Se realizó un estudio sobre el contenido estomacal de dos especies de peces de consumo de agua dulce, Brycon hilarii “sábalo cola roja” y Leporinus friderici “lisa”, en la parte baja del río Palcazú (Pasco) con la finalidad de conocer su alimentación natural e identificar los ítems de mayor importancia durante un ciclo anual, usando la frecuencia de ocurrencia y peso de los ítems. Además, asociar los cambios en la composición de los ítems alimenticios con cambios estacionales y determinar la amplitud de nicho trófico.
Las muestras fueron colectadas mensualmente, entre agosto del 2009 y agosto del 2010, y procesadas mediante metodología estandarizada. Se colectaron en total 120 muestras pertenecientes a B. hilarii (67) y L. friderici (53). Se identificaron 60 ítems en la alimentación de B. hilarii, la cual es básicamente omnívora con preferencia por ítems vegetales, principalmente por frutos y semillas de “caucho” (Hevea brasiliensis) y pudiendo considerarse como un dispersor de semillas de Cecropia sp.
B. hilarii presenta un mayor consumo de restos de insectos (16%) y restos vegetales (63%, principalmente semillas y frutos) en época lluviosa, mientras que en época seca disminuye en consumo de restos vegetales (30%) e insectos (1.4%) y aumenta el consumo de peces (54%). L. friderici presenta una alimentación básicamente omnívora con tendencia por la herbivoría, para la época lluviosa se identificaron 51 ítems, representado principalmente por material vegetal, siendo los restos vegetales (53%) y de peces (36.6%) los ítems preferidos. La amplitud de nicho trófico para ambas especies refieren una marcada especialización de B. hilarii (0.12) por H. brasiliensis y de L. friderici (0.07) por restos vegetales. En ambos casos se registra un alto valor perteneciente a material vegetal alóctono, considerando las especies vegetales ribereñas una fuente importante de abastecimiento de alimento para ambas especies.
-- Palabras claves: peces, hábitos alimentarios, Cuenca del Pachitea, ecología, herbivoría / --- A research of stomach contents of two species of freshwater fish of consumption have been done, Brycon hilarii “sábalo cola roja” and Leporinus friderici “lisa”, in the lower part of the Palcazú river (Pasco) in order to know their natural feeding and to identify the ítems of greater importance during an annual cycle, using the frequency of occurrence and weight of ítems. In addition, to associate the composition of the ítems with the seasonal changes and to determine the trophic niche amplitude.
The samples were collected monthly, since August 2009 to August 2010, and processed using an standardized methodology. A total of 120 samples were collected, belonging to B. hilarii (67) and L. friderici (53). Sixty ítems were identified in the diet of B. hilarii, which is basically omnivorous feeding with preference for vegetable ítems, mainly by fruits and seeds of “rubber” (Hevea brasiliensis) and can be considered as a seed dispersal of Cecropia sp.
B. hilarii has a greater consumption of rests of insects (16%) and rest of vegetables (63%, seeds and fruits) at rainfall season, whereas at dry season the consumption of rest of vegetables (30%) and rest of insects (1.4%) decreases and the consumption of fish (54%) increases. L. friderici presents a diet basically omnivorous tending to herbivory, at rainfall season were identified 51 ítems and presents mainly vegetable ítems, the vegetable material (53%) and fish (36.6%) are considered preferred ítems. The amplitude of trophic niche for both species refers a noticeable specialization of B. hilarii (0.12) by H. brasiliensis and of L. friderici (0.07) by vegetable ítems. For both species is registered a high value of allochthonous vegetable material that is why the riparian forest species are considered as an important source of food supplying for both species.
-- Key words: freshwater fishes, feeding habits, Pachitea Basin, ecology, herbivory
| Identifer | oai:union.ndltd.org:Cybertesis/oai:cybertesis.unmsm.edu.pe:cybertesis/3348 |
| Date | January 2012 |
| Creators | Cortijo Villaverde, Ana María Fiorella |
| Contributors | Ortega Torres, T. Hernán |
| Publisher | Universidad Nacional Mayor de San Marcos |
| Source Sets | Universidad Nacional Mayor de San Marcos - SISBIB PERU |
| Language | Spanish |
| Detected Language | Spanish |
| Type | info:eu-repo/semantics/bacherlorThesis |
| Source | Universidad Nacional Mayor de San Marcos, Repositorio de Tesis - UNMSM |
| Rights | info:eu-repo/semantics/openAccess |
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