Living in the waterfalls: A new species of Trichomycterus (Siluriformes: Trichomycteridae) from Tabay stream, Misiones, Argentina

Guillermo Enrique Terán, Juliano Ferrerresearchgate logoMauricio Benitez, Felipe Alonso, Gastón Aguilera  & Juan Marcos Mirande.

Abstract

A new species assigned to the genus Trichomycterus from the area of the waterfalls of Tabay stream, Paraná River basin, Misiones, Argentina, is described. Trichomycterus ytororo sp. nov. is distinguished from all other species in the genus by the presence of 31–35 dorsal procurrent caudal-fin rays and the combination of some external characters such as: coloration, number of pectoral–fin rays and pores of the laterosensory canals. The new taxon belongs to a presumably monophyletic group of species composed of TcrassicaudatusTigobi, and Tstawiarski based on the presence of 24 or more thickly ossified and rigid procurrent caudal-fin rays with a slender distal tip extending along the tips of at least ten neural spines.

Artigo completo: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0179594

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Fig 1. Trichomycterus ytororo, holotype, CI–FML 7240, 94.2 mm SL; Argentina, Misiones Province, Jardín América, Tabay stream, Paraná River basin.

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Fig 4. Geographic distribution of the species assigned to the Trichomycterus stawiarski group: T. crassicaudatus (green symbols), T. igobi (white symbols), T. stawiarski (yellow symbols) and T. ytororo (red symbol). Stars represent the type localities. Some triangles symbols represent more than one collection locality. Numbers 1, 2, 3 indicate the Paraguay, Paraná and Iguazú Rivers, respectively.

 

Laboratório de Ictiologia da UFRGS participando do evento PORTAS ABERTAS.

Alunos de iniciação científica, mestrado, doutorado, Pós-doutorado e professores, participaram de um evento muito importante, que ocorre anualmente em nossa Universidade, que é o de abrir as portas do laboratório e mostrar à comunidade todas as pesquisas que o grupo vem fazendo durante sua vida acadêmica. Visitantes de diferentes idades, desde crianças até famílias inteiras e, principalmente, alunos do ensino médio que estão prestes a participar do Enem e vestibular, vieram até o laboratório  e mostraram todo o interesse em aprender um pouco mais sobre os peixes, passando por diferentes experiências.

Em um primeiro momento houve a apresentação dos integrantes do laboratório, que é formado por alunos de diferentes nacionalidades, seguido de uma explicação de como se faz uma correta coleta de peixes com diferentes metodologias como: rede de espera, rede de arrastro, puçá, tarrafa e pesca elétrica. Em continuação às coletas, foi mostrado também como se faz a  triagem e catalogação das espécies que são depositadas na coleção científica da UFRGS.   Posteriormente se mostrou as diferentes técnicas para estudar os peixes em trabalhos de taxonômica e evolução, desde como estudar a osteologia com a técnica de diafanização até os trabalhos utilizando DNA. Além disso, o grupo também mostrou como se fazem pesquisas relacionadas à biologia alimentar e reprodutiva de peixes que incluem, respectivamente, análises da dieta e definição do período reprodutivo utilizando técnicas de cortes histológicos. Foi chamada a atenção dos visitantes que todos esses resultados de pesquisas do laboratório são publicados em congressos, revistas científicas e relatórios, ficando, portanto, disponíveis à sociedade. E, para finalizar foi enfatizada a importância que essas pesquisas apresentam, uma vez que aportam um melhor e maior conhecimento de nossa biodiversidade e nos capacitam a propor medidas de manejo e conservação dos mais variados tipos de ambientes aquáticos.

 

A new predatory herring-like fish (Teleostei: Clupeiformes) from the early Cretaceous of Brazil, and implications for relationships in the Clupeoidei

Abstract

Cynoclupea nelsoni gen. et sp. nov., is described from Lower Cretaceous (Barremian-Aptian) sediments of the Morro do Chaves Formation in north-eastern Brazil. Diagnostic characters of the Clupeomorpha, such as abdominal and dorsal scutes, a pre-epiotic fossa, and an otophysic connection, were identified in C. nelsoni. The presence of the recessus lateralis furthermore indicates that the species is a member of the Clupeiformes. Given the absence of odontodes covering the skull bones, which are synapomorphic to the Denticipitoidei, and the apparent presence of a postorbital branch of the supraorbital sensory canal located deep within the body of the lateral wing of the frontal, C. nelsoni is assigned to the suborder Clupeoidei. In this suborder, derived character states of the suspensorium indicate that Cynoclupea is the sister group of a clade composed of the Chirocentridae (wolf-herrings) and Engraulidae (anchovies). The evolution of abdominal scutes and of microphagy vs. macrophagy in the Clupeoidei are discussed in light of this hypothesis. The discovery of Cynoclupea supports not only the existence of a diversified freshwater clupeiform fauna as early as in the Barremian-Aptian, but also indicates that the divergence between the Clupeoidei and Denticipitoidei must have occurred before this interval.Artigo completo: https://academic.oup.com/zoolinnean/article/180/1/175/3799580

Figure 2. Cynoclupea nelsoni gen. et sp. nov., MCP3447-PV (holotype), part (A) and counterpart (B). Scale bars = 1 cm.

PARABÉNS Priscilla C. Silva, NOVA DOUTORA DO LABORATÓRIO DE ICTIOLOGIA!!

Priscilla C. Silva defendeu na última sexta-feira, dia 26 de abril , sua tese de doutorado

SISTEMÁTICA INTEGRATIVA – DIVERSIDADE E RELAÇÕES DE DEUTERODON E GÊNEROS AFINS

A banca esteve constituída pelo

                                                  Prof. Dr. Fernando Rogério de Carvalho (UFMS)

                                                  Prof. Dr. Fernando Camargo Jerep (UEL)

                                                  Prof. Dr. Jorge Abdala Dergam dos Santos (UFV)

Orientada pelo Prof. Dr. Luiz Roberto Malabarba

Mostrando IMG-20170426-WA0017.jpg

Mostrando IMG-20170426-WA0021.jpg

Review of the Odontesthes perugiae species group from Río de La Plata drainage, with the description of a new species (Atherinomorpha: Atherinopsidae)

JULIANA M. WINGERTresearchgate logo , JULIANO FERRERresearchgate logo, LUIZ R. MALABARBA researchgate logo

Specimens presently identified as belonging to Odontesthes perugiae species group from rio Paraná, rio Uruguay and rio Negro in Argentina, Brazil and Uruguay are revised. Two species are recognized: Odontesthes perugiae, type species of the genus with Odontesthes orientalis as a junior synonym, and a new species described herein. Odontesthes perugiae is redescribed and its distribution restricted to the lower rio Paraná, lower rio Uruguay and rio Negro basins. The new species is endemic from the upper rio Uruguay above Salto do Yucumã (Brazil) or Saltos del Moconá (Argentina) falls. Both species share with the remaining taxa included in the O. perugiae species-group (O. bicudo, O. ledae, O. mirinensis, and O. piquava) the possession of teeth of the outer row on dentary and premaxilla shorter than those in the inner row, being distinguished from them by the number of gill rakers, body measurements and some osteological characters.

Artigo completo: http://biotaxa.org/Zootaxa/article/view/zootaxa.4250.6.1

FIGURE 17. Odontesthes yucuman, nontype, UFRGS 19389, 168.7 mm SL, just after fixation, rio Uruguay at reservoir of the Itá Hydroelectric Power Plant, Itá, Santa Catarina State, Brazil (Photo by Renata Guereschi).

FIGURE 18. Detail of teeth on dentary and premaxilla from medial view of Odontesthes yucuman, paratype, UFRGS 17840, 114.2 mm SL, indicating the small teeth of the outer row and the large teeth of the inner row. Scale bar = 1 mm.

 

FIGURE 5. Lateral views of head of Odontesthes perugiae (a), MCP 43030, 148.5 mm SL, and O. yucuman (b), paratype, UFRGS 11671, 156.6 mm SL, showing the differences in head shape and size of snout and eye.

 

Using ancient DNA to unravel taxonomic puzzles: the identity of Deuterodon pedri (Ostariophysi: Characidae)

Priscilla C. Silvaresearchgate logoMaria C. Malabarbaresearchgate logoLuiz R. Malabarbaresearchgate logo

Accurate identification is essential for any study exploring biodiversity. Unfortunately, museum type specimens preserved for more than a hundred years are often not informative enough for precise identification of the species represented by the name-bearing type. The use of ancient DNA can help solve taxonomic problems when name-bearing types no longer have diagnostic morphological features that allow for an accurate identification of the species involved. That is the case for Deuterodon pedri, an endemic species from a small drainage in the rio Doce basin in Minas Gerais, Brazil, for which the type material is in poor condition. Specimens of D. pedri were collected in 1865 by the Thayer Expedition to Brazil and fixed in spirits, enabling them to yield viable DNA. As the morphology alone of the type material does not allow for an accurate identification, we used both morphological and ancient DNA (aDNA) methods to decisively establish the identity of D. pedri. This identification allowed us to recognize the species among recently collected specimens and then, based on them, redescribe the species. A genetype for the lectotype of D. pedri is presented.

Artigo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000100224&lng=en&nrm=iso&tlng=en

Fig. 3 Two paralectotypes of Deuterodon pedri, MCZ 17510. a-c. Photograph and X-ray computed tomography of the paralectotype with 72.1 mm SL, showing the dentary teeth decreasing gradually in size, corresponding to D. pedri. b-d. Photograph and X-ray computed tomography of the paralectotype with 58.6 mm SL, showing the dentary teeth decreasing abruptly, corresponding to Astyanax intermedius

Fig. 2 Neighbor Joining tree and Haplotype network showing high similarity between specimens collected at rio Santo Antônio basin and sequence of the lectotype of Deuterodon pedri. a. Neighbor joining tree with bootstrap values. b. Haplotype network of D. pedri clade. Numbers in each branch of the net refer to number of mutational steps between haplotypes. 

Ontogenetic changes in mouth morphology triggers conflicting hypotheses of relationships in characid fishes (Ostariophysi: Characiformes)

Hirschmann Aliceresearchgate logo; Fagundes Nelson J. R.; Malabarba, Luiz Rresearchgate logo.

Bryconamericus lethostigmus is the type-species of the monotypic genus Odontostoechus, diagnosed in part based on the presence of a unique tooth series in the premaxilla. Recently a new proposal of classification of the Stevardiinae placed Odontostoechus as a junior synonym of a monophyletic genus Bryconamericus sensu stricto, a genus characterized by the presence of two tooth series. Bryconamericus lethostigmus is redescribed herein and the single tooth series in the premaxilla is demonstrated to originate from merging of the external tooth row with the inner row during ontogeny refuting primary hypothesis of homology between the mouth morphology of B. lethostigmus and the genera Bryconacidnus, Ceratobranchia, Monotocheirodon, Othonocheirodus, Rhinopetitia and Rhinobrycon. A phylogeographic analysis indicated that the pattern described for the sympatric species Diapoma itaimbe is not mirrored by B. lethostigmus. The results also do not support the hypothesis of a new species in the rio Araranguá drainage.

Artigo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000100212&lng=en&nrm=iso&tlng=en

Fig. 2 Bryconamericus lethostigmus. a. holotype, 48.68 mm SL (UMMZ 143272); b. color in life in a fresh collected specimen, rio Três Forquilhas basin, Itati, Rio Grande do Sul, Brazil, UFRGS 16500. 

Fig. 3 Bryconamericus lethostigmus. a. detail of the mouth of a small specimen, with teeth covered by the lips (UFRGS 16083, 24.5 mm SL); b. detail of the mouth of a large specimen with upper lip atrophied and showing the premaxillary teeth (UFRGS 20660, 54.3 mm SL). 

Fig. 5 Ontogenetic changes in the number of tooth rows of the premaxilla, number of teeth in the maxilla and shape of these bones in Bryconamericus lethostigmus. a. 24.1 mm SL (UFRGS 19488); b. 50.4 mm SL (MCP10774); c. 60.9 mm SL (MCP 19173). 

A new species of Hoplomyzon (Siluriformes: Aspredinidae) from Maracaibo Basin, Venezuela: osteological description using high-resolution computed microtomography of a miniature species

Tiago P. Carvalhoresearchgate logo Roberto E. Reis,   John P. Friel

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).

Artigo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000100216&lng=en&nrm=iso&tlng=en

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

Fig. 3 HRXCT model of skull and anterior body of Hoplomyzon cardosoi, MCNG 375, holotype, 18.5 mm SL. a. Dorsal view. b. Lateral view of left side. acf: anterior cranial fontanel; ang: anguloarticular; bp: basipterygium; br: branchiostegal rays; cl: cleithrum; cv: complex vertebrae; den: dentary; dfr: dorsal-fin rays; fr: frontal; hyo: hyomandibula; iop: interopercle; let: lateral ethmoid; mes: mesethmoid; met: metapterygoid; mnp: middle nuchal plate; mx: maxilla; na: nasal; pal: autopalatine; pcf: posterior cranial fontanel; pch: posterior ceratohyal; pfr: pectoral fin rays; pll: posterior lateral line plates; pmx: premaxilla; ps: pectoral-fin spine; pto: pterotic; qu: quadrate; sc: postemporo-supracleithrum; soc: parietal-supraoccipital; spo: sphenotic; io1: infraorbitals; iop: interopercle; infraorbital 1; sup: subpreopercle; pv5: parapophysis of vertebra 5; v6: vertebra 6; v9: vertebra 9; v11: vertebra 11; vdp11: vertebral dorsal process of vertebra 11; vfr: pelvic-fin rays. Scale bar = 1 mm. 

Biological invasion at an early stage? First record of the banjo catfish Pseudobunocephalus iheringii (Siluriformes: Aspredinidae) in the Tramandaí river basin, Brazil and the potential invasion pathway to this system

R. A. Silveira, J. Ferrerresearchgate logo , F. G. Becker and S. M. Hartz

Biological invasion by species that are not naturally present in a native assemblage (nonnative species) is a multi-stage process (Blackburn et al., 2011). However, perception of an invasive process is difficult in early stages of the process, when abundance is very low and distribution is very limited. Understanding biological invasions and, eventually, taking management measures to prevent them, depends on early detection of the invasion process (Kolar and Lodge 2001). The presence of nonnative fish species has been reported in the Tramandaí river basin (Schifino et al., 2004; Artioli and Maia 2010; Artioli et al., 2013), but their introduction pathway in the Tramandaí river basin is unknown. A plausible possibility points to the artificial water channels in the wetlands and rice fields at the watershed divide between the Laguna dos Patos basin and the Tramandaí river basin. The aim of this paper is to report the occurrence of Pseudobunocephalus iheringii (Boulenger 1891) in an artificial channel in the watershed divide between the Laguna dos Patos basin and the Tramandaí river basin, in southern Brazil. This report represents the first record of an additional nonnative species in the Tramandaí basin, documents the early stage of a potential invasion process in this system, and represents the first evidence for the role of artificial water channels as invasion pathways for nonnative fish species into the Tramandaí basin, affecting two aquatic ecoregions (Laguna dos Patos and Tramandaí-Mampituba; Abell et al., 2008).

We argue that the absence of previous records in the Tramandaí river basin and the current establishment of artificial channels connecting the Laguna dos Patos and Tramandaí basin corroborate the hypothesis that this area may be the invasion pathway not only for P. iheringii, but probably for other previously recorded invasive species (Schifino et al., 2004; Artioli and Maia, 2010; Artioli et al., 2013). This inter-basin connection has been facilitated by local landscape characteristics, such as low terrain and large wetland areas, which allowed the development of rice fields and their associated network of artificial water channels (Becker et al., 2007), increasing the connectivity between two aquatic ecoregions (the Laguna dos Patos and Tramandaí-Mampituba).

Article: http://www.scielo.br/pdf/bjb/2017nahead/1519-6984-bjb-1519-698401716.pdf

Figure 1. (A) Map showing the sample unit where the three specimens of Pseudobunocephalus iheringii were collected; (B) The dorsal and ventral views of one individual of P. iheringii (UFRGS 20672, SL =30.94 mm).

 

Description of a New Blind and Rare Species of Xyliphius (Siluriformes: Aspredinidae) from the Amazon Basin Using High-Resolution Computed Tomography

Tiago P. Carvalhoresearchgate logo, Roberto E. Reis and Mark H. Sabaj

Xyliphius sofiae, new species, is described based on a unique specimen exhibiting four autapomorphies: eyes absent vs. present (though reduced); color pale, lacking pigment vs. head and body darkly pigmented; branchiostegal rays five vs. four; and unculiferous tubercles on posterior body distributed evenly vs. enlarged unculiferous tubercles typically arranged in five distinct rows above pelvic-fin base to posterior end of caudal peduncle. In addition, the pectoral fin of X. sofiae, new species, has one ossified proximal radial vs. two in congeners (except X. magdalenae, not examined). Xyliphius sofiae, new species, differs from all congeners except X. lepturus by snout tip elongated and narrowly rounded vs. short and broadly rounded, often with small median notch; fifth ceratobranchial relatively narrow with elongate acicular teeth vs. broadly expanded, leaf-shaped, with shorter and broader, conical teeth; anterior limits of branchial apertures separated by distance less than length of aperture vs. greater than length of aperture; anal-fin rays modally nine vs. seven; and lateral line extending onto base of caudal-fin rays vs. finishing in hypural region. Based on the single specimen collected in the main channel of the Río Amazonas near Iquitos, Peru, we describe the osteology of X. sofiae, new species, using a non-invasive technique: high-resolution X-ray computed tomography (HRXCT). We consider Xyliphius lombarderoi Risso and Risso, 1964, a species based on a unique holotype that is now lost, to be a subjective junior synonym of X. barbatus Alonso de Arámburu and Arámburu, 1962. Variable characteristics are summarized for the seven species of Xyliphius treated here as valid, and their distributions are plotted based on a comprehensive review of museum specimens.

Article: http://www.asihcopeiaonline.org/doi/abs/10.1643/CI-16-456

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Holotype of Xyliphius sofiae, ANSP 182322, 44.1 mm SL, Rio Amazonas in vicinity of Iquitos, Loreto, Peru. (A–C) Alcohol preserved (scale bar =5 mm). (D) Live. Photos by M. Sabaj.