Ontogenetic changes in the feeding strategy of Lepidonotothen nudifrons (Pisces, Nototheniidae) off the South Shetland Islands and the Antarctic Peninsula

  • Gabriela Blasina Laboratorio de Vertebrados, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina, and Instituto Argentino de Oceanografía, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Nacional del Su (UNS), Bahía Blanca
  • Andrea Lopez Cazorla Laboratorio de Vertebrados, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina, and Instituto Argentino de Oceanografía, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Nacional del Su (UNS), Bahía Blanca
  • Mariana Deli Antoni Instituto de Investigaciones Marinas y Costeras, Consejo Nacional de Investigaciones Científicas y Técnica (CONICET)/Universidad Nacional de Mar del Plata (UNMdP), Mar del Plata, Argentina, and Grupo de Biotaxonomía Morfológica y Molecular de Peces, /Universidad Nacional de Mar del Plata (UNMdP), Mar del Plata
  • Daniel Bruno Laboratorio de Ecología, Fisiología y Evolución de Organismos Acuáticos, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ushuaia
  • Matías Delpiani Instituto de Investigaciones Marinas y Costeras, Consejo Nacional de Investigaciones Científicas y Técnica (CONICET)/Universidad Nacional de Mar del Plata (UNMdP), Mar del Plata, Argentina, and Grupo de Biotaxonomía Morfológica y Molecular de Peces, /Universidad Nacional de Mar del Plata (UNMdP), Mar del Plata
  • Juan Martín Díaz de Astarloa Instituto de Investigaciones Marinas y Costeras, Consejo Nacional de Investigaciones Científicas y Técnica (CONICET)/Universidad Nacional de Mar del Plata (UNMdP), Mar del Plata, Argentina, and Grupo de Biotaxonomía Morfológica y Molecular de Peces, /Universidad Nacional de Mar del Plata (UNMdP), Mar del Plata
Keywords: Antarctic fish diet; zonerelated changes; dominant prey; feeding strategy; trophic level; food web

Abstract

The diet and feeding strategy of Lepidonotothen nudifrons off the South Shetland Islands and the Antarctic Peninsula, as well as their variation in relation to ontogenetic stage (juvenile– adult) and sampling area, were determined by stomach contents analysis. Additionally, the trophic level of this species was estimated to determine its position within the Antarctic food web. Out of 247 specimens with prey in their stomachs, 144 were caught near the South Shetland Islands and 103 off the Antarctic Peninsula. Ontogenetic changes in the trophic ecology of L. nudifrons were observed in both areas and were mainly related to a decrease of copepods and an increase of euphausiids in the diet. The diet of juveniles from the South Shetland Islands was characterized by the dominance of calanoid copepods, followed by isopods and amphipods, whereas diet off the Antarctic Peninsula was dominated by amphipods and cyclopoid copepods. The diet in adults was dominated by amphipods and euphausiids in both areas. The specialization of individual predators on different prey types was observed when considering the whole population of L. nudifrons, but when ontogenetic stages were considered separately it showed a more mixed feeding strategy, with different dominant prey for each class. Although the trophic level increased with fish size, L. nudifrons can be classified as secondary consumer throughout its lifespan.

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Published
2017-06-19
How to Cite
Blasina, G., Cazorla, A., Antoni, M., Bruno, D., Delpiani, M., & Díaz de Astarloa, J. (2017). Ontogenetic changes in the feeding strategy of <em>Lepidonotothen nudifrons</em&gt; (Pisces, Nototheniidae) off the South Shetland Islands and the Antarctic Peninsula. Polar Research, 36. Retrieved from https://polarresearch.net/index.php/polar/article/view/2652
Section
Research Articles