本属魚類は2種知られ,太平洋にはR. pacificaテングギンザメが産する。本属魚類の特徴とされる尾鰭上縁の皮質の小棘は第二次性徴のひとつらしく,未成魚,ほとんどのR. atlanticaの雌では発現しないという(Bigelow and Schroeder, 1954b; Inada and Garrick, 1979)。長い吻を備えるNeoharriottaは臀鰭を備え,Harriottaアズマギンザメ属の歯板には歯棒がある。 (上野・佐々木)
Distinctive characters:
Snout extremely long and depressed. Anal fin absent. Denticulations along upper margin of caudal fin developed in adult males, but absent in young and females. Tip of pectoral just reaching to insertion of pelvic when depressed. Eye small, its diameter 1/4 of dorsal spine length. Mouth placed somewhat forward of anterior margin of eye. Dental plates on jaws smooth without griding ridges and knobs; cutting edges of lower dental plates nearly straight. Pattern of mucous canals on head is shown in the figure. Clasper lod-like and slender.
Distribution:
North Atlantic and off the Atlantic coast of South Africa. Newly recorded from the tropical zone of the Atlantic here.
Remarks:
Bigelow and Schroeder (1954b) and Inada and Garrick (1979) noted that the denticulations are secondary sexual characters of mature males (except in R. pacifica). (Uyeno and Sasaki)