Feeding ecology of the deep-sea lanternshark Etmopterus pusillus (Elasmobranchii: Etmopteridae) in the northeast Atlantic
This study provides the first description of the feeding ecology of the smooth lanternshark Etmopterus pusillus based on stomach contents of specimens caught as bycatch in the Algarve (southern Portugal) with bottom trawling and bottom longline. The diet of E. pusillus consists mainly of fish (dry w...
Published in: | Scientia Marina |
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Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Consejo Superior de Investigaciones Científicas
2012
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Subjects: | |
Online Access: | https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1343 https://doi.org/10.3989/scimar.03540.07B |
Summary: | This study provides the first description of the feeding ecology of the smooth lanternshark Etmopterus pusillus based on stomach contents of specimens caught as bycatch in the Algarve (southern Portugal) with bottom trawling and bottom longline. The diet of E. pusillus consists mainly of fish (dry weight (% W)=87.1%; frequency of occurrence (%FO)=28.6%; number (%N)=30.3%), crustaceans (%W=7.7%; %FO=36.7%; %N=3.4%) and cephalopods (%W=4.7%; %FO=11.3%; %N=11.1%). The diet did not vary between sexes. Ontogenic changes were detected: crustaceans decreased in importance as the sharks increased in size and fish became dominant in the diet of adults. Combining two fishing methods provided broad information on the diet of E. pusillus, as bottom trawling caught smaller specimens and longlines caught larger individuals. E. pusillus feeds mainly on non-commercial species, and therefore does not compete directly with commercial fisheries. Finally, E. pusillus feeds in various parts of the water column and thus it can access a wide range of prey; however, this also means that it can be caught by both gears, making it more vulnerable in terms of conservation. Se proporciona la primera descripción de la ecología alimentaria del tiburón tollo lucero liso Etmopterus pusillus mediante el análisis de contenidos estomacales de individuos capturados accidentalmente en el Algarve (sur de Portugal) mediante arrastre y palangre de fondo. La dieta de E. pusillus consiste mayoritariamente en peces (%W=87.1%; %FO=28.6%; %N=30.3%), crustáceos (%W=7.7%; %FO=36.7%; %N=53.4%) y cefalópodos (%W=4.7%; %FO=11.3%; %N=11.1%; % W=peso seco, %FO=Frecuencia de aparición, %N=Número). No se observaron diferencias entre sexos en su dieta, pero sí cambios ontogénicos, con los crustáceos disminuyendo en importancia a medida que el tiburón alcanza tallas mayores, y los peces dominando la dieta de los adultos. Ambos tipos de pesquería proporcionaron información adecuada sobre la dieta de E. pusillus, con el arrastre capturando tallas menores, y el palangre capturando animales mayores. Al alimentarse mayoritariamente de especies sin interés comercial, este tiburón no compite activamente con ninguna pesquería para obtener recursos alimentarios. Finalmente, E. pusillus se alimenta en varios niveles de la columna del agua, lo que le aporta mayor diversidad de presas, aunque también significa que puede ser capturado por ambos artes de pesca, convirtiéndolo en más vulnerable en términos de conservación. |
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