Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil

The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main...

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Main Authors: Pablo D. B. Guilherme, Leonardo C. Rosa
Format: Article
Language:English
Published: Vicerractoría Investigación 2014-03-01
Series:Revista de Biología Tropical
Subjects:
Online Access:http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442014000200006&lng=en&tlng=en
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author Pablo D. B. Guilherme
Leonardo C. Rosa
author_facet Pablo D. B. Guilherme
Leonardo C. Rosa
author_sort Pablo D. B. Guilherme
collection DOAJ
description The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.
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spelling doaj.art-d18cac61f16d4c9fb30e9694d28973a02023-09-02T18:34:38ZengVicerractoría InvestigaciónRevista de Biología Tropical0034-77442014-03-016217383S0034-77442014000200006Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern BrazilPablo D. B. Guilherme0Leonardo C. Rosa1Universidade Federal do ParanáUniversidade Federal do SergipeThe sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442014000200006&lng=en&tlng=enAsteroideaEchinodermataestructura etaria de la poblacióncomponentes alimenticiosvariación estacionaldisponibilidad de presas
spellingShingle Pablo D. B. Guilherme
Leonardo C. Rosa
Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil
Revista de Biología Tropical
Asteroidea
Echinodermata
estructura etaria de la población
componentes alimenticios
variación estacional
disponibilidad de presas
title Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil
title_full Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil
title_fullStr Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil
title_full_unstemmed Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil
title_short Seasonal variation in body size and diet of the sea star Astropecten marginatus (Paxillosida, Astropectinidae) off coast of Paraná, Southern Brazil
title_sort seasonal variation in body size and diet of the sea star astropecten marginatus paxillosida astropectinidae off coast of parana southern brazil
topic Asteroidea
Echinodermata
estructura etaria de la población
componentes alimenticios
variación estacional
disponibilidad de presas
url http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442014000200006&lng=en&tlng=en
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