Diet seasonality and food overlap among fishes of the upper Orituco stream, northern Venezuela
Diet seasonality and food overlap among fishes of the upper Orituco stream, northern Venezuela
| dc.creator | Ortaz, Mario | |
| dc.date | 2001-03-01 | |
| dc.date.accessioned | 2023-08-03T17:54:44Z | |
| dc.date.available | 2023-08-03T17:54:44Z | |
| dc.identifier | https://revistas.ucr.ac.cr/index.php/rbt/article/view/16867 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/7897627 | |
| dc.description | The diets of four diurnal fish species (Creagrutus bolivari, Knodus deuterodonoides, Knodus sp. and Poecilia reticulata) were examined during a year in the Orituco stream at northern Venezuela. The fishes were sampled monthly from February 1991 to March 1992 (except October 1991 and February 1992) in the stream main channel with a beach seine and a cast net. Diet is reported as frequency of ocurrence and numeric proportion because variation in prey sizes was small. Non-parametric statistical tests were applied. A total of 18 distinct prey items were found in stomachs. The diet of these fishes consisted of aquatic insects (Coleoptera, Diptera, Hemiptera, Odonata, Plecoptera and Trichoptera), allochthonous plant matter (fragments of leaves and seeds), microalgae (Chlorophyta and Bacillariophyceae) and terrestrial arthropods (Coleoptera, Diptera, Hymenoptera and Arachnida). The low percentage of empty guts and the high fullness percentage of guts suggest that food was always abundant. Aquatic insects were more important in the dry season (November - April) while plant matter and terrestrial arthropods increased in the wet season (May - October). The Proportional Similarity Measure (PS) was high between characid species and low between characids and P. reticulata in the dry season. PS decreased during the wet season because of a reduction in aquatic insect consumption. The seasonal diet shift indicated the greater importance of allochthonous food only in the wet season. | en-US |
| dc.description | Se analizó la dieta de cuatro especies de peces (Creagrutus bolivari, Knodus deuterodonoides, Knodus sp. y Poecilia reticulata) que habitan el río Orituco al norte de Venezuela. Los muestreos se realizaron mensualmente entre febrero de 1991 y marzo de 1992 (excepto octubre/91 y febrero/92). Los peces se recolectaron con chinchorro y atarraya en el canal principal del río. La dieta se expresó como frecuencia numérica y de ocurrencia y se analizó con pruebas estadísticas no paramétricas. Se encontraron 18 items en la dieta y esta consistió de insectos acuáticos (Coleoptera, Diptera, Ephemeroptera, Hemiptera, Odonata, Plecoptera y Trichoptera), material vegetal alóctono (fragmentos de hojas y semillas), microalgas (Chlorophyta y Bacillariophyceae) y artrópodos terrestres (Coleoptera, Diptera, Hymenoptera y Arachnida). El bajo porcentaje de estómagos vacíos y el alto grado de llenura estomacal sugirieron que el alimento siempre fue abundante. En la época de sequía (noviembre - abril), los insectos acuáticos fueron los más consumidos mientras que en lluvias incrementó el consumo de artrópodos terrestres y de material vegetal. En la época de sequía el Indice de Similaridad Proporcional (PS) fue alto entre los carácidos y bajo entre ellos y P. reticulata. En lluvias, PS disminuyó debido a la reducción en el consumo de insectos acuáticos. El cambio estacional estacional en la dieta de las especies indicó la mayor importancia del material alóctono sólo en lluvias. | es-ES |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | Universidad de Costa Rica | en-US |
| dc.relation | https://revistas.ucr.ac.cr/index.php/rbt/article/view/16867/16346 | |
| dc.rights | Derechos de autor 2001 Revista de Biología Tropical | es-ES |
| dc.rights | http://creativecommons.org/licenses/by/4.0 | es-ES |
| dc.source | Revista de Biología Tropical; Vol. 49 No. 1 (2001): Volume 49 – Regular number 1 – March 2001; 191–197 | en-US |
| dc.source | Revista de Biología Tropical; Vol. 49 Núm. 1 (2001): Volumen 49 – Número regular 1 – Marzo 2001; 191–197 | es-ES |
| dc.source | Revista Biología Tropical; Vol. 49 N.º 1 (2001): Volumen 49 – Número regular 1 – Marzo 2001; 191–197 | pt-PT |
| dc.source | 2215-2075 | |
| dc.source | 0034-7744 | |
| dc.source | 10.15517/rbt.v49i1 | |
| dc.subject | Tropical fishes | en-US |
| dc.subject | Characidae | en-US |
| dc.subject | Poecilidae | en-US |
| dc.subject | Creagrutus bolivari | en-US |
| dc.subject | Poecilia reticulata | en-US |
| dc.subject | Knodus deuterodonoides | en-US |
| dc.subject | Stomach content analysis | en-US |
| dc.subject | Orituco stream | en-US |
| dc.subject | Venezuela | en-US |
| dc.title | Diet seasonality and food overlap among fishes of the upper Orituco stream, northern Venezuela | en-US |
| dc.title | Diet seasonality and food overlap among fishes of the upper Orituco stream, northern Venezuela | es-ES |
| dc.type | info:eu-repo/semantics/article | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | Article | en-US |