Polar Biology

, Volume 23, Issue 1, pp 38–45

Feeding plasticity of Trematomus newnesi (Pisces, Nototheniidae) in Terra Nova Bay, Ross Sea, in relation to environmental conditions

  • M. La Mesa
  • M. Vacchi
  • T. Zunini Sertorio
ORIGINAL PAPER

DOI: 10.1007/s003000050006

Cite this article as:
Mesa, M., Vacchi, M. & Zunini Sertorio, T. Polar Biol (2000) 23: 38. doi:10.1007/s003000050006

Abstract

Forty-three and 49 specimens of the Antarctic fish Trematomus newnesi were collected in the coastal waters of Terra Nova Bay, Ross Sea, during December 1994 and February 1998, respectively. The dietary composition of the two fish samples was determined by means of stomach content analysis and then compared. In general, as reported in most of the previous studies, planktivory appeared to be the main feeding habit of T. newnesi. However, the different environmental conditions occurring in the study area in the two periods investigated, such as the degree of the sea-ice coverage and the related amount of light available below the ice, influenced the food composition of T. newnesi. In December 1994, the whole area investigated was covered by a thick layer of sea ice and the diet of T. newnesi consisted of few prey taxa. Some species that characterize the so-called “cryopelagic habitat”, such as the euphausiid Euphausia crystallorophias and the copepod Metridia gerlachei, were by far the most important prey, followed by amphipods and the pteropod Limacina helicina. Conversely, the ostracod Alacia belgicae and larval stages of fish (Pleuragramma antarcticum) were consumed occasionally. In late summer (February 1998), the lack of sea-ice coverage and changes in the associated fauna influenced the feeding habit of T. newnesi. In this period the food spectrum appeared to be more diverse, revealing an active feeding search in the water column. The bulk of food was composed of several prey groups, such as E. crystallorophias, hyperiid amphipods (Hyperiella dilatata), copepods, L. helicina and several species of fish larvae. Present data provide evidence of a marked feeding plasticity of T. newnesi, in response to diverse environmental conditions that characterize the High-Antarctic Zone.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • M. La Mesa
    • 1
  • M. Vacchi
    • 2
  • T. Zunini Sertorio
    • 3
  1. 1.Irpem-CNR, Largo Fiera della Pesca, I-60100 Ancona, ItalyIT
  2. 2.Icram, Via di Casalotti 300, I-00100 Rome, ItalyIT
  3. 3.DIP.TE.RIS., University of Genoa, Corso Rainusso 14, S. Margherita Ligure (Ge), ItalyIT