Selected Helminth Parasites (Cestoda, Nematoda) of Bobcat, Lynx rufus (Carnivora: Felidae), in Northeastern Arkansas

The bobcat, Lynx rufus is a relatively common Arkansas carnivore that ranges statewide. Although there is a great deal of information on the natural history of this species in the state, there have been few studies where parasites have been documented in Arkansas bobcats. Here, a single specimen was examined and found to be infected with a tapeworm, Taenia rileyi and 2 nematodes, Toxoascaris leonina and Toxocara cati. We document the first record of T. rileyi from Arkansas and the first report of T. leonina from a bobcat in the state

Novel Reproductive Data on Pealip Redhorse, Moxostoma pisolabrum (Cypriniformes: Catostomidae), from Northeastern Arkansas

Little is known about the natural history of the Pealip Redhorse (Moxostoma pisolabrum), particularly on its reproductive biology in Arkansas. We examined 11 female M. pisolabrum collected in late February 2020 and 2021 from the Black River, Lawrence County. Egg mass (g) represented 9‒14% of the total weight of these gravid females. This is the first time information on female reproduction in this species has been reported from any population of M. pisolabrum in the state

\u3ci\u3eClinostomum poteae\u3c/i\u3e n. sp. (Digenea: Clinostomidae), in the trachea of a double-crested cormorant \u3ci\u3ePhalacrocorax auritus\u3c/i\u3e Lesson, 1831 and molecular data linking the life-cycle stages of \u3ci\u3eClinostomum album\u3c/i\u3e Rosser, Alberson, Woodyard, Cunningham, Pote & Griffin, 2017 in Mississippi, USA

Clinostomum spp. (Digenea: Clinostomidae) are a group of trematodes commonly found in the buccal cavity and oesophagus of a variety of piscivorous birds. The metacercariae, colloquially known as ‘‘yellow grubs,’’ have been reported from a diverse group of freshwater fishes worldwide. In the catfish farming region of the southeastern USA, piscivorous birds present a continuous challenge for aquaculturists in the form of fish depredation and the introduction of trematodes into these static, earthen pond systems. Clinostomum spp. are commonly encountered in farmraised catfish. While generally considered pests of minimal importance, heavy infections can result in unmarketable fillets. Of the piscivorous birds that frequent catfish aquaculture operations in the southeastern US, the double-crested cormorant (Phalacrocorax auritus Lesson) is one of the most damaging, although reports of Clinostomum spp. from P. auritus are limited. In this study, adult trematodes morphologically consistent with Clinostomum sp. were found in the trachea of a double-crested cormorant captured in Lowndes Co., Mississippi, USA. These specimens differed from other recognised Clinostomum spp. in several key morphological characters. Moreover, sequence data of mitochondrial cytochrome c oxidase subunit 1 gene (cox1), nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene (nad1) and ribosomal internal transcribed spacer (ITS) regions did not match any known Clinostomum sp. for which sequence data are available. While genetically similar to C. marginatum and C. album Rosser, Alberson, Woodyard, Cunningham, Pote & Griffin, 2017 reported from the great egret Ardea alba L. in Mississippi, these adult clinostomids were larger in size and limited to the trachea, whereas both C. marginatum Rudolphi, 1819 and C. album are found in the oral cavity and esophagus. Given these distinct morphological and molecular characters we propose a new member of the genus, known hereafter as Clinostomum poteae n. sp. Additionally, larval stages in the life-cycle of C. album are morphologically and molecularly identified for the first time from ramshorn snails Planorbella trivolvis Say and fathead minnows Pimephales promelas Rafinesque

Experimental Elucidation of the Life Cycle of \u3ci\u3eDrepanocephalus Spathans\u3c/i\u3e (Digenea: Echinostomatidae) with Notes on the Morphological Plasticity of \u3ci\u3eD. Spathans\u3c/i\u3e in the United States

The echinostomatid Drepanocephalus spathans (syn. Drepanocephalus auritus) parasitizes the doublecrested cormorant Phalacrocorax auritus. In North America, the marsh rams-horn snail Planorbella trivolvis and ghost rams-horn snail Biomphalaria havanensis serve as snail intermediate hosts, both of which inhabit catfish aquaculture ponds in the southeastern United States. Studies have demonstrated D. spathans exposure can be lethal to juvenile channel catfish Ictalurus punctatus. Two studies were undertaken to elucidate the life cycle of D. spathans to establish a developmental time line. In both studies, D. spathans cercariae collected from naturally infected P. trivolvis individuals were used to infect channel catfish fingerlings, which were then fed to double-crested cormorants (DCCOs) that had been pharmaceutically dewormed. In study 1, laboratory-reared P. trivolvis and B. havanensis individuals were placed in aviary ponds with experimentally infected DCCO and examined bi-weekly for release of cercariae. Trematode eggs were observed in the feces of exposed birds 3 days post-infection. Birds were sacrificed 18 days post-exposure (dpe), and gravid adults morphologically and molecularly consistent with D. spathans were recovered. Snails from the aviary pond were observed shedding D. spathans cercariae 18–54 dpe. In study 2, trematode eggs were observed in the feces of exposed DCCOs beginning 8 dpe. Once eggs were observed, birds were allowed to defecate into clean tanks containing naı¨ve laboratory-reared P. trivolvis individuals. Additionally, eggs from experimental DCCO feces were recovered by sedimentation and placed in an aquarium housing laboratory-reared P. trivolvis individuals. Birds in study 2 were sacrificed after 60 days, and gravid D. spathans specimens were recovered. Snails from the experimental DCCO tanks shed D. spathans cercariae 89–97 dpe. Lastly, trematode eggs were isolated and observed for the hatching of miracidia, which emerged on average after 16 days at ambient temperatures. No D. spathans adults were observed in control birds fed non-parasitized fish. This is the first experimental confirmation of the D. spathans life cycle, resolving previously unknown developmental time lines. In addition, the effects of fixation on adult trematode morphology were assessed, clarifying reports of pronounced morphological plasticity for D. spathans

\u3ci\u3eClinostomum album\u3c/i\u3e n. sp. and \u3ci\u3eClinostomum marginatum\u3c/i\u3e (Rudolphi, 1819), parasites of the great egret \u3ci\u3eArdea alba\u3c/i\u3e L. from Mississippi, USA

Members of the genus Clinostomum Leidy, 1856, colloquially known as yellow grubs, are cosmopolitan parasites of piscivorous birds, freshwater snails, fish and amphibians. In the southeastern United States, piscivorous birds present a continuous challenge for producers of farm-raised catfish. Ciconiiform birds are common hosts of Clinostomum spp. in North America and are endemic on most commercial catfish operations. The great egret Ardea alba L. is an avian predator often found foraging on commercial catfish operations, but to date the trematode fauna of great egrets preying on catfish ponds remains mostly understudied. Thirteen great egrets were captured from commercial catfish ponds in northeast Mississippi, and examined for trematode infections. Two morphologically distinct Clinostomum spp. were observed in the great egrets sampled, one morphologically consistent with Clinostomum marginatum (Rudolphi, 1819) and one morphologically unique species. These morphological descriptions were supplemented with molecular sequence data (c.4,800 bp of ribosomal DNA and c.600 bp of mitochondrial DNA). Gene sequences confirmed the identification of C. marginatum. However, the second species differed significantly from its congeners in both morphology and DNA sequence. Given these distinct morphological and molecular characters we propose this second species as Clinostomum album n. sp

\u3ci\u3eClinostomum poteae\u3c/i\u3e n. sp. (Digenea: Clinostomidae), in the trachea of a double-crested cormorant \u3ci\u3ePhalacrocorax auritus\u3c/i\u3e Lesson, 1831 and molecular data linking the life-cycle stages of \u3ci\u3eClinostomum album\u3c/i\u3e Rosser, Alberson, Woodyard, Cunningham, Pote & Griffin, 2017 in Mississippi, USA

Clinostomum spp. (Digenea: Clinostomidae) are a group of trematodes commonly found in the buccal cavity and oesophagus of a variety of piscivorous birds. The metacercariae, colloquially known as ‘‘yellow grubs,’’ have been reported from a diverse group of freshwater fishes worldwide. In the catfish farming region of the southeastern USA, piscivorous birds present a continuous challenge for aquaculturists in the form of fish depredation and the introduction of trematodes into these static, earthen pond systems. Clinostomum spp. are commonly encountered in farmraised catfish. While generally considered pests of minimal importance, heavy infections can result in unmarketable fillets. Of the piscivorous birds that frequent catfish aquaculture operations in the southeastern US, the double-crested cormorant (Phalacrocorax auritus Lesson) is one of the most damaging, although reports of Clinostomum spp. from P. auritus are limited. In this study, adult trematodes morphologically consistent with Clinostomum sp. were found in the trachea of a double-crested cormorant captured in Lowndes Co., Mississippi, USA. These specimens differed from other recognised Clinostomum spp. in several key morphological characters. Moreover, sequence data of mitochondrial cytochrome c oxidase subunit 1 gene (cox1), nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene (nad1) and ribosomal internal transcribed spacer (ITS) regions did not match any known Clinostomum sp. for which sequence data are available. While genetically similar to C. marginatum and C. album Rosser, Alberson, Woodyard, Cunningham, Pote & Griffin, 2017 reported from the great egret Ardea alba L. in Mississippi, these adult clinostomids were larger in size and limited to the trachea, whereas both C. marginatum Rudolphi, 1819 and C. album are found in the oral cavity and esophagus. Given these distinct morphological and molecular characters we propose a new member of the genus, known hereafter as Clinostomum poteae n. sp. Additionally, larval stages in the life-cycle of C. album are morphologically and molecularly identified for the first time from ramshorn snails Planorbella trivolvis Say and fathead minnows Pimephales promelas Rafinesque