Browsing by Autor "Wilson S. Serra"

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A new species of the Phalloceros harpagos species complex (Cyprinodontiformes: Poeciliidae) from the middle and lower Uruguay River floodplains
(Fundación Miguel Lillo, 2025) Wilson S. Serra; Fabrizio Scarabino; Noelia Gobel; Gabriel Laufer
Phalloceros mimbi sp. nov. is described from specimens collected in the floodplains of the middle and lower Uruguay River in Uruguay (Río Negro and Salto Departments) and Argentina (Entre Ríos Province). This species belongs to the P. harpagos species complex and is diagnosed by the following unique combination of characters: 1) presence of a symmetric hood-like structure located immediately anterior to the urogenital papilla in females, 2) absence of large papillae at the mandibular symphysis of large adult females, 3) possession of well-developed hooks positioned in distal portion of gonopodial appendices of males and4) lateral spot usually present in both sexes. To date, P. mimbi has not been found coexisting in sympatry with other Phalloceros species. The geographically closest species is P. caudimaculatus, who differs from P. mimbi by the absence of hooks in gonopodial appendix in males. Two of the three known populations of P. mimbi are relatively protected from the main threats to the species. However, conservation initiatives should consider its presence and ensure that it receives the necessary attention; considering that its global distribution occupies less than 200.000 km2 and its occurrence area represents less than 10% of the national territory it must be considered a priority for conservation and an Threatened Species for the species list of Sistema Nacional de Áreas Protegidas (SNAP) of Uruguay.
Characidium serrano Buckup & Reis, 1997 (Characiformes, Crenuchidae): insights into phylogenetic relationships, and comments on distribution
(Fundación Miguel Lillo, 2025) Wilson S. Serra; Fabrizio Scarabino; Víctor Ezequiel Mettola; Martín Miguel Montes; Guillermo Terán; Melisa Moncada; Graciela Sanguinetti; Alejandro Duarte; Matías García
Characidium is the most diverse genus within the family Crenuchidae, with a total of 88 valid species, although there is evidence that it is probably a polyphyletic group. Recent expeditions to northern Uruguay revealed the first records of Characidium serrano Buckup & Reis, 1997, extending its distribution in about 300 km to the south and allowingto consider it as an endangered species for Uruguay, considering its restricted distribution in the country. Different phylogenetic reconstructions and comparisons based on COI (Model-based analysis, Parsimony analysis and Evolutionary Divergence between sequences) of new sequences with those previously published indicate: 1) a closer phylogenetic relationship of C. serrano with C. clistenesi or alternatively with (C. rachovii + C. orientale) than with C. pterostictum and 2) non-coincident topologies that in all cases suggest the non-monophyly of Characidium.The analyzed sequences of the genus Characidium formed 9 main stables groups that are obtained in each of the analyzes carried out, which were also recovered in studies previously performed by other authors, but with general topologies not coincident and poorly supported in their basal nodes.
Expect the unexpected: a new species of killifish from a highly stochastic temporary wetland near Iguazú Falls (Cyprinodontiformes: Rivulidae)
(NRC Research Press, 2024) Felipe Alonso; Guillermo Terán; Pablo Calviño; Wilson S. Serra; Martín Miguel Montes; Ignacio García; Jorge Barneche; Liliana Ciotek; Pablo Giorgis; Jorge Rafael Casciotta
We describe Argolebias adrianae, a new species of killifish from a small temporary wetland in the Paraná Forest ecoregion with no regular or predictable temporal pattern of water availability. This habitat is in the Lower Iguazú River Basin, known for its high fish endemism, but until now, only two species of Rivulidae were reported from it, but from the Araucarian Forest ecoregion. The genus Argolebias was previously only known from the lower portions of the Paraguay, Paraná, and Uruguay basins and middle Paraná. The new species is distinguished from all congeners by its unique coloration, which includes a conspicuously dark grey anterior third portion of the dorsal fin and the absence of iridescent spots on the basal half of the pectoral fin in live adult males, as well as dark grey spots on the anterocentral portion of the flanks of females. Our phylogenetic analysis shows A. adrianae to be closely related to Argolebias guarani from the adjacent Middle Paraná basin. We also provide data on the ecology, ontogeny of coloration, and chorion ornamentation of this species. Our findings have important implications for understanding the biogeography, ecology, and evolution of mechanisms that enable organisms to thrive in highly stochastic environments like this one.
FIRST RECORD OF ‘Hemiancistrus’ punctulatus CARDOZO & MALABARBA, 1999 FOR URUGUAY (SILURIFORMES: LORICARIIDAE)
(2020) Wilson S. Serra; Fabrizio Scarabino; Sabina Wlodek; Giovanni Minervino Furtado; Andrés Balao
A recent expedition to lower Yaguarón river basin in northeastern Uruguay, revealed the presence of the loricariid catfish ‘Hemiancistrus’ punctulatus Cardozo & Malabarba, 1999, which represents the first record of this species for the country. We propose it as an endangered species for Uruguay considering its restricted distribution.
First report of four characiform fishes (Ostariophysi: Characiformes) for Uruguay
(Pensoft Publishers, 2013) Wilson S. Serra; Matías Zarucki; Alejandro Duarte; Edward D. Burress; Franco Teixeira de Mello; Ivan González‐Bergonzoni; Marcelo Loureiro
In this article the authors present the first report of four characiform fish species for Uruguay, extending their current distribution to the middle and lower Uruguay River basin: Astyanax saguazu Casciotta, Almirón and Azpelicueta, 2003; Hypobrycon poi Almirón, Casciotta, Azpelicueta and Cione, 2001; Leporinus amae Gody, 1980; Cyphocharax saladensis (Meinken, 1933). These species were previously recorded from either the upper Uruguay River, Patos-Merín lagoon system or Paraná River. Color pattern in life for A. saguazu and H. poi are described for the first time.
Species‐specific ontogenetic diet shifts among <scp>Neotropical</scp><i>Crenicichla</i>: using stable isotopes and tissue stoichiometry
(Wiley, 2013) Edward D. Burress; Ana Maria Ribeiro de Castro Duarte; Wilson S. Serra; Michael M. Gangloff; Lynn Siefferman
Ontogenetic diet shifts were compared among five sympatric pike cichlids Crenicichla in a subtropical South American stream using stable C and N isotopes and tissue stoichiometry (C:N). Within species, stable N isotopes were positively related to body size while C:N showed negative relationships. Stable C isotopes, however, were not related to body size in any species. By modelling the switch to piscivory using gut content-isotope-body size relationships, diet shifts were shown to be species-specific with regard to both rate and degree of piscivory. Compared to other piscivorous lineages, Crenicichla appear to be unusually small-bodied (based on maximum body size). Because of their diversity, abundance and dynamic size-structured functional roles, Crenicichla may exert broad and complex predation pressures on the aquatic community.