Population aspects of Themisto gaudichaudii, a key species in the food web of the southern Patagonian Shelf

Authors

  • Luciano Padovani Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) - Instituto de Investigaciones Marinas y Costeras (IIMyC) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
  • María Delia Viñas Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) - Instituto de Investigaciones Marinas y Costeras (IIMyC) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
  • Marina Sabatini Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) - Instituto de Investigaciones Marinas y Costeras (IIMyC) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
  • Gustavo Álvarez Colombo Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP)
  • Hermes Mianzan † Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) - Instituto de Investigaciones Marinas y Costeras (IIMyC) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Keywords:

Themisto gaudichaudii, population dynamics, life history, southern Patagonian shelf

Abstract

With the aim of studying population aspects of Themisto gaudichaudii, samples from 12 research cruises carried out in different seasons were analyzed. Abundances and biomass were among the highest recorded for the species throughout its distribution range. These parameters showed a strong seasonal variation with the highest values recorded during spring-summer (maximum at the end of the period: 16.6 ind. m-3 and 20 mg m-3), and minimum values in winter (0.9 ind. m-3 and 1.7 mg m-3). The highest concentrations were located between 50° S and 52° S in the Bahía Grande. These biomasses would be developed by adaptations to local environmental conditions, particularly to high food availability and temperature. The population of T. gaudichaudii analyzed presents a more extended reproductive period (spring-summer), a larger number of cohorts (two main cohorts) and a smaller size at maturity (~ 10 mm) than other populations at similar latitudes. These adaptations would favor a larger population of T. gaudichaudii placing the ecosystem of the southern Patagonian shelf among the most favorable for the development of the species throughout its global distribution range. 

Dr. Hermes W. Mianzan passed away on July 9, 2014.

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Published

2015-07-27

How to Cite

1.
Padovani L, Viñas MD, Sabatini M, Álvarez Colombo G, Mianzan † H. Population aspects of Themisto gaudichaudii, a key species in the food web of the southern Patagonian Shelf. Mar Fish Sci [Internet]. 2015Jul.27 [cited 2021Sep.17];26:69-88. Available from: https://ojs.inidep.edu.ar/index.php/mafis/article/view/65