12.6 ± 2.3) µm. Polar capsules measured 5.6-7.4 (6.6 ± 0.4) µm in length and 3.7-4.9 (4.5 ± 0.8) µm in width and each contained a coiled polar filament with 5-6 turns. Myxospores of Myxobolus minutus n. sp. were circular in shape and measured 7.4-9.6 (8.6 ± 0.7) µm in length and 7.5-9.9 (8.8 ± 0.7) µm in width with a thickness of 6.5-7.3 (6.7 ± 0.3) µm. Polar capsules measured 3.6-4.9 (4.3 ± 0.3) µm in length and 2.8-3.8 (3.3 ± 0.3) µm and each contained a coiled polar filament with 5-6 turns. Supplemental 18S rRNA gene sequencing identified unique sequences for each isolate. Phylogenetic analysis of 18S rRNA sequences demonstrated a strong clustering of both isolates with other species of Myxobolus from cypriniform fish.

Monoculture of ♀ channel (Ictalurus punctatus) × ♂ blue (I. furcatus) hybrid catfish mitigates proliferative gill disease caused by Henneguya ictaluri (Cnidaria: Myxobolidae) in catfish aquaculture ponds

“…These conditions, in addition to the static nature of catfish ponds, allow for the acceleration of parasite loading rates not normally observed in natural water bodies . Several myxozoan species have been reported and molecularly confirmed from catfish aquaculture ponds in the southeastern United States Griffin et al, 2008a;2009b;2010b;2016a;2016b). While many myxozoan species are present within these systems, only H. ictaluri has been associated with significant losses.…”

A new species of Myxobolus Butschli, 1882 (Bivalvulida: Myxobolidae) infecting stratum spongiosum of the imperiled sicklefin redhorse, Moxostoma sp. (Cypriniformes: Catostomidae) from the Little Tennessee River, North Carolina, USA

“…2A-C While reviewing Myxobolus spp. that infect catostomids, it was observed that Myxobolus minutus Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016 is a primary junior homonym of Myxobolus minutus Nemeczek, 1911(Nemeczek 1911, Rosser et al 2016. Per the code of International Code of Zoological Nomenclature (ICZN) article 53.3, two taxa erected within a genus with the same specific epithet constitutes primary ho- 3, the junior homonym must be rejected and replaced with an available substitute name (Ride et al 1999).…”

“…Per the code of International Code of Zoological Nomenclature (ICZN) article 53.3, two taxa erected within a genus with the same specific epithet constitutes primary ho- 3, the junior homonym must be rejected and replaced with an available substitute name (Ride et al 1999). We consulted with two of the taxonomic authorities of the latter proposed "M. minutus" (Rosser et al 2016).…”

Morphological, histological and molecular characteristics of Myxobolus spp. (Cnidaria: Myxozoa) infecting the kidney of silver carp in Lake Taihu

“…Myxozoans are widespread endoparasitic cnidarians of aquatic vertebrates and invertebrates, and most have been described from marine and freshwater shes (Rosser et al 2016). Until now, over 2500 named species have been described using morphological characteristics of myxospores (Okamura et Silver carp Hypophthalmichthys molitrix (Valenciennes, 1844), a lter-feeding freshwater sh and indigenous cyprinid in East Asia (Zhao et al 2018).…”