Reprodução, alimentação, idade e crescimento de Dasyatis guttata (Bloch & Schneider, 1801) (Elasmobranchii; Dasyatidae) na região de Caiçara do Norte - RN

Abstract

The coast of Caiçara do Norte-RN is a known elasmobranchs nursery area, where the stingray Dasyatis guttata females and males of different sizes are captured. Since the species biological informations are scarce, the present study aimed to investigate the reproductive biology, the diet and the age and growth patterns of D. guttata in this area. Juvenile stingrays, including newborns, were more frequent in the catches. Dasyatis guttata reproduces throughout the year, but showed higher reproductive activity in the dry season. The LD 50 estimated for females was 51.3 cm and for males was 43.5 cm. Regarding the diet, results characterized D. guttata as a generalist predator, that feeds upon the prey more available in the environment, and indicated that there are no significant differences between the diet composition of males and females, and between seasons of the year. However, an ontogenetic change was found, with the young feeding preferentially on crustaceans and the adults on bivalve molluscs. The species presented also a slow growth rate for both genders and it is suggested that the deposition of periodic growth marks occur once a year. The growth curve was fitted and the estimated growth parameters were: L ∞ = 100.76 cm; k = 0.07; t 0 =-2.18 for males; and L ∞ = 137.57 cm; k = 0.06; t 0 =-1.86 for females. Males and females achieve the maturity at about five years old.

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

“…Typical of Myliobatiformes, the species displays matrotrophic viviparity (with lipidic histotrophy) and gives birth to 2–4 embryos each year, with the young 14–17 cm disc width. Males are known to mature at 41–46 cm DW, females at 50–56 cm DW (Menni & Lessa, 1998; Yokota & Lessa, 2007; Gianeti, 2011). The age-at-maturity in males and females is 5 years and 7 years, respectively (Gianeti et al ., 2019).…”

Age structure and multi‐model growth estimation of longnose stingray Hypanus guttatus (Dasyatidae: Myliobatoidei) from north‐east Brazil

“…Growth parameters for H. guttatus were estimated adjusting different models and showed that female growth is slower than that of males (lower growth rates) reaching greater sizes in identical age classes. The mean age at maturity of 43.5 cm W D for males and 51.3 cm W D for females (Gianeti, ) corresponded to 5 and 7 years, respectively. The age composition of the entire sample shows that most specimens (84%) were juveniles aged between 0 and 2 years (Figure ), mostly distributed in very shallow waters ( c .…”

“…Growth parameters for H. guttatus were estimated adjusting different models and showed that female growth is slower than that of males (lower growth rates) reaching greater sizes in identical age classes. The mean age at maturity of 43.5 cm W D for males and 51.3 cm W D for females (Gianeti, 2011) (Cervigón & Alcalá, 1999;Léopold, 2004;Stehmann et al 1978;Tagliafico et al, 2013), have not been recorded anywhere in Brazil.…”

Mercury concentrations in coastal Elasmobranchs (Hypanus guttatus and Rhizoprionodon porosus) and human exposure in Pernambuco, Northeastern Brazil

“…Hypanus guttatus is a demersal coastal marine ray, widely distributed in shallow tropical and subtropical waters down to ~35 m deep, found in estuarine sandy and muddy bottoms. Juveniles of H. guttatus live in higher salinity environments while adults prefer lower salinity environments, including intertidal zones (Bigelow & Schroeder 1953, Figueiredo 1977, Menni & Lessa 1998, Yokota & Lessa 2007, Gomes et al 2010, Gianeti 2011, Melo 2016. In Pernambuco there is a bottom gillnet fishing directed to the rays displaying an average height of 10 to 20 meshes, called "raieira" (Lira et al Compared to other areas in the Brazilian coast, concentrations found in stingrays from the Pernambuco coast, like sharpnose sharks, are in general higher than previously reported elsewhere and are also the highest ever reported for the Atlantic Ocean and the North Pacific Ocean (Table II).…”