 The whip @-@ like tail generally measures up to one and half times the length of the disc , and bears one ( more if replacements have grown in ) long , slender , serrated spine on the upper surface , closer to the base than the tip . Behind the spine , there are long dorsal and ventral fin folds that rise gradually , reaching a relatively high apex before sloping down abruptly . The presence of the upper fin fold separates this species from the similar longtail stingray ( D. longa ) , which shares most of its range . However , the tail is often damaged , in which case differentiating the two species in the field becomes all but impossible . Young rays have completely smooth skin , while adults develop a row of low tubercles along the midline of the back , flanked by two shorter rows on the " shoulders " . The tail also becomes covered in prickles . This species is a uniform olive to brown to gray above , darkening to black on the tail , and off @-@ white below . 
 The whip @-@ like tail generally <a href='uninflect' title='1'><mark>measures</mark></a> up to one and half times the length of the disc , and <a href='uninflect' title='2'><mark>bears</mark></a> one ( more if replacements <a href='been_done' title='3'><mark>have</mark></a> grown in ) long , slender , serrated spine on the upper surface , closer to the base than the tip . Behind the spine , <a href='dey_it' title='4'><mark>there</mark></a> are long dorsal and ventral fin folds <a href='null_relcl' title='5'><mark>that</mark></a>rise gradually , reaching a relatively high apex before sloping down abruptly . The presence of the upper fin fold separates this species from the similar longtail stingray ( D. longa ) , which <a href='uninflect' title='6'><mark>shares</mark></a> most of its range . However , the tail is often damaged , in which case differentiating the two species in the field <a href='uninflect' title='7'><mark>becomes</mark></a> all but impossible . Young rays <a href='got' title='8'><mark>have</mark></a> completely smooth skin , while adults develop a row of low tubercles along the midline of the back , flanked by two shorter rows on the " shoulders " . The tail also <a href='uninflect' title='9'><mark>becomes</mark></a> covered in prickles . This species <a href='drop_aux' title='10'><mark>is</mark></a>a uniform olive to brown to gray above , darkening to black on the tail , and off @-@ white below . 
The whip @-@ like tail generally measure up to one and half times the length of da disc , and bear one ( more if replacements done grown in ) long , slender , serrated spine on the upper surface , closer to the base den tdatip . Behind the spine , it is long dorsal and ventral fin folds rise gradually , reachin a relatively high apex before sloping dwn abruptly . The presence of the upper fin fold separates this species from the similar longtail stingray ( D. longa ) , which share most of its range . However , the tail is often damaged , in which case differentiating the two species in thdaield become all but impossible . Young rays got completely smooth skin , while adults develop a row of low tubercles along the midline of the back , flanked by 2 shorter rows on the " shoulders " . The tail also become covered in prickles . dis species a uniform olive to brown to gray above , darkening to black on the tail , and off @-@ white below .