A 2018 study published in the peer-reviewed journal Gulf and Caribbean Research represents a collaborative effort between ANAMAR biologist Jason Seitz and colleagues at the University of New England and the Florida Fish and Wildlife Research Institute. Southern stingrays (Hypanus americanus, previously Dasyatis americana) were sampled and measured at fishing tournaments from 2004 and 2012 in Charlotte Harbor, Florida. Vertebral centra obtained from the stingrays were sectioned and mounted on slides, and their growth bands were counted by two independent readers. A total of 18 female southern stingrays, measuring from 412 to 1127 mm disc width (DW) were aged. Ages ranged from 0 to 17 years. The results suggest that southern stingrays obtain relatively old ages (17 years) and large sizes (to at least 1127 mm DW). The results are comparable to other large stingray species such as the brown stingray (Bathytoshia lata; to at least 24 years and 1790 mm DW) and the common stingray (Dasyatis pastinaca; to at least 16 years and 1140 mm DW). The results are also comparable to size-at-width data from a captive population of southern stingrays (13 years for a 1000-mm DW captive female, compared to an estimated 12 years for a 1005-mm DW wild female in this study). The age-at-width estimates given in the 2018 study provide a preliminary foundation for future studies on age and growth of southern stingrays for the generation of mortality rates, production rates, and growth models, such as a Von Bertalanffy growth function or a Gompertz function, once ages of each life stage are obtained. This study is the first investigation of the age-at-widths of wild southern stingrays.
Here is a link to the open-access paper: Southern-stingray-age-and-growth-FINAL-2018
Hayne, A.H.P., G.R. Poulakis, J.C. Seitz, and J.A. Sulikowski. 2018. Preliminary age estimates for female Southern Stingrays (Hypanus americanus) from southwestern Florida, USA. Gulf and Caribbean Research 29:SC1–4. DOI:10.18785/gcr.2901.03