Ecological distribution of Nematopalaemon schmitti and Exhippolysmata oplophoroides (Crustacea: Caridea) near an upwelling area off southeastern Brazil

Abstract

ABSTRACT.Regions affected by upwelling show environmental characteristics that may change the distribution of the species. This study evaluated the influence of environmental factors on the spatiotemporal distribution of two caridean shrimps, Nematopalaemon schmitti and Exhippolysmata oplophoroides, in a region of the Brazilian coast affected by Cabo Frio upwelling. Shrimps were collected monthly from July 2010 through June 2011 off Macaé off the northern coast of Rio de Janeiro State, at six locations: three at 5 m, and the other three at 15 m depth. Shrimp abundance was compared among seasons and sampling sites. Nematopalaemon schmitti (n = 1200) was more abundant at 5 m depth while E. oplophoroides (n = 2176) occurred predominately at 15 m. There were significant seasonal fluctuations in the distribution of the species in the region, resulting from variation in bottom temperature. The presence of the South Atlantic Central Water (SACW) favors the decrease in the abundance of N. schmitti and highest abundance of E. oplophoroides. The abundance of E. oplophoroides and the percentage of organic matter were significantly and positively correlated. The organic matter content in the sediment and water temperature was among the most important variables affecting seasonal distribution of the species. The distinct environmental characteristic between the bathymetric regions were a determinant factor in their spatial distribution.

Effects of the upwelling system on the assessment of reproductive parameters of the caridean shrimp Nematopalaemonschmitti (Holthuis, 1950) in the Western Atlantic

“…Grain size categories were expressed on φ = −log 2 (grain diameter in millimeters) (Tucker, 1988): gravel (<−1), very coarse sand (−1φ < 0); coarse sand (0 φ < 1); medium sand (1 φ < 2); fine sand (2 φ < 3); very fine sand (3 φ < 4); and silt and clay (>4). Detailed descriptions of the procedures for the sediment and organic matter content analysis can be found in Herrera et al (2017).…”

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Nematopalaemon schmitti (Holthuis, 1950) is a caridean shrimp of the Palaemonidae family (Rafinesque, 1815) (Martin & Davis, 2001), distributed on the marine and estuarine waters of the Western Atlantic Ocean in shallow areas to 75 m depth (Ferreira et al, 2010;Holthuis, 1980). This species plays an important trophic role in the structure of non-consolidated environments both as a carnivorous predator and as a prey item for higher trophic levels (Herrera et al, 2017;Marioghae, 1989). Furthermore, it constitutes part of the bycatch taken in penaeid shrimp fisheries of high economic interest in Brazil, for example, seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) (Costa et al, 2016).In the marine environment, the upwelling regions are considered as the most productive areas in the ocean due to cold and rich nutrient waters (Smith, 1968).

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“…Shrimps are an important link between primary production and higher trophic levels (Kikuchi, 1966;Unsworth et al, 2007), and such information can assist in responsible planning for the conservation of species. Studies involving N. schmitti have been conducted in Brazil, including its ecological distribution (Almeida et al, 2012;Fransozo et al, 2009;Herrera et al, 2017), population structure (Almeida et al, 2011), fecundity and reproductive investment (Pereira et al, 2017) and relative growth and morphological sexual maturity (Herrera et al, 2018). Despite these studies, there is still a knowledge gap about assessing the reproductive parameters of species in a region with unusual features such as upwelling.…”

Relative growth and morphological sexual maturity of the caridean shrimpNematopalaemon schmitti(Decapoda: Caridea: Palaemonidae) in an upwelling region in the Western Atlantic

“…As a result, upwelling regions are the most productive areas of the ocean (Coelho-Souza et al 2012). The orientation of the Rio de Janeiro coast, particularly its coastline which changes abruptly in direction from north-south to east-west, shunts coastal water away from the coast and toward the ocean; this favors the intrusion and spread of the South Atlantic Central Water (SACW) (Herrera et al 2017), which usually has temperatures below 20º C and high nutrient concentrations. The influence of the SACW is more intense in summer, but the Macaé coastal area is strongly influenced by this mass of water throughout the year as a result of the upwelling off Cabo Frio, resulting in low water temperatures (Valentin 1984).…”

“…Only a few studies have been conducted on N. schmitti, including its ecological distribution (Fransozo et al 2009;Almeida et al 2012;Herrera et al 2017), population structure (Almeida et al 2011), and fecundity and reproductive investment (Perreira et al 2017). These studies were focused on southeastern Brazil, mainly off Ubatuba on the northern coast of São Paulo.…”