Merluccius hubbsi (Teleostei: Merlucciidae): stock identification based on reproductive biology in the south-southeast brazilian region

  • André Martins Vaz-dos-Santos Universidade São Judas Tadeu
  • Carmen Lúcia Del Bianco Rossi-Wongtschowski Universidade de São Paulo; Instituto Oceanográfico
  • José Lima de Figueiredo Universidade de São Paulo; Museu de Zoologia
Keywords: Merluccius hubbsi, Reproduction, Spawning, Stocks, Southeast-South Brazilian Region

Abstract

The Argentine hake, Merluccius hubbsi, a demersal-pelagic species found from Rio de Janeiro, Brazil to the Tierra del Fuego, Argentina, has become an important target of the Brazilian bottom-trawler fleet since 2001. Earlier studies focusing on the species have suggested that more than one stock might occur off the Brazilian coast, in accordance with environmental features. In order to evaluate this hypothesis, fish were collected from four different areas in the Brazilian waters in which the hake is distributed, during the summers and winters of 1996-2001 and 2004, the females being used to analyze and compare spatial-temporal variations in ovarian maturation. Gonad indexes were also applied for the same purpose. Results indicate a north-south spawning gradient occurring as from summer at around 21°S to winter near 34°S, leading to the identification of two distinct stocks: one located between 21°S and 29°S (Southeastern stock) and the other between 29°S and 34°S (Southern stock), this latter shared with Uruguay and Argentina. Brazilian stocks present clear signs of overexploitation, the situation calling for an urgent solution.

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Published
2009-03-01
How to Cite
Vaz-dos-Santos, A., Rossi-Wongtschowski, C., & Figueiredo, J. (2009). Merluccius hubbsi (Teleostei: Merlucciidae): stock identification based on reproductive biology in the south-southeast brazilian region. Brazilian Journal of Oceanography, 57(1), 17-31. https://doi.org/10.1590/S1679-87592009000100003
Section
naodefinida