 The sixgill stingray ( Hexatrygon bickelli ) is a species of stingray and the only extant member of the family Hexatrygonidae . Although several species of sixgill stingrays have been described historically , they may represent variations in a single , widespread species . This flabby , heavy @-@ bodied fish , described only in 1980 , is unique among rays in having six pairs of gill slits rather than five . Growing up to 1 @.@ 7 m ( 5 @.@ 6 ft ) long , it has a rounded pectoral fin disc and a long , triangular , and flexible snout filled with a gelatinous substance . It is brownish above and white below , and lacks dermal denticles . 
