Weight/carapace length relationship and condition factor of the roughneck shrimp, Rimapenaeus constrictus (Stimpson, 1874), on the southeastern Brazilian coast.

Ana Elisa B Lopes,Raphael C Grabowski,Antonio L Castilho,Alexandre R Da Silva

doi:10.1590/0001-3765202120190570

Abstract

Rimapenaeus constrictus is a penaeid shrimp widely distributed in the Western Atlantic, frequently captured as bycatch in trawling activities. Here we describe the weight vs. carapace length relationship and the condition factor of the species. Shrimps were sampled in the Ubatuba region, northern littoral of São Paulo State, monthly. We analyzed 4,952 individuals (1,371 males and 3,581 females). We measured the individuals' weight and carapace length, and the condition factor (CF) was calculated for both sexes. Females had a heavier body when compared to males, probably due to their greater maximum body size achieved. Both sexes presented a negative allometric growth in weight, probably due to their reproductive pattern and activities. We found similar mean CF values for males and females. From temporal analysis, the highest CF values for females were observed during the seasons with lower water temperatures. Such a situation may happen because females' CF tend to be influenced by a greater food availability in the environment, induced by the intrusion of the South Atlantic Central Water during the spring and early summer in the Ubatuba. The information presented here could be used as subside in protection actions and management of bycatch species.

Highlights

Rimapenaeus constrictus (Stimpson, 1874), known as ‘roughneck shrimp’ exhibits a wide geographical distribution, with occurrences recorded from Nova Scotia (Canada, 44°N) through Santa Catarina (Brazil, 26°S) (Costa et al 2003)
Their broad geographical range may result in an high influence from the shrimp-fishing activities. This species is among the most often accidentally caught by non-selective fishing gear during trawling activities, mainly in the northern coast of São Paulo State (Brazil) (Keunecke et al 2007, Mantelatto et al 2016), and due to its small size, it is not commercially exploited (Lopes et al 2017)
Shrimps were measured with an analog caliper (0.05 mm precision) to their carapace length (CL, a standard body measurement that corresponds to the linear distance from the post-orbital angle and the posterior margin of the carapace)

Summary

Introduction

Rimapenaeus constrictus (Stimpson, 1874), known as ‘roughneck shrimp’ exhibits a wide geographical distribution, with occurrences recorded from Nova Scotia (Canada, 44°N) through Santa Catarina (Brazil, 26°S) (Costa et al 2003) Their broad geographical range may result in an high influence from the shrimp-fishing activities. This species is among the most often accidentally caught by non-selective fishing gear during trawling activities, mainly in the northern coast of São Paulo State (Brazil) (Keunecke et al 2007, Mantelatto et al 2016), and due to its small size, it is not commercially exploited (Lopes et al 2017).

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Results

Conclusion