scholarly journals Conservation status and bio-ecology of Brycon orbignyanus (Characiformes: Bryconidae), an endemic fish species from the Paraná River basin (Brazil) threatened with extinction

2019 ◽  
Vol 17 (3) ◽  
Author(s):  
Lívia Helena Tonella ◽  
Rosa Maria Dias ◽  
Oscar Barroso Vitorino Junior ◽  
Rosemara Fugi ◽  
Angelo Antonio Agostinho

ABSTRACT Brycon orbignyanus is an endemic species from La Plata basin whose stocks have been presenting significant reductions throughout the Paraná River. Brycon orbignyanus is categorized as an endangered species. This study evaluated aspects of the bio-ecology of this species that may be related to this threat, highlighting its distribution, abundance, and diet as well as the corresponding relationships between its recruitment and flood regimes. Data were obtained from different parts of the upper Paraná River (stretches free and regulated by dams) from 1986 to 2010 with more detailed data collected from the free remnant of this basin. The results indicate that no records for species exist at more than half of the sampling points located in dam-regulated sections of the Paraná River, whereas specimens were collected from 75% sites in the free plain remnant. We observed a remarkable effect of the hydrological regime on recruitment as well as distinct food demands during ontogenetic development, with adults almost exclusively consuming fruits and seeds, revealing that these individuals are supported by riparian vegetation. Thus, it is concluded that changes in the natural flood regime as well as riparian vegetation removal threaten B. orbignyanus populations in the Paraná River basin.

Biotemas ◽  
2018 ◽  
Vol 31 (4) ◽  
pp. 47-56 ◽  
Author(s):  
Maria José Alencar Vilela ◽  
Francisco Severo-Neto ◽  
Fernando Rogério Carvalho

Astyanax biotae é uma espécie originalmente descrita em um afluente do Rio Paranapanema, bacia do alto Paraná. Durante amostragens realizadas em drenagens dos rios Ivinhema e Verde, no sistema do alto Paraná, em Mato Grosso do Sul, exemplares de A. biotae foram coletados em cabeceiras de pequenos riachos e em lagoas de várzea, tanto em Unidades de Conservação como em áreas de agricultura intensiva. Os dados morfomerísticos de 20 indivíduos analisados foram similares aos da série-tipo. Exemplares testemunhos estão depositados nas coleções ictiológicas da UFMS (ZUFMS), UEMS (CPUEMS) e UNESP (DZSJRP). Com base nos critérios da IUCN, sugerimos sua classificação como Menos Preocupante (LC) no estado de Mato Grosso do Sul, considerando principalmente a inexistência de ameaças efetivas em duas das áreas de ocorrência da espécie, situadas dentro de Unidades de Conservação. No entanto, reforçamos a urgência em medidas para a proteção das regiões de cabeceiras de riachos, a fim de evitar o aumento do desmatamento, assoreamento e poluição agrícola, problemas recorrentes no Cerrado, que comprometem severamente a manutenção desses hábitats e suas espécies. É necessário investir em estudos sobre a biologia da espécie e ampliar as amostragens, buscando diminuir os vazios amostrais ainda existentes nas drenagens estaduais.


Check List ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 519 ◽  
Author(s):  
Alexandro Derly Augusto Costa ◽  
Dhiego Gomes Ferreira ◽  
Wilson Frantine da Silva ◽  
Augusto Seawright Zanatta ◽  
Oscar Akio Shibatta ◽  
...  

The focus of this work was to survey the ichthyofauna of the Penacho stream, a tributary of the Laranjinha River, northeastern Paraná State, in an area of the Upper Paraná River basin still devoid of ichthyofaunal studies. In general, the banks of the Penacho Stream are predominantly characterized by pasture or agricultural activities and may exhibit little riparian vegetation in few stretches. Fishes were collected at eight different locations, from its headwaters to its mouth, between February 2009 to March 2010. A total of seven orders, twelve families and thirty-three species, three of which not native to the basin, were reported. The fish species captured along the Penacho stream are those that still manage to stay in those environments, even in changed conditions. However, to better understand the effects of degradation on fish diversity, it is necessary to monitor it along time.


2013 ◽  
Vol 11 (1) ◽  
pp. 199-210 ◽  
Author(s):  
Claudio Baigún ◽  
Priscilla Minotti ◽  
Norberto Oldani

This study assesses the change in fish exploitation patterns of the sábalo fisheries of the lower Paraná River basin based on hydrological, biological, and fishery indicators. From historical catch records, we recorded a shift from a lightly and moderate exploited status before 2001 to a heavily exploited one, as a result of the development of sábalo exports from 2001 onwards. Channel and floodplain connectivity indices demonstrated that the Paraná exhibited highly favorable hydrological conditions between 1972 and 1999 but more adverse conditions from 1999 to 2009, as a consequence of flood pulses reduction coincident with a fishing mortality increment. A total catch of 15,000 tons, including local consumption, regional market, informal sales, and exportation volumes, was estimated as the maximum sustainable catch. That level was instead exceeded 3 fold in 2004, in parallel with a decrease in the mean fish length from 48 to 42 cm, along with a reduction in both the mesh size from 16 to 12 cm and megaspawner proportion, and an increase of fishing mortality. Although growth overfishing was not noted, an analysis of the spawning potential ratio trend indicated that recruitment overfishing took place during 2005, since the fishing mortality rate was 4 times greater than the natural mortality rate. These observations suggest that less favorable hydrological conditions after 1999 coupled with a coincident high fishing pressure could have impacted the sábalo population biomass. Management of sábalo fisheries requires to set aside a single economic vision of the resource use moving to an ecosystem-oriented approach that incorporate, among others components, the hydrological regime, species life history traits, fishing impacts on other species, and main stakeholders socioeconomic requirements as key elements for the preservation of fishery sustainability.


2011 ◽  
Vol 11 (2) ◽  
pp. 55-62 ◽  
Author(s):  
Lilian Paula Vasconcelos ◽  
Yzel Rondon Súarez ◽  
Sidnei Eduardo Lima-Junior

In order to describe some aspects of the population ecology of Bryconamericus stramineus in the Guiraí River basin, upper Paraná River basin, samples were taken bimonthly from October 2006 to August 2007 at seven sites in the basin. A total of 960 individuals, including 532 females, 316 males, and 112 of undetermined sex, were collected. A significant variation in the sex ratio was observed (Χ2 = 32.82; p < 0.001). Females were larger (59.7 mm) than males (58.9 mm); however, males showed a larger angular growth coefficient (b) than females. It was estimated that 50% of females were sexually mature at 36.4 mm. The highest rate of ovary development was observed in October, while in June 2007 no mature females were found. Mean fecundity was estimated at 313 eggs, and the relative fecundity was 184.6 eggs/g. The asymptotic was estimated at 62.8 mm and the growth rate at 0.76. The growth performance index was calculated at 3.47, the longevity at 3.94 years and the mortality (M) at 1.18 years. The recruitment pattern of the species showed peaks concentrated in periods of low rainfall.


Biologia ◽  
2017 ◽  
Vol 72 (6) ◽  
Author(s):  
Carlos Alexandre Fernandes ◽  
Lucas Baumgärtner ◽  
Leonardo Marcel Paiz ◽  
Vladimir Pavan Margarido ◽  
Ana Luiza de Brito Portela-Castro

AbstractKaryotype and chromosomal characteristics of both minor and major rDNA of


2000 ◽  
Vol 60 (4) ◽  
pp. 633-636 ◽  
Author(s):  
L. F. M. VELHO ◽  
F. A. LANSAC-TÔHA ◽  
C. C. BONECKER

In this paper we register the first occurrence of Bosmina huaroensis Delachaux, 1918 in the upper Paraná River basin, which is probably the first record to Brazil. Illustrations and an updated description of the species are given.


2012 ◽  
Vol 12 (4) ◽  
pp. 41-49 ◽  
Author(s):  
Lucileine de Assumpção ◽  
Maristela Cavicchioli Makrakis ◽  
Sergio Makrakis ◽  
Pitágoras Augusto Piana ◽  
Patrícia Sarai da Silva ◽  
...  

This study characterized the morphological differences among migratory fish species from the Paraná River Basin. A total of 177 adult fish of Leporinus elongatus, Leporinus macrocephalus, Prochilodus lineatus, Salminus brasiliensis, Pimelodus maculatus, Pinirampus pirinampu, Pseudoplatystoma corruscans, Pterodoras granulosus, and Rhaphiodon vulpinus were sampled in the Canal da Piracema, a fish passage system at Itaipu Dam, Paraná River. The migratory species were analyzed through 22 morphometric measurements and fineness ratio to identify morphological patterns related to swimming performance. Four species groups were indicated by the Cluster analysis: I) R. vulpinus; II) P. corruscans; III) L. macrocephalus, L. elongatus, P. lineatus, P. maculatus, and S. brasiliensis - measurements of head height and anal fin length formed this group; and IV) P. granulosus and P. pirinampu - measurements of maximum body width and caudal peduncle width contributed to form this group. The morphometric variables that most contributed to the distinction were head length and mouth width for groups I and II. The species R. vulpinus and P. granulosus differed from other species, showing fineness ratios of 9.4 and 3.7, respectively. Leporinus elongatus, L. macrocephalus, P. lineatus, P. maculatus, and S. brasiliensis showed significant differences from other species, with ratios ranging from 4.57 to 5.19, indicating that these species may be better swimmers. Long-distance migratory species using the Piracema Canal to ascend upstream areas differed morphologically, morphological characteristics such as a narrow caudal peduncle and maximum body length, besides to the values of the fineness ratio, were essential to differentiate the migratory species.


Sign in / Sign up

Export Citation Format

Share Document