RESUMO
This study investigated the identity of 2 lepocreadiid digenean species belonging in the genus Opechona Looss, 1907 that infect littoral fishes of the northern Gulf of Mexico. Opechona chloroscombriNahhas and Cable, 1964, a species previously known only from the Caribbean Sea and the Atlantic Ocean off Brazil, is reported herein from the Atlantic bumper, Chloroscombrus chrysurus (L.), in the northern Gulf of Mexico. A second species infects the gulf butterfish, Peprilus burti Fowler, and the American harvestfish, Peprilus paru (L.), and it is described as a new species that occurs in coastal waters of the north-central and northeastern Gulf of Mexico. Metacercariae infecting the mesoglea of pelagic jellyfishes (Bougainvillia carolinensis [McCady], Chrysaora quinquecirrha [Desor], and Stomolophus meleagris Agassiz) and pelagic comb jellies (Mnemiopsis leidyi Agassiz and Beroe ovata Bruguière) were collected that resemble the new species but require further study to identify. Newly generated sequence fragments (28S rDNA) from both species of Opechona plus 2 other lepocreadiids collected during the study were aligned with publicly available sequences from 18 other lepocreadiids, 6 species of Aephnidiogenidae Yamaguti, 1934, and 2 species of Gorgocephalidae Manter, 1966. The alignment was subjected to Bayesian inference analysis rooted using a gorgocephalid. The resulting tree estimated the positions of both Opechona spp. as being unresolved within a group of taxa that included all available species of Opechona plus available species from the morphologically similar genera ProdistomumLinton, 1910, Preptetos Pritchard, 1960, and Clavogalea Bray, 1985. Although relatively similar in morphology, the 2 studied species of Opechona were surprisingly not closely related. Opechona cablei (Stunkard, 1980) Bray and Gibson, 1990 is herein considered to be a junior synonym of Opechona pyriformis (Linton, 1900) Bray and Gibson, 1990.
Assuntos
DNA Ribossômico/química , Doenças dos Peixes/parasitologia , RNA Ribossômico 28S/genética , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Doenças dos Peixes/epidemiologia , Peixes , Golfo do México/epidemiologia , Filogenia , Trematódeos/anatomia & histologia , Trematódeos/genética , Trematódeos/isolamento & purificação , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologiaRESUMO
Cardicola Short, 1953 is the most speciose aporocotylid genus (35 species) and includes marine and estuarine species of fish blood flukes that infect "higher ray-finned fishes" (Euteleostei). Several clades within Cardicola are recovered in phylogenetic analyses of the large subunit ribosomal DNA (28S), but morphological synapomorphies for those nucleotide-based clades remain elusive. The type species, Cardicola cardiocola (Manter, 1947) Short, 1953, has not been recollected in 73 yr and the original description was incomplete; making a genus revision challenging because of the ambiguous systematic position of its type species. Herein, we redescribe C. cardiocola by using the holotype (USNM 1337732) and new specimens collected from the type host, jolthead porgy, Calamus bajonado (Sparidae), from nearby the type locality. It differs from its congeners by the combination of having a body that is 5 times longer than wide, an anterior sucker with concentric rows of spines, 2-6 tegumental body spines per row, an esophageal gland that is 22-43% of the esophageal length, a testis that is 3-5 times longer than wide and that fills the intercecal space, a vitelline duct connecting to the anterior aspect of the oötype, an ascending uterus that lacks any coil, a descending uterus yielding a single coil, an obvious cirrus sac separated by constriction from the seminal vesicle, a tegumental protrusion surrounding the terminal end of cirrus sac, and a male genital pore that is posterior to the remainder of the genitalia. We also describe a new congener infecting the heart of yellowedge grouper, Hyporthodus flavolimbatus (Serranidae), from the Gulf of Mexico. It differs from its congeners by the combination of having an anterior sucker that does not extend beyond the anterior body margin, 2-5 tegumental body spines per row, posterior ceca that are 9 times length of the anterior ceca and that lack any coil, a testis that is 3 times longer than wide and that does not fill the intercecal space, an ovary that is >60% of the body width, a vitelline duct that connects to the anterior aspect of the oötype, a uterus that is >10% of the body width and that extends posterior to all genitalia, and a rounded posterior body margin. It is the first species of Cardicola to be described from a grouper (Serranidae). The 28S and internal transcribed spacer 2 phylogenetic analyses recovered the new species as a distinct lineage within the clade of Cardicola spp.
Assuntos
Bass/parasitologia , Doenças dos Peixes/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Teorema de Bayes , Doenças dos Peixes/epidemiologia , Florida/epidemiologia , Golfo do México/epidemiologia , Coração/parasitologia , Filogenia , Prevalência , Trematódeos/anatomia & histologia , Trematódeos/genética , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologiaRESUMO
Achorovermis testisinuosus gen. et sp. n. (Digenea: Aporocotylidae) infects the heart of the smalltooth sawfish, Pristis pectinata Latham (Rhinopristiformes: Pristidae), in the eastern Gulf of Mexico. Specimens of the new genus, along with the other blood flukes that infect batoids are similar by having an inverse U-shaped intestine and a curving testis as well as by lacking tegumental spines. The new genus differs from all of the other blood flukes infecting batoids by having an elongate body (>50 × longer than wide), a testis having >100 curves, and an ovary wholly anterior to the uterus. It differs from Ogawaia glaucostegi Cutmore, Cribb et Yong, 2018, the only other blood fluke infecting a rhinopristiform, by having a body that is >50 × (vs <30 ×) longer than wide, a testis that is >75 × (vs <40 ×) longer than wide and has >100 (vs <70) curves, an ovary wholly anterior to (vs lateral and dorsal to) the seminal vesicle, a uterus wholly posterior to (vs overlapping and lateral to both) the testis and ovary, and a sinuous (vs convoluted) uterus. The new species joins a small group of chondrichthyan blood flukes that lack tegumental spines: O. glaucostegi, Orchispirium heterovitellatum Madhavi et Rao, 1970, Myliobaticola richardheardi Bullard et Jensen, 2008, Electrovermis zappum Warren et Bullard, 2019. Blood flukes infecting batoids are further unique by having a curving testis. That is, the blood flukes infecting species within Selachii are morphologically distinct from those infecting species within the Batoidea (excluding Gymnurahemecus bulbosus Warren et Bullard, 2019). Based on the morphological similarity, we suspect that the new species shares a recent common ancestor with O. glaucostegi. The discovery of the new species brings the total number of chondrichthyan blood flukes to 11 species assigned to nine genera.
Assuntos
Doenças dos Peixes/epidemiologia , Rajidae , Trematódeos/classificação , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , Espécies em Perigo de Extinção , Feminino , Doenças dos Peixes/parasitologia , Golfo do México/epidemiologia , Masculino , Prevalência , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologiaRESUMO
Herein we describe a new species of turtle blood fluke (TBF) and propose a new genus to accommodate it, Pitiutrema revelae n. gen., n. sp. This blood fluke infects the heart of six-tubercled Amazon River turtles (Podocnemis sextuberculata [Cornalia, 1849] [Pleurodira: Podocnemididae]) in the headwaters of the Amazon River near Iquitos, Peru. It resembles the other 2 described species of South American freshwater TBFs (Atamatam amazoniensis Bullard and Roberts, 2019, and Paratamatam iquitosiensis Bullard and Roberts, 2019) by having a dorsoventrally flattened and ovoid body, an oral sucker with anteroventral spines, 2 inter-cecal testes arranged in a column, inter-gonadal terminal genitalia, an inter-cecal and post-ovarian Laurer's canal pore, and a Y-shaped excretory bladder. It differs from all other nominal TBFs by having the combination of an aspinose body that lacks mammillae, a tapered (not broadly rounded) posterior body end, a ventral sucker, slightly M-shaped or inverse U-shaped ceca, a deeply-lobed (dendritic) ovary, a transverse uterus, and a dispersed vitellarium. The new genus is further unique among TBF genera by having an anterior to posterior sequence of ventral sucker, anterior testis, ovary, cirrus sac (lateral to posterior half of ovary), and posterior testis. The phylogenetic results and placement of the new taxon (1) were both predicted by our morphological diagnosis and comparisons with related taxa, (2) further indicated monophyly of the nominal South American freshwater TBFs, (3) reaffirmed the marine derived lineage identity of the nominal South American freshwater TBFs, and (4) highlighted that the single cercarial sequence (TBF sp. W-810) from an ampullariid in Brazil does not share a recent common ancestor with any of the nominal South American freshwater TBFs. The new species is the eighth TBF reported from a side-necked turtle (Pleurodira), the first TBF from a member of Podocnemididae, and the third freshwater TBF from South America.
Assuntos
Trematódeos/classificação , Infecções por Trematódeos/veterinária , Tartarugas/parasitologia , Animais , Teorema de Bayes , Peru , Filogenia , Rios , Trematódeos/anatomia & histologia , Trematódeos/genética , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologiaRESUMO
Two new genera and species of freshwater turtle blood flukes (TBFs) are described herein based on specimens infecting the nephritic and mesenteric blood vessels of "matamatas" (a side-necked turtle, Chelus fimbriata [Schneider, 1783] [Pleurodira: Chelidae]) from the Amazon River Basin, Peru. These taxa comprise the first-named species and the first-proposed genera of freshwater TBFs from the continent of South America. A new comparison of all TBF genera produced 6 morphologically diagnosed groups that are discussed in light of previous TBF classification schemes and a novel phylogenetic hypothesis based on the nuclear large subunit ribosomal DNA (28S). Considering external and internal anatomical features, species of the new genera (Atamatam Bullard and Roberts n. gen., Paratamatam Bullard and Roberts n. gen.) are most similar to each other and are together most similar to those of several marine TBF genera. The 28S phylogenetic analysis supported the monophyly of all 6 morphologically diagnosed groups of genera. Most notably, the freshwater TBFs of South America comprise a derived group nested within the clade that includes the paraphyletic marine TBFs. Not surprisingly in light of morphology, another marine TBF lineage (Neospirorchis Price, 1934) clustered with the freshwater TBFs of Baracktrema Roberts, Platt, and Bullard, 2016 and Unicaecum Stunkard, 1925. Our results, including an ancestral state reconstruction, indicated that (1) freshwater TBFs have colonized marine turtles twice independently and that (2) the South American freshwater TBFs comprise a marine-derived lineage. This is the first evidence that TBFs have twice independently transitioned from a marine to freshwater definitive host. Marine incursion is considered as a possible mechanism affecting the natural history of marine-derived freshwater TBFs in South America. A dichotomous key to accepted TBF genera is provided.
Assuntos
Trematódeos/classificação , Infecções por Trematódeos/veterinária , Tartarugas/parasitologia , Animais , Teorema de Bayes , DNA de Helmintos/química , DNA de Helmintos/isolamento & purificação , Água Doce , Funções Verossimilhança , Mesentério/irrigação sanguínea , Microscopia Eletrônica de Varredura/veterinária , Peru , Filogenia , Rios , Alinhamento de Sequência/veterinária , Trematódeos/anatomia & histologia , Trematódeos/genética , Trematódeos/ultraestrutura , Infecções por Trematódeos/parasitologiaRESUMO
Gymnurahemecus bulbosus gen. et sp. nov. infects the heart of smooth butterfly rays, Gymnura micrura in the Gulf of Mexico. Gymnurahemecus differs from all other accepted aporocotylid genera by having one column of C-shaped lateral tegumental spines, a medial oesophageal bulb anterior to a diverticulate region of the oesophagus, inverse U-shaped intestinal caeca, a non-looped testis, an oviducal ampulla, a Laurer's canal, and a post-caecal common genital pore. The new species, the shark blood flukes (Selachohemecus spp. and Hyperandrotrema spp.), and the chimaera blood fluke Chimaerohemecus trondheimensis are unique by having C-shaped lateral tegumental spines. Selachohemecus spp. and the new species have a single column of lateral tegumental spines, whereas Hyperandrotrema spp. and C. trondheimensis have 2-7 columns of lateral tegumental spines. The new species differs from Selachohemecus spp. most notably by having an inverse U-shaped intestine. The other ray blood flukes (Orchispirium heterovitellatum, Myliobaticola richardheardi, and Ogawaia glaucostegi) differ from the new species by lacking lateral tegumental spines, a medial oesophageal bulb, and a Laurer's canal and by having a looped testis. Phylogenetic analysis using large subunit ribosomal DNA (28S) indicated that the new species is sister to the clade that includes the other sequenced adult blood fluke (O. glaucostegi), which infects a ray in Australia. These results agree with and extend previous morphology- and nucleotide-based phylogenetic assertions that the blood flukes of early-branching jawed craniates (Chondrichthyes) are monophyletic and phylogenetically separated from the blood flukes of later-branching ray-finned fishes (Actinopterygii: Euteleostei).
Assuntos
Doenças dos Peixes/parasitologia , Rajidae/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Feminino , Golfo do México , Coração/parasitologia , Masculino , Filogenia , Trematódeos/genética , Infecções por Trematódeos/parasitologiaRESUMO
A new species of Empruthotrema Johnston & Tiegs, 1922 is described based on specimens collected from the olfactory sacs of smooth butterfly rays Gymnura micrura (Bloch & Schneider) captured in Mobile Bay (northcentral Gulf of Mexico), Alabama, USA. Empruthotrema longipenis n. sp. is most similar to the type-species Empruthotrema raiae (MacCallum, 1916) Johnston & Tiegs, 1922 by having 12 marginal and two interhamular loculi with members of haptoral hook pair 1 located midway along the periphery of each interhamular loculus and those of hook pair 2 located at the marginal termini of the bilateral septa flanking the interhamular loculi. Empruthotrema longipenis n. sp. differs from E. raiae by having a much longer male copulatory organ and from its remaining congeners by the sinistral and extracecal ejaculatory bulb flanking the pharynx, the number of interhamular and marginal septa, and the distribution of hook pairs 1 and 2 along the haptoral margin. This is the first report of a monocotylid from the smooth butterfly ray and from Mobile Bay. The diversity of haptoral morphotypes among the currently accepted species of Empruthotrema is detailed and discussed in the context of monophyly of the genus.