[Ichthyology • 2019] Review of Ancistrus (Siluriformes: Loricariidae) from the northwestern Guiana Shield, Orinoco Andes, and Adjacent Basins with Description of Six New Species

Ancistrus patronus 

De Souza, Taphorn & Armbruster, 2019

  DOI:  10.11646/zootaxa.4552.1.1

Abstract

The Orinoco Andes and northwestern Guiana Shield (Essequibo, Orinoco, Branco, and upper Negro) were found to contain 11 species of Ancistrus, six of which are new. We additionally examine A. brevifilis from the Río Tuy of Venezuela and A. trinitatis from the island of Trinidad. The species in the region can be broken up into dorsoventrally flattened species (Ancistrus leoni new species, A. lithurgicus, and A. macropthalmus), white to yellow-dotted species (Ancistrus kellerae new species, A. nudiceps, and A. patronus new species), wide-jawed species (Ancistrus amaris new species and Ancistrus yutajae new species), and white-spotted species (A. brevifilis, A. leucostictus, A. trinitatis, A. saudades new species, and A. triradiatus). Distributions of Ancistrus support the Proto-Berbice hypothesis as A. saudades is found in the upper reaches of the Ventuari, Caura, and Caroni rivers, which were thought to have once flowed into the Proto-Berbice. In addition, although A. nudiceps does not appear to have split once the Takutu River was captured by the Branco, the progenitor of A. leucostictus and A. saudades did speciate with the populations on either side of the Rupununi Portal differing by 7% sequence divergence of the mitochondrial Cytochrome b gene. Besides the descriptions of the new species, we redescribe the others occurring in the area, and adjacent watersheds. We provide a key for their identification, and a preliminary hypothesis of relationships based on DNA sequences of the few species for which tissue samples are available.

Keywords: Pisces, Ancistrini, Colombia, Guyana, Venezuela, Taxonomy

Ancistrus patronus De Souza, Taphorn & Armbruster, 2019

Ancistrus patronus De Souza, Taphorn & Armbruster, 2019

Ancistrus patronus, named for the genus's paternal care of offspring.

photos: Jonathan W. Armbruster.

Lesley S De Souza, Donald C. Taphorn and Jonathan W. Armbruster. 2019. Review of Ancistrus (Siluriformes: Loricariidae) from the northwestern Guiana Shield, Orinoco Andes, and Adjacent Basins with Description of Six New Species. Zootaxa. 4552(1); 1-67. DOI:  10.11646/zootaxa.4552.1.1

Six new species of hideously adorable tentacle-nosed catfish discovered in Amazon  phys.org/news/2019-02-species-hideously-adorable-tentacle-nosed-catfish.html via @physorg_com

[Ichthyology • 2018] Using Morphology to Test DNA-Based Phylogenetic Relationships within the Guiana Shield Catfish Tribe Lithoxini (Siluriformes: Loricariidae)

 Avalithoxus jantjae AUM 39478 (31.9 mm SL), Exastilithoxus fimbriatus AUM 36668 (23.6 mm SL), Lithoxus lithoides AUM 39040 (43.0 mm SL), Paralithoxus bovallii AUM 67127 (51.7 mm SL), P. sp. nov. aff. bovallii (Konawaruk) AUM 35549 (42.6 mm SL), P. planquettei AUM 50395 (47.0 mm SL), and P. surinamensis AUM 51737 (34.7 mm SL). 

in Armbruster, Greene & Lujan, 2018.  

 DOI: 10.1643/CI-18-121 

Photos by Jonathan W. Armbruster. facebook.com/JonArmbruster56

As DNA-based phylogenetic analyses have exploded, historically phenotype-based evolutionary hypotheses throughout the tree of life have been rewritten. However, rarely are DNA-based phylogenetic hypotheses tested via the reanalysis of phenotypic data. Skeletons representing all four recognized genera of the Guiana Shield endemic suckermouth armored catfish clade Lithoxini were examined to test a recently published DNA-based phylogenetic hypothesis using morphological evidence. Phylogenetic analysis of 54 mostly osteological characters yielded a single most parsimonious tree of 90 steps that was congruent with the molecular hypothesis: (Avalithoxus, ((Exastilithoxus), (Lithoxus, Paralithoxus))). Lithoxini was a well-supported clade with 20 synapomorphies, as was each of the genera within this clade. Avalithoxus jantjae, which was originally described in Lithoxus, was found to be missing the unique synapomorphies of Lithoxus + Paralithoxus: a spoon-shaped, ventrally oriented process on the metapterygoid and a process on the preoperculo-hyomandibular ridge.

Fig. 6. Single most parsimonious tree of 90 steps, CI ¼ 0.722, numbers above branches are bootstrap values/Bremer decay indices. Avalithoxus jantjae AUM 39478 (31.9 mm SL), Exastilithoxus fimbriatus AUM 36668 (23.6 mm SL), Lithoxus lithoides AUM 39040 (43.0 mm SL), Paralithoxus bovallii AUM 67127 (51.7 mm SL), P. sp. nov. aff. bovallii (Konawaruk) AUM 35549 (42.6 mm SL), P. planquettei AUM 50395 (47.0 mm SL), and P. surinamensis AUM 51737 (34.7 mm SL). 

Photos by Jonathan W. Armbruster.

   

Jonathan W. Armbruster, Lauren Greene and Nathan K. Lujan. 2018. Using Morphology to Test DNA-Based Phylogenetic Relationships within the Guiana Shield Catfish Tribe Lithoxini (Siluriformes: Loricariidae). Copeia. 106(4); 671-680.  DOI: 10.1643/CI-18-121  

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[Ichthyology • 2018] Curculionichthys scaius • A New Species of Curculionichthys (Siluriformes: Hypoptopomatinae) from the Western Border of the Brazilian Shield, Madeira River Basin, Brazil

Curculionichthys scaius 

Calegari, Gamarra & Reis, 2018

DOI:  10.1643/CI-18-133

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Curculionichthys scaius, new species, is distinguished from other congeners by having two usually conspicuous, somewhat triangular dark brown speckles lateral to the anal-fin origin, a pointed snout with paired rostral plates, numerous lateral abdominal plates, a single series of large median abdominal plates, numerous dentary and premaxillary teeth, and several morphometric proportions of the body and head, mostly involving prepelvic, prepectoral, and preanal distances, head and cleithral width, caudal peduncle length, and dorsal-fin spine. The new species represents the first record of the genus Curculionichthys in the Madeira River basin and is the most westerly distribution in the Amazon.

Fig. 1. Curculionichthys scaius, holotype, MCP 53800,
female, 21.5 mm SL. Brazil, Mato Grosso, Aripuanã River drainage.

Curculionichthys scaius, new species

Etymology.— The specific epithet scaius, from the Greek Rjaior (skaios), meaning west, westward, in allusion to the westerly distribution in the Brazilian Shield. An adjective.

Bárbara B. Calegari, Suelen P. Gamarra, and Roberto E. Reis. 2018. A New Species of Curculionichthys (Siluriformes: Hypoptopomatinae) from the Western Border of the Brazilian Shield, Madeira River Basin, Brazil. Copeia. 106(4); 663-670. DOI:  10.1643/CI-18-133  

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Curculionichthys scaius, espécies nova, é distinguida dos demais congêneres por possuir um par de pequenas manchas escuras triangulares laterais à origem da nadadeira anal, margem anterior do focinho pontiaguda com uma placa rostral pareada, numerosas placas abdominais laterais, uma série única de grandes placas medianas abdominais, numerosos dentes no dentário e pré-maxila, e diversas proporções morfométricas do corpo e da cabeça, a maioria envolvendo as distâncias pré-pélvica, pré-peitoral, e pré-anal, a largura da cabeça e do cleitro, o comprimento do pedúnculo caudal, e o espinho da nadadeira dorsal. Esta nova espécie representa o primeiro registro do gênero Curculionichthys para a bacia do Rio Madeira, sendo a espécie com distribuição mais a oeste na bacia Amazônica.

[Ichthyology • 2018] Ancistrus shuar • Species of Ancistrus (Siluriformes, Loricariidae) from Ecuador, with the Description of A New Species from the Amazon River Basin

Ancistrus shuar

Provenzano R. & Barriga-Salazar, 2018

  DOI:  10.11646/zootaxa.4527.2.4ption

Abstract

To elucidate the species of the genus Ancistrus that inhabit freshwater systems of Ecuador, cataloged lots of the Fish Collection, Museo de la Escuela Politécnica Nacional (MEPN), in Quito, were analyzed. Four species were identified: Ancistrus alga (Cope, 1872), A. malacops (Cope, 1872), A. clementinae Rendahl, 1937, and a new species that herein is described. Ancistrus clementinae inhabits aquatic systems of the Pacific slope, mostly in the Guayas River drainage. The other three species live in freshwater systems that drain to the Amazon River Basin. Ancistrus alga inhabit the northern and central portions of eastern Ecuador. Ancistrus malacops has a broad distribution from north to south, but is absent from the Santiago River. Both species occasionally live in sympatry. The new species is restricted to the Santiago River, in Morona-Santiago province. Each species has unique external morphological features and/or a coloration pattern that allow unambiguous identification, at least of males. This paper provides a description of the new species, and a re-description and images of the other three.

Keywords: Pisces, catfishes, Neotropical freshwater Fishes, taxonomy, systematics, South America

FIGURE 4. Ancistrus shuar, MECN-DP-1637, 96.5 mm SL, male, paratype when alive.

Photo: Jorge Brito  

Ancistrus shuar new species

Etymology. Dedicated to ancient and brave Shuar, indigenous group that live in the Morona-Santiago province. It is considered a noun in apposition. 

Francisco Provenzano R. and Ramiro Barriga-Salazar. 2018. Species of Ancistrus (Siluriformes, Loricariidae) from Ecuador, with the Description of A New Species from the Amazon River Basin. Zootaxa. 4527(2); 211–238. DOI:  10.11646/zootaxa.4527.2.4

Resumen: Para dilucidar las especies del género Ancistrus que habitan los sistemas de agua dulce del Ecuador, se analizaron los lotes catalogados de la Colección de Peces, Museo de la Escuela Politécnica Nacional (MEPN), en Quito. Se identificaron cuatro especies: Ancistrus alga (Cope, 1872), A. malacops (Cope, 1872), A. clementinae Rendahl, 1937, y una nueva especie que aquí se describe. Ancistrus clementinae habita en sistemas acuáticos de la vertiente del Pacífico, principalmente en el drenaje del río Guayas. Las otras tres especies viven en sistemas de agua dulce que drenan a la cuenca del río Amazonas. Ancistrus alga habita la zona norte y central del oriente de Ecuador. Ancistrus malacops tiene una amplia distribución de norte a sur, pero está ausente del río Santiago. Ambas especies ocasionalmente viven en simpatría. La nueva especie está restringida al río Santiago, en la provincia de Morona-Santiago. Cada una de las especies posee características morfológicas externas y/o un patrón de coloración que permiten su identificación sin ambigüedades, al menos en los ejemplares machos. En este trabajo se presenta la descripción de la nueva especie y la re-descripción y figuras de las otras tres.

 Palabras clave: Corronchos, Peces dulceacuícolas Neotropicales, Taxonomía, Sistemática, Sur América

[Ichthyology • 2018] Spatuloricaria terracanticum • A New Species of Spatuloricaria Schultz, 1944 (Siluriformes: Loricariidae), from the Orinoco River Basin, Colombia

Spatuloricaria terracanticum 

Londoño-Burbano, Urbano-Bonilla, Rojas-Molina, Ramírez-Gil, & Prada-Pedreros, 2018

DOI: 10.1643/CI-18-087 
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A new species of Spatuloricaria is described from the Orinoco River basin, Colombia. The new species can be distinguished from its congeners by the following characters: a broad, dark brown stripe on the first pre-dorsal plate, which occupies the entire plate, reaching the preopercle, and sometimes reaching the second pre-dorsal plate; the possession of a small group of plates posterior to the urogenital pore; the abdominal surface with scattered, very small plates leaving naked areas; the possession of five transverse dark brown bands on the dorsal region; and four to five premaxillary teeth. The new species is the first valid species of Spatuloricaria distributed in the Orinoco River basin. Ecological notes of the species and comments regarding the taxonomy and phylogenetic relationships of the genus are offered.

Fig. 2. Spatuloricaria terracanticum, coloration in life; MPUJ 13401, Colombia, Meta, Villavicencio, Guayuriba River, tributary to the upper Meta River, Orinoco basin.

Photograph by A. Ortega-Lara. 

Spatuloricaria terracanticum, new species

Spatuloricaria sp.—Urbano-Bonilla et al., 2018:74 [listed; included in identification key for Loricariidae genera and species of the Cusiana River, Orinoco River basin].

Etymology.—The specific epithet is from the latin terra [earth] and canticum [song]. It is dedicated to the Llanos work songs (cantos de vaquería). Its origin dates back to the 16th century and has been transferred from generation to generation in the Llanos region of Colombia and Venezuela. Sung a cappella, melodies reflect the feeling and the close relationship of the llanero with their myths, beliefs, nature, climate, and animals. Although these songs have been gradually lost within modern society due to economic, political, and social causes, UNESCO has declared them as intangible cultural heritage of humanity

Alejandro Londoño-Burbano, Alexander Urbano-Bonilla, Yecid Rojas-Molina, Hernando Ramírez-Gil, and Saúl Prada-Pedreros. 2018. A New Species of Spatuloricaria Schultz, 1944 (Siluriformes: Loricariidae), from the Orinoco River Basin, Colombia. Copeia. 106(4); 611-621. DOI: 10.1643/CI-18-087   

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Una nueva especie de Spatuloricaria, proveniente del río Orinoco, Colombia, es descrita. La nueva especie se distingue de sus congéneres por los siguientes caracteres: una banda transversal ancha en la primera placa predorsal, la cual ocupa toda la placa y el preopérculo, alcanzado algunas veces la segunda placa predorsal; un grupo de pequeñas placas posterior al poro urogenital; abdomen cubierto por placas pequeñas y dispersas, las cuales dejan áreas desnudas; presencia de cinco bandas transversales marrón oscuro en la región dorsal; y cuatro a cinco dientes en el premaxilar. La nueva especie es la primera especie válida de Spatuloricaria distribuida en la cuenca del río Orinoco. Se presentan notas ecológicas de la especie, y comentarios con relación a la taxonomía y relaciones filogenéticas del género.

[Ichthyology • 2017] Hoplomyzon cardosoi • A New Species of Hoplomyzon (Siluriformes: Aspredinidae) from Maracaibo Basin, Venezuela: Osteological Description Using High-resolution Computed Microtomography of A Miniature Species

Hoplomyzon cardosoi Carvalho, Reis & Friel, 2017

Fig. 1 Hoplomyzon cardosoi, holotype, MCNG 375, 18.5 mm SL, Caño La Raya, Zulia, Venezuela.  Dorsal, left side lateral and ventral views.

DOI: 10.1590/1982-0224-20160143 

ABSTRACT

A new miniature species of banjo catfish of the genus Hoplomyzon is described from the Lake Maracaibo Basin in Venezuela. The new species is distinguished from all its congeners by the straight anterior margin of the mesethmoid (vs. a medial notch); a smooth and straight ventral surface of the premaxilla (vs. presence of bony knobs on the ventral surface of premaxilla); absence of teeth on dentary (vs. teeth present on dentary); configuration of ventral vertebral processes anterior to anal fin, which are composed of single processes anterior to anal-fin pterygiophore (vs. paired process); presence of several filamentous barbel-like structures on the ventral surface of head of adults (vs. small papillous structures in the ventral surface of head of adults); and 8 anal-fin rays (vs. 6 or 7). An extensive osteological description is made of the holotype using high-resolution x-ray computed microtomography (HRXCT).

Keywords: Endemism; Ernstichthys intonsus; Miniaturization; Synapomorphy; Taxonomy

Distribution and habitat. Known from three tributaries, which drain southwestern portions of Lake Maracaibo Basin in Zulia State, Venezuela. The Caño raya at type locality is a medium size stream (~12m wide) with mostly slow flowing white waters running over sand intercalated with riffles of fast flowing waters over pebbles; little marginal and floating vegetation.

Etymology. Hoplomyzon cardosoi is named in honor and memory of a dear colleague who prematurely passed away, Alexandre Rodrigues Cardoso, for his humbleness, positive attitude, and dedicated friendship, and furthermore for his contributions to the taxonomy of Neotropical fishes, including the family Aspredinidae.

Tiago P. Carvalho, Roberto E. Reis and John P. Friel. 2017.  A New Species of Hoplomyzon (Siluriformes: Aspredinidae) from Maracaibo Basin, Venezuela: Osteological Description Using High-resolution Computed Microtomography of A Miniature Species.   Neotropical Ichthyology. 15(1);  DOI: 10.1590/1982-0224-20160143 

[Ichthyology • 2017] Aphanotorulus rubrocauda • A New Species of Aphanotorulus (Siluriformes: Loricariidae) from the rio Aripuanã basin, Brazil

Aphanotorulus rubrocauda Oliveira, Py-Daniel & Zawadzki, 2017 
Aphanotorulus emarginatus (Valenciennes, 1840)

DOI: 10.1590/1982-0224-20160034 

Aphanotorulus rubrocauda 

Oliveira, Py-Daniel & Zawadzki, 2017 

 DOI: 10.1590/1982-0224-20160034

ABSTRACT

The cis-Andean genus Aphanotorulus was recently revised and comprises six valid species: A. ammophilus, A. emarginatus, A. gomesi, A. horridus, A. phrixosoma and A. unicolor. Herein, a new species is described from tributaries of the rio Aripuanã basin, in Amazonas and Mato Grosso states, Brazil. The new species is easily distinguished from congeners by its color pattern: caudal fin with upper lobe mostly hyaline with dark spots along rays and membranes, and lower lobe red and without dark spots; and absence of dark spots in the lateral series of mid-ventral plates.

Keywords: Amazon basin; Fishes; Hypostominae; Taxonomy

Fig. 2 Lateral view of Aphanotorulus rubrocauda, MNRJ 37551, paratype, 118.6 mm SL, Brazil, Mato Grosso State, Aripuanã Municipality, rio Aripuanã basin, 500 meters downstream of the rapids of Dardanelos waterfalls. Photographed alive by Fabio Pupo.
 Fig. 3 Lateral view of Aphanotorulus emarginatus, NUP 17748, 257.3 mm SL, Brazil, Amazonas State, Parintins Municipality, Paraná do Ramos, rio Amazon basin. Photographed alive by Hugmar Pains da Silva. 

Diagnosis. Aphanotorulus rubrocauda can be distinguished from all other species of Aphanotorulus by its color pattern: having a uniformly red colored lower caudal-fin lobe (vs. lower lobe of caudal fin with dark spots on creamy colored background), by the absence of dark spots on the posterior half of mid-ventral lateral plate series (vs. presence of dark spots in all lateral plate series). Additionally, Aphanotorulus rubrocauda is distinguished from congeners by having more premaxillary teeth (32-65 per ramus, mean = 45; vs. 15-34, mean = 24) and dentary teeth (30-63 per ramus, mean = 44; vs. 14-34, mean = 25). Aphanotorulus rubrocauda further differs from A. emarginatus by having small round dark spots (vs. dark large and elongated spots) (Fig. 3).

Fig. 1 Holotype of Aphanotorulus rubrocauda, INPA 33666, 150.5 mm SL, Brazil, Amazonas State, Apuí Municipality, Resex do Guariba, rio Aripuanã drainage, tributary of the rio Madeira basin, in lateral, dorsal, and ventral views. 

Andreza S. Oliveira, Lúcia Rapp Py-Daniel and Cláudio H. Zawadzki. 2017. A New Species of Aphanotorulus (Siluriformes: Loricariidae) from the rio Aripuanã basin, Brazil. Neotropical Ichthyology. 15(1);  e160034.  DOI: 10.1590/1982-0224-20160034. 

[Ichthyology • 2017] Parotocinclus fluminense • A New Species of Parotocinclus (Siluriformes: Loricariidae) from Coastal Drainages of Rio de Janeiro, southeastern Brazil

 Parotocinclus fluminense

Roxo, Melo, Silva & Oliveira, 2017

DOI:  10.11646/zootaxa.4232.2.9 

Abstract

A new species of Parotocinclus is described from tributaries of rio São João, an Atlantic coastal river of Rio de Janeiro, southeastern Brazil. The new species is distinguished from its congeners by the possession of a triangular patch of dark pigmentation on the anterior portion of the dorsal-fin base, a fully developed adipose fin, complete exposure of the ventral surface of the pectoral girdle, and a distinctive pigmentation pattern of the caudal fin. The caudal fin has a hyaline background with a large black blotch covering its anterior portion, tapering irregularly through distal portions of the ventral lobe with a hyaline rounded area, and a small patch of dark pigmentation on distal portions of the dorsal lobe.

Keywords: Pisces, biodiversity, freshwater fishes, Neotropical, Otothyrini, taxonomy

Roxo, F.F., Melo, B.F., Silva, G.S.C. and Oliveira, C. 2017. New Species of Parotocinclus (Siluriformes: Loricariidae) from Coastal Drainages of Rio de Janeiro, southeastern Brazil. Zootaxa. 4232(2);  DOI:  10.11646/zootaxa.4232.2.9

[Ichthyology • 2016] Curculionichthys karipuna • A New Species of Curculionichthys (Siluriformes: Loricariidae) from the eastern Guiana Shield

  Curculionichthys karipuna

  Silva, Roxo, Melo & Oliveira, 2016   

 DOI: 10.11646/zootaxa.4175.3.7 

Abstract

We describe a new species of Curculionichthys from northern Brazil. The new species is known from the rio Cassiporé, an Atlantic coastal river and an unnamed affluent of the rio Jari, left tributary of the Amazon river. It can be distinguished from congeners by (1) the irregular concentration of chromatophores that cover the anal-fin origin and adjacent region, and distal portions of the first unbranched anal-fin ray, (2) lack of dark-brown spots scattered over the body, (3) lack of contrasting dark spots over the anterodorsal region of the body, (4) presence of papillae randomly distributed across the lower lip, (5) small, inconspicuous odontodes that form rows over the head and trunk, (6) anterior profile of the head pointed, (7) higher number of premaxillary and dentary teeth, (8) lack of an unpaired platelet on the dorsal portion of the caudal peduncle, (9) lower number of vertebrae, and (10) higher number of lateral abdomen plates. A discussion on the morphological variation of diagnostic features within Curculionichthys is also provided.

Keywords: Pisces, Amazon basin, Cascudinhos, Freshwater fishes, Otothyrini, taxonomy

Gabriel S. C. Silva, Fábio F. Roxo, Bruno F. Melo and Claudio Oliveira. 2016. New Species of Curculionichthys (Siluriformes: Loricariidae) from the eastern Guiana Shield.
Zootaxa. 4175(3); 281–291. DOI: 10.11646/zootaxa.4175.3.7

[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

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[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

   DOI: 10.1590/1982-0224-20150063  

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 

http://www.scielo.br/pdf/ni/v14n1/1982-0224-ni-14-01-e150063.pdf

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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.