RESUMEN
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.
Asunto(s)
ADN Ribosómico/química , Enfermedades de los Peces/parasitología , ARN Ribosómico 28S/genética , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , Enfermedades de los Peces/epidemiología , Peces , Golfo de México/epidemiología , Filogenia , Trematodos/anatomía & histología , Trematodos/genética , Trematodos/aislamiento & purificación , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/parasitologíaRESUMEN
Two cryptic species of haploporid digeneans belonging in Saccocoelioides are described from Costa Rica: one from a poeciliid fish, Poecilia gillii, and the other from a characid fish, Astyanax aeneus. Traditional morphological features are examined and found to be largely inefficient for differentiating among the new species and 20 New World congeners. Comparison of ribosomal DNA sequences among the 2 new species, 2 North American, 4 Middle American, and 3 South American species of Saccocoelioides, including the type-species Saccocoelioides nanii from Argentina and Saccocoelioides sogandaresi from Texas, is effective in differentiating among these species. A Bayesian inference analysis is conducted using a concatenated alignment of the same 2 ribosomal gene regions from 35 species belonging in the Haploporoidea and rooted by the atractotrematid Isorchis anomalus. The analysis provides stronger support for a close relationship between species in Saccocoelioides and Intromugil; thus, Intromugil is transferred from the Waretrematinae to the Chalcinotrematinae. Additionally, interrelationships among 11 species of Saccocoelioides are resolved and reveal a distinct genetic rift suggesting the presence of 2 distinct lineages within the genus, 1 containing the type-species and the other containing a group of species that more closely resemble other genera in the subfamily. Taxonomy of Saccocoelioides is discussed, and observations made during the present study justify taking several taxonomic actions: new combinations are proposed for Saccocoelioides tilapiae n. comb., formerly in the now-defunct Culuwiya, and Saccocoelioides ruedasueltensis n. comb., formerly in Chalcinotrema; Saccocoelioides guaporense nomen novem is proposed for Lecithobotrioides elongatus; Saccocoelioides papernai is considered a junior subjective synonym of Saccocoelioides overstreeti; Saccocoelioides godoyi is considered a junior subjective synonym of Saccocoelioides szidati; Saccocoelioides magnorchis and Saccocoelioides saccodontis are considered species inquirendae; and Saccocoelioides adelae is considered a nomen nudum. Four new hosts are reported for Saccocoelioides cichlidorum: Amphilophus lyonsi, Amatitlania nigrofasciatus, Amatitlania septemfasciatus, and Hypsophrys nicaraguensis. Molecular data call into question some existing species identifications in Saccocoelioides and reveal that molecular tools combined with traditional taxonomy are required for accurately identifying species in the genus. Twenty-two species of Saccocoelioides are formally accepted, but it is noted that as new molecular data become available, some of these species may be transferred to other genera in the subfamily.
Asunto(s)
Characidae/parasitología , Enfermedades de los Peces/parasitología , Filogenia , Poecilia/parasitología , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , Argentina , Teorema de Bayes , Costa Rica , ADN de Helmintos/química , ADN Ribosómico/química , ADN Espaciador Ribosómico/química , Tracto Gastrointestinal/parasitología , ARN Ribosómico 28S/genética , Ríos , Alineación de Secuencia/veterinaria , Texas , Trematodos/anatomía & histología , Trematodos/genética , Infecciones por Trematodos/parasitologíaRESUMEN
The plagioporine opecoelids Helicometra fasciata (Rudolphi, 1819) Odhner, 1902, and Macvicaria crassigula (Linton, 1910) Bartoli, Bray, and Gibson, 1989 have been reported from fishes in expansive geographic regions, disjointed from their type localities. New material of M. crassigula was collected from near its type locality as well as specimens resembling Helicometra fasciata sensu lato from three triglids in the Gulf of Mexico. Comparisons of the ribosomal DNA (rDNA) sequences, comprising the partial 18S rDNA, internal transcribed spacer region (= ITS1, 5.8S, and ITS2), and partial 28S rDNA gene, from M. crassigula and Helicometra fasciata sensu lato in the Gulf of Mexico were made with sequences deposited in GenBank from those species from the Mediterranean Sea. Results reveal that M. crassigula sensu stricto from the Gulf of Mexico is distinct from the two cryptic species of M. crassigula sensu lato from the Mediterranean Sea and Helicometra fasciata sensu lato in this study differs from H. fasciata sequences from the Mediterranean Sea, thus Helicometra manteri sp. nov. is described.
Asunto(s)
Enfermedades de los Peces/parasitología , Perciformes/parasitología , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , Secuencia de Bases , ADN Ribosómico/genética , ADN Espaciador Ribosómico/genética , Golfo de México , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN/veterinaria , Especificidad de la Especie , Trematodos/genética , Trematodos/aislamiento & purificación , Infecciones por Trematodos/parasitologíaRESUMEN
Homalometron palmeri n. sp. is described and reported from the following fishes in the northern Gulf of Mexico: Micropogonias undulatus, Sciaenops ocellatus, Bairdiella chrysoura, Pogonias cromis, Fundulus grandis, Fundulus similis, and Eucinostomus argenteus. This species historically has been misidentified as Homalometron pallidum by some, and treated as Homalometron sp. by others. The new species differs from H. manteri by having a smaller body size, relatively longer postcecal space ranging from 7 to 15% of body length compared with 6-8%, body spines from 12 to 17 µm long compared with 15-20 µm, and an oral-to-ventral sucker width ratio of 1:1.2-1.3 compared with 1:1.3-1.5. Ribosomal DNA sequences from H. palmeri n. sp., H. pallidum, Homalometron manteri, and Homalometron pseudopallidum are compared and the new species is found to be most similar to H. manteri, a sympatric species. Comparison between 2 mitochondrial genes from H. palmeri n. sp. and H. manteri provided further evidence for their status as distinct species. Pairwise comparison of 503 aligned bases from ND1 gene revealed 33 variable sites (6.5%) between the 2 species. Pairwise comparison of 1,152 aligned bases from COI gene revealed 73 variable sites (6.3%) between the 2 species. Interspecific variability in mitochondrial sequences between the 2 species was 3-16 times greater than intraspecific variability in either species.
Asunto(s)
Enfermedades de los Peces/parasitología , Fundulidae/parasitología , Perciformes/parasitología , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , ADN de Helmintos/química , ADN Ribosómico/química , ADN Espaciador Ribosómico/química , Louisiana , Mississippi , New England , ARN Ribosómico 18S/genética , ARN Ribosómico 28S/genética , ARN Ribosómico 5.8S/genética , Trematodos/anatomía & histología , Trematodos/genética , Trematodos/aislamiento & purificación , Infecciones por Trematodos/parasitologíaRESUMEN
Two new allocreadiid trematodes are described from the intestine of characid fishes from Rio Itaya, a tributary of the Amazon River near Iquitos, Peru. Auriculostoma foliaceum n. sp. is described from Bryconops cf. caudomaculatus (Günther, 1864) Backup, 2003, and Auriculostoma diagonale n. sp. from Stethaprion cf. erythrops Cope, 1870. Auriculostoma foliaceum n. sp. differs from its congeners by having a foliated lateral margin and lacking vitelline follicles in the forebody. Auriculostoma diagonale n. sp. differs from all of its congeners except Auriculostoma platense (Szidat, 1954) Scholz, Aguirre-Macedo, and Choudhury, 2004, by having oblique rather than tandem testes and differs from A. platense by having a much more elongated cirrus sac. Phylogenetic hypotheses based on analyses of 3 alignments of partial sequences of the 28S rDNA gene conducted in this study provide a framework for revaluating the classification of Allocreadiidae Looss, 1902. The present analyses show that (1) Paracreptotrematina limi Amin and Myer, 1982, does not belong in the Allocreadiidae; (2) Creptotrematina aguirrepequenoi Jiménez-Guzmán, 1973 (spelled here without diacritic mark), does not belong to Paracreptotrematina Amin and Myer, 1982, but remains in the Allocreadiidae; (3) Auriculostoma astyanace Scholz, Aguirre-Macedo, and Choudhury, 2004, is closely related to C. aguirrepequenoi and Wallinia chavarriae Choudhury, Hartvigsen-Daverdin, and Brooks, 2002; (4) Megalogonia Surber, 1928, is retained as an accepted genus in the Allocreadiidae; and (5) Margotrema Lamothe-Argumedo, 1970, is found to be nested among 3 species of Crepidostomum Braun, 1900.
Asunto(s)
Enfermedades de los Peces/parasitología , Filogenia , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , ADN de Helmintos/química , ADN Ribosómico/química , Peces , Datos de Secuencia Molecular , Perú , ARN Ribosómico 28S/genética , Ríos , Trematodos/anatomía & histología , Trematodos/genética , Infecciones por Trematodos/parasitologíaRESUMEN
Psettarium anthicum sp. n. (Digenea: Sanguinicolidae) infects the myocardium and atrial wall of the cobia Rachycentron canadum (Linnaeus, 1766) (Rachycentridae) in the northern Gulf of Mexico off Mississippi, USA. It is the first member of Psettarium Goto et Ozaki, 1930 reported from other than the Indian Ocean or Pacific Ocean and the second species of the genus reported from cobia. It differs from its congeners by the combination of having posterior caeca with lateral projections appearing as thorns in lateral view and the male pore anterior to the oötype. The species of Psettarium, P. japonicum (Goto et Ozaki, 1929) (type species), P. tropicum Manter, 1940, P. sebastodorum Holmes, 1971, P. rachycentri (Lebedev et Parukhin, 1972) comb. n. (syn. Psettarioides rachycentri Lebedev et Parukhin, 1972) and P. anthicum sp. n., differ from other sanguinicolids by the combination of having an elongate body with a sinistral posterolateral protuberance, minute, straight tegumental body spines in ventrolateral transverse rows, posterior caeca greater than seven time the anterior caeca length, the o6type near the posterior end of the body, a uterus primarily between the ovary and oötype and an oviduct and vitelline duct extending posteriad primarily between the uterus and dextral body margin. We emend Psettarium and provide a diagnostic key to the species. Psettarioides is regarded as a junior synonym of Psettarium because herein we return its type species, P. tropicum, to Psettarium. Regarding the three other sanguinicolids formerly of Psettarioides, we suspect that P. pseudupenei Lebedev et Parukhin, 1972 belongs to Psettarium but include it only tentatively pending an examination of type or other material; we tentatively place P. kurochkini Parukhin, 1976 in Cardicola Short, 1952; and we designate P. grandis (Lebedev et Mamaev, 1968) as incertae sedis pending examination of type or other appropriate material.
Asunto(s)
Enfermedades de los Peces/parasitología , Corazón/parasitología , Perciformes/parasitología , Trematodos/clasificación , Animales , Femenino , Masculino , Trematodos/anatomía & histologíaRESUMEN
Selachohemecus benzi Bullard & Overstreet n. sp. infects the heart and kidney of the blacktip shark Carcharhinus limbatus in the northern Gulf of Mexico off Florida and Mississippi, USA. Specimens of S. olsoni Short, 1954, the only congener and only other named blood fluke reported from a chondrichthyan in the Gulf of Mexico, were collected from the heart of the Atlantic sharpnose shark Rhizoprionodon terraenovae from two new localities, Apalachicola Bay, Florida, and Mississippi Sound, Mississippi, USA. The new species differs from S. olsoni by having a larger body (1.4-3.8 mm long), robust tegumental body spines numbering 51-63 along each lateral body margin, a testis extending from the posterior caeca to the ovary, and a medial ovary with lobes. We amend the diagnosis of Selachohemecus Short, 1954 to accommodate it and provide a diagnostic key for all named chondrichthyan blood flukes.
Asunto(s)
Platelmintos/anatomía & histología , Platelmintos/clasificación , Tiburones/parasitología , Animales , Femenino , Corazón/parasitología , Masculino , México , Océanos y MaresRESUMEN
Two epibiotic peritrichs infested the blue crab, Callinectes sapidus, from the Gulf of Mexico, Mississippi, USA. Epistylis callinectes n. sp. was isolated from the epipods of maxillipeds, bases of gill-cleaning setae, and gills, and Epistylis clampi n. sp. was isolated from the exterior surfaces of the exoskeleton. Epistylis callinectes has short, symmetrically and dichotomously branched stalks; its zooid is elongate ovoid and conspicuously longer than the individual stalk branches, measuring 40-57 (49) x 18-33 (26) microm in vivo and containing a thick, undivided peristomial lip (PL). It has a single contractile vacuole and a transverse horseshoe-shaped macronucleus. Its haplokinety (H) and polykinety (Po) complete one and one-half circuits on the peristome before entering the infundibulum. There is a distal kinetal fragment present at the distal end of both the H and Po. Epistylis callinectes has 48-70 transverse silverlines from the oral area to the trochal band (TB) and 19-26 from the TB to the scopula. Epistylis clampi has long, asymmetrically, and dichotomously branched stalks. Its zooid is elongate vase-shaped, measuring 35-64 (48) x 21-30 (27) microm in vivo and with a thick, transversely folded PL. The stalks supporting zooids are unequal in length. Its zooid has a single contractile vacuole and a transverse horseshoe-shaped macronucleus occurs in the upper half of the body. Its H and Po complete approximately one circuit around the peristome before entering the infundibulum. There is a distal kinetal fragment present at the distal end of both the H and Po. This species has 71-112 transverse silverlines from the peristome to the scopula.
Asunto(s)
Braquiuros/parasitología , Cilióforos/clasificación , Cilióforos/ultraestructura , Animales , México , Microscopía de Interferencia/métodos , Agua de Mar , Plata , Proteínas de Plata , Especificidad de la Especie , Coloración y Etiquetado/métodosRESUMEN
A new species of Petasiger inhabits Pelecanus occidentalis, from the Area de Conservación Guanacaste, Costa Rica. The new species most closely resembles Petasiger novemdecim Lutz 1929 and Petasiger caribbensis Nassi, 1980 by having 19 circumoral spines and vitelline follicles confluent between the ventral sucker and gonads. The new species differs from both of these species by having a cirrus sac that is anteroposteriorly elongate and that reaches posteriorly to the midventral sucker, an ovary and Mehlis' gland that overlap the anterior testis dorsally, a uterus that lies dorsal to the ventral sucker, and a dextromedial genital pore. In P. novemdecim and P. caribbensis the cirrus sac is round and does not extend posteriorly to the anterior margin of the ventral sucker, both the ovary and Mehlis' gland are anterior to the anterior testis, the uterus runs lateral to and not dorsal to the ventral sucker, and the genital pore opens medially and sinistromedially, respectively.
Asunto(s)
Enfermedades de las Aves/parasitología , Echinostomatidae/clasificación , Infecciones por Trematodos/veterinaria , Animales , Aves , Costa Rica , Echinostomatidae/anatomía & histología , Infecciones por Trematodos/parasitologíaRESUMEN
A new species of digenean, Microphallus fonti, is described from the red swamp crawfish in Lousiania, U.S.A. It has a small pharynx and a rudimentary gut like M. opacus and a possibly related species from crayfishes, but it differs from them by its relatively large male copulatory papilla and a conspicuous metraterm