Morphological descriptions of the nymph and adults of Ornithodoros clarki, the larva and nymph of Ornithodoros rondoniensis, with notes on their phylogenetic relationships.

Based on tick specimens collected recently in Mexico, Nicaragua, Panama and Brazil, we provide morphological descriptions of the nymph and adults of Ornithodoros clarki Jones & Clifford, 1972 from the first three countries, and the larva and nymph of Ornithodoros rondoniensis (Labruna, Terassini, Camargo, Brandão, Ribeiro & Estrada-Peña, 2008) from Brazil. Also, an analysis of mitochondrial 16S rDNA sequences was performed to analyze the phylogenetic relationships of these tick species. Adults and nymphs of O. clarki and O. rondoniensis are unique among the Argasidae family by presenting exceptionally large spiracular plates with small goblets, and an integument with smooth polygonal mammillae. However, these two species are morphologically distinct based on specific patterns of coxal folds, idiosomal mammillae and pilosity, and female genital flap. In contrast, the larvae of O. clarki and O. rondoniensis are morphologically identical, except for a general larger size of the former species; this slight difference is corroborated by Principal Component Analysis (PCA) by using 40 morphometric variables. Phylogenetic analyses including 16S rDNA partial sequences of different Ornithodoros taxa from Central and South America indicate that O. rondoniensis from Brazil diverges from O. clarki from Mexico, Nicaragua and Panama. However, phylogenetic distance separating both alleged species is similar or slightly lower than the distances depicted for conspecific populations of a few other Ornithodoros species. Nonetheless, our primary criterion to maintain O. rondoniensis as a valid species is because its adult and nymphal stages do present distinct morphological traits that easily distinguish these postlarval stages from O. clarki.

Reassessment of the taxonomic status of Amblyomma cajennense () with the description of three new species, Amblyomma tonelliae n. sp., Amblyomma interandinum n. sp. and Amblyomma patinoi n. sp., and reinstatement of Amblyomma mixtum, and Amblyomma sculptum (Ixodida: Ixodidae).

A reassessment of the taxonomic status of Amblyomma cajennense based on the morphological analyses of ticks from the whole distribution area of the species resulted in the redescription of A. cajennense, the validation of 2 species which had been reduced to synonymy in the past, Amblyomma mixtum and Amblyomma sculptum, and the description and definition of 3 new species, Amblyomma tonelliae n. sp., Amblyomma interandinum n. sp., and Amblyomma patinoi n. sp. This study provides descriptions and redescriptions, scanning electron microscopic and stereomicroscopic images, updated synonymies, information on geographical distributions, and host associations for each of the 6 species. Amblyomma cajennense s.s. is found in the Amazonian region of South America, A. interandinum is reported from the northern part of the Inter-Andean valley of Peru, A. mixtum is present from Texas (U.S.A.) to western Ecuador, A. patinoi occurs in the Eastern Cordillera of Colombia, A. tonelliae is associated with the dry areas of the Chaco region which spans from central-northern Argentina to Bolivia and Paraguay, whereas A. sculptum is distributed from the humid areas of northern Argentina, to the contiguous regions of Bolivia and Paraguay and the coastal and central-western states of Brazil.

Revalidação de Cathorops arenatus e Cathorops agassizii (Siluriformes, Ariidae), bagres marinhos das regiões norte e nordeste da América do Sul

Nominal species from north and northeast South America, traditionally recognized in the literature as synonymous of Cathorops spixii (Agassiz, 1829), have their specific status redefined. Type specimens of Arius arenatus Valenciennes, 1840, Arius fissus Valenciennes, 1840, Tachisurus agassizii Eigenmann & Eigenmann, 1888 and Arius pleurops Boulenger, 1897 were examined. Cathorops arenatus and Cathorops agassizii are considered valid, Cathorops fissus is a junior synonym of Cathorops arenatus and Cathorops pleurops a junior synonym of Cathorops agassizii. The morphometric characters traditionally used in descriptions and keys in the family Ariidae are redefined and new characters are used.

As espécies nominais das regiões norte e nordeste da América do Sul, reconhecidas na literatura como sinônimos júnior de Cathorops spixii (Agassiz, 1829) têm seu status específico revisto. Os tipos de Arius arenatus Valenciennes, 1840, Arius fissus Valenciennes, 1840, Tachisurus agassizii Eigenmann & Eigenmann, 1888 e Arius pleurops Boulenger, 1897 foram examinados. Cathorops arenatus e Cathorops agassizii são espécies válidas, Cathorops fissus é sinônimo júnior de Cathorops arenatus e Cathorops pleurops sinônimo júnior de Cathorops agassizii. Os caracteres morfométricos tradicionalmente usados em descrições e chaves de identificação para espécies da família Ariidae são redefinidos e novos caracteres são utilizados.

Revalidação de Cathorops arenatus e Cathorops agassizii (Siluriformes, Ariidae), bagres marinhos das regiões norte e nordeste da América do Sul

Nominal species from north and northeast South America, traditionally recognized in the literature as synonymous of Cathorops spixii (Agassiz, 1829), have their specific status redefined. Type specimens of Arius arenatus Valenciennes, 1840, Arius fissus Valenciennes, 1840, Tachisurus agassizii Eigenmann & Eigenmann, 1888 and Arius pleurops Boulenger, 1897 were examined. Cathorops arenatus and Cathorops agassizii are considered valid, Cathorops fissus is a junior synonym of Cathorops arenatus and Cathorops pleurops a junior synonym of Cathorops agassizii. The morphometric characters traditionally used in descriptions and keys in the family Ariidae are redefined and new characters are used.

As espécies nominais das regiões norte e nordeste da América do Sul, reconhecidas na literatura como sinônimos júnior de Cathorops spixii (Agassiz, 1829) têm seu status específico revisto. Os tipos de Arius arenatus Valenciennes, 1840, Arius fissus Valenciennes, 1840, Tachisurus agassizii Eigenmann & Eigenmann, 1888 e Arius pleurops Boulenger, 1897 foram examinados. Cathorops arenatus e Cathorops agassizii são espécies válidas, Cathorops fissus é sinônimo júnior de Cathorops arenatus e Cathorops pleurops sinônimo júnior de Cathorops agassizii. Os caracteres morfométricos tradicionalmente usados em descrições e chaves de identificação para espécies da família Ariidae são redefinidos e novos caracteres são utilizados.