ABSTRACT A new species of the Copionodontinae genus Copionodon is described from riacho do Mosquito, tributary to rio Santo Antônio, Paraguaçu basin in Diamantina Plateau, Bahia State, northeastern Brazil. This represents northernmost occurrence subfamily yet known and a relictual population, apparently restricted an underground sector stream its immediate downstream exit. The can be readily recognized by combination presence opercular odontodes, mostly uniform coloration body, lack free...

A new species of Cetopsis is described from Guiana Shield drainages in Guyana and Suriname. The found the Konawaruk River tributaries, Essequibo basin, Guyana, Mauritie Creek, tributary to Tempati River, upper Commewijne taxon can be distinguished all congeners by a combination features: dark spots on sides body eye-sized or larger, dark, bilobed patch at base caudal fin, absence humeral spot, pigmentation along fin-membrane posterior first dorsal-fin ray, dorsal extending ventrally bases...

The gross morphology of the brain pseudopimelodid Pseudopimelodus bufonius is described and compared with congeners. Observations were made on removed brains after elimination bones from top skull severing cranial nerves spinal cord. Nine morphometric characters associated major subdivisions identified, seven which revealed significant differences among species examined. corpus cerebelli in all examined genus largest structure brain. behavior still unknown, but other teleosts that condition...

Among the order Characiformes, secondary sexual dimorphism is commonly associated to occurrence of bony hooks on fins, shape and length dorsal anal dichromatism. The analysis a new miniature Characidae species genus Tyttobrycon, described herein, yielded discovery sexually dimorphic trait related nostril aperture number olfactory lamellae. In this type dimorphism, mature males present larger higher lamella than females. A organ for first time recorded member Characiformes. Gross morphology...

The Neotropical catfish family Pseudopimelodidae includes seven genera and 50 valid species, widely distributed in South America. To address the lack of comparative information on siluriform brains, gross morphology major brain subdivisions is described, illustrated interpreted. A comprehensive comparison based shape, relative size position main presented for representative species all family. Comparisons with other phylogenetically related families, Pimelodidae Heptapteridae, non-related...

This study presents a list of species from igarapés tributaries the rio Acre, Acre State, Brazil. Fish assemblages were sampled in October 2009, August and 2010, using standard ichthyological gear, along fifteen sampling sites. A total 11,395 specimens, distributed 94 species, 24 families six orders collected. The most species-rich Characiformes with 45 (48.4%) Siluriformes 33 (34.7%); which Serrapinnus gr. microdon (22.4%), Otocinclus vittatus (20.4%), Phenacogaster pectinatus (10.9%),...

The lack of knowledge on the distribution and taxonomy ichthyofauna from coastal Atlantic Rainforest Santa Catarina state, Brazil, is noteworthy. This study presents a rapid but comprehensive survey fish species hydrographic regions Catarina. samples were conducted in October 2012, 19 sampling sites five regions, using sieves, seine nets, throw nets. A total 1,878 individuals belonging to 51 distributed 16 families are reported; four freshwater represent novelties for region. Characidae...

We advance on the knowledge of Eigenmanniinae by proposing a hypothesis phylogenetic relationships based parsimony analysis diverse set 144 anatomical characters, 12% them treated as quantitative and 88% qualitative (8% external morphology, 51% osteology, 21% myology, 8% neuroanatomy). Thirty-seven 45 valid species are examined in study, including incertae sedis "Eigenmannia" goajira. The final tree yields new insights relationships, thus, producing classification to Eigenmanninae. Our...

A new species of Hyphessobrycon is described from the Rio Juma, a tributary lower Aripuanã–Rio Madeira basin, Amazonas, Brazil. platyodus can be distinguished its congeners by the: presence an elongated dorsal fin in adult males, 25–28 branched anal‐fin rays and absence dark blotches caudal peduncle. The multicuspid teeth Characidae relation with feeding habits are briefly commented on.

The southern region of Brazil is characterized by high species diversity and endemism freshwater fishes distributed across geographically isolated river basins. Microglanis cottoides has a widespread range these basins occurs in sympatry with other endemic the genus (e.g. M. cibelae, eurystoma, malabarbai). Herein we tested monophyly presented for first time information about molecular phylogeny genus. results suggest that currently forms non-monophyletic group which includes populations to...

Abstract Lophiosilurus is a monotypic genus represented by L. alexandri, species endemic to the São Francisco river basin, Brazil. In previous phylogenetic analyses, has been recovered as sister group of Cephalosilurus. However, few Cephalosilurus or characters were included in those studies. Thus, current study aims test monophyletic hypothesis genera and with more comprehensive analysis, including all representative number characters. Phylogenetic analyses 18 terminal taxa (15 ingroups...

Abstract The gross brain morphology and the peripheral olfactory organ of Microglanis garavelloi are described throughout development, relationship these organs to general behaviour species is discussed. During main subdivisions undergo a series morphological changes keeping relatively constant volume increase. However, we observed different growth rates in brains males females when were compared. maturation process, hormonal events result development some secondary sexual traits male...

Cetopsis varii sp. nov. Cetopsidae (Cetopsinae) is described from the Río Meta basin in eastern Colombia, at middle portions of Orinoco basin. The new species differs congeners by a combination features: absence humeral spot, presence eye, conical teeth on vomer and dentary rounded posterior nares, along with details body, dorsal caudal-fin pigmentation. osteology investigated through high-resolution X-ray computed tomography cleared stained specimens. Data thus obtained are used to code for...

The brain gross morphology of Rhamdia quelen is described and compared with seven species six genera Heptapteridae. Interspecific variation in shape, size, position subdivisions was observed all examined species. posterior the hypophysis on hypothalamus presence a lateral subdivision lobus facialis are shared by heptapterids. Pimelodella gracilis, currently considered closely related within family Heptapteridae, exhibit anterior area telencephalon equivalent widths, line lobe reaching vagi....