[Ichthyology • 2026] Leptorhamdia kamilai • Phylogenetic Placement and Description of A New Species of Leptorhamdia (Siluriformes: Heptapteridae) from the Amazon Basin

Leptorhamdia kamilai

Silva, Reia, Souza, Ywamoto & Oliveira, 2026

 

 DOI: doi.org/10.1590/1982-0224-2025-0037  

 

Abstract

Brachyglaniini is a recently described tribe of Heptapterinae, composed of four genera: Brachyglanis, Gladioglanis, Leptorhamdia, and Myoglanis. Expeditions to the Aripuanã and Tapajós River basins revealed an undescribed species of Brachyglaniini, characterized by a conspicuous light-colored band posterior to the head. Our phylogenetic results provide strong evidence that this new Brachyglaniini species belongs to the genus Leptorhamdia and is closely related to L. marmorata and L. aspredinoides. In addition to the color pattern, the new species can be distinguished from its congeners by having 19-22 anal-fin rays and 47 vertebrae.

Keywords: Brazilian shield; Catfish; Integrative taxonomy; Systematics

 Leptorhamdia kamilai
Left column: holotype, DZSJRP 16293, 92.4 mm SL.
Right column: paratypes, LBP 30639, from top to bottom: 66.3 mm SL; 47.8 mm SL; 31.4 mm SL.

Live specimens of Leptorhamdia kamilai, paratype, LBP 30639, 66.3 mm SL. Photographed by Eric V. Ywamoto. 
 Habitat: rio dos Patos, tributary of the upper Arinos River in Tapajós River basin.

Leptorhamdia kamilai, new species

 Diagnosis. Leptorhamdia kamilai can be readily distinguished among its congeners by having a conspicuous light collar-band, yellowish in live specimens, posterior to the head (vs. coloration uniformly throughout body and head, lacking any distinctive bar). Additionally, L. kamilai differs from its congeners by having 19-22 anal-fin rays (vs. 17 in L. essequibensis; 15 in L. marmorata; 32-35 in L. aspredinoides; 12 in L. nocturna, 15-16 in L. schultzi) and by having 46-47 vertebrae (vs. 45 in L. essequibensis; 43 in L.marmorata; 38 in L. nocturna; 56-57 vertebrae in L. aspredinoides and 43 vertebrae in L. schultzi).

Etymology. The specific name, kamilai, honors our dear friend Dr. Kamila Mayumi Duarte Kuabara, an entomologist and lab manager of the Ornithology Department at The Academy of Natural Sciences of Drexel University. A noun in a genitive case.

Gabriel de S. C. Silva, Lais Reia, Camila S. Souza, Eric V. Ywamoto and Claudio Oliveira. 2026. Phylogenetic Placement and Description of A New Species of Leptorhamdia (Siluriformes: Heptapteridae) from the Amazon Basin. Neotrop. ichthyol. 24 (01); DOI: doi.org/10.1590/1982-0224-2025-0037  

[Ichthyology • 2026] Hemigrammus serrazul • A New Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho Drainages, upper rio Paraguai Basin, Mato Grosso, Brazil

   

Hemigrammus serrazul  

Ferreira, Ribeiro & Carvalho, 2026

DOI: doi.org/10.1590/1982-0224-2025-0157

 

Abstract

A new species of Hemigrammus is described from tributaries of the rio Cuiabazinho, upper rio Paraguai basin, Mato Grosso State, Brazil. It can be readily distinguished from all its congeners by a unique combination of characters, including a distinctive body coloration pattern without spots, the number of perforated lateral-line scales (12–15), the number of branched rays on anal fin (21–25), and the presence of small bony hooks at the tips of the lepidotrichia of the second to fourth branched rays of the pelvic fins, which are absent in the anal fin. We also provide a brief discussion on the recent taxonomic reconfiguration of Hemigrammus.

Keywords: Freshwater fish; Rio Cuiabá drainage; Serra Azul; Serrana Province of Mato Grosso; Taxonomy

 Color pattern variations in live specimens of Hemigrammus serrazul: A. Male; B. Female.

Photo by Alexandre C. Ribeiro.  

Hemigrammus serrazul, new species

Diagnosis. Hemigrammus serrazul can be distinguished from most congeners (except of H. apiaka (Esguícero& Castro, 2017), H. erythrozonus Durbin, 1909, H. gracilis (Lütken, 1875), H. mimus Böhlke, 1955, and H. tupebas (Esguícero& Castro, 2017) by flank uniformly colored, without spots, i.e., no humeral and caudal spots, just a tiny and narrow longitudinal stripe (vs. species with spots in humeral and/or caudal peduncle). From H. apiaka, H. erythrozonus, H. gracilis, H. mimus, and H. tupebas, H. serrazul differs by premaxillary teeth in two rows: outer with three to five tricuspid teeth, inner with five ...

Etymology. The specific epithet serrazul refers to the type locality where the new species was collected, the Serra Azul, the local portion of the so-called Serrana Province of Mato Grosso, a range of escarped relief that serves as a watershed divide between the rio Cuiabá, Paraguai, and Arinos basins. A noun in apposition.

Hemigrammus serrazul, live specimen in aquarium, photographed just after capture in córrego Cocal (CPUFMT 8218), upper rio Paraguai basin, municipality of Rosário Oeste, Mato Grosso State, Brazil. Inserir:

Photo by Alexandre C. Ribeiro.

Katiane Mara Ferreira, Alexandre Cunha Ribeiro and Fernando Rogério Carvalho. 2026. A New Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho Drainages, upper rio Paraguai Basin.  Neotrop. ichthyol. 24 (01); DOI: doi.org/10.1590/1982-0224-2025-0157

[Ichthyology • 2026] Pterobunocephalus carvalhoi • After Eight decades: A New Species of Pterobunocephalus (Siluriformes: Aspredinidae) from the upper Putumayo, Napo and Pastaza Rivers, Ecuador

Pterobunocephalus carvalhoi 

 Crispim, Argüello, Silva, Oliveira, Luckenbill & Sabaj, 2026

.  

 DOI: doi.org/10.1590/1982-0224-2025-0162  

Abstract

Pterobunocephalus currently comprises two valid species: P. depressus described from the Guaporé River basin and P. dolichurus from the Trombetas River at its confluence with the Amazon River. A third nominal species, Bunocephalus albofasciatus, described from the upper Mamoré River basin, is presently considered a junior synonym of P. depressus. Based on a morphological approach, we describe here a new species of Pterobunocephalus from the upper Amazon basin (Napo, Pastaza, and Putumayo rivers) in Ecuador. The new species is distinguished from its congeners by the following combination of characters: (1) large eyes; (2) anterior margin of the mesethmoid relatively wide, shallowly concave, and sunken between anterior margins of premaxillae; (3) total number of anal-fin rays 10–11; and (4) in dorsal view, parapophysis of the fifth vertebra shaped like the blade of a shepherd’s axe with distal portion conspicuously and abruptly expanded.

Keywords: Banjo catfish; CT Scan; Morphology; Taxonomy

Pterobunocephalus carvalhoi, new species

  Holotype, MEPN-I 20199, 69.9 mm SL (left), and paratype, ANSP 130605, 64.1 mm SL (right) of Pterobunocephalus carvalhoi showing variation in color pattern. 

 

 

Jefferson Luan Crispim, Pablo Argüello,Gabriel de Souza da Costa e Silva, Claudio Oliveira,Kyle R. Luckenbill and Mark H. Sabaj. 2026. After Eight decades: A New Species of Pterobunocephalus (Siluriformes: Aspredinidae) from the upper Putumayo, Napo and Pastaza rivers, Ecuador. Neotrop. ichthyol. 24(1):e250162. DOI: doi.org/10.1590/1982-0224-2025-0162 [17 Apr 2026]

 

[Ichthyology • 2025] Baryancistrus isaaci & B. quilombola • Two New Species of the ornamental loricariid Genus Baryancistrus (Siluriformes: Loricariidae: Hypostominae) from rio Trombetas Basin, Pará, Brazil

 

Baryancistrus isaaci
Baryancistrus quilombola

 Oliveira & Rapp Py-Daniel, 2025 

 

DOI: doi.org/10.1590/1982-0224-2025-0066

 

Abstract

Two new species of Baryancistrus are described from the rio Trombetas basin. These new species were collected in the late 1980’s and were analyzed morphologically and compared to the eight currently assigned species of Baryancistrus. Both new species are distinguished from their congeners by a set of non-unique characters, such as coloration, extension of dorsal-fin membrane, abdominal covering, number of mandibular teeth and size of fins. These new species are only registered for strong-energy and clear waters, powerful cataracts, with rocky substrates, being sometimes, syntopic. The patterns of distribution and morphological features among all Baryancistrus species are discussed, and an identification key is presented. Despite of occurring in a protected area, previous studies on hydroelectric plants for the rio Trombetas, as the Hydropower Plant of Cachoeira Porteira, are being re-examined by current authorities, raising deep concerns on the future conservation of the unique biodiversity of the rio Trombetas basin.

Keywords: Amazon; Conservation; Freshwater; Hydroelectric; Identification key

   Baryancistrus isaaci, uncatalogued specimen, from Cachoeira da Enseada, 
Baryancistrus quilombola, INPA-ICT 52435, paratype, 119.4 mm SL, from rio Trombetas,
Oriximiná, Pará, Brazil. 

Photos: Douglas A. Bastos.

Baryancistrus isaaci, new species 

Etymology. The specific name, a noun (masculine, singular), honors Isaäc Isbrücker, for his contribution to the knowledge of Neotropical Ichthyology, especially loricariids. Isaäc is an excellent ichthyologist and aquarist, and an example of resilience against preconceived ideas, deserving to be honored by his extreme talent and knowledge on loricariids. He has dedicated a relevant part of his career as ichthyologist sharing his knowledge with the academia and general aquarium experts. A noun in a genitive case.

Baryancistrus quilombola, new species

Etymology. The specific name quilombola (a noun in the nominative singular standing in apposition to the generic name) honors the Quilombola’s communities of the rio Trombetas, also called Quilombos. Quilombolas are Afro-Brazilian descendents that escaped from slavery, or after abolition of slavery, that organized agrarian communities according to cultural, religious and geographic backgrounds in different areas in Brazil. The presence of large quilombos in the Amazon and, particularly, in the rio Trombetas basin deserves recognition, as the first Quilombo fully recognized by the Brazilian government was in rio Trombetas (Duque, 2009). They are eximious fishermen and profound connoisseurs of the dangerous waters in the rio Trombetas, as well as important activists of the Quilombola cause in South America.

  Renildo Ribeiro de Oliveira and Lúcia H. Rapp Py-Daniel. 2025. Two New Species of the ornamental loricariid Genus Baryancistrus (Siluriformes: Hypostominae) from rio Trombetas Basin, Pará, Brazil.   Neotrop. ichthyol. 23 (03); DOI: doi.org/10.1590/1982-0224-2025-0066

[Ichthyology • 2025] Inpaichthys luizae • An Ode to Beauty: the Discovery of one of the most spectacular Tetras (Characiformes: Acestrorhamphidae) - A New Species of Inpaichthys from the rio Juruena, Brazil

 Inpaichthys luizae

 Dagosta, 2025

 

DOI: doi.org/10.1590/1982-0224-2025-0052

 

Abstract

Inpaichthys luizae is described from tributaries of the rio dos Peixes basin, a tributary of the rio Juruena basin in central Brazil. The species is distinguished from all its congeners by the presence of well-defined, relatively broad oblique dark ventrolateral stripe on body, extending approximately from end of pectoral fin rays to base of middle caudal-fin rays, and continuing straight onto the tip of the middle caudal-fin rays. It shares seven of the eight synapomorphies attributed to the genus and exhibits all the defining characteristics of the clade I. kerri + I. parauapiranga, suggesting a close relationship with these species. Several morphological characters found in I. luizae, other species of Inpaichthys, and closely related groups are discussed. The biogeography of Inpaichthys is briefly addressed.

Keywords: Amazon; Biogeography; Rio Tapajós basin; Taxonomy

 Inpaichthys luizae 
Life coloration of the holotype, MZUSP 130243 (male, 30.2 mm SL). 
 Sexual dimorphism of I. luizae: A. MUBIO 691 (male, 31.5 mm SL); B. MUBIO 691 (female, 38.2 mm SL);
C. Unvouchered specimen (male); D. Unvouchered specimen (female).

Photos C–D by André Bulgarelli.

Inpaichthys luizae, new species

 

Diagnosis. Inpaichthys luizae can be easily distinguished from all congeners by the autapomorphic presence of a well-defined, relatively broad oblique dark ventrolateral stripe on body, extending approximately from end of pectoral fin rays to base of middle caudal-fin rays, and continuing straight onto the tip of the middle caudal-fin rays (vs. well-defined longitudinal stripe absent, or dark lateral stripe never oblique). Additionally, I. luizae can also be distinguished from I. nambiquara and I. parauapiranga by the absence of humeral blotch (vs. two in I. parauapiranga and one in I. nambiquara). It is further distinguished from I. kerri by 19–21 branched anal-fin rays (vs. 22–26 branched anal-fin rays).

  Fernando Cesar Paiva Dagosta. 2025. An Ode to Beauty: the Discovery of one of the most spectacular Tetras (Characiformes: Acestrorhamphidae) - A New Species of Inpaichthys from the rio Juruena, Brazil. Neotrop Ichthyol. 23(3):e250052. DOI: doi.org/10.1590/1982-0224-2025-0052

[Ichthyology • 2025] Moenkhausia solaris • A New Species of Moenkhausia (Characiformes: Acestrorhamphidae) from the Amazon basin at Serra do Cachimbo, Pará, Brazil

Moenkhausia solaris

da Silva, de Santana & Marinho, 2025

 DOI: doi.org/10.1590/1982-0224-2025-0089 

 

Abstract

A new species of Moenkhausia is described from the headwaters of the Curuá and Teles Pires River basin, localities restricted to the Serra do Cachimbo, Pará, Brazil. The new species is diagnosed by the presence of dark blotches concentrated on the anterior portion of scales from the second to seventh longitudinal series, presence of red pigmentation on the adipose and caudal fins in life, green coloration in the ventral portion of the eye and absence of a longitudinal black stripe on body. The new species is morphologically similar and probably closely related to other Moenkhausia species endemic to the Brazilian Shield tributaries, particularly those restricted to the Serra do Cachimbo, sharing with them unique pigmentation traits. The ichthyofauna of the Serra do Cachimbo is notably distinct and characterized by high levels of endemism, likely influenced by geological barriers such as rapids and waterfalls that act as biogeographic barriers. The restricted and disjunct distribution of the new species in tributaries of Xingu and Tapajós basins suggests a historic headwater capture event in the Serra do Cachimbo plateau.

Keywords: Biogeography; Headwater capture; Moenkhausia clorophthalma; Tapajós; Xingu

   Live specimens of Moenkhausia solaris, aquarium specimens, not preserved. Photo by Oliver Lucanus. 

Moenkhausia solaris, new species

Diagnosis. Moenkhausia solaris is distinguished from all congeners, except M. cambacica Marinho, Ohara & Dagosta, 2021, M. clorophthalma Sousa, Netto-Ferreira & Birindelli, 2010, M. lineomaculata Dagosta, Marinho & Benine, 2015, M. parecis Ohara & Marinho, 2016, M. petymbuaba Lima & Birindelli, 2006, and M. plumbea Sousa, Netto-Ferreira & Birindelli, 2010, by the presence of a dark blotch on the anterior portion of each scale of the second to seventh longitudinal series (vs. pigmentation absent or, when present, concentrated at the posterior margin of scales, forming a reticulate pattern). Moenkhausia solaris can be distinguished from all the aforementioned species, except M. petymbuaba, by having the adipose fin and the base of caudal-fin lobes red (vs. hyaline in M. lineomaculata and yellowish in ...

Etymology. The specific epithet solaris comes from Latin, meaning sunny or pertaining to the sun. In allusion to the bright gold color of body and red color of the adipose and caudal fin present in live specimens. An adjective.

 

One of the localities where Moenkhausia solaris was collected, MZUSP 128883, a small stream tributary of 13 de Maio River at the area of PCH Salto Três de Maio, upstream of the dam.

 

 José Igor da Silva, Yasmim de Santana and Manoela Maria Ferreira Marinho. 2025. A New Species of Moenkhausia (Characiformes: Acestrorhamphidae) from the Amazon basin at Serra do Cachimbo, Pará, Brazil. Neotrop. ichthyol. 23(03) DOI: doi.org/10.1590/1982-0224-2025-0089 

[Ichthyology • 2025] Profundulus hectori • A New Species of Profundulus (Cyprinodontiformes: Profundulidae) from southeastern Mexico

[A-B] Profundulus hectori
  [C-D] P. punctatus 

Domínguez-Cisneros, Velázquez-Velázquez, Domínguez-Domínguez & Beltrán-López, 2025

 DOI: doi.org/10.1590/1982-0224-2024-0096  

Abstract

A new species of Profundulus is described from several localities in the Grijalva river basin and rivers of the Isthmus of Tehuantepec, in southern Mexico, using a combination of morphological and molecular data. Genetically, it is separated from other Profundulus species analyzed by a minimum of 3.86% uncorrected p-distance for the nd2 mitochondrial gene. The new species can be distinguished from its congeners by the following combination of characters: presence of a set of large black spots on the scales on the sides of the body, a set of black spots whose size is equal to or greater than 50% of the diameter of the pupil in the new species, a larger number of scales on the lateral line and a larger number of predorsal scales. Based on the phylogenetic analysis of molecular sequence data, the new species is recovered close related to P. chimalapensis, supported by posterior probability of 0.96, and this clade was recovered close related to P. oaxacae, with a posterior probability of 1.0 and bootstrap support of 100. This is the twelfth member of the genus Profundulus.

Keywords: Biodiversity; Freshwater fish; Phylogeny; Profundulids; Taxonomy

 

General morphology and live coloration patterns in
Profundulus hectori, A. Male, B. Female, Sabinal River, tributary of Grijalva River, Tuxtla Gutierrez, Chiapas. Collected in December 16, 2022 by E. Velázquez-Velázquez and M. Anzueto-Calvo.
 Profudulus punctatus, C. Male, D. Female, Arroyo tributario del Río Zanatenco, Tonalá Chiapas. Collected on March 21, 2023 by Ernesto Velázquez and Manuel Anzueto.

Profundulus hectori, new species

Etymology. In recognition of his many contributions to the study and conservation of freshwater fishes in Mexico, this species is named after our friend and colleague, the Mexican ichthyologist Hector Espinosa Perez, recently deceased. A noun in a genitive case.

Sara Elizabeth Domínguez-Cisneros, Ernesto Velázquez-Velázquez, Omar Domínguez-Domínguez and Rosa Gabriela Beltrán-López. 2025. A New Species of Profundulus (Cyprinodontiformes: Profundulidae) from southeastern Mexico. Neotrop Ichthyol. 23(2):e240096. DOI: doi.org/10.1590/1982-0224-2024-0096  

[Ichthyology • 2025] Rineloricaria buckupi • A New Species of Whiptail Catfish Rineloricaria (Siluriformes: Loricariidae) from Macaé and São João River Basins, southeastern Brazil

 

 Rineloricaria buckupi

Mejia, Ferraro & Souto-Santos, 2025

DOI: doi.org/10.1590/1982-0224-2024-0087 

Abstract

A new species of Rineloricaria from the São João and Macaé river basins in Rio de Janeiro State, southeastern Brazil is described. The new species is distinguished from most of its congeners by possessing of five series of lateral plates below the dorsal fin; mid-dorsal series consisting of four or five keeled plates extending posteriorly beyond the origin of the dorsal fin; pectoral girdle covered by plates; snout tip with naked area not reaching most anterior pore of infraorbital ramus of sensory canal; dorsal-fin spinelet present. The new species differs from R. zawadzkii, the most similar and geographically closest species, by having mid-ventral and lateral abdominal plates in contact (vs. separated by skin), the dorsal fin with a dark brown terminal band not reaching the edge, with inconspicuous dark dots along the lower edge (vs. band reaching the edge), and the caudal fin with a diffuse distal band with variegated white spots (vs. a well-defined distal band). The genetic distance based on cytochrome c oxidase I between the new species and the closest congeners supports its validity. The current distribution of the new species in the São João and Macaé basins is consistent with paleo-drainage connections influenced by sea-level fluctuations.

Keywords: DNA barcode; Freshwater fishes; Loricariinae; Sea-level variations; Suckermouth armored catfishes

 Rineloricaria buckupi, holotype, MNRJ 51116, 111.2 mm SL, Brazil, Macaé, Macaé River;
lateral, dorsal, and ventral views.

 Rineloricaria buckupi, paratypes. Note the remarkable dark brown transverse bars on dorsal surface.
A. MNRJ 54658, 77.9 mm SL; five bars on dorsal surface.
B. MNRJ 54658, 101.8 mm SL; notice third and fourth bars fused. 

Rineloricaria buckupi, new species

Diagnosis. Rineloricaria buckupi can be distinguished from most congeners except for R. aequalicuspis Reis & Cardoso, 2001, R. altipinnis, R. anhaguapitan Ghazzi, 2008, R. anitae Ghazzi, 2008, R. baliola Rodriguez & Reis, 2008, R. cacerensis (Miranda Ribeiro, 1912), R. cachivera, ..., R. zaina Ghazzi, 2008 and R. zawadzkii by having five lateral series of plates below the dorsal fin (vs. four lateral series of plates below the dorsal fin), and mid-dorsal series extending below and posterior to dorsal fin (vs. mid-dorsal series not extending beyond the origin of dorsal fin). Rineloricaria buckupi differs from R. aequalicuspis, R. anhaguapitan, R. baliola, R. capitonia, R. latirostris, R. maacki, R. malabarbai, R. maquinensis, R. microlepidogaster, R. nudipectoris, R. reisi, and R. tropeira by the extensive ventral covering of the pectoral girdle by plates (vs. absence of plates on most of the ventral surface of the pectoral girdle). It differs from R. cacerensis, R. fallax,  ...

Etymology. The specific name buckupi (noun, masculine, singular genitive), is a patronym for Paulo A. Buckup, in recognition of his valuable teachings as an advisor to numerous students, including the authors of this paper. Paulo has done outstanding work and made numerous contributions to Neotropical ichthyology, including advances in the systematics of Rineloricaria over the past 25 years.

 

Mejia, Eduardo; Ferraro, Gustavo A. and Souto-Santos, Igor C. A. 2025. A New Species of Whiptail Catfish Rineloricaria (Siluriformes: Loricariidae) from Macaé and São João River Basins, southeastern Brazil. Neotrop. ichthyol. 23 (02); DOI: doi.org/10.1590/1982-0224-2024-0087 

[Ichthyology • 2022] Moema juanderibaensis • A New Species of the Seasonal Killifish Genus Moema (Cyprinodontiformes: Rivulidae) from the Piraí watershed in the Southwest Amazon Basin

 

Moema juanderibaensis

 Drawert, 2022 

DOI: 10.1590/1982-0224-2022-0067  

   Researchgate.net/publication/366335860

 

Abstract

Moema, a genus of the Rivulidae family, currently comprises 20 valid species. Most of these species inhabit temporary pools in the Amazon basin and only one species is found in the upper Paraguay basin. A new member of this genus from the upper Río Madeira drainage is here described. Males of the new species differ from all congeners by the combination of a color pattern consisting of oblique, sometimes chevron-like, irregular rows of red and light blue double-dots on body; dark yellowish to golden pectoral fins with no visible markings; and a stripe pattern on the ventral section of caudal fin with a very narrow black marginal line, intermittent or even absent. The existence of infrageneric species groups within Moema, the geographic distribution and taxonomic aspects of the species present in the Ríos Mamoré and Iténez/Guaporé rivers drainages, and the observation of intraspecific aggression between males and amphibious lifestyle in the new species are discussed.

Keywords: Bolivian Amazon basin; New species; Rivulids; Taxonomy; Temporary water bodies

 

Moema juanderibaensis, MNKP 16539, holotype, male, 41.9 mm SL
(24 days after collection, left side),
Bolivia, Santa Cruz, Santa Rosa del Sara.

Moema juanderibaensis, MNKP 16539, holotype, male, 41.9 mm SL
(2 days after collection, right side),
Bolivia, Santa Cruz, Santa Rosa del Sara.

Moema juanderibaensis, new species

Diagnosis. Moema juanderibaensis differs from congeners by a unique combination of the following characters on males: pattern of oblique, sometimes chevron-like, irregular rows of red and light blue double-dots on flanks; dark yellowish to golden pectoral fin with no visible markings (dots or spots); and ventral part of caudal-fin stripe pattern with very narrow black marginal line, intermittent or even absent (vs. never in this combination). The new species is distinguished from Moema apurinan, M. beucheyi, M. funkneri, M. hellneri, M. heterostigma, M. nudifrontata, M. pepotei, M. piriana, M. portugali, M. quiii, M. schleseri, and M. staecki by the oblique arrangement of red and light blue double-dots on flanks (vs. flank color pattern arranged in horizontal lines or rows of dots). It differs from M. manuensis, M. obliqua, M. peruensis, M. rubrocaudata, M. schleseri, and M. wischmanni by the presence of red dots on flanks mostly arranged in oblique, sometimes chevron-like, rows (vs. absence of dots, or arranged in vertical rows or randomly distributed). It is distinguishable from M. boticarioi, M. kenwoodi, and M. obliqua by the absence of dots, spots or any other markings on pectoral fins of males (vs. presence of dark reddish-brown dots, few dark green dots or longitudinally elongated dark brown spots); from M. claudiae by the absence of black humeral blotch in males (vs. presence); and from M. schleseri by the ground color of pectoral fins (brown-yellowish to golden vs. hyaline) and color pattern of ventral section of caudal fin (thin black marginal line, sometimes intermittent and inconspicuous or even absent, and broad deep orange to red stripe vs. ventralmost black stripe broad, and orange stripe with dark red dots). Additionally, it is also distinguished from M. boticarioi by the absence of brown dots or other marks on dorsum (vs. dorsum with brown dots).

Etymology. Named juanderibaensis in reference to the name of the ranch “Juan Deriba” where the type locality is situated. An adjective.

Heinz Arno Drawert. 2022. A New Species of the Seasonal Killifish Genus Moema (Cyprinodontiformes: Rivulidae) from the Piraí watershed in the Southwest Amazon basin.   Neotrop. ichthyol. 20(4). DOI: 10.1590/1982-0224-2022-0067   

  Researchgate.net/publication/366335860_A_new_species_of_Moema_from_the_Pirai_watershed_in_the_SW_Amazon_basin

Resumen: Moema, un género de la familia Rivulidae, actualmente comprende 20 especies válidas. La mayoría de estas especies habitan en charcos temporales de la cuenca amazónica y solo una especie se encuentra en la cuenca alta del Río Paraguay. Un nuevo miembro de este género de la cuenca alta del Río Madeira es descrito aquí. Los machos de la especie nueva se diferencian de todos los congéneres por la combinación de un patrón de color de filas irregulares oblicuas, a veces en forma de chevrón, de puntos dobles rojos y azul claro en el cuerpo; aletas pectorales de color amarillento oscuro a dorado sin marcas visibles; y un patrón de rayas en la sección ventral de la aleta caudal con una línea marginal negra muy estrecha, intermitente o incluso ausente. Se discute la existencia de grupos infragenéricos de especies dentro de Moema, la distribución geográfica y aspectos taxonómicos de las especies presentes en el drenaje de los Ríos Mamoré e Iténez/Guaporé, y la observación de agresión intraespecífica entre machos y estilo de vida anfibio en la nueva especie.

Palabras clave: Cuenca amazónica de Bolivia; Cuerpos de agua temporales; Nueva especie; Rivúlidos; Taxonomía

[Ichthyology • 2019] Farlowella azpelicuetae • A New Species of Farlowella (Siluriformes: Loricariidae) from the upper Bermejo River, La Plata River basin, northwestern Argentina

 

  Farlowella azpelicuetae  

 Terán, Ballen, Alonso, Aguilera & Mirande, 2019

 DOI: 10.1590/1982-0224-20180114 

 Researchgate.net/publication/334060121

 

ABSTRACT

A new species of Farlowella is described from the Bermejo River basin, in Salta and Jujuy provinces, northwestern Argentina. The new species belongs to the Farlowella nattereri species group. The new species is diagnosed by the following combination of characters: marbled rostrum, five rows of lateral plates series, relatively short snout (snout-mouth length less than 50.0% of head length), complete half-moon shaped spot on caudal fin, and short predorsal distance (37.8-41.8% of standard length).

Keywords: Armored catfish; Chaco Ecoregion; Endemic species; Loricariinae; Taxonomy

  Farlowella azpelicuetae 

Argentina, Salta, Bermejo River, La Plata River basin. 

 holotype, CI-FML 7277, 142.4 mm SL, a. lateral, b. dorsal, and c. ventral views. 
 paratype, CI-FML 7265, 193.9 mm SL. a. detail of the coloration of the snout; b. coloration pattern of caudal fin; c. coloration of live specimen.

 
Farlowella azpelicuetae, new species

Diagnosis. Farlowella azpelicuetae differs from most congeners, except F. altocorpus, F. gianetii, F. gracilis, F. hasemani, F. isbrueckeri, F. jauruensis, F. nattereri, and F. odontotumulus, by the presence of five rows on lateral plate series of body (vs. four). Farlowella azpelicuetae differs from F. gracilis, F. hasemani, F. isbrueckeri, F. nattereri, and F. odontotumulus by having proportionally-shorter snout-mouth length (less than 50% HL vs. more than 50% HL). The new species differs from F. jauruensis and F. gianetii by its marbled coloration pattern of snout (vs. snout completely dark and snout darkly pigmented only laterally, respectively). Farlowella azpelicuetae differs from F. altocorpus by having a continuous half-moon pigmentation pattern on the caudal fin (vs. discontinuous half-moon shaped pattern) and by the shorter predorsal length (37.8-41.8 % SL vs. 43.7-45.6% SL). The new species can be further distinguished by the presence of three rows of abdominal plates (vs. two in F. acus, F. amazonum, F. colombiensis, F. henriquei, F. martini, F. rugosa, F. venezuelensis, F. vittata, and F. yarigui and an incomplete median disjunct row of abdominal plates in F. mitoupibo). Additionally, F. azpelicuetae differs from F. hahni, F. knerii, F. oxyrryncha, F. reticulata, and F. schreitmuelleri by having irregular dark brown blotches on ...

Etymology. The species is named azpelicuetae after Dr. María de las Mercedes Azpelicueta, in recognition of her prominent contributions to ichthyology, especially to the systematics of Argentinian fishes. She described numerous species and was essential to the formation of subsequent generations of freshwater fish systematists in Argentina. A matronym in genitive case. 

Guillermo E. Terán, Gustavo A. Ballen, Felipe Alonso, Gastón Aguilera and J. Marcos Mirande. 2019. A New Species of Farlowella (Siluriformes: Loricariidae) from the upper Bermejo River, La Plata River basin, northwestern Argentina. Neotropical Ichthyology. 17(2); e180114. DOI: doi.org/10.1590/1982-0224-20180114

  Researchgate.net/publication/334060121_A_new_species_of_Farlowella_from_La_Plata_River_basin_NW_Argentina

RESUMEN: Se describe una nueva especie de Farlowella de la cuenca del Río Bermejo, en las provincias de Salta y Jujuy, en el noroeste de Argentina. La nueva especie pertenece al grupo de Farlowella nattereri. La nueva especie se diagnostica con la siguiente combinación de caracteres: rostro veteado, cinco hileras de placas laterales en el cuerpo, hocico relativamente corto (longitud hocico-boca menor a 50.0% longitud cabeza), mancha en forma de media luna completa en la aleta caudal, y distancia predorsal corta (37.8-41.8% longitud estándar).

Palabras clave: Ecoregion Chaco; Especie endémica; Loricariinae; Taxonomía; Viejita del agua

[Ichthyology • 2024] Pseudacanthicus nyktos • A New Species of Pseudacanthicus (Siluriformes: Loricariidae) from the rio Xingu, Amazon, Brazil

Pseudacanthicus nyktos

  Lopes, Sousa & Chamon, 2024

www.scielo.br/j/NI 

Abstract

The genus Pseudacanthicus encompasses eight recognized species so far: P. histrix, P. serratus, P. spinosus, P. fordii, P. leopardus, P. pitanga, P. pirarara, P. major. Only P. pirarara has been formally described from the rio Xingu basin. To address this gap in taxonomic knowledge of the region, a new species of the Pseudacanthicus is described here, aimed at enhancing our understanding of the genus within the rio Xingu basin and contributing to conservation efforts. The new species is primarily found downstream the impact zone of the Belo Monte Hydroelectric Power Plant. It can be promptly diagnosed from congeners by the color pattern of the body dark brown to black with light gray vermicular spots on the dorsal and ventral surfaces, and fins; lower maximum number of teeth in premaxilla and dentary; and other osteological characters. It’s worth noting that the ichthyofauna of the Amazonian drainages lacks comprehensive taxonomic and biological information regarding Pseudacanthicus. In this context, unchecked anthropogenic activities are leading to changes in the ecosystem, often resulting in the extinction of species even before they are scientifically addressed.

Keywords: Acanthicus clade; Amazon basin; Ancistrini; Conservation; Taxonomy

Holotype of Pseudacanthicus nyktos, INPA-ICT 060701, 190.18 mm SL, rio Xingu, Vitória do Xingu.
A. Dorsal view; B. Lateral view; C. Ventral view.

Ventral view of mouth and barbels of Pseudacanthicus nyktos. Specimen not preserved.
Premaxillary and dentary teeth of a skeletonized paratype of Pseudacanthicus nyktos (LIA 8173, 154 mm SL).

 

Pseudacanthicus nyktos, new species

Diagnosis: Pseudacanthicus nyktos differs from all congeners by a dark brown to black body with light gray vermicular spots on the dorsal and ventral surfaces, and fins (vs. body with dark gray to dark brown background with black dots or spots and fins with intense orange to red color in P. leopardus, P. pitanga and P. pirarara; body and fins with dark gray background color and white dots or spots in P. serratus and P. fordii, more conspicuous in ventral region; body with a gray color and black dots or spots in P. histrix and P. spinosus; and body with a dark brown color without spots or dots; with white transverse bars on the dorsal and caudal fins ...  

Etymology: The specific epithet nyktos derives from Greek meaning “night”, in allusion to the dark color of the specimens in comparison with other species of the genus and also to the deep locations where they can be found, where there is no light. An adjective.

  Body shape and color in life of Pseudacanthicus nyktos shown to scale.
 Specimens not preserved. Scale bars = 1 cm.

Maria Letícia Batista Galvão Lopes, Leandro Melo de Sousa and Carine Cavalcante Chamon. 2024. New Species of Pseudacanthicus (Siluriformes: Loricariidae) from the rio Xingu, Amazon, Brazil.  Neotrop. ichthyol. 22(3) • 2024 • DOI: 10.1590/1982-0224-2024-0033 www.scielo.br/j/ni/a/XHfLffzyJxq445HxZs4bnkF 

[Ichthyology • 2024] Austrolebias ayoreode • Redescription of Austrolebias accorsii (Cyprinodontiformes: Rivulidae) and Description of A New Species of the Genus from the upper Paraguay River Basin

Austrolebias ayoreode

 Drawert & Ergueta, 2024

DOI: 10.1590/1982-0224-2024-0001  

Abstract

Austrolebias accorsii is redescribed based on specimens from type-locality, nearby temporary pools, and other locations within the same hydrologic unit. Additionally, a novel Austrolebias species is described, exclusively found in two temporary waterbodies in “Abayoy”, a unique vegetation type situated in the transitional zone between the Dry Chaco, Chiquitano Dry Forest, and Pantanal Flooded Savannas ecoregions in southeastern Bolivia, bordering Paraguay, where the last voluntarily isolated indigenous people outside the Amazon in America reside. Diagnostic characters for both species are presented. Within Austrolebias two species groups are recognized with different morphological characters, geographical distribution, and ecological traits of their habitats. Furthermore, we suggest the usage of median and interquartile range rather than mean and standard deviation to analyze morphometric and meristic data of rivulids, given the typically non-Gaussian distribution of this data.

Keywords: Chaco; Killifish; Seasonal fish; Taxonomy; Temporary water bodies

Austrolebias ayoreode. Males (immediately after collection).
Two uppermost: MNKP 16590, paratypes, 34.7–34.8 mm SL, Bolivia, Santa Cruz, Cordillera, Charagua Iyambae Guarani Autonomous Territory, Ñembi Guasu Conservation and Ecological Importance Area.
Lower six: MNKP 16587, paratypes, 21.2–34.7 mm SL, collected with uppermost.

Austrolebias ayoreode. Male and female (1 day after collection).
Above: MNKP 16612, holotype, male, 50.7 mm SL, Bolivia, Santa Cruz, Cordillera, Charagua Iyambae Guarani Autonomous Territory, Ñembi Guasu Conservation and Ecological Importance Area.
Below: MNKP 16587, paratype, female, 38.1 mm SL, collected with holotype.

Austrolebias ayoreode. Females (immediately after collection).
Above: MNKP 16590, paratype, 26.1 mm SL; Bolivia, Santa Cruz, Cordillera, Charagua Iyambae Guarani Autonomous Territory, Ñembi Guasu Conservation and Ecological Importance Area.
Below: MNKP 16587 (vertically flipped), paratype, female, 38.1 mm SL, collected with MNKP 16590.

Austrolebias ayoreode, new species 

Diagnosis. Austrolebias ayoreode males differs from all congeners, except A. accorsii, A. ephemerus,and A. vandenbergi, by presence of 1–3 transverse rows of scales on basal anterior and median portion of anal fin. Males of A. ayoreode can be distinguished from A. accorsii, A. ephemerus, A. melanoorus, A. queguay, and A. vandenbergi by presence of whitish to pale yellowish dots on flanks usually vertically aligned in unarranged rows (vs. absent in A. accorsii; mostly coalesced in vertical bars in A. ephemerus, A. melanoorus, and A. queguay; absent or, when rarely present, sparse and scattered in A. vandenbergi); from A. accorsii and A. vandenbergi by urogenital papilla mostly ...

Etymology. The name ayoreode is an eponym conferred in reference to the indigenous Ayoréode people, who historically occupied vast expanses of the northern Dry Chaco, and of whom a few groups still persist in the area of the type-locality of this species, standing as the last indigenous people in voluntary isolation outside of the Amazon in the Americas. Through this nomenclature, we intent to perpetuate the memory of the existence of the Ayoréode and emphasize the imperative of preserving their ancestral territory, which also is the habitat of the species described herein.

Heinz Arno Drawert and Carlos Ergueta. 2024. Redescription of Austrolebias accorsii (Cyprinodontiformes: Rivulidae) and Description of A New Species of the Genus from the upper Paraguay River basin.   Neotrop. ichthyol. 22 (2); DOI: 10.1590/1982-0224-2024-0001