Diet of longnose stingrayHypanus guttatus(Myliobatiformes: Dasyatidae) in tropical coastal waters of Brazil

Abstract

This study investigated the diet of longnose stingray Hypanus guttatus in the tropical waters of north-eastern Brazil. Samples were obtained from monthly sampling of artisanal fisheries from August 2007 to July 2008. A total of 258 specimens were examined, 127 females and 131 males, and stomach contents analysis suggested H. guttatus to be a generalist and opportunistic predator feeding on the most available prey in the environment. There was no significant difference in the diet composition of males and females, or between seasons. However, an ontogenetic dietary shift was observed with larger individuals having an increased proportion of molluscs in the diet, whilst smaller individuals predated primarily on small crustaceans.

First record of plastic ingestion by a freshwater stingray

“…The high prevalence of fibers found in gastrointestinal tracts were similar to other studies of marine stingrays (De Lucia et al, 2014, 2018Rochman et al, 2014;Neves et al, 2015;Alomar et al, 2016;Gianeti et al, 2019;Consales and Marsili, 2021;Argeswara et al, 2021;Pegado et al, 2021). The distribution of plastic particles in rivers is influenced directly by anthropogenic processes.…”

Habitat use and nursery evaluation for the longnose stingray Hypanus guttatus (Bloch & Schneider, 1801) using vertebral microchemistry

“…In contrast, Mn is considered as a reliable element to reflect environmental concentrations, especially considering hypoxic zones and proximity to mangrove areas (Hüssy et al, 2020;Limburg et al, 2015;Limburg & Casini, 2018;Paillon et al, 2014). In our study, Mn:Ca ratios from Rio Grande do Norte were much lower than those for any other site, which is further supported by species reliance on estuaries and coastal areas during its life cycle (Gianeti et al, 2019b;Queiroz, 2017). Therefore, the smaller concentrations of Mn in samples from Rio Grande do Norte may be related to the lack of estuarine zones.…”

“…Ca concentrations between areas might be better explained by differences in prey types rather than habitat use, since diet compositions are distinct between Maranhão, Rio Grande do Norte and Pernambuco (Carvalho-Neta & da Almeida, 2001;Gianeti et al, 2019b;Queiroz, 2017). Furthermore, we suggest that small increasing trends in Mg:Ca for the representative females are likely related to physiological processes involved in sexual maturity (Aoba et al, 1992;Okumura & Kitano, 1986).…”

“…This feature probably enables a larger carrying capacity to sustain both juvenile and adult phases in the same habitat throughout life. This hypothesis is supported by the similarity in prey items between sexes and life stages in Maranhão(Carvalho-Neta & da Almeida, 2001), which is the opposite of whatQueiroz (2017) andGianeti et al (2019b) found for Pernambuco and…”

Trophic ecology of three stingrays (Myliobatoidei: Dasyatidae) off the Brazilian north‐eastern coast: Habitat use and resource partitioning

“…The longnose stingray H. guttatus is found from the southern Gulf of Mexico to southern Brazil (Bigelow & Schroeder, 1953), inhabiting estuaries to coastal marine areas up to 70 m deep across its range (Feitosa et al ., 2021; Melo et al ., 2021; Weigmann, 2016). It is a generalist opportunistic predator exhibiting slow growth (female k = 0.112 year −1 , males k = 0.219 year −1 ), late maturity (7 years for females and 5 years for males) and low fecundity (average one to two embryos per hatch) (Carvalho Neta & Almeida, 2002; Gianeti, Santana, et al ., 2019; Gianeti, Yokota, et al ., 2019; Silva et al ., 2001).…”