Regobothrium microhamulinum n. gen. and n. sp. (Bothriocephalidea: Bothriocephalidae) is proposed to accommodate a new cestode from flatfish Catathyridium jenynsii (Chabanaud, 1922) (Pleuronectiformes: Acharidae; type host) and another 3 freshwater fishes of the orders Characiformes, Cyprinodontiformes, and Siluriformes in the Neotropical Region. The new genus is placed in the Bothriocephalidae because it possesses medioventral uterine and mediodorsal genital pores and a follicular vitellarium. Regobothrium n. gen. is characterized by possessing a tiny, slightly subovate scolex narrower than the strobila, with an apical disc armed with 2 semicircles of 15-17 tiny hooks in each and an acraspedote strobila. Regobothrium n. gen. differs from all bothriocephalid cestodes that have a scolex armed with hooks by their small size (maximum length less than 20 μm) and a triangular shape with the basal part (handle or basal plate) shorter than the distal coniform part (blade). In the other hooked bothriocephalids, hooks have a longer handle than a blade. Regobothrium microhamulinum n. gen. and n. sp. is the third bothriocephalidean cestode described from freshwater teleosts in South America but the first out of Patagonia. Molecular phylogenetics consider Regobothrium as a member of a lineage consisting of (up to now exclusively) freshwater bothriocephalids from the Ethiopian biogeographic region, thus indicating Gondwanan relationship.
- MeSH
- Cestoda anatomie a histologie klasifikace ultrastruktura MeSH
- Characiformes parazitologie MeSH
- Cyprinodontiformes parazitologie MeSH
- fylogeneze MeSH
- mikroskopie elektronová rastrovací MeSH
- nemoci ryb parazitologie MeSH
- platýsi parazitologie MeSH
- sladká voda MeSH
- sumci parazitologie MeSH
- tropické klima MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Brazílie MeSH
- Etiopie MeSH
- Jižní Amerika MeSH
During investigations of gill ectoparasites (Platyhelminthes) parasitising freshwater fish from Central America (Guatemala, Honduras, El Salvador and Panama) and southeastern Mexico (Guerrero, Oaxaca and Chiapas), the following dactylogyrid monogenoidean were found: Urocleidoides simonae sp. n. from Profundulus punctatus (Günther) (type host), Profundulus balsanus Ahl, Profundulus guatemalensis (Günther), Profundulus kreiseri Matamoros, Shaefer, Hernández et Chakrabarty, Profundulus labialis (Günther), Profundulus oaxacae (Meek), Profundulus sp. 1 and Profundulus sp. 2 (all Profundulidae); Urocleidoides vaginoclaustroides sp. n. from Pseudoxiphophorus bimaculata (Heckel) (type host) and Poeciliopsis retropinna (Regan) (both Poeciliidae); and Urocleidoides vaginoclaustrum Jogunoori, Kritsky et Venkatanarasaiah, 2004 from P. labialis, Profundulus portillorum Matamoros et Shaefer and Xiphophorus hellerii Heckel (Poeciliidae). Urocleidoides simonae sp. n. differs from all other congeneric species in having anchors with well-differentiated roots, curved elongate shaft and short point. Urocleidoides vaginoclaustroides sp. n. most closely resembles U. vaginoclaustrum, but differs from this species mainly in the shape of its anchors (i.e. evenly curved shaft and short point vs curved shaft and elongate point extending just past the tip of the superficial anchor root). The complexity of potential hosts for species of Urocleidoides and their effect on its distribution on profundulid and poeciliid fishes are briefly discussed.
- MeSH
- Cyprinodontiformes * parazitologie MeSH
- Trematoda * anatomie a histologie klasifikace MeSH
- žábry parazitologie MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Geografické názvy
- Mexiko MeSH
- Střední Amerika MeSH
BACKGROUND: Parasite switches to new host species are of fundamental scientific interest and may be considered an important speciation mechanism. For numerous monogenean fish parasites, infecting different hosts is associated with morphological adaptations, in particular of the attachment organ (haptor). However, haptoral morphology in Cichlidogyrus spp. (Monogenea, Dactylogyridea), parasites of African cichlids, has been mainly linked to phylogenetic rather than to host constraints. Here we determined the position of Cichlidogyrus amieti, a parasite of species of Aphyosemion (Cyprinodontiformes, Nothobranchiidae) in the phylogeny of its congeners in order to infer its origin and assess the morphological changes associated with host-switching events. METHODS: The DNA of specimens of C. amieti isolated from Aphyosemion cameronense in Cameroon was sequenced and analyzed together with that of Cichlidogyrus spp. from cichlid hosts. In order to highlight the influence of the lateral transfer of C. amieti on the haptoral sclerotised parts we performed a Principal Component Analysis (PCA) to compare the attachment organ structure of C. amieti to that of congeners infecting cichlids. RESULTS: Cichlidogyrus amieti was found to be nested within a strongly supported clade of species described from Hemichromis spp. (i.e. C. longicirrus and C. dracolemma). This clade is located at a derived position of the tree, suggesting that C. amieti transferred from cichlids to Cyprinodontiformes and not inversely. The morphological similarity between features of their copulatory organs suggested that C. amieti shares a recent ancestor with C. dracolemma. It also indicates that in this case, these organs do not seem subjected to strong divergent selection pressure. On the other hand, there are substantial differences in haptoral morphology between C. amieti and all of its closely related congeners described from Hemichromis spp.. CONCLUSIONS: Our study provides new evidence supporting the hypothesis of the adaptive nature of haptor morphology. It demonstrates this adaptive component for the first time within Cichlidogyrus, the attachment organs of which were usually considered to be mainly phylogenetically constrained.
- MeSH
- anatomické struktury zvířat anatomie a histologie MeSH
- biologická adaptace * MeSH
- cichlidy parazitologie MeSH
- Cyprinodontiformes parazitologie MeSH
- DNA helmintů chemie genetika MeSH
- fylogeneze * MeSH
- molekulární sekvence - údaje MeSH
- nemoci ryb parazitologie MeSH
- ploštěnci anatomie a histologie klasifikace genetika MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Kamerun MeSH
From August 2008 to July 2010, 1,471 fish belonging to the subfamily Goodeinae (representing 28 species) were collected from 47 localities across central Mexico and analyzed for helminth parasites. In addition, a database with all available published accounts of the helminth parasite fauna of goodeines was assembled. Based on both sources of information, a checklist containing all the records was compiled as a necessary first step to address future questions in the areas of ecology, evolutionary biology and biogeography of this host-parasite association. The checklist is presented in two tables, a parasite-host list and a host-parasite list. The checklist contains 51 nominal species, from 34 genera and 26 families of helminth parasites. It includes 8 species of adult digeneans, 9 metacercarie, 6 monogeneans, 3 adult cestodes, 9 metacestodes, 1 adult acanthocephalan, 1 cystacanth, 6 adult nematodes and 8 larval nematodes. Based on the amount of information contained in the checklist, we pose that goodeines, a subfamily of viviparous freshwater fishes endemic to central Mexico, might be regarded as the first group of wildlife vertebrate for which a complete inventory of their helminth parasite fauna has been completed.
- MeSH
- cizopasní červi klasifikace MeSH
- Cyprinodontiformes parazitologie MeSH
- helmintózy zvířat parazitologie MeSH
- kontrolní seznam MeSH
- nemoci ryb parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Mexiko MeSH
