Source: FAO 2002.
| Family | Scientific Name | Author | Year | Common Name |
| Istiophoridae | Istiophorus platypterus | (Shaw) | 1792 | Sailfish |
Istiophorus platypterus
Unique Characters: First dorsal fin sail-like and remarkably higher than body depth at level of midbody. Pelvic fin rays very long, nearly reaching to anal fin origin, with well developed membrane. Dorsal fin bluish black to dark brownish blue with dark spots.
Similar Species:
Blue Marlin
Makaira nigricans
Longbill Spearfish Tetrapturus pfluegeri
White Marlin
Kajikia albida
Source: FAO 2002
Blue Marlin, Makaira nigricans. First dorsal fin lower than body depth at level of midbody, not sail-like. Pelvic in rays shorter than pectoral fins, well separate from origin of anal fin, with moderately developed membrane. Height of anterior lobe of first dorsal fin lower than body depth; nape highly elevated. Body not compressed laterally. First dorsal fin dark blue to black.
Longbill Spearfish, Tetrapturus pfluegeri. First dorsal fin lower than body depth at level of midbody, not sail-like. Pelvic in rays short, well separate from origin of anal fin, with moderately developed membrane. Height of anterior lobe of first dorsal fin slightly greater than, or nearly equal to, body depth. Nape slightly elevated or not elevated. Body well compressed laterally. Anterior lobe of first dorsal fin slightly higher than rest of fin which remains of about equal height almost to the end. Anus situated far anterior to first anal fin origin, the distance between them greater than height of first anal fin. Bill comparatively short. First dorsal fin blackish blue; spots absent.
White Marlin, Kajikia albida. First dorsal fin lower than body depth at level of midbody, not sail-like. Pelvic in rays short, well separate from origin of anal fin, with moderately developed membrane. Height of anterior lobe of first dorsal fin slightly greater than, or nearly equal to, body depth. Nape slightly elevated or not elevated. Body well compressed laterally. Anterior lobe of first dorsal fin somewhat higher than remainder of the fin, the height decreasing gradually backward. Anus situated near origin of first anal fin, the distance between them smaller than height of first anal fin. Scales on sides pointed anteriorly, stiff, and 1-2 pronged posteriorly. Dorsal and anal fins rounded at tips; pectoral fins usually rounded at tips. First dorsal fin blue with blackish spots.
Roundscale Spearfish, Tetrapturus georgii
Source: FAO 1985
Roundscale Spearfish, Tetrapturus georgii. First dorsal fin lower than body depth at level of midbody, not sail-like. Pelvic in rays short, well separate from origin of anal fin, with moderately developed membrane. Height of anterior lobe of first dorsal fin slightly greater than, or nearly equal to, body depth. Nape slightly elevated or not elevated. Body well compressed laterally. Anterior lobe of first dorsal fin somewhat higher than remainder of the fin, the height decreasing gradually backward. Anus situated near origin of first anal fin, the distance between them smaller than height of first anal fin. Scales on midbody soft and rounded anteriorly, softly, and 2-3 pronged posteriorly. Dorsal and first anal fins usually blunt at tips; pectoral fins usually pointed at tips. Dorsal fin dark blue, spots absent.
References
FAO. 2002. The living marine resources of the Western Central Atlantic. Volumes 1-3. K.E. Carpenter (ed.). Food and Agriculture Organization of the United Nations, Rome, Italy. 4099pp.
Kells, V.A., and K. Carpenter. 2011. A field guide to coastal fishes: from Maine to Texas. Johns Hopkins University Press, Baltimore, MD. 447pp.
Nakamura, I. 1985. An annotated and illustrated catalogue of marlins, sailfishes, spearfishes, and swordfishes known to date. Volume 5. Billfishes of the world. FAO Fisheries Synopsis. No. 125. Volume 5. 65 pp.