Population dynamics of Rimapenaeus constrictus (Stimpson, 1874) (Penaeoidea) on the southeastern Brazilian coast: implications for shrimp fishing management from a 5-year study on a bycatch species

Abstract

This is the first study to evaluate in broad spatiotemporal scales the growth parameters and population structure of Rimapenaeus constrictus, a barely damaged species composing the bycatch from shrimp fishing in the Western Atlantic. The abundance and size-class frequency distribution, growth, longevity and sex ratio were evaluated from monthly samples obtained in the northern littoral of São Paulo state from Jan/1998 to Jun/2003. We measured 5,812 individuals in which the sex ratio was skewed toward females; this was more evident in size classes greater than 10 mm in CL (carapace length) (binomial test, p<0.05). We selected 16 growth cohorts of females, and 8 of males, the majority consisting of younger individual cohorts excluded from the fisheries closure period. Growth estimates resulted in a CL ∞ of 17.42 mm, a growth coefficient of 0.008 and a longevity of 579 days (1.60 year) for females, as well as a CL ∞ of 16.3 mm, a growth coefficient of 0.01 and a longevity of 425 days (1.17 year) for males. Our results provide information of incontestable relevance to our knowledge of fishing management. We therefore strongly recommend that the fisheries closure period be changed to protect this species' recruitment period and consequently its adult individuals.

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

“…In this sense, such morphological difference is nothing but a result of the different energetic output and reproductive roles between sexes. Individuals of R. constrictus were widely reported displaying such a sexual dimorphism, since females usually reach greater sizes than males, as observed in our results (Costa & Fransozo 2004a, Garcia et al 2016, Lopes et al 2017. Some authors suggest that this difference in CL might be related to their reproductive aspects (Gab-Alla et al 1990, Costa & Fransozo 2004a.…”

“…Unfortunately, their broad geographical range may result in an equally high infl uence from the shrimp-fi shing 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). In this sense, even though R. constrictus does not represent an expressive economic resource, as it is part of the bycatch fauna, and are an important species in nutrient cycling having an important ecological role in marine food webs (Pérez-Farfante & Kensley 1997, Costa & Fransozo 2004a, b, Keunecke et al 2007.…”

“…Even being substantially captured by the trawling fleet, only a few studies have been undertaken to elucidate the basic biology of this species. Along the Brazilian coast, specifically in the northern coast of São Paulo State (Brazil) several studies were conducted focusing on its distribution, reproductive ecology and growth (Costa & Fransozo 2004a, b, Hiroki et al 2011, Lopes et al 2017). In the southern littoral of São Paulo State, Garcia et al (2016) addressed its reproductive dynamics and growth.…”

Dynamics of a subtropical population of the purse crab Persephona punctata (Decapoda: Brachyura: Leucosiidae) in Southeastern Brazil

“…This activity employs a variety of techniques to capture fishes, mollusks, and crustaceans, and especially shrimps, which are the main marine resource of the region (Mendonça, 2015). Given that trawling uses non-selective gear, shrimp and prawn fisheries have a high bycatch rate, which represents 35% of the global commercial fishery discards (Lopes et al, 2017;Varisco et al, 2017). Due to the ineffective implementation of fishery management regulations in tropical and subtropical countries, the bycatch of tropical shrimp fisheries is 3-15 times higher than the captured target species (FAO, 2015).…”

Comparison of the spatio‐temporal distribution of the roughneck shrimp Rimapenaeus constrictus (Stimpson, 1874) (Crustacea, Penaeoidea) from monthly samples collected 20 years apart: Effects of a marine protected area in southeastern Brazil

“…Regarding the present knowledge about the biology and ecology of R. constrictus, there are studies about its ecological distribution by Costa and Fransozo (2004a) and Hiroki et al, (2011) on the northern coast of São Paulo; reproductive biology and population dynamics by Costa and Fransozo (2004b) and Lopes et al, (2017); population structure by Oliveira-Souza and Lavrado (2017); and growth and longevity by Garcia, Wolf, Costa, and Castilho, (2016). In addition to these studies, on the southeastern coast of Brazil, Bauer and Lin (1994) Considering that the region of Ubatuba was included in a marine protected area in 2008, we tested the hypothesis that the spatio-temporal distribution of R. constrictus has changed in response to changes in environmental and anthropogenic factors.…”