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We report the first record of a species of Pareiorhaphis in the Manhuaçu River basin, an affluent to the right bank of the middle Doce River drainage in eastern Brazil. The description is based on a series of specimens recently collected and also on historical samples. All specimens were obtained from habitats with very strong water current running over flat bedrock. The new species is readily diagnosed from congeners by features related to the distinct morphology of lower lip papillae, unique pattern of plates covering the pectoral girdle between insertions of pectoral fins, and the lack of a maxillary barbel. In addition, the combination of longer snout, smaller orbital diameter, shape of the pectoral-fin spine, low number of dentary teeth, and lack of a dorsal-fin spinelet also distinguishes the new species from all species of Pareiorhaphis. The new species is further compared to Pareiorhaphis nasuta, P. scutula, P. proskynita, and P. vetula, congeners from the Doce River basin, and hypothesized to have traits that represent important adaptations for living in torrential habitats. [ABSTRACT FROM AUTHOR]

A new species of Parotocinclus is described from the Rio Mamanguape basin, in the State of Paraíba, north‐eastern Brazil. The new species can be distinguished from all of its congeners, except for P. bahiensis, P. cesarpintoi, P. jumbo, P. nandae and P. spilosoma, by the presence of an abdomen covered by a few small and dispersed platelets (vs. an abdomen entirely covered by large plates in adult individuals or the absence of plates in that region). The new species differs from those mentioned above with respect to several features, such as an exposed pectoral girdle and supporting odontodes medially and laterally, the number of premaxillary and dentary teeth, odontodes covering only the lateral portion of the cleithrum and the absence of irregular golden lines on the head and body (colour in vivo). The new species was collected only in the upper and middle portions of the Rio Mamanguape basin, suggesting a geographic distribution restricted to the Caatinga biome. [ABSTRACT FROM AUTHOR]

The Trichomycterinae is a diversified catfish clade exhibiting numerous ecological specializations, thus offering fine opportunities for studies on vertebrate evolution, but insufficient knowledge on phylogenetic relationships and taxonomy impedes advanced evolutionary studies. Recent studies have contributed to a better taxonomical resolution of some trichomycterine groups, but several taxa remain poorly known, with taxonomical placement still undetermined. This study is directed to two similar undescribed species with unclear generic placement, collected in the savannahs of central Brazil, in the headwaters of the two most important South American river systems, the Amazon and Paraná basins central Brazil. A multigene phylogeny integrated to a comparative osteological analysis supports a clade, with the new species forming a subclade sister to a trichomycterine subclade endemic to southern South America. The comparative osteological analysis provided some characters from the jaw suspensorium, opercular series, branchial arches, neurocranium, and pectoral girdle that are useful to diagnose members of the clade. The two species may be distinguished by meristic data, morphometrics, osteology, and colour pattern. Following recent efforts for a better understanding about diversity and relationships of trichomycterines, the present study provides phylogenetic and morphological basis for the taxonomical resolution of this important trichomycterine clade. However, much more research is necessary to improve trichomycterine taxonomy, including further studies providing a proper generic classification encompassing the whole Trichomycterinae. [ABSTRACT FROM AUTHOR]

Characidium iaquira, a new species from the upper rio Juruena, rio Tapajós basin, Brazil, is described. The new species can be promptly distinguished from all congeners by having a unique v‐shaped dark mark lying along the caudal‐fin extension, in medium‐ and large‐sized specimens, and a remarkable iridescent green colouration in life. Characidium iaquira is closely related to Characidium crandellii and Characidium declivirostre by sharing unambiguous synapomorphies such as branchiostegal membranes united to each other across the isthmus, a scaleless area extending from the isthmus to the pectoral girdle, and dermal flaps surrounding anterior and posterior naris independent, but touching each other distally. Morphological specializations of the paired fins in the three riffle‐dwellers species are discussed, including the wing‐like shape, robustness, and inclination of the pectoral fin. [ABSTRACT FROM AUTHOR]

A new species of Corumbataia is described from Rio Maranhão, Rio Tocantins basin, central Brazil. The new species is distinguished from all congeners by the presence of a small, naked area on snout tip; by having the abdomen covered with small platelets forming a shield which reaches the lateral mid-ventral plates; by the anterior profile of the head rounded in dorsal view; by the lower lip not reaching the transversal line of the pectoral girdle; and by the presence of 28 or 29 vertebrae. High genetic divergence in mitochondrial cytochrome c oxidase subunit I (COI) further supports the validity of this new species. Our phylogenetic analysis shows a derived subclade in Corumbataia, herein named as the Corumbataia cuestae group, composed of the new species plus C. cuestae, C. tocantinensis, C. britskii, C. liliai, and C. lucianoi. This group is defined by having a conspicuous crest of hypertrophied odontodes on head; absence of the adipose fin or a single series of platelets at adipose-fin position; and anastomosis of the infraorbital and otic sensory canals over the pterotic-supracleithrum. Here we also restrict the distribution of C. tocantinensis to the Rio Araguaia basin. [ABSTRACT FROM AUTHOR]

A new species of Parotocinclus from the upper Rio Paraguaçu, Bahia, Brazil, is described. The new species is distinguished from all congeners by its unique color pattern, with irregular dark blotches resulting in a somewhat marble-spotted pattern on head and trunk of most specimens and dorsum of head with a conspicuous V-shaped light mark from tip of snout to nares. The new species is also distinguished from congeners by having the lower lip elongated posteriorly and reaching or surpassing the anterior margin of cleithrum on the pectoral girdle, the canal cheek plate on the ventral surface of the head reduced and with a slightly concave margin, and abdomen covered by small embedded platelets, without contact with each other and not arranged in a line between the pectoral-fin axilla and pelvic-fin origin. The presence of a thick and rough skin in the interradial membrane of pelvic fin exclusively in the females of P. nandae is reported by the first time to occurs in Siluriformes. [ABSTRACT FROM AUTHOR]

Parotocinclus adamanteus, new species, is described from a series of specimens collected in the upper portion of the Rio Paraguaçu basin, a coastal river within the Chapada Diamantina domain, a large plateau on the State of Bahia in northeastern Brazil. The description of this new species represents the first record of a member of the Hypoptopomatinae from this relictual area. The new species is diagnosed from other Parotocinclus by having a distinct rostral border forming a fleshy intumescence on the lateral portion of head ornamented with moderately hypertrophied odontodes in adult males. It is also diagnosed from congeners by a remarkable secondary sexual dimorphism in the shape of the pelvic fin, in which the branched rays of males decrease in size, resulting in a pointed posterior fin margin (branched pelvic-fin rays in females have approximately the same size, producing a round posterior fin margin). In addition, the new species can be further distinguished from other species of Parotocinclus by lacking a rostral plate covering the tip of the mesethmoid anteriorly, by lacking abdominal plates between the pectoral girdle and the anus, by having numerous premaxillary teeth (45–61), and by having a short and mesially expanded ventral portion of the cheek canal plate. Recent phylogenetic analysis indicates that Parotocinclus adamanteus, new species, is closely related to P. jequi, P. prata, and P. robustus. [ABSTRACT FROM AUTHOR]

The parameters of muscle origin and insertion points in the pectoral girdle and forelimbs of Caiman latirostris were identified by basic anatomical, kinesiological and biomechanical approach. This identification was made with two adults males specimens of C. latirostris, on average, 1.50cm in length, belonging to the collection of the Wild Animal Research Laboratory of the Federal University of Uberlândia/MG, Brazil. In this study, isometric postures intercalated with rotary movements were found, as well as a large cross-sectional area in most of the extensor and stabilizer muscles, giving them greater strength and denoting functional and organizational inferences. Based on the findings, it was possible to recognize and predefine the behavior of the species under investigation, correlating the duration, direction and dimension of the activity levels. [ABSTRACT FROM AUTHOR]

The article aims to provide new data on the morphology of the pectoral fin and shoulder girdle in Tribodus on the basis of the undescribed material of the hybodont shark Tribodus limae, from the Lower Cretaceous of north eastern Brazil. It also aims to provide a revised reconstruction of the pectoral endoskeleton in Tribodus. The article then examines the phylogenetic relationships of Tribodus to other elasmobranch taxa based on potentially new and previously described pectoral skeletal characters.