Showing posts with label Corydoras. Show all posts
Showing posts with label Corydoras. Show all posts

Saturday, October 1, 2016

[Ichthyology • 2016] Corydoras hephaestus • Wrapped in Flames: A New Remarkably Colored Species (Teleostei: Callichthyidae) from the Rio Madeira basin, Rondônia State, Brazil


Corydoras hephaestus 
Ohara, Tencatt & Britto, 2016

Abstract

A new species of Corydoras is described from the upper Rio Machado, Rio Madeira basin, Rondônia State, Brazil. The new species can be distinguished from its congeners by the absence of contact between the posterior process of the parieto-supraoccipital and the nuchal plate; a ventral laminar expansion of the infraorbital 1 conspicuously developed; and the posterior margin of the pectoral-fin spine with serrations along almost of its entire length, only lacking in the distal portion. Additionally, Corydoras hephaestus possesses dorsal and pectoral spines short, and exhibits an unusual color pattern in life. The conservation status of the new species and other endemic species are briefly commented.

Keywords: Pisces, Amazon, Corydoradinae, Fish, Endemism, Conservation





Etymology. The specific epithet hephaestus is from the Greek, Ἥφαιστος (or Hēphaistos), the Greek god of fire, metalworking, forges, and blacksmiths. Alluding to the red color of the body and fins. A noun in apposition.


Ohara, Willian M., Luiz F. C. Tencatt & Marcelo R. Britto. 2016. Wrapped in Flames: Corydoras hephaestus, A New Remarkably Colored Species from the Rio Madeira basin (Teleostei: Callichthyidae). Zootaxa. 4170(3): 539–552. DOI: 10.11646/zootaxa.4170.3.7

    

Sunday, July 31, 2016

[Ichthyology • 2016] Corydoras zawadzkii • A New Long-snouted Species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin, Brazil


Corydoras zawadzkii  
Tencatt & Ohara, 2016 
DOI: 10.11646/zootaxa.4144.3.9

Abstract

A new species of Corydoras is described from the rio Aripuanã, rio Madeira basin, Mato Grosso State, Brazil. The new species can be distinguished from its congeners by the presence of the following features: long mesethmoid, with anterior tip well developed, conspicuously larger than 50% of bone length; posterior margin of dorsal-fin spine with serrations directed towards tip of spine; one to two longitudinal black stripes on flanks; absence of a black blotch across the eyes (mask); absence of a large black blotch on dorsal fin; and transversal black bars on caudal fin. Comments on endemism in interfluvial region between Madeira and Tapajós rivers are briefly discussed.

Keywords: Pisces, Neotropical region, Amazon, fish, Corydoradinae, taxonomy





  Luiz Fernando Caserta Tencatt and Willian Massaharu Ohara. 2016. A New Long-snouted Species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin. Zootaxa. 4144 (3): 430-442. DOI: 10.11646/zootaxa.4144.3.9

[Ichthyology • 2016] Corydoras brittoi & C. pavanelliae • Two New Species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin, Brazil


Corydoras brittoi C. pavanelliae
Fernando Tencatt & Ohara, 2016

ABSTRACT

Two new species of Corydoras are described from the rio Madeira basin, Brazil. The intermediate long-snouted new species can be distinguished from its congeners by presenting the following combination of features: posterior margin of dorsal-fin spine with laminar serrations directed towards the origin of the spine; presence of two longitudinal black stripes on flanks; anterior portion of dorsal fin with sparse black chromatophores, not forming any conspicuous pattern; absence of a conspicuous black marbled coloration pattern on head; black spots on caudal fin, some spots arranged, forming transversal bars; and brownish dorsal-fin spine. The short-snouted new speciescan be distinguished from its congeners by the following combination of features: short mesethmoid; posterior laminar expansion of infraorbital 2 very reduced, not in contact with compound pterotic; two or three longitudinal black stripes on flanks; absence of an oblique or vertical black blotch across the eye; anterior portion of dorsal fin with sparse black chromatophores, not forming any conspicuous pattern; and ventral surface of trunk naked or covered by sparse platelets.

Key words: Amazon; Corydoradinae; Mato Grosso; rio Aripuanã; Taxonomy


Corydoras brittoi, new species

Distribution. The new species is known from the rio Aripuanã basin, Mato Grosso State (Fig. 5).

Ecological notes. The type locality of Corydoras brittoi is located at 110 meters above sea level, and is a small clear water stream, with 2-3 m width and 0.5-2 m depth, with preserved riparian vegetation, swift water current, and bottom composed mainly of sand and dead leaves. Specimens of C. brittoi were observed at night during capture at shallow portions of the stream in small groups (5-15 individuals), and sometimes associated with a other new species described below.

Etymology. Corydoras brittoi is named in honor of Marcelo Ribeiro de Britto, a dear friend and mentor, for his extensive contributions to the taxonomy and systematics of the Corydoradinae. A genitive.


Corydoras pavanelliae, new species

Distribution. The new species is known from its type-locality, a tributary to the rio Aripuanã, Mato Grosso State (Fig. 5).

Ecological notes. The only known specimens of Corydoras pavanelliae were collected among C. brittoi specimens. For notes on its ecology, see Ecological notes of C. brittoi.

Etymology. Corydoras pavanelliae is named in honor of Carla Simone Pavanelli, advisor of the first author and dear friend, for her extensive contributions to the knowledge of the ecology and taxonomy of the Neotropical fishes. A genitive.




Luiz Fernando Caserta Tencatt and Willian Massaharu Ohara. 2016. Two New Species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin, Brazil. Neotrop. ichthyol. 14(1);  DOI: 10.1590/1982-0224-20150063 

RESUMO: Duas espécies novas de Corydoras são descritas da bacia do rio Madeira, Brasil. A espécie nova de focinho longo intermediário pode ser distinguida de suas congêneres por apresentar a seguinte combinação de características: margem posterior do espinho da nadadeira dorsal com serrilhas laminares direcionadas para origem do espinho; presença de duas faixas pretas longitudinais nos flancos; porção anterior da nadadeira dorsal com cromatóforos pretos esparsos, sem formar nenhum padrão conspícuo; ausência de um padrão de coloração marmoreado de preto conspícuo na cabeça; manchas pretas na nadadeira caudal, algumas delas alinhadas, formando barras transversais; e espinho dorsal amarronzado. A espécie nova de focinho curto pode ser distinguida de suas congêneres por apresentar a seguinte combinação de características: mesetmóide curto; expansão laminar posterior do infraorbital 2 muito reduzida, sem contato com o pterótico composto; duas ou três faixas pretas longitudinais nos flancos; ausência de uma mancha preta oblíqua ou vertical através do olho; porção anterior da nadadeira dorsal com cromatóforos pretos esparsos, sem formar nenhum padrão conspícuo; e superfície ventral do tronco nua ou coberta por plaquetas esparsas.

Wednesday, March 16, 2016

[Ichthyology • 2016] Corydoras eversi • A New Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about C. araguaiaensis


Corydoras eversi 
 Tencatt & Britto, 2016 

A new species of Corydoras is described from the rio Araguaia basin, Goiás, Brazil. The new species can be distinguished from its congeners by presenting the following features: infraorbital 1 with very large ventral laminar expansion; infraorbital 2 contacting compound pterotic; flanks densely covered by irregular black spots; and ventral surface of trunk densely covered by coalescent relatively well-developed platelets. It is also discussed the possibility that C. araguaiaensis comprehends a complex of species.

Keywords: C65, Corydoradinae, Corydoras sp. “Guaraná”, Goiás State, Taxonomy.


Distribution. Corydoras eversi is known from its type locality, an unnamed stream tributary to the rio Araguaia (Fig. 6).

Ecological notes. The specimens examined herein were captured in a clear water stream, with sandy ground and fast flowing. After capture the specimens are light orange. This color remains in aquarium when the water conditions are adequate to its biological aspects. In the type locality of the new species no other congener were observed in syntopy (H.-G. Evers pers. comm.).

Etymology. Corydoras eversi is named in honor of Hans-Georg Evers, a dear friend and great enthusiast in the fishkeeping hobby, especially in the breeding of Corydoras species. Hans collected the specimens of C. eversi that apparently originated all the stock present in the hobby until the present day and also the specimens used herein for the description.


Luiz Fernando Caserta Tencatt and Marcelo Ribeiro de Britto. 2016. A New Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about Corydoras araguaiaensis Sands, 1990Neotropical Ichthyology. 14(1): e150062. DOI: 10.1590/1982-0224-20150062

Uma espécie nova de Corydoras é descrita da bacia do rio Araguaia, Goiás, Brasil. A espécie nova pode ser distinguida de suas congêneres por apresentar as seguintes características: infraorbital 1 com expansão laminar ventral muito grande; infraorbital 2 em contato com o pterótico composto; flancos densamente cobertos por manchas pretas irregulares e superfície ventral do tronco densamente coberta por plaquetas coalescentes relativamente bem desenvolvidas. Discute-se também a possibilidade de C. araguaiaensis compreender um complexo de espécies.