Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina

Shallow lakes are found in the Eastern region of La Pampa province which were stockedwith Odontesthes bonariensis, becoming a fish catchment opportunity. Such a fish species exhibits a preference for plankton as food, but if that resource were scarce, other kind offeeds can be included in its diet as a consequence of its feeding plasticity. Diet compositionvaries according to fish size, with occurrence of cannibalism at an old age. The objectiveof this work was to assess the percentage diet composition by the total number of individuals, and by body size, of O. bonariensis feeding in the shallow lakes of Bajo Giuliani and Don Tomás. Catchment of fish was performed using gillnets of different mesh sizes. Stomachs removed from fish were fixed in 10% formol, and their contents were observed withstereoscopic optical microscope. Prey volume and its frequency of occurrence were measured. Ten types of preys in Bajo Giuliani lake, and 6 in Don Tomás lake, were identified. In both environments, the plankton was the main food for fish smaller in size, whereas the biggest ones turned out to be piscivores. Jenynsia multidentata was the most predatedfish. It is considered necessary to carry out a study that allow surveying fish trophic behavior throughout the year.

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Main Authors: Del Ponti, Omar, García, Mariana
Format: Digital revista
Language:spa
Published: Facultad de Agronomía 2018
Online Access:https://cerac.unlpam.edu.ar/index.php/semiarida/article/view/2666
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spelling oai:ojs.cerac.unlpam.edu.ar:article26662023-11-22T14:41:19Z Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina Alimentación del pejerrey (Odontesthes bonariensis) en las lagunas Bajo Giuliani y Don Tomás, provincia de La Pampa, Argentina Del Ponti, Omar García, Mariana Odontesthes bonariensis feeding shallow lakes La Pampa Odontesthes bonariensis alimentación lagunas La Pampa Shallow lakes are found in the Eastern region of La Pampa province which were stockedwith Odontesthes bonariensis, becoming a fish catchment opportunity. Such a fish species exhibits a preference for plankton as food, but if that resource were scarce, other kind offeeds can be included in its diet as a consequence of its feeding plasticity. Diet compositionvaries according to fish size, with occurrence of cannibalism at an old age. The objectiveof this work was to assess the percentage diet composition by the total number of individuals, and by body size, of O. bonariensis feeding in the shallow lakes of Bajo Giuliani and Don Tomás. Catchment of fish was performed using gillnets of different mesh sizes. Stomachs removed from fish were fixed in 10% formol, and their contents were observed withstereoscopic optical microscope. Prey volume and its frequency of occurrence were measured. Ten types of preys in Bajo Giuliani lake, and 6 in Don Tomás lake, were identified. In both environments, the plankton was the main food for fish smaller in size, whereas the biggest ones turned out to be piscivores. Jenynsia multidentata was the most predatedfish. It is considered necessary to carry out a study that allow surveying fish trophic behavior throughout the year. En la región oriental de la provincia de La Pampa existen lagunas que fueron sembradas con pejerrey (Odontesthes bonariensis), debido a lo atractivo que resulta su pesca. Se define a este pez como planctívoro por preferencia; pero, si el plancton es escaso, su plasticidad alimentaria le permite predar otras comunidades. Su dieta varía de acuerdo al tamaño, pudiendo ser caníbal en la senectud. El objetivo de este trabajo es mostrar la composición porcentual, general y discriminada por tallas, de la alimentación de O. bonariensis en las lagunas Bajo Giuliani y Don Tomás. La pesca se realizó por medio de redes agalleras de distinta abertura de malla. Los tractos digestivos fueron fijados en formol al 10% y su contenido fue observado con microscopio óptico estereoscópico. Se midió el volumen y la frecuencia de ocurrencia que tuvieron las presas. Se identificaron 10 y 6 ítems presa en los peces de Bajo Giuliani y Don Tomás, respectivamente. En ambos ambientes el plancton fue el alimento principal en los ejemplares de menor talla, los mayores resultaron piscívoros. El pez más predado fue Jenynsia multidentata. Se estima necesario efectuar un estudio que permita analizar el comportamiento trófico a lo largo del año. Facultad de Agronomía 2018-06-05 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion application/pdf https://cerac.unlpam.edu.ar/index.php/semiarida/article/view/2666 Semiárida; Vol. 25 Núm. 1 (2015); 7-15 2408-4077 2362-4337 spa https://cerac.unlpam.edu.ar/index.php/semiarida/article/view/2666/2537 Derechos de autor 2018 Omar Del Ponti, Mariana García
institution UNLPam
collection OJS
country Argentina
countrycode AR
component Revista
access En linea
databasecode rev-semiarida
tag revista
region America del Sur
libraryname Biblioteca de la Facultad de Agronomía 'Eduardo Cano'
language spa
format Digital
author Del Ponti, Omar
García, Mariana
spellingShingle Del Ponti, Omar
García, Mariana
Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina
author_facet Del Ponti, Omar
García, Mariana
author_sort Del Ponti, Omar
title Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina
title_short Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina
title_full Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina
title_fullStr Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina
title_full_unstemmed Feeding of silverside (Odontesthes bonariensis) in Bajo Giuliani and Don Tomás Shallow lakes, La Pampa Province, Argentina
title_sort feeding of silverside (odontesthes bonariensis) in bajo giuliani and don tomás shallow lakes, la pampa province, argentina
description Shallow lakes are found in the Eastern region of La Pampa province which were stockedwith Odontesthes bonariensis, becoming a fish catchment opportunity. Such a fish species exhibits a preference for plankton as food, but if that resource were scarce, other kind offeeds can be included in its diet as a consequence of its feeding plasticity. Diet compositionvaries according to fish size, with occurrence of cannibalism at an old age. The objectiveof this work was to assess the percentage diet composition by the total number of individuals, and by body size, of O. bonariensis feeding in the shallow lakes of Bajo Giuliani and Don Tomás. Catchment of fish was performed using gillnets of different mesh sizes. Stomachs removed from fish were fixed in 10% formol, and their contents were observed withstereoscopic optical microscope. Prey volume and its frequency of occurrence were measured. Ten types of preys in Bajo Giuliani lake, and 6 in Don Tomás lake, were identified. In both environments, the plankton was the main food for fish smaller in size, whereas the biggest ones turned out to be piscivores. Jenynsia multidentata was the most predatedfish. It is considered necessary to carry out a study that allow surveying fish trophic behavior throughout the year.
publisher Facultad de Agronomía
publishDate 2018
url https://cerac.unlpam.edu.ar/index.php/semiarida/article/view/2666
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