Distribution Patterns and Biological Characteristics of Aristeus Antennatus (Risso, 1816) and Aristeus Virilis (Bate, 1881) in Mozambique Waters of the Western Indian Ocean

Abstract

Abstract—The blue and red shrimp, Aristeus antennatus (Risso, 1816), and the stout red shrimp, Aristeus virilis (Bate, 1881), represent two of the most valuable demersal deep waters shrimp species subject to exploitation in Mozambique. This paper analyses the distribution, abundance and biological parameters of these species for the first time in this area. During 13th March to 10th April a survey on board the R/V Vizconde de Eza has been carried out to assess deep water crustacean resources in Mozambique waters. The sampling design followed a random stratified scheme with five sectors (Sofala, Bazaruto A, Bazaruto B, Boa Paz and Inhaca) and also five depth strata (A: 100-200 m, B: 200-400 m, C: 400-500 m, D: 500-600 m, E: 600-700 m). For the overall area surveyed, A. virilis was twice more abundant than A. antennatus (95.44 tons and 37 tons respectively) and more abundant in central and south area (Bazaruto B; Boa Paz and Inhaca), while A. antennatus was more abundant in the north area (Sofala). Both species live in deep water and were caught between 420 to 675 m and 520 to 690 m, for A. antennatus and A. virilis respectively. Size of first maturity occurred at of 19.8 mm and 25.5 mm of cephalotorax length (CL) for males of A. antennatus and A. virilis respectively, and 34.7 mm and 47.5 mm of CL for females of A. antennatus and A. virilis, respectively.

Keywords: Aristeus antennatus; Aristeus virilis; distribution, biology, deep water shrimp, Mozambique.