RESUMO
A new genus, Cordicestus, is proposed to accommodate proteocephalid tapeworms parasitising gars (Lepisosteiformes: Lepisosteidae) in North and Central America that were previously placed in the polyphyletic genus Proteocephalus Weinland, 1858. The new genus differs from other proteocephalid genera by the particular morphology of the scolex, which is small, protrudes apically but has no apical organ, and bears flat, heart-shaped (= cordis) suckers. In addition, the species of the new genus have an elongated cirrus sac with an almost straight internal vas deferens and wide, sinuous ventral osmoregulatory canals with secondary canals directed outwards. The type species of the new genus, Cordicestus singularis (La Rue, 1911) n. comb., is redescribed based on new material from the shortnose gar, Lepisosteus platostomus Rafinesque (type host), and the spotted gar, L. oculatus Winchell, in the United States. Cordicestus rafaeli n. sp. is described from the tropical gar, Atractosteus tropicus Gill, in Mexico. The new species differs from its relatives primarily by the presence of craspedote proglottids (acraspedote in other species) and some biometric features. All species of Cordicestus are revised, including unidentified specimens from A. tropicus and the Cuban gar A. tristoechus (Bloch and Schneider) in Nicaragua and Cuba, respectively, which may be new species, and a key to the identification of these taxa is provided. Molecular data available for two nominal species of the new genus indicate the possible existence of another species of Cordicestus in Lepisosteus in the USA.
Assuntos
Cestoides , Infecções por Cestoides , Doenças dos Peixes , Peixes , Animais , Cestoides/classificação , Cestoides/anatomia & histologia , Cestoides/isolamento & purificação , Doenças dos Peixes/parasitologia , Infecções por Cestoides/veterinária , Infecções por Cestoides/parasitologia , Peixes/parasitologia , Fósseis , Estados Unidos , América Central , FilogeniaRESUMO
Platybothrium Linton, 1890 is a genus parasitizing sharks of the families Carcharhinidae and Sphyrnidae. No new species has been assigned to the genus in the 20 years since its last treatment. In the present study, a new species is described from the Persian Gulf, which is the second report of a species of Platybothrium in the Indian Ocean. Platybothrium yanae sp. nov. differs from P. auriculatum Yamaguti, 1952, P. cervinum Linton, 1890, P. tantulum Healy, 2003, and P. kirstenae Healy, 2003 in lacking, rather than having, an accessory piece between its hooks. This new species is distinguished from its other congeners by having a particular combination of features including its measurements, morphology, and meristic features, bringing the number of valid species in the genus to 11.
Assuntos
Cestoides , Tubarões , Especificidade da Espécie , Animais , Tubarões/parasitologia , Cestoides/classificação , Cestoides/anatomia & histologia , Irã (Geográfico) , Oceano ÍndicoRESUMO
BACKGROUND: Up to now, five cestode species have been reported infecting five hummingbird species. To date, there have been no reports of cestode infections in hummingbirds in Mexico. METHODS: A Berylline hummingbird (Saucerottia beryllina) was found dead in a backyard at Toluca City, Mexico, and a window collision was assumed as the cause of death. The bird was preserved in 10% neutral buffered formalin for routine histological examination. RESULTS: At the histological study, liver parenchymal disruption was observed. This lesion could be the result of the assume collision. No lesions were observed in other tissues examined. Conspicuous cestode structures were observed in the lumen of the small intestine. Structure of cestodes, as revealed from histological sections, suggests their position in the genus Anonchotaenia Cohn, 1900 (family Paruterinidae). CONCLUSION: This is the first report of intestinal cestodosis in a Berylline hummingbird (S. beryllina) in Mexico.
Assuntos
Doenças das Aves , Aves , Cestoides , Infecções por Cestoides , Animais , México , Doenças das Aves/parasitologia , Infecções por Cestoides/veterinária , Infecções por Cestoides/parasitologia , Cestoides/isolamento & purificação , Cestoides/classificação , Cestoides/anatomia & histologia , Aves/parasitologia , Fígado/parasitologia , Intestinos/parasitologiaRESUMO
Among the 10 native cats of Iran, the Felis chaus is considered as one of the largely unknown species. Despite the reports on jungle cats in southeast Iran, there is no comprehensive information about their parasitic diseases. Scanning electron microscope (SEM) provides a valuable tool for the study of these organisms. In October 2022, a 15-year-old male jungle cat (F. chaus) was examined for gastrointestinal parasites using SEM which revealed exact parasite structures such as the mouth, shape of the lips, teeth and their position, papillae, excretory pore, and amphids. SEM of the Taenia taeniaeformis found in the F. chaus intestinal epithelium revealed that this tapeworm consisted of four unarmed suckers and a large armed rostellum. The rostellum was observed bearing double rings of alternating and circular hook arrangements. There were 21 large hooks in the anterior ring and 21 slightly smaller hooks in the posterior one. This study is the first report of Joyeuxiella echinorhyncoides from a jungle cat (F. chaus) in southeastern Iran. The rostellum was cylindrical and armed with thorn shape hooks that covered the whole rostellum with similar density. It was armed with 20-30 long hooks arranged in 16 rows. Four big suckers were visible at the base of the rostellum, two on each side. The suckers were round, and unlike the rostellum, these structures were unarmed. The results of the present study observed under SEM, indicated that organs such as sucker and rostellum in cestodes and mouth and the shape of lips and teeth in nematodes played a significant role in the biology of these helminths. The SEM reveals the surface structures and their relationships which results in better distinguishing the species and showing their detailed differences. More SEM studies need to be conducted on other species of cestodes and nematodes, along with pathological tests, to obtain more comprehensive and precise information about how these parasites harm this jungle cat host. The results of present study indicate that morphological details are important which should be considered in the classification. Meanwhile, external structures described herein using SEM, further investigation using transmission electron microscope provide more data on the biology of the parasites. RESEARCH HIGHLIGHTS: Light microscopy is the first step to identify the parasites. High magnification 3D images of the SEM reveal the surface structures of parasites and their relationships precisely. SEM study of the parasites results in distinguishing the species and showing their detailed differences.
Assuntos
Cestoides , Parasitos , Animais , Masculino , Cestoides/anatomia & histologia , Trato Gastrointestinal , Irã (Geográfico) , Microscopia Eletrônica de Varredura , Felis/parasitologiaRESUMO
Hydatigera taeniaeformis is a cestode that uses felines and rodents as definitive and intermediate hosts, respectively. Its larval stage, or metacestode, infects a wide variety of rodent species and develops in the liver parenchyma into a cyst. The aim of this study was to evaluate the occurrence of H. taeniaeformis metacestode in various species of wild rodents from Peru. For this, the livers of 356 rodents were macroscopically examined for any parasitic form compatible with metacestodes. Metacestodes were identified by measuring characteristic morphological parameters, and the diagnosis was confirmed by molecular analysis of a fragment of the cytochrome c oxidase subunit 1 gene (cox1). Five rodents: two small-eared pygmy rice rats (Oligoryzomys microtis), two white-naped squirrels (Simosciurus nebouxii), and one pygmy rice rat (Oligoryzomys sp.) were infected with H. taeniaeformis metacestodes. The cox1 sequences from our metacestodes showed up to 100% identity with previous H. taeniaeformis sequences from the GenBank. These results demonstrated the occurrence of H. taeniaeformis in new intermediate hosts, as well as the first molecular contribution for H. taeniaeformis from Peru.
Assuntos
Cestoides , Taenia , Ratos , Gatos , Animais , Peru/epidemiologia , Taenia/genética , Cestoides/genética , Cestoides/anatomia & histologia , Sciuridae , Larva , SigmodontinaeRESUMO
This paper aims to expand understanding of a poorly known group of cestodes that parasitize an intriguingly diverse suite of elasmobranchs. The group's three currently described members (i.e., Pentaloculum macrocephalum, Pentaloculum hoi, and Zyxibothrium kamienae) parasitize an electric ray, a carpet shark, and a skate, respectively. Pentaloculum grahami n. sp. is described from a second genus of carpet shark, specifically Parascyllium collare, in Australia. Zyxibothrium duffyi n. sp. and Zyxibothrium healyae n. sp. are described from the deep-sea skates Brochiraja asperula and Brochiraja spinifera, respectively off New Zealand. The three new species share distinctive bothridia that bear a small number of large, circular, facial loculi and lateral bands of vitelline follicles that converge posterior to the ovary-features which are found in all other members of these genera. Zyxibothrium healyae n. sp. is unique in possessing three, rather than four or five, facial loculi. Zyxibothrium duffyi n. sp. possesses a combination of five facial loculi and vitelline follicles that stop short of the anterior margin of the proglottid. Pentaloculum grahami n. sp. is the largest member of the group with the greatest number of proglottids. Based on striking similarities in scolex morphology, Pentaloculum and Zyxibothrium have been hypothesized to belong to a distinct subgroup of "tetraphyllideans" provisionally designated as Clade 1. Based on sequence data for the D1-D3 region of the 28S rDNA gene generated for species of Zyxibothrium for the first time, we confirm the reciprocal monophyly of both genera as well as the monophyly of Clade 1 and its status as a distinct lineage among the "Tetraphyllidea". This work also suggests that the presence of five facial loculi is homoplasious given this character state is found in members of both genera. The new species expand the host associations of Clade 1 to include additional skate and carpet shark genera. Moving forward we would expect to find additional members of this group parasitizing other species of parascyliid carpet sharks as well as other species of the rajid genus Malacoraja and the arhynchobatid genus Brochiraja. Here we have doubled the number of described species in the taxon referred to as Clade 1 while simultaneously expanding our understanding of the morphology and anatomy of its members. This additional information will help inform the ultimate revision of the ordinal classification of the cestodes to address the highly polyphyletic nature of the order "Tetraphyllidea" as it is currently configured.
Assuntos
Cestoides , Infecções por Cestoides , Doenças dos Peixes , Tubarões , Rajidae , Feminino , Animais , Filogenia , Cestoides/genética , Cestoides/anatomia & histologia , Infecções por Cestoides/veterinária , Microscopia Eletrônica de VarreduraRESUMO
PURPOSE: Tapeworms of Avitellina spp. are among those gastrointestinal parasitic helminths which infect wild and domestic ruminants worldwide leading to various clinical manifestations in the ruminant hosts, thereby causing considerable economic losses in livestock production. While these worms are among the major constraints in ruminant livestock raising, there is very meagre molecular information available making their identity error-prone. This study aimed to provide insights into the genetic characterization of these economically important tapeworms. METHODS: In the present study, we examined 480 guts of slaughtered goats (n = 413) and sheep (n = 67) of which 74 guts were found infected with anoplocephalid cestodes (sheep gut:18; goat gut:56). A total of 27 Avitellina lahorea worms (19 from goat and 8 from sheep) were isolated, fixed, relaxed and stained using Gower's carmine stain. For molecular analyses, the genomic DNA was extracted and fragments of cytochrome c oxidase subunit 1 (cox1) gene, internal transcribed spacer1-5.8S ribosomal RNA (ITS1-5.8S rRNA) gene, and small subunit ribosomal RNA (18S rRNA) gene were amplified and sequenced. RESULTS: Based on snail-shaped paruterine organs and other morphological and morphometric features, the worms were identified as Avitellina lahorea. The phylogenetic analyses, based on our original cox1 gene sequence and those available from NCBI GenBank, showed Avitellina tapeworms as a sister lineage of Thysaniezia with 14 to 17% genetic divergence. Molecular analyses of 18S rRNA gene sequences depicted the present isolate as one of the species of the genus Avitellina clustering with A. centripunctata as a separate species in the phylogenetic tree with 92% homogeneity in sequences. In conjunction with existing data of internal transcribed spacer1-5.8S rRNA (ITS1-5.8S rRNA) gene, the phylogenetic analysis placed the present isolate among the anoplocephalids as one of the species. CONCLUSION: The present study is the first molecular report on A. lahorea isolated from sheep and goats with the simultaneous use of a morphological approach, and certainly contributes to bridging the existing gaps in the understanding of these economically important parasites.
Assuntos
Cestoides , Doenças dos Ovinos , Animais , Ovinos , Cabras , Filogenia , RNA Ribossômico 5,8S , Cestoides/anatomia & histologia , Ruminantes , RNA Ribossômico 18S/genética , Gado , Doenças dos Ovinos/parasitologiaRESUMO
The main objective of this study was to analyze the function of the myzorhynchus and remnant apical organ of adult cestodes in the order Rhinebothriidea. Several features of these structures were analyzed in 12 species belonging to six genera and two families. In particular, the glandular composition of the myzorhynchus of four species from Echeneibothriidae (i.e., Notomegarhynchus navonae and three species of Echeneibothrium) was studied using histochemical techniques and/or transmission electron microscopy. In addition, the presence of a remnant apical organ and its glandular composition were analized in six species of Rhinebothriidae and in two species of Semiorbiseptum, whose familial assignment is uncertain. We also evaluated the importance of these characters for diagnosis. The same type of gland cell was found in the myzorhynchus of Echeneibothrium species and in the remnant apical organ of Semiorbiseptum species. These gland cells were Coomassie brilliant blue-positive, periodic acid Schiff-positive and Alcian blue-negative, consistent with a glycoprotein secretion possibly involved in adhesion to the host mucosa and proteolysis. The type of gland cells found in the myzorhynchus of N. navonae were Coomassie brilliant blue-negative, periodic acid Schiff-positive and Alcian blue-positive, consistent with the production of adhesive and protective substances. The type of gland cells in the myzorhynchus and in the remnant apical organ could be a useful character for the generic diagnosis of Echeneibothrium and Semiorbiseptum, respectively. A remnant apical organ was only found in Semiorbiseptum, with its presence/absence being important as a diagnostic character at the generic level for Semiorbiseptum, Scalithrium, and Rhinebothroides. A secondary objective was to characterize the microthrix pattern of the myzorhynchus of N. navonae. An extended distribution of spinitriches was detected, which may allow a better adhesion of this large species to the host mucosa, as the main function of spinitriches is presumably that of adhesion.
Assuntos
Cestoides , Animais , Argentina , Azul Alciano , Ácido Periódico , Cestoides/anatomia & histologiaRESUMO
The larval form of the Phyllobothriidea cestode was found in the blubber of a Cape fur seal (Arctocephalus pusillus pusillus) from a zoo in Japan. Bladder-bearing larval cestodes with a scolex have been occasionally reported from blubbers of pinnipeds and morphologically identified as Clistobothrium delphini (formerly known as Phyllobothrium delphini) or rarely Clistobothrium grimaldii (Monorygma grimaldii). Although the larvae here morphologically resembled C. delphini, the 28S rDNA sequence was 100% (1,430/1,430 bp) homologous to the registered sequence of C. grimaldii (GenBank Accession No. KU724058). This discrepancy between morphological and molecular analyses confirms the difficulty of identifying C. delphini and C. grimaldii larvae based solely on morphology, and the need for molecular data to elucidate the morphological variations in Clistobothrium parasites.
Assuntos
Cestoides , Otárias , Animais , Larva , Japão , Cestoides/genética , Cestoides/anatomia & histologia , Tecido AdiposoRESUMO
INTRODUCTION: Species of Fimbriaria are common tapeworms of ducks (Anseriformes). In this study, cestode specimens identified as F. fasciolaris, F. czaplinskii and F. teresae from the Helminthological Collection of IZSHK are re-examined and newly collected cestodes of the genus Fimbriaria from various anseriform birds in Ukraine are examined. METHODS: Cestode specimens were studied using light microscopy. For two of these species, Fimbriaria fasciolaris and Fimbriaria teresae, partial sequences of the genes 18S, 28S, COX1 and NAD were obtained. Also, archived specimens from Ukrainian and Poland were also studied and partly re-identified. RESULTS: The revision of all collected cestodes identified as Fimbriaria spp. revealed that species of the genus differ by the morphology of the copulative apparatus. Based on the analysis of our data and literature sources, a key to Fimbriaria species is provided.
Assuntos
Anseriformes , Cestoides , Infecções por Cestoides , Animais , Ucrânia , Infecções por Cestoides/veterinária , Cestoides/anatomia & histologia , AvesRESUMO
Two new species of cestodes were described from the Brazilian guitarfish, Pseudobatos horkelii (Mller and Henle) (Rhinopristiformes: Rhinobatidae), from coastal waters off Argentina in the southwestern Atlantic Ocean. Rhinebothrium quequense n. sp. (Rhinebothriidea) differs from its congeners by a combination of morphological characters, including the total number of loculi, the absence of loculi at the level of bothridial constriction, the number of testes per proglottid, and the number of proglottids per worm. Caulobothrium pieroi n. sp. (Tetraphyllidea) can be distinguished from the other members of the genus by the following set of morphological features including the presence of stalked bothridia with apical sucker, the number of loculi per bothridium, the number of testes per proglottid, and the number of proglottids per worm. The discovery of R. quequense n. sp. and C. pieroi n. sp. in the Brazilian guitarfish not only increases the number of rhinebothriideans and tetraphyllideans in the southwestern Atlantic, but also expands the elasmobranchs list to include P. horkelii for the first time as a new host record for cestodes globally. In addition, this is not only the first report of a species of Rhinebothrium in rhinobatids in the region, but it is also the first Caulobothrium species infecting a rhinopristiform batoid.
Assuntos
Cestoides , Infecções por Cestoides , Elasmobrânquios , Doenças dos Peixes , Rajidae , Animais , Cestoides/anatomia & histologia , Infecções por Cestoides/veterinária , Microscopia Eletrônica de VarreduraRESUMO
This paper provides new morphological and molecular data for identifying Monoecocestus species from rodents: a) morphological update of Monoecocestus spp., b) morphological data on Anoplocephalidae taxa from Sigmodontinae rodents, c) analyses of the genetic distances between the specimens studied and other Anoplocephalidae from rodents available in GenBank, and phylogenetic inferences. A total of 25 specimens of Holochilus spp. were examined from four provinces of Argentina. Cestodes specimens were removed from the rodents small intestines. Conventional studies were used for the morphological and molecular analysis. Four taxa of Monoecocestus were identified. Monoecocestus threlkeldi was identified as first record in Holochilus chacarius and from Argentina. Molecular and morphological aspects of Monoecocestus sp.1, Monoecocestus sp.2 and Monoecocestus sp.3 were described. Specimens belonging to the genus Monoecocestus may represent closely related species, demonstrating the importance of using integrative taxonomic approaches to understand biological diversity. The continuity of the studies on Anoplocephalidae will allows to advance in investigation of molecular analyses and ecological aspects that determine parasite-host-environment relationship.
Assuntos
Cestoides , Infecções por Cestoides , Doenças dos Roedores , Animais , Roedores/genética , Sigmodontinae/genética , Filogenia , Cestoides/genética , Cestoides/anatomia & histologiaRESUMO
Based on morphological and molecular data, a new species of tapeworm, Bothriocephalus kupermani n. sp., is described from pumpkinseed, Lepomis gibbosus (Linnaeus, 1758) (type host), and green sunfish, L. cyanellus Rafinesque, 1819 (Actinopterygii: Centrarchidae) in the United States. The new species differs from its North American congeners mainly in the shape of its scolex, which is almost rectangular in dorsoventral and lateral views (nearly parallel margins in the bothrial region), with shallow, wide bothria, and by an extensive field of vitelline follicles that are also variably present, albeit more sparsely, medially in the cortex of the ovarian and uterine areas. This tapeworm appears to be typically associated with Lepomis sunfishes. Examination of museum specimens of Bothriocephalus species from Lepomis spp. indicates that the tapeworm also parasitizes bluegill, Lepomis macrochirus, longear sunfish, Lepomis megalotis, and that previous records of Bothriocephalus cuspidatus and Bothriocephalus claviceps in these fishes are of the new species, B. kupermani.
Assuntos
Cestoides , Infecções por Cestoides , Perciformes , Animais , Cestoides/anatomia & histologia , Cestoides/genética , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/veterinária , Peixes , América do Norte , Perciformes/anatomia & histologiaRESUMO
Members of the order Trypanorhyncha are cestode parasites that are frequently found infecting the muscles of several marine fish species, affecting fish health and resulting in consumers' rejection. Seventy-five specimens of marine fish were freshly caught from boat landing sites at the Alexandria coast along the Mediterranean Sea in Egypt, including two Carangids, the greater amberjack Seriola dumerili and the gulley jack Pseudocarans dentex; two Serranids, the Haifa grouper Epinephelus haifensis and the mottled grouper Mycteroperca rubra. Forty-five fish were infected; the infection was recorded as blastocysts embedded in fish flesh. Blastocysts were isolated and ruptured; the generated plerocerci were described morphologically, where, four different species were recovered; Callitetrarhynchus gracilis, Callitetrarhynchus speciosus, Protogrillotia zerbiae, and Grillotia brayi. The taxonomic position of these parasites was justified by multiple-sequence alignment and a phylogenetic tree was constructed following maximum likelihood analysis of the 18s rRNA sequences of the recovered worms. The accession numbers MN625168, MN625169, MN611431and MN611432 were respectively assigned to the recovered parasites. The results obtained from the molecular analyses confirmed the morphological records of the recovered parasites. Since metacestodes are found in the musculature of infected fish specimens, it is necessary to remove these areas in the commercialization of fish.
Assuntos
Bass , Cestoides , Cisticercose , Doenças dos Peixes , Perciformes , Animais , Cestoides/anatomia & histologia , Cisticercose/veterinária , Doenças dos Peixes/parasitologia , Mar Mediterrâneo , Perciformes/parasitologia , FilogeniaRESUMO
Chickens and ducks are important sources of essential proteins and nutrition for global consumption, especially their eggs and meat. Tapeworm infections in chickens and ducks are the cause of serious poultry health and economic problems in the processing of livestock and food production systems. Raillietina are cosmopolitan in distribution and are possibly the most common tapeworm parasites. There are three important species regarding avian infection, with different pathogenicity, including Raillietina echinobothrida, R. tetragona, and R. cesticillus. Co-infection diagnosis of these tapeworms using morphological analysis can be performed, but this is time-consuming and complicated. Therefore, this study aimed to develop a triplex PCR for the detection and discrimination of three Raillietina species. The triplex PCR assay specifically amplified target DNAs with no inter-specific interference and produced a specific band for each species. According to the specificity test, there was no cross-amplification with the DNA template of related parasites and their hosts. The lowest detectable DNA concentrations were evaluated and provided sensitivities of 0.5 pg/µL for R. echinobothrida, 5 pg/µL for R. tetragona, 50 fg/µL for R. cesticillus, and 5 pg/µL for the combination of DNA from all three species. Simultaneous detection limits of egg capsules and gravid proglottids was also performed, with and without feces. The interference of feces in the reaction was related to a decrease in sensitivity, but simultaneous detection of three Raillietina species in amounts lower than one gravid proglottid and ten egg capsules was still successful. Thus, this study is the first triplex PCR assay for Raillietina detection and can be utilized as an alternative diagnostic tool for the detection and discrimination of R. echinobothrida, R. tetragona, and R. cesticillus infection in poultry through the verification of fecal specimens. In addition, it could improve the performance of specific treatments and promote veterinary healthcare.
Assuntos
Cestoides , Infecções por Cestoides , Doenças das Aves Domésticas , Animais , Cápsulas , Cestoides/anatomia & histologia , Infecções por Cestoides/diagnóstico , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , Galinhas/parasitologia , Reação em Cadeia da Polimerase Multiplex , Aves Domésticas , Doenças das Aves Domésticas/diagnósticoRESUMO
Rodents are hosts of a wide diversity of cestodes. Fifteen genera included in the family Hymenolepididae parasitize rodents, and only four of these genera have been recorded from the Neotropical region. The purpose of this paper is to update species of Hymenolepididae from rodents, describe a new species of Hymenolepis based on morphological and molecular characterization (ITS1 rDNA and cox1 mtDNA), comparing the features among the species from North and South American rodents, and provide phylogenetic inferences of Hymenolepididae from rodents based on sequences available in the GenBank. Rodents were collected in the Parque Provincial Ernesto Tornquist, Buenos Aires, Argentina. Hymenolepis ivanovae n. sp. differs from other Hymenolepis species registered from North and South American rodents by body size, scolex, suckers, cirrus sac, cirrus, testes, and eggs, among others. Comparative morphometric data for Hymenolepis species from North and South American rodents is provided. Molecular analyses place H. ivanovae n. sp. within the genus Hymenolepis with strong support, and show it close to species of zoonotic importance. The new species is the first species of Hymenolepis described from Sigmodontinae rodents.
Assuntos
Asteraceae , Cestoides , Infecções por Cestoides , Hymenolepis , Animais , Cestoides/anatomia & histologia , Hymenolepis/anatomia & histologia , Hymenolepis/genética , Filogenia , Roedores , América do SulRESUMO
To avoid confusions related to the resurrection of AdenocephalusNybelin, 1931 (Cestoda: Diphyllobothriidea), the type material of the Pacific broad tapeworm, Adenocephalus pacificusNybelin, 1931, which also infects humans, is morphologically characterized. Transverse protuberances on the ventral side of proglottids anterior to gonopores, which are a diagnostic feature of the genus, are illustrated for the first time. The present study supports the importance of a study of type material even in the 'molecular era' of taxonomy, where the value of morphology is often underestimated. It also points out the need for specimen deposition in publicly accessible collections.
Assuntos
Cestoides/classificação , Animais , Cestoides/anatomia & histologia , Humanos , MuseusRESUMO
Acanthobothrium is the most speciose genus of onchoproteocephalidean cestodes, whose adults parasitize the intestine of elasmobranch fishes. Acanthobothrium coronatum, the type species of the genus described from Mediterranean elasmobranchs, remains a little known parasite, with the most recent reports dating back to the fifties. We hereby investigate host-specificity and redescribe A. coronatum from the same locality of its original description by using light and scanning electron microscopy approaches. Moreover, molecular and phylogenetic data inferred from the analysis of the 28S rDNA gene are reported for the first time. Out of the nine elasmobranch species examined from Gulf of Naples, we only detected A. coronatum in the intestine of Scyliorhinus stellaris, with infection patterns that supports evident host-specificity for this shark species. The genetic characterization of 28S rDNA showed 99.8-100% similarity with larvae previously found in Octopus vulgaris from the same area investigated here. Conspecificity between the present material and the larvae found in the octopus was also confirmed by the tree topology. The host-parasite phylogeny is discussed, even if additional molecular data are needed to clarify potential host-parasite patterns. Notwithstanding this limitation, this is the first molecular study revealing conspecificity between an adult Acanthobothrium species from a shark and the larvae found in an intermediate/paratenic host, shedding light on the transmission pathway of A. coronatum in S. stellaris. Finally, the taxonomic, molecular, and phylogenetic data presented here allow a better characterization of a neglected parasite.
Assuntos
Cestoides/fisiologia , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Tubarões , Animais , Cestoides/anatomia & histologia , Cestoides/genética , Infecções por Cestoides/patologiaRESUMO
Specimens representing two new species of Guidus Ivanov, 2006 were collected from the Magellan skate (Bathyraja magellanica [Philippi]) in the Patagonian Continental Shelf of Argentina, Southwestern Atlantic Ocean. Guidus francoi sp. n. and Guidus magellanicus sp. n. differ from their congeners by a particular combination of features, including type of bothridia, worm length, number of testes, and distribution of vitelline follicles. Guidus francoi sp. n. is distinguished from G. magellanicus sp. n. by having fewer proglottids, fewer testes and a higher ratio between the cirrus sac length and the proglottid width. The microthrix pattern of species of Guidus from the Southwestern Atlantic is described, based on specimens of G. francoi sp. n., Guidus magellanicus sp. n., and newly collected specimens of Guidus argentinense Ivanov, 2006. These three species share the presence of wide aristate gladiate spinitriches on the proximal bothridial surface, narrow gladiate spinitriches on the bothridial rim, and filitriches on the distal bothridial surface. The diagnosis of Guidus is revised to include several features exhibited by the new species (i.e., presence of bothridial indentations and bothridial stalks, distribution of vitelline follicles, and eggs grouped in cocoons). The discovery of G. francoi sp. n. and G. magellanicus sp. n. from B. magellanica increases the number of species of Guidus collected from batoids in the Southwestern Atlantic from one to three. The specificity exhibited by the species herein described reinforces the tight association between rays in the genera Guidus and Bathyraja.
Assuntos
Cestoides/classificação , Infecções por Cestoides/veterinária , Doenças dos Peixes/epidemiologia , Rajidae , Animais , Cestoides/anatomia & histologia , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/parasitologia , Doenças dos Peixes/parasitologia , PrevalênciaRESUMO
A new genus, Megancestus n. gen., is proposed to accommodate the caryophyllidean tapeworm Biacetabulum carpiodi Mackiewicz, 1969 from carpsuckers and quillback (Carpiodes spp.) in North America. This species is not closely related to other species of Biacetabulum Hunter, 1927 and is transferred to a newly erected genus. This new genus is typified by the possession of a small body (total length of 3.1-7.5 mm) with a scolex that bears a pair of large acetabulum-like loculi, two pairs of shallow lateral loculi, and a slightly convex apical disc, testes arranged in one or two layers, oval, thick-walled cirrus-sac, well-developed external seminal vesicle, separate gonopores, H-shaped ovary, few median vitelline follicles, and the uterus extending by a single loop anterior to the cirrus-sac. Megancestus differs from all Nearctic caryophyllidean genera (family Capingentidae), including Biacetabulum, by vitelline follicles dorsal to the ovary that connect the preovarian and postovarian vitelline fields. The most closely related Hunterella Mackiewicz et McCrae, 1962 differs by shape of the scolex (tholate, i.e., devoid of any loculi), dumbbell-shaped ovary and the uterus not extending anterior to the cirrus-sac. Megancestus carpiodi (Mackiewicz, 1969) n. comb. is the only species of the genus and it is a stenoxenous parasite, which has been found only in the river carpsucker (Carpiodes carpio-type host), quillback (Carpiodes cyprinus) and highfin carpsucker (Carpiodes velifer) (Catostomidae: Ictiobinae) in the lower and middle Mississippi basin.