Distribución, parámetros poblacionales y dieta de Astropecten marginatus (Asteroidea: Astropectinidae) en el Atlántico venezolano
Rev. biol. trop
;
59(1): 53-69, mar. 2011. ilus, graf, tab
Artigo
em Espanhol
| LILACS
| ID: lil-638045
ABSTRACT
Distribution, population parameters, and diet of Astropecten marginatus (Asteroidea Astropectinidae) in the Venezuelan Atlantic coast. Astropecten marginatus is a sea star widely distributed in Northern and Eastern South America, found on sandy and muddy bottoms, in shallow and deep waters. To describe some of its ecological characteristics, we calculated it spatial-temporal distribution, population parameters (based on size and weight) and diet in the Orinoco Delta ecoregion (Venezuela). The ecoregion was divided in three sections Golfo de Paria, Boca de Serpiente and Plataforma Deltana. Samples for the rainy and dry seasons came from megabenthos surveys of the "Línea Base Ambiental Plataforma Deltana (LBAPD)" and "Corocoro Fase I (CFI)" projects. The collected sea stars were measured, weighted and dissected by the oral side to extract their stomach and identify the preys consumed. A total of 570 sea stars were collected in LBAPD project and 306 in CFI one. The highest densities were found during the dry season in almost all sections. In LBAPD project the highest density was in "Plataforma Deltana" section (0.007±0.022ind/m² in dry season and 0.014±0.06ind/m² in rainy season) and in the CFI project the densities in "Golfo de Paria" section were 0.705±0.829ind/m² in rainy season and 1.027±1.107ind/m² in dry season. The most frequent size range was 3.1-4.6cm. The highest biomass was found in "Golfo de Paria" section (7.581±0.018mg/m² in dry season and 0.005±6.542x10-06mg/m² in rainy season for 2004-2005 and 3.979±4.024mg/m² in dry season; and 3.117±3.137mg/m² in rainy season for 2006). A linear relationship was found between the sea star size and its weight but no relationship was observed between its size and the depth where it was collected. Mollusks are dominant in the sea star diet (47.4% in abundance). The diet in any of the sections, seasons or between projects or size class was heterogeneous, using multivariate ordinations (MDS) and SIMPER analysis and there was no difference in the prey number or food elements that a sea star can eat. Although A. marginatus has been described as a predator, in this study were also inferred scavenger and detritivorous habits. Rev. Biol. Trop. 59 (1) 53-69. Epub 2011 March 01.
RESUMEN
Astropecten marginatus Gray 1840 presenta una amplia distribución en el norte y este de sur América, encontrándose en fondos arenosos y fangosos de aguas someras y profundas. Se determinó su distribución, parámetros poblacionales tales como talla, peso y dieta, de los ejemplares provenientes de los muestreos de megabentos de los proyectos LBAPD y CFI en las épocas de lluvia y sequía en la ecorregión Delta del Orinoco, Venezuela. Se dividió la ecorregión en tres sectores Golfo de Paria, Boca de Serpiente y Plataforma Deltana. Las estrellas fueron medidas, pesadas y se extrajo su estómago para la determinación de las presas. Las mayores densidades se encontraron en época de sequía en Golfo de Paria (2006) y en época de lluvia en Plataforma Deltana (2005). El intervalo de tallas más frecuente fue 3.1-4.6cm. La mayor biomasa se encontró en Golfo de Paria en época de sequía. No se observaron relaciones entre el tamaño de la estrella y la profundidad de muestreo. Existe una dominancia de los moluscos en la dieta, a pesar de tener una alimentación heterogénea. Se observó que aparte de la depredación, también pueden presentar comportamientos carroñeros y detritívoros.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Estrelas-do-Mar
/
Comportamento Alimentar
/
Conteúdo Gastrointestinal
Tipo de estudo:
Estudo prognóstico
Limite:
Animais
País/Região como assunto:
América do Sul
/
Venezuela
Idioma:
Espanhol
Revista:
Rev. biol. trop
Assunto da revista:
Biologia
/
Medicina Tropical
Ano de publicação:
2011
Tipo de documento:
Artigo
País de afiliação:
Venezuela
Instituição/País de afiliação:
Universidad Simón Bolivar/VE
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