 The pectoral fin disc of the reticulate whipray is diamond @-@ shaped and wider than long , with the leading margins almost straight and the snout and outer corners angular . In juveniles , the disc is about as wide as long , with a more obtuse snout and rounded corners . The eyes are small and immediately followed by the spiracles ( paired respiratory openings ) . A short and wide curtain of skin with a minutely fringed rear margin is present between the long , thin nostrils . The mouth is relatively small , with a deep concavity at the center of the lower jaw and shallow furrows at the corners extending onto the lower jaw . A row of 4 – 5 papillae ( nipple @-@ like structures ) is found across the floor of the mouth . There are 26 – 40 upper tooth rows and 27 – 44 lower tooth rows . The pelvic fins are small and triangular . The tail is whip @-@ like and extremely thin , measuring 3 – 3 @.@ 5 times as long as the disc when intact , and lacks fin folds . Usually one serrated stinging spine is located on the upper surface on the tail , some distance from the base . 
