George M. T. Mattox

Revision of the Neotropical trahiras of the Hoplias lacerdae species-group (Ostariophysi: Characiformes: Erythrinidae) with descriptions of two new species

Hoplias lacerdae was originally described from the rio Ribeira de Iguape, Iporanga, Sao Paulo State. The Hoplias lacerdae group is defined as containing generally large trahiras with the medial margins of dentaries running parallel to each other and lacking teeth on the basihyal compared to the H. malabaricus group in which the medial margins of the dentaries converge towards the mandibular symphysis and which have teeth on the basihyal. A taxonomic revision of the group based on meristic and morphometric data identified five distinct species: H. lacerdae distributed in the rio Ribeira de Iguape and rio Uruguai; H. intermedius from the rio Sao Francisco, upper rio Parana basin, and rio Doce; H. brasiliensis from rivers of the Atlantic Coastal drainage from the rio Paraguacu to the rio Jequitinhonha; H. australis new species, endemic to the rio Uruguai; and H. curupira new species present in northern South America, including the rios Negro, Trombetas, Tapajos, Xingu, Tocantins and Capim in the Amazon basin, upper rio Orinoco near the rio Casiquiare (Venezuela), and coastal rivers of Guyana and Suriname. A lectotype for Hoplias intermedius and a neotype for H. brasiliensis are designated. Hoplias lacerdae foi descrita originalmente do rio Ribeira de Iguape, Iporanga, Sao Paulo. O grupo Hoplias lacerdae foi definido como um conjunto de especies para abrigar as trairas geralmente de grande porte, com as margens mediais dos dentarios dispostas paralelamente e sem dentes no basi-hial, em oposicao as trairas do grupo Hoplias malabaricus, cujas margens mediais dos dentarios convergem em direcao a sinfise mandibular e possuem dentes no basi-hial. A revisao taxonomica do grupo baseada em dados meristicos e morfometricos identificou cinco especies distintas: Hoplias lacerdae distribuida nos rios Ribeira de Iguape e Uruguai; H. intermedius no rio Sao Francisco, alto rio Parana e rio Doce; H. brasiliensis nos rios costeiros da drenagem Atlântica, desde o rio Paraguacu ate o rio Jequitinhonha; H. australis especie nova, endemica ao rio Uruguai; e H. curupira especie nova no norte da America do Sul, incluindo os rios Negro, Trombetas, Tapajos, Xingu, Tocantins e Capim na bacia Amazonica; alto rio Orinoco proximo ao rio Casiquiare (Venezuela) e rios costeiros da Guiana e Suriname. Sao designados um lectotipo para Hoplias intermedius e um neotipo para H. brasiliensis.

Para que servem os inventários de fauna

Inventarios de fauna acessam diretamente a diversidade de uma localidade, em um determinado espaco e tempo. Os dados primarios gerados pelos inventarios compoem uma das ferramentas mais importantes na tomada de decisoes a respeito do manejo de areas naturais. Entretanto, varios problemas tem sido observados em diversos niveis relacionados aos inventarios de fauna no Brasil e vao desde a formacao de recursos humanos ate a ausencia de padronizacao, de desenho experimental e de selecao de metodos inadequados. Sao apresentados estudos de caso com mamiferos, repteis, anfibios e peixes, nos quais sao discutidos problemas como variabilidade temporal e metodos para deteccao de fauna terrestre, sugerindo que tanto os inventarios quanto os programas de monitoramento devam se estender por prazos maiores e que os inventarios devem incluir diferentes metodologias para que os seus objetivos sejam plenamente alcancados.

Surface and subterranean ichthyofauna in the Serra do Ramalho karst area, northeastern Brazil, with updated lists of Brazilian troglobitic and troglophilic fishes

After an ichthyofaunistic survey in several epigean (surface) water bodies of the Serra do Ramalho, southern Bahia, conducted in May 2007, 44 species were recorded; in addition, three non-troglomorphic (normally eyed and pigmented) and two troglomorphic species were recorded only in caves, totaling 49 species of fishes for the area, which represents a little more than one fourth of the total registered in the literature for the entire Rio Sao Francisco basin. In these caves, which have been studied since 2005, eight non-troglomorphic species were sampled and their presence in both epigean and subterranean habitats, associated to the lack of morphological differences, indicate that they may be either troglophiles (species encompassing individuals able to live and complete their life cycle either in the surface or in the subterranean environment), trogloxenes (individuals regularly found in subterranean habitats, but which must return periodically to the surface in order to complete their life cycle) or even accidental in caves. In addition, two troglomorphic species (with reduced eyes and melanic pigmentation when compared to close epigean relatives), belonging respectively to the genera Rhamdia and Trichomycterus, were recorded exclusively in caves, thus classified as troglobites. Interestingly, no epigean representative of the genus Trichomycterus was collected. The new data are integrated into updated lists of Brazilian troglobitic and troglophilic fishes, based on published data and new records recently confirmed.

Priocharax nanus, a new miniature characid from the rio Negro, Amazon basin (Ostariophysi: Characiformes), with an updated list of miniature Neotropical freshwater fishes

Priocharax nanus, new species, is described from the rio Negro, Brazil. It is a miniature fish that retains as an adult the larval rayless pectoral fin, a diagnostic character of the genus. Priocharax nanus possesses fewer reductive features compared to congeners, P. ariel and P. pygmaeus, from which it can be distinguished by the presence of i,6 pelvic-fin rays ( vs. i,5), the presence of the claustrum (vs. claustrum absent) and the presence of two postcleithra (vs. postcleithra absent). An updated list of 213 species of miniature Neotropical freshwater fishes is presented. The greatest diversity among them is represented by the Characiformes with 87 miniature species. Priocharax nanus, especie nova, e descrita do rio Negro, Brasil. E um peixe miniatura que retem no adulto a forma larval da nadadeira peitoral, um carater diagnostico do genero. Priocharax nanus possui um numero menor de caracteres redutivos quando comparado aos congeneres, P. ariel and P. pygmaeus, dos quais pode ser distinguida pela presenca de i,6 raios na nadadeira pelvica (vs. i,5), presenca do claustrum (vs. claustrum ausente) e presenca de dois pos-cleitros (vs. pos-cleitros ausentes). Uma lista atualizada de 213 especies de peixes miniatura de agua doce neotropicais e apresentada. A maior diversidade entre eles e representada pelos Characiformes, com 87 especies miniatura.

Taxonomic Study of Hoplias aimara (Valenciennes, 1846) and Hoplias macrophthalmus (Pellegrin, 1907) (Ostariophysi, Characiformes, Erythrinidae)

Abstract The taxonomy of the nominal species of giant trahiras Hoplias aimara (Valenciennes, 1846) and Hoplias macrophthalmus (Pellegrin, 1907), both described from Cayenne (French Guiana), was evaluated to determine whether they constitute distinct forms and to determine the geographic distribution of the recognized species. A total of 200 specimens were examined (30–624 mm standard length). Analysis of meristic and morphometric data resulted in the recognition of a single species. Study of the type-specimens revealed that both species names, H. aimara and H. macrophthalmus, refer to the same taxon. According to the Principle of Priority of the International Code of Zoological Nomenclature the name Hoplias aimara has precedence. This species is distinguished from congeners by the presence of a vertically-elongate dark spot on the median portion of the opercular membrane and by the absence of the accessory ectopterygoid. Hoplias aimara occurs in the drainages of Rio Tocantins, Rio Xingu, Rio Tapajós, Rio Jarí, and Rio Trombetas, in coastal drainages of the Guyanas, Suriname, and state of Amapá, Brazil. In the Río Orinoco basin, the species occurs only in the Río Caroní and rivers to the east of this drainage. Literature records of Hoplias aimara for the Rio Purus and upper Río Orinoco were based on misidentifications. This pattern of geographic distribution of Hoplias aimara in rivers of the Guyanas and Brazilian Shields also occurs in other Neotropical species of fishes.

Ichthyofauna of Rio Jurubatuba, Santos, São Paulo: a high diversity refuge in impacted lands

Levantamentos ictiofaunisticos na Mata Atlântica tem sido publicados em relativamente poucos trabalhos, apesar da grande importância biologica deste bioma que, mais vasto no passado, vem rapidamente desaparecendo por causa do crescimento desordenado das populacoes humanas e super exploracao dos recursos naturais. O presente estudo objetivou acessar a fauna de peixes de uma bacia relativamente bem conservada entre as cidades de Santos e Cubatao (SP), uma area muito alterada pela atividade humana e carente de levantamentos ictiofaunisticos recentes. Coletas foram realizadas durante tres campanhas no Rio Jurubatuba, um rio costeiro de medio porte, e no Riacho Sabao, um de seus afluentes. Foram amostrados 2773 individuos pertencentes a 25 especies de 14 familias. Seis especies sao primariamente marinhas e utilizam a porcao mais alta do Rio Jurubatuba. Doze das 19 especies de agua doce sao endemicas da Mata Atlântica e quatro estao relacionadas em listas regionais de especies ameacadas. Apenas cinco especies ocorreram no Rio Jurubatuba e Riacho Sabao concomitantemente. A familia mais diversa foi Characidae, seguida de Poeciliidae, Rivulidae e Heptapteridae. Phalloceros caudimaculatus foi a especie mais abundante, seguida de Poecilia vivipara e Geophagus brasiliensis. A area de estudo e considerada bem preservada e por causa de sua localizacao critica, necessita de politicas conservacionistas para proteger sua diversidade de peixes.

Atherinella blackburni (Schultz, 1949) at Itamambuca Beach, Ubatuba, SP: ecological characterization and distribution on the Brazilian coast (Teleostei: Atheriniformes: Atherinopsidae)

Atherinella blackburni is a silverside species whose occurrence on the Brazilian coast was not properly registered until recently. So far, records of its distribution along the Brazilian shore were limited to Itaparica Island, Bahia State, and Porto Inhaúma, Rio de Janeiro State. In a recent survey of the ichthyofauna of Itamambuca Beach, Ubatuba, São Paulo State, 100 specimens of this species were collected, yielding a considerable source of information regarding its ecology and a new southern limit of its distribution. A detailed survey of an ichthyological collection revealed lots of this species from regions of the Brazilian Northeast, resulting in a northward expansion of the occurrence of A. blackburni in Brazilian waters. Besides the populations found on the Brazilian coast, the species also occurs discontinuously in the Atlantic coasts of Costa Rica, Panama and Venezuela. Meristic and morphometric analysis showed overlapped values between Brazilian populations and the ones closer to the Caribbean. An ecological study of A. blackburni at Itamambuca Beach revealed that it is a predominantly diurnal species with preference for warm and salty waters, often occurring in sandy-bottom environments. It was more abundant in Summer and Winter, when individuals with smaller values of length and weight also occurred.

Taxonomic study of Hoplias microlepis (Günther, 1864), a trans-Andean species of trahiras (Ostariophysi: Characiformes: Erythrinidae)

The Hoplias malabaricus species group represents one of the most complexes taxonomical problems in the systematics of Neotropical fishes, including specimens widely distributed in most drainages of South America and part of Central America with great variation or overlap of putative diagnostic characters. The large number of nominal species, many of which without known type material, renders the problem more complicated. Currently, at least three nominal species can be included in the Hopliasmalabaricusspecies group based on the form of the medial margins of dentaries and presence of tooth plates on the tongue: Hoplias malabaricus, H. teres, and H. microlepis, the latter representing the only exclusively trans-Andean known species of the genus. We present herein a taxonomic study of Hoplias microlepis based on examination of syntypes and recently collected specimens, including a redescription of the species. Hoplias microlepisoccurs in the Pacific drainages of Panama and Southwestern Costa Rica, in addition to the rio Guayas basin in Ecuador and the region near its mouth (rio Tumbes, Northwestern Peru). Records of the species on the Atlantic coast of Panama are restricted to the Canal Zone, suggesting dispersal through the Panama Canal. We also designate lectotype and paralectotypes.

Headwater stream fish fauna from the Upper Paranapanema River basin

The Parana River basin has about 600 fish species. In the Upper Parana, 310 fish species were recorded, with 52 species were registered in the streams and headwaters of the Paranapanema River. The aim of this study was to characterize the stream fish communities in the Upper Paranapanema River basin. Samplings were conducted with electrofishing during the dry season in the year of 2014. The collection effort consisted of 30 streams stretches. As a result, 41 species of stream fish were recorded in the Upper Paranapanema River basin, distributed in 26 genera, 11 families and 7 orders. Thirty-nine percent of the species can be considered rare, 41% intermediate and 20% common. We captured approximately eight species by stream stretch and the estimated richness (Schao2) was 40 ± 6 species. Around 40% of the individuals had less than 50 mm in length.

Ontogenetic development of heterocharax macrolepis eigenmann (Ostariophysi: characiformes: characidae) with comments on the form of the yolk sac in the heterocharacinae

Fishes in early developmental stages frequently have morphological features that differ from those of adult stages, and many characters found later in ontogeny are not available in initial stages. Hence, morphological descriptions of early stages are useful to provide information for the identification of eggs and larvae, a knowledge still restricted among Neotropical fishes. We studied the development of Heterocharax macrolepis, a heterocharacine whose adult specimens from the aquarium trade were kept and spawned at around 23-24oC. A developmental series of 51 specimens was preserved, ranging from 3.2 mm notochord length to 18.6 mm standard length, covering approximately the first 73 days post-hatching. We described the development of main morphological features emphasizing those useful in the identification of H. macrolepis larvae (i.e., appearance of preopercle spine and development of the pseudotympanum). We also compared H. macrolepis with photographs taken of live larval specimens of Gnathocharax steindachneri, recently included in the Heterocharacinae. Both species have a yolk sac with a small rounded projection directed posteroventrally. Although this information is not yet available for all pertinent taxa, the different yolk sac shape in other representatives of the Characiformes may indicate that this peculiar yolk sac represents an additional synapomorphy of the Heterocharacini. Peixes em estagios iniciais de desenvolvimento frequentemente apresentam caracteristicas morfologicas distintas dos adultos e muitos caracteres presentes em estagios avancados nao sao disponiveis em estagios iniciais. Assim, descricoes morfologicas dos estagios iniciais de desenvolvimento de peixes sao uteis por fornecerem subsidios para a identificacao de ovos e larvas, um conhecimento ainda escasso entre peixes Neotropicais. Estudamos o desenvolvimento de Heterocharax macrolepis, especie de Heterocharacinae cujos exemplares adultos provenientes do aquarismo foram mantidos e reproduzidos entre 23-24oC. Uma serie de desenvolvimento de 51 exemplares foi preservada, medindo entre 3,2 mm de comprimento da notocorda e 18,6 mm de comprimento padrao, incluindo os primeiros 73 dias pos-eclosao. Descreveram-se detalhadamente os principais aspectos morfologicos, enfatizando caracteristicas uteis na identificacao de larvas de H. macrolepis (i.e., surgimento do espinho do preoperculo, desenvolvimento do pseudotimpano). Comparamos H. macrolepis com fotografias de larvas vivas de Gnathocharax steindachneri, recentemente incluida em Heterocharacinae. Ambas especies possuem saco vitelinico com pequena projecao arredondada postero-ventral. Ainda que a informacao nao esteja disponivel para os taxons pertinentes, o distinto formato do saco vitelinico em outras linhagens de Characiformes pode indicar que esta forma do saco vitelinico peculiar represente sinapomorfia adicional de Heterocharacini.