Luisa Maria Sarmento-Soares

A systematic revision of Tatia (Siluriformes: Auchenipteridae: Centromochlinae)

The auchenipterid catfish genus Tatia is revised. Twelve species are recognized including three described as new. Tatia is diagnosed by the hyomandibula elongated anterodorsally, the anal-fin base of adult males reduced in length, and the caudal peduncle laterally compressed and deep with a middorsal keel. Tatia aulopygia occurs in the Madeira river drainage and is distinguished by the reduced cranial fontanel in adults and male modified anal fin with middle rays reduced in length. Tatia boemia, known from the upper Uruguay river drainage, is distinguished by its unique color pattern with dark chromatophores on the sides of body. Tatia brunnea from river basins in Suriname and French Guiana and the Negro river drainage, Amazon basin, is recognized by its wide head and mouth and by the male modified anal fin with sharply pointed tip. Tatia dunni, from the upper Amazon basin, is recognized by its narrow head, long postcleithral process in some specimens, and body coloration with irregular blotches or stripes. Tatia galaxias, endemic to the Orinoco river basin, is distinguished by its large eye and short snout. Tatia gyrina, distributed in the upper and central Amazon basin and in northern Suriname, has a uniquely reduced mesethmoid, slightly protruding lower jaw, second nuchal plate with slightly concave lateral borders, third nuchal plate reduced, small prevomer, low number of ribs, low number of vertebrae and sexual dimorphism regarding intumescent male genital papilla. Tatia intermedia, recorded from central and lower Amazon basin, Tocantins river, and coastal drainages in Guyana, Suriname, French Guiana, and eastern Para State, Brazil, is distinguished by the short postcleithral process, small eye and long snout. Tatia neivai, from the upper Parana river , Paraguay river and upper Paraiba do Sul river basin, is distinguished by its unique vertebral count and caudal-fin coloration consisting of transverse dark bars. Tatia strigata, from central Amazon basin and Negro river, is distinguished by its horizontally striped color pattern and the modified male anal fin with middle rays reduced in length. Tatia caxiuanensis, a new species described from the Curua river, lower Amazon basin, is recognized by its wide cranial fontanel and distinctive anal fin in mature males. Tatia meesi, a new species described from the Essequibo river basin, Guyana, is distinguished from congeners by the cranial fontanel with two separate openings and thin nasal bone. Tatia nigra, a new species described from the central Amazon basin, is distinguished by its short postcleithral process, low number of vertebrae, and dark color pattern. All twelve species of Tatia are described or redescribed and a key to species is provided.

A fauna de peixes na bacia do Rio Peruípe, extremo Sul da Bahia

Hydrological richness on extreme southern Bahia contrasts with the poorly known freshwater fish fauna. It is surprising the presence of several species still undescribed. The present study is the first contribution dealing with the fish fauna of the local river basins. We herein investigate fish fauna of Rio Peruipe basin, a remarkably freshwater drainage, with a wide estuary. Eleven localities, geo-referred, were evaluated in streams and rivulets along that freshwater drainage. The employment of methodology for collecting the environmental data and the fishes made possible the description of each locality sampled, as well as the documentation of the taxonomic composition of the fish fauna. Illustrations of the collecting localities and of individuals of some representative species, in live coloration, are provided. There were found 26 species belonging to 12 families in 6 orders. Within the species sampled Trichomycterus pradensis Sarmento-Soares et al. (2005) and Microglanis pataxo Sarmento Soares et al. (2006) were recently described as new. About 48.7% of total amount of fishes caught belong to the order Siluriformes, 38.5% to Characiformes, 34.6% to Perciformes, 11.5% to Cyprinodontiformes, 7.7% to Gymnotiformes, 3.8% to Synbranchiformes, and 3.8% to Pleuronectiformes. The most frequent species in terms of constancy of occurrence were Geophagus brasiliensis (present in 82% of sampled localities), Hoplias malabaricus (64%), Astyanax cf. rivularis (55%), Poecilia vivipara (55%), Astyanax cf. lacustris (45%) and Hyphessobrycon bifasciatus (45%). Based on information about the fishes caught in each collecting locality there were estimated the richness, the diversity, the equitability and the dominance. The potential loss of microenvironments in some portions of rivers is pointed as a factor influencing on the occurrence and distribution of some species. The dominance of small sized fishes, not exceeding 150 mm CP, is associated to a high regional endemism.

Ituglanis cahyensis, a new catfish from Bahia, Brazil (Siluriformes: Trichomycteridae)

A new trichomycterid catfish of the genus Ituglanis is described from the rio Palmares, a tributary of the rio Cahy in southeast Bahia State, Brazil. Ituglanis cahyensis is distinguished from all other congeners through a combination of characters, as the supraorbital laterosensory canal branch with pores s3 and s6 present, the low count of branched pectoral fin rays, and low number of paired ribs. It is further distinguished in proportional measurements, such as elongate nasal, maxillary, and rictal barbels, and small eye diameter.

Microglanis pataxo, a new catfish from southern Bahia coastal rivers, northeastern Brazil (Siluriformes: Pseudopimelodidae)

A new pseudopimelodid catfish of the genus Microglanis, collected in small rivers at the lower and middle Peruipe, middle Jucurucu and Cahy basins, in the southeastern coast of the Bahia state, is described. The new species has a comparatively high number of anal fin proximal radials, 12, shaped as thin tubes, the last one bearing a laminar extension; a pectoral fin spine with a bony point and with a smaller number of serrations on its posterior border; seven pleural ribs and a narrow head width. We provide information on the external morphology and also on some osteological features for the new species. A key to species is presented for the coastal drainages between Rio de Janeiro and Bahia states. E descrito um novo pseudopimelodideo do genero Microglanis, coletado em riachos tributarios das bacias do baixo e medio rio Peruipe, medio rio Jucurucu e rio Cahy, na costa sudeste do estado da Bahia. A nova especie tem comparativamente um maior numero de radiais proximais da nadadeira anal, 12, em formato de finos tubos, sendo que o ultimo elemento possui uma extensao laminar; nadadeira peitoral com extremidade ossea e com pequeno numero de serrilhas no bordo posterior; sete costelas pleurais e cabeca estreita. Sao fornecidas informacoes sobre a morfologia externa bem como sobre alguns aspectos da osteologia da nova especie. E apresentada uma chave para as especies nas drenagens costeiras entre os estados do Rio de Janeiro e Bahia.

Parotocinclus arandai, a new species of hypoptopomatine catfish (Siluriformes: Loricariidae) from the upper rios Jucuruçu and Buranhém, States of Bahia and Minas Gerais, Brazil

Parotocinclus arandai, new species of the hypoptopomatine catfish, is described from small creeks in the upper rios Jucurucu and Buranhem basins, at the border of Brazilian States of Bahia and Minas Gerais. Parotocinclus arandai is distinguished from all congeners from the Atlantic coastal basins of southeastern and eastern Brazil, except Parotocinclus bahiensis, by having the branched rays and interradial membranes of the pectoral and pelvic fins unpigmented in ventral view. The new species is distinguished from most Parotocinclus species, by having a small eye, 14.8-19.3 mm HL (except P. maculicauda and P. planicauda) and by the presence of a tuft of hypertrophied odontodes on the supraoccipital (except P. cristatus and P. cesarpintoi). Parotocinclus arandai is further distinguished by having an abdomen extensively naked, with a mosaic of few rounded platelets of irregular size and distributed over the pre-anal region (except P. bahiensis, P. minutus, P. spilosoma, P. cearensis, P. cesarpintoi and P. prata). A detailed comparison with congeners on eastern Brazil hydrographical region is provided, and information on the species habitat is given.

Trichomycterus payaya, new catfish (Siluriformes: Trichomycteridae) from headwaters of rio Itapicuru, Bahia, Brazil

Trichomycterus payaya, new species, is described from tributaries to the upper rio Itapicuru basin, northern Bahia State, Brazil. The new species is distinguished from congeners by having the head rounded anteriorly in dorsal view and slightly depressed in lateral view, supraorbital pores s6 paired, opening laterally on the supraorbital sensory branch, not emerging from an epiphyseal branch, lateral process of the urohyal distally sharp and with pointed tip, interopercular patch of odontodes longer than deep, with 21-26 odontodes, small number of pleural ribs (5-6 ribs), and dorsal fin in a posterior position. This is the first record of a Trichomycterus from the semiarid region of northeastern Brazil.

First record of genus Imparfinis from a northeastern coastal Brazilian river basin: I. borodini Mees & Cala, 1989 in Rio de Contas, Bahia

Imparfinis borodini Mees & Cala, 1989 is recorded in low population abundance in the upper Parana, Tocantins and Sao Francisco river drainages according to the scientific literature and available collection data, but it has not been previously recorded from a coastal Brazilian river. Herein, the geographic range of this species is extended to the Rio de Contas basin in northeastern Brazil. This represents the first record in a coastal system. Additionally, I. borodini was captured in the middle Rio Sao Francisco at Barreiras. Both new records are the first from Bahia state, Northeastern Brazil.