Relationship between diet and pharyngeal jaw morphology of Crenicichla species (Cichliformes: Cichlidae) in streams from Uruguay and Jacuí basins, Southern Brazil

Fernanda Kuhn, Mayara Pereira Neves, Karine Orlandi Bonato & Clarice Bernhardt Fialho

Abstract

Cichlidae have a magnificent ecological versatility that provides the species to explore many trophic niches, and behavioural biology. This versatility was achieved by modifications in the cranial and pharyngeal apparatus of cichlids. Accordingly, we aim to examine the relationships between pharyngeal morphology and diet of three species of the genus Crenicichla. We analysed the stomach contents and the morphology (through the geometric morphometric and teeth types) of their lower pharyngeal jaws (LPJ). We tested the hypothesis that LPJ morphology predicts the diet of Crenicichla species in streams. Our results indicated that the diet and the patterns of pharyngeal jaws were different among the species of Crenicichla, mainly the posterior process of the LPJ, the region of muscle insertion of LPJs with the neurocranium and the curvature of LPJ. Variation among the lower pharyngeal jaw shapes was shown to be directly associated with the use of food resources. Crenicichla species had a carnivorous diet based on fish and invertebrates (Aegla and aquatic insects). Higher fish consumption was observed in species with elongated lateral process in the LPJ and larger numbers of teeth, mainly recurved and conical unicuspid and bicuspid teeth (C. scottii and C. lepidota). On the other hand, higher consumption of Aegla was associated with a robust LPJ and molariform teeth (C. punctata). The total number of teeth was positively correlated with higher fish consumption. In addition, our results point to the need for investigations about spatial-temporal variations in Crenicichla diets to understand this group’s success in several freshwater environments

Link: https://link.springer.com/article/10.1007%2Fs10641-020-00963-y

a Live representatives of C. lepidota (1), C. punctata (2), and C. scottii (3); b ventral view of lower pharyngeal jaw; c summaries of their stomach contents. Aquatic insects; Terrestrial insects; Other aquatic invertebrates; Aegla; Fish; Plant remains; ■ Detritus

Ventral and lateral view of lower pharyngeal jaw and dentition of 1C. lepidota; 2C. punctata; 3C. scottii from streams, Upper Jacuí and Ibicuí sub-basins, Southern Brazil. Teeth types: a) Bicuspid; b) Recurved unicuspid; c) Conical unicuspid; d) Molariform

A new species of Hemiodus Müller (Characiformes: Hemiodontidae) from the lower Rio Xingu, Brazil

Ivanilza Da Silveira Silva, Acácio Freitas Nogueira, Andre Luiz Netto-Ferreira, Alberto Akama & Guilherme Moreira Dutra,

Abstract
A new species of Hemiodus is described from the Rio Xingu basin, Pará, Brazil. It is distinguished from congeners by the combination of presence of a dark longitudinal stripe extending from head to tip of lower caudal-fin lobe, an oblique blotch on dorsal-fin, 9–11 scale rows above lateral line, 58–66 perforated lateral line scales, and 17–20 circumpeduncular
scales. Comments on the conservation status of the new species, as well as its relationships among Hemiodus species, are made.

Link: https://www.biotaxa.org/Zootaxa/article/view/zootaxa.4751.1.11

Upper : Hemiodus tucupi, MPEG 36362, holotype, 66.5 mm SL, Igarapé Bacajaí, Rio Xingu basin, Pará, Brazil.        Lower: Hemiodus tucupi, live specimen, paratype, INPA 43494, 62.7 mm SL, Rio Xingu at middle portion of Volta Grande, Pará, Brazil. Photo by Mark Sabaj.

Morphological traits correlated with resource partitioning among small characin fish species coexisting in a Neotropical river

Rosilene Luciana Delariva and Mayara Pereira Neves

Abstract

Body shape variation should play a central role in determining the feeding ability of a fish species. We tested whether variations in feeding resource use of sympatric and closely related fish species could be explained by differences in ecologically relevant metrics, such as body morphology, trophic apparatus or combinations thereof. Fish were sampled at 14 sampling sites from Pelotas River and tributaries, Upper Uruguay, Brazil. The stomach contents of five species of Characidae (Astyanax and Bryconamericus ) were analysed by the volumetric method. A geometric morphometric approach was used together with internal morphological traits to predict their patterns of prey use. Significant differences in body depth, snout and caudal peduncle lengths were found. Concomitant pronounced variations were verified to occur among species in structures related to digestion and absorption. Increased numbers of cusps, more pyloric caeca and higher intestinal coefficient values were observed in species that consumed greater proportions of plants. The opposite trends occurred in species that consumed greater proportions of insects. Mixed linear models indicated that the characin species differed significantly in the use of algae, aquatic insects, terrestrial insects, plant remains/seeds and detritus. Dietary differences reflected in low trophic niche overlap. Partial least squares regression results indicated strong correlations between morphological divergences and the corresponding variations in species diet. These outcomes combined confirm that the morphological traits that best enables the exploration of certain resource were an important factor in the resource‐related divergence and were the underlying reasons for these species’ respective feeding modes.

Link: https://onlinelibrary.wiley.com/doi/abs/10.1111/eff.12540

Study area and sampling sites in the main channel of the Pelotas River (C) and its tributaries (T), Upper Uruguay ecoregion, Brazil. The pie charts represent the numerical abundance (%) of the species

Principal component analysis (PCA) results showing biologically important differences in body shape among characin fish species in the Pelotas River basin, Upper Uruguay ecoregion. Thin-plate spline transformations of landmark positions represent the extreme transformations of body shape measurements along the PC axes

PARABÉNS Emília W. Wendt, NOVA DOUTORA DO LABORATÓRIO DE ICTIOLOGIA!!

Emília W. Wendt, defendeu na última quarta-feira, día 29 de abril , sua tese de doutorado

ASSOCIAÇÃO PARASITO-HOSPEDEIRO: ABORDAGENS FILOGENÉTICA, BIOGEOGRÁFICA E COEVOLUTIVAS EM GRUPOS DE AGUA DOCE NO SUDESTE DA AMÉRICA DO SUL

A banca esteve constituída pelos

Prof. Dr. Rogerio Tubino Vianna –  FURG/ICB/LABIPOA/PPGBAC

Prof. Dr. Augusto Ferrari – FURG/ICB

Prof. Dr. Brian Sidlauskas – Fisheries Oregon State University, Corvallis, USA.

Orientada pelo Prof. Dr. Tiago Pinto Carvalho

Co-orientada pelo Prof. Dr. Luiz Roberto Malabarba

  

Rapid assessment of the ichthyofauna of the southern Guiana Shield tributaries of the Amazonas River in Pará, Brazil

Guilherme M. DUTRA, Tiago M. S. FREITAS, Bruno S. PRUDENTE, Gilberto N. SALVADOR, Manuela D. V. LEÃO, Luiz A. W. PEIXOTO, Marina B. MENDONÇA, André L. NETTO-FERREIRA, Fabio R. SILVA, Luciano F. A. MONTAG, Wolmar B. WOSIACKI

ABSTRACT

The Northern Pará Drainage System encompasses the left-bank tributaries of the Amazonas River in the southern Guiana Shield region of Pará state, Brazil. Five of the region’s state protected areas are considered strategic for the conservation of its biodiversity. In the present study, we assessed the ichthyofauna of the five state protected areas of the Northern Pará Drainage System. Seven expeditions were conducted between January 2008 and January 2009, which surveyed stretches of the Cuminá, Cuminapanema, Curuá, Jari, Mapuera, Nhamundá, and Paru rivers. These surveys yielded 286 species belonging to 38 families and eight orders, including seven new records of fish species for Brazil, six of which are also new records for the Amazon basin. Our results provide a valuable database for future research and conservation programs in the protected areas of the region.

Keywords: Northern Pará Drainage System; protected areas; Amazon; inventory; fish

link: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672020000100024&tlng=en

Figure 5 Examples of the fish species collected in the southern Guiana Shield tributaries of the Amazonas River, in the five state protected areas of the Northern Pará Drainage System, in northern Brazil. (A) Astyanax anterior, MPEG 18207, 81.6 mm SL. (B) Hyphessobrycon cf. agulha, MPEG 18181, 25.8 mm SL; (C) Hyphessobrycon georgettae, MPEG 34100, 19.0 mm SL; (D) Jupiaba abramoides, MPEG 18204, 70.8 mm SL; (E) Jupiaba atypindi, MPEG 17244, 39.8 mm SL; (F) Jupiaba potaroensis, MPEG 18159, 20.9 mm SL; (G) Moenkhausia chrysargyrea, MPEG 18204, 61.8 mm SL; (H) Phenacogaster simulata, MPEG 15597, 22.8 mm SL; (I) Bryconops aff. affinis, MPEG 18149, 22.3 mm SL; (J) Bryconops cf. colaroja, MPEG 17232, 94.5 mm SL; (K) Corydoras sp., MPEG 19162, 22.2 mm SL; (L) Corydoras baderi, MPEG 18238, 26.9 mm SL; (M) Corydoras guianensis, MPEG 15715, 25.8 mm SL. This figure is in color in the electronic version

 

PARABÉNS MATEUS SANTOS DE SOUZA , NOVO MESTRE EM ICTIOLOGIA!!

Mateus Santos de Souza apresentou na última sexta-feira, dia 28 de fevereiro, sua Dissertação:

PIRATAS DE AGUA DOCE: TESTANDO HISTÓRIAS DE CAPTURA DE RIO EM PEIXES ATRAVÉS DE DADOS GENÉTICOS

A banca esteve constituída pelo:

Dr. Marcelo Gehara (Rutgers University)

Dr. Sandro Bonatto (PURCS)

Dr. Luiz Roberto Malabarba (UFRGS-PPGBAN)

Orientado pelo Prof. Dr. Neslon Jurandi Rosa Fagundes

Co-orientado pela: Dra. Andréa Tonolli Thomaz

 

Phylogenetic relationships of a new genus and species of stevardiine fish (Characiformes: Characidae: Stevardiinae) from the Río Amazonas basin, Peru

James A. Vanegas‐Ríos, Dario R. Faustino‐Fuster, Vanessa Meza‐Vargas, Hernán Ortega

Abstract

Varicharax nigrolineatus, a new genus and species of stevardiine fish, is described from the Río Amazonas basin, Peru, based on a comprehensive phylogenetic comparison with other characids. Two data sets (A: combined morphological and molecular matrix, 474 species and 6,653 characters; B: morphological matrix, 216 species and 524 characters) were used to estimate the phylogenetic relationships of the new genus. Morphological and molecular data from these data sets were taken from two previously published matrices on characids. Varicharax nigrolineatus is phylogenetically diagnosed by 18 autapomorphies in total (from both data sets), which are related to different anatomical characteristics of the neurocranium, body, and fins. Furthermore, V. nigrolineatus can be easily differentiated from all characids (except Acrobrycon in part) by the following combination of characters: the presence of a hypertrophied caudal‐fin squamation on the lower caudal‐fin lobe forming a remarkable pouch‐like structure, consisting of multiple series of large adjacent scales (being almost similar or slightly more pronounced in males than in females), the presence of caudal‐fin bony hooks on the lower lobe in adult males, complete lateral line, and a dark mid‐lateral stripe that extends from the posterior border of the head to caudal peduncle. In the resulting topologies from both data sets, the phylogenetic placement of V. nigrolineatus was well supported within Stevardiinae. Additionally, V. nigrolineatus was resolved within the tribe Stevardiini as sister group of a clade formed by Chrysobrycon + Pseudocorynopoma and Corynopoma + Gephyrocharax in the final hypothesis from the combined data set, whereas in the final topology from the morphological data set, V. nigrolineatus was placed as sister group of a clade comprised of Acrobrycon and the Stevardiini without Argopleura.
https://onlinelibrary.wiley.com/doi/full/10.1111/jzs.12346

Phylogenetic relationships of Varicharax nigrolineatus within Stevardiinae obtained from the data set A (combined molecular and morphological matrix) (L = 58,206; Fit = 968.263752) using extended implied weighting. Node numbers are indicated above branches. Support values are presented below branches and separated by a slash (Absolute frequency/GC value). Full tree available as Figure S1

Varicharax nigrolineatus, (a) MUSM 60288, male, holotype, 36.1 mm SL; (b) MUSM 58235, female, paratype, 27.9 mm SL, collected with holotype

First record of Astyanax bifasciatus Garavello & Sampaio, 2010 (Teleostei, Ostariophysi, Characidae) in the Piquiri river basin, upper Paraná river basin

Mayara P. Neves, Priscilla C. Silva, Rosilene L. Delariva, Clarice B. Fialho, Andre L. Netto-Ferreira

Abstract

Astyanax bifasciatus Garavelo & Sampaio, 2010 was originally described as endemic to the Iguaçu river basin. Between March 2017 and January 2018, specimens of A. bifasciatus were sampled during expeditions to headwater streams of the Piquiri river basin, upper Paraná river basin. The identification was confirmed both by morphological and molecular analyses, representing, therefore, the first record of the species outside of the basin of the Iguaçu River. In addition, the lack of structuring in the haplotype network confirms that the representatives of A. bifasciatus from both basins appear to comprise a single population.

Keywords: Distribution range, DNA barcode, endemicity, headwater streams, species identification

https://checklist.pensoft.net/article/47628/

Figure 2. Astyanax bifasciatus. A. UFRGS 26235, 85.0 mm SL, Arquimedes stream, lower Iguaçu river basin, Paraná, Brazil. B. UFRGS 26231, 91.3 mm SL, Carreira stream, Piquiri river basin, upper Paraná river basin, Paraná, Brazil.

Fishes community composition and patterns of species distribution in Neotropical streams

Laísa Wociechoski Cavalheiro  & Clarice Bernhardt Fialho

ABSTRACT:

The ichthyofauna of streams in the Neotropical region is not yet fully known. This study aims to investigate the ichthyofauna composition of six streams of the Ijuí River sub-basin, Rio Grande do Sul State, inserted in the Uruguay River basin, as to contribute to the knowledge of fishes species richness and distribution in the south of Brazil. Sampling was carried out between July 2015 and May 2016, bimonthly, using the technique of electric fishing to collect the fishes. Spatial variations (per sampled stream) in the ichthyofauna composition were tested with a permutational multivariate analysis of variance. In total, we collected 5,029 individuals from 55 species, 13 families and five orders. From these species, 17 are endemic to the Uruguay River basin. Five species alone represented approximately 70% of the ichthyofauna abundance sampled. Our hypothesis that the fish community composition is not homogeneous along the streams sampled was confirmed and we observed that species complexity increases from the upstream closest area to the downstream according to the river continuum concept.

Keywords: Abundance; Characidae; Heptapteridae; Loricariidae; Richness; Uruguay River basin

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032020000100302

Figure 1 Location of the sampled streams in the Ijuí River sub-basin and its respective position into the Uruguay River hydrographic basin, Brazil.

Biogeography, habitat transitions and hybridization in a radiation of South American silverside fishes revealed by mitochondrial and genomic RAD data

Lily C. Hughes , Yamila P. Cardoso, Julie A. Sommer, Roberto Cifuentes, Mariela Cuello, Gustavo M. Somoza, Mariano González‐Castro, Luiz R. Malabarba, Victor Cussac, Evelyn M. Habit, Ricardo Betancur‐R & Guillermo Ortí

Abstract

Rivers and lake systems in the southern cone of South America have been widely influenced by historical glaciations, carrying important implications for the evolution of aquatic organisms, including prompting transitions between marine and freshwater habitats and by triggering hybridization among incipient species via waterway connectivity and stream capture events. Silverside fishes (Odontesthes) in the region comprise a radiation of 19 marine and freshwater species that have been hypothesized on the basis of morphological or mitochondrial DNA data to have either transitioned repeatedly into continental waters from the sea or colonized marine habitats following freshwater diversification. New double digest restriction‐site associated DNA data presented here provide a robust framework to investigate the biogeographical history of and habitat transitions in Odontesthes. We show that Odontesthes silversides originally diversified in the Pacific but independently colonized the Atlantic three times, producing three independent marine‐to‐freshwater transitions. Our results also indicate recent introgression of marine mitochondrial haplotypes into two freshwater clades, with more recurring instances of hybridization among Atlantic‐ versus Pacific‐slope species. In Pacific freshwater drainages, hybridization with a marine species appears to be geographically isolated and may be related to glaciation events. Substantial structural differences of estuarine gradients between these two geographical areas may have influenced the frequency, intensity and evolutionary effects of hybridization events.

https://onlinelibrary.wiley.com/doi/full/10.1111/mec.15350

(a) Marine and freshwater areas currently occupied by species of Odontesthes in southern South America, and photograph of Odontesthes perugiae by Y. P. Cardoso. (b) Sampling localities for ddRAD‐sequenced samples (see Appendix S1: Table S2 for description of population codes). (c) 2006 Morphological phylogenetic hypothesis for all Odontesthes species (Dyer, 2006), although lacking the newly described O. yacuman (Wingert, Ferrer, & Malabarba, 2017). Marine lineages are shown with grey branches. Shapes with black outlines indicate that cytb or ddRAD data were collected for this study for that species. (d) Maximum likelihood molecular hypothesis based on seven nuclear genes and cytb (Campanella et al., 2015), including three outgroups that inhabit the northern Pacific Ocean that are not otherwise included in this study. Branch lengths for molecular hypotheses are shown in substitutions per site, and grey branches indicate marine lineages. Species included in this study have black outlines around their shapes