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| Registros recuperados: 13 | |
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| Vitorino Júnior,Oscar B.; Agostinho,Carlos S.; Pelicice,Fernando M.. |
| ABSTRACT Mylesinus paucisquamatus is a threatened fish endemic to the rio Tocantins basin, with little information about its natural history. Using monitoring data obtained between 1998 and 2009, we investigated the spatial distribution, feeding and reproduction of this species in a long stretch of the middle-upper rio Tocantins. Eighty-one individuals were captured over a decade of intensive sampling. In addition, we recorded the species in only 13 out of 35 sites, particularly in the Tocantins and Paranã rivers. Most individuals were captured alone, while the remaining formed small groups. These results indicate that this fish is rheophilic and rare. We recorded seasonal variation in fish abundance, with higher values during the dry season, indicating... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Conservation; Rare species; Rheophilic; River regulation. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200204 |
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| Kibaara, D.. |
| The importance of water masses, natural or otherwise, in supporting fisheries, and the importance of fish as human food, cannot be overemphasized. The inland waters of Kenya act as habitats for fish, harbouring many different fish species. It has been observed with interest that certain fish species have decreased in numbers over the years within the inland waters. The decline has been at a rate which, if left unchecked, will eventually cause total disappearance of the species concerned. Thus those species have been correctly termed "endangered". Among them are Labeo, Schilbe, Alestes, Clarias and Barbus spp. |
| Tipo: Journal Contribution |
Palavras-chave: Rare species; Kenya Fishery management Fishery resources Inland fisheries Fishery management Fishery resources Inland fisheries http://aims.fao.org/aos/agrovoc/c_24026 http://aims.fao.org/aos/agrovoc/c_2942 http://aims.fao.org/aos/agrovoc/c_3873. |
| Ano: 1986 |
URL: http://hdl.handle.net/1834/1287 |
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| Cetra,Mauricio; Mattox,George Mendes Taliaferro; Ferreira,Fabio Cop; Guinato,Rayssa Bernardi; Silva,Fernando Vieira; Pedrosa,Marina. |
| Abstract The Paraná River basin has about 600 fish species. In the Upper Paraná, 310 fish species were recorded, with 52 species were registered in the streams and headwaters of the Paranapanema River. The aim of this study was to characterize the stream fish communities in the Upper Paranapanema River basin. Samplings were conducted with electrofishing during the dry season in the year of 2014. The collection effort consisted of 30 streams stretches. As a result, 41 species of stream fish were recorded in the Upper Paranapanema River basin, distributed in 26 genera, 11 families and 7 orders. Thirty-nine percent of the species can be considered rare, 41% intermediate and 20% common. We captured approximately eight species by stream stretch and the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish communities; Estimated richness; Rare species. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000300304 |
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| Villaron Franceschinelli,Edivani; Stehmann,João Renato; Melo-Silva,Carlos; Neiva Mesquita Neto,José. |
| Rare and narrowly endemic species are more vulnerable to extinction due to their restricted geographical distribution. the genus Petunia has 14 species and most of them are endemic to a restricted area. Four Petunia species that grow in Southern Brazil were studied: P. bonjardinensis, P. reitzii, P. integrifolia subsp. depauperata, and P. exserta. We presented a preliminary study on the genetic diversity of five populations of Petunia, using allozyme markers. For the genetic analyses, allozyme electrophoresis was carried out and eight enzyme systems were reliably scored. Standard measures of allozyme diversity were calculated. The highest genetic diversity and the highest fixation index was found in the two studied populations of P. bonjardinensis (P = 90,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allozyme; Rare species; Tropical plants. |
| Ano: 2013 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0011-67932013000200003 |
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| Perbiche-Neves,Gilmar; Previattelli,Daniel; Nogueira,Marcos Gomes. |
| The first record of Argyrodiaptomus bergi (Richard, 1897) from a small roadside pool at high altitude in the southern region of Brazil is presented. This is the ninth record of this species in South America (previously known from Argentina and Uruguay) since its original description, and a new occurrence after 36 years, extending its known distribution to the northeast. The environments where this species was found differ sharply, and possible explanations include the loss of habitat, high species selectivity or deficient sampling efforts. An additional description is provided, with scanning electron microscopy (SEM) photomicrographs and line drawings. Similarly to other species of Argyrodiaptomus, such as Argyrodiaptomus falcifer (Daday, 1905),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: New record; Rare species; Santa Catarina. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000500001 |
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| Rego,Juliana Ordones; Franceschinelli,Edivani Villaron; Zappi,Daniela Cristina. |
| Cipocereus laniflorus N.P. Taylor & Zappi is an endemic species from the Serra do Caraça, State of Minas Gerais, Brazil. In order to propose conservation strategies for this species, its reproductive strategies were investigated, including reproductive phenology, floral biology, floral visitors and breeding system. The flowering and fruiting period extends from May to October. Few flowers per plant open each night, producing up to 0.4 ml nectar, but 30% of them are nectarless. Probably pollen is also offered as a resource. Fruiting efficiency of C. laniflorus (47%) is close to that found in other Cactaceae species. Pollen of this species was detected in Anoura geoffroy, Soricina glossophaga and Pygoderma bilabiatum bats. Amongst the characteristics... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bat-pollination; Endemic species; Rare species; Serra do Caraça. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062012000100023 |
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| Rezende,Vanessa Leite; Eisenlohr,Pedro V.; Gasper,André Luís de; Vibrans,Alexander Christian; Oliveira-Filho,Ary Teixeira de. |
| Accurate knowledge of floristic composition is crucial when planning and designing research projects and public policies. In this study, our goal was to assess tree sampling accuracy and to identify sites with higher concentrations of rare tree species, as well as those with the highest tree species richness, in the state of Santa Catarina, Brazil. We determined sampling accuracy using the first-order jackknife and Chao 2 estimators, calculated the number of rare species (singletons and doubletons) and applied sampled-based rarefaction. We found that sample accuracy (estimated vs. observed values) was over 90% for the state as a whole, the best estimates having been obtained for the areas of rain forest (first-order jackknife: 91%; Chao 2: 95%). Of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chao 2; Rainforest; First-order jackknife; Rare species; Semideciduous forest. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062014000300011 |
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| Registros recuperados: 13 | |
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