Tylosurus acus

Tylosurus acus
Atlantic Agujon – Tylosurus acus
FamilyScientific NameAuthorYearCommon Name
BelonidaeTylosurus acus(Lacepède)1803Atlantic Agujón

Tylosurus acus

Unique Characters: Body rounded or squarish in cross-section. No vertical bars present. Anal-fin rays 13-24. Caudal peduncle not strongly depressed. Caudal peduncle deeper than wide. Gill rakers absent. Dorsal-fin rays 21-26. A weak, darkly pigmented lateral keel on each side of caudal peduncle. Lower lobe of caudal fin much longer than upper lobe. Juveniles with an expanded black lobe in the posterior part of the dorsal fin. Dorsal- and anal-fin lobes relatively low compared to body length (10.1 -13.3 and 9.7-11.7 times in body length, respectively). Pectoral and pelvic fins relatively short (8.0-12.4 and 10.0-14.1 times in body length, respectively). Upper and lower jaw teeth straight at all sizes. Left gonad absent or greatly reduced in length.

Similar Species: Houndfish Tylosurus crocodilus. Body rounded or squarish in cross-section. No vertical bars present. Anal-fin rays 13-24. Caudal peduncle not strongly depressed. Caudal peduncle deeper than wide. Gill rakers absent. Dorsal-fin rays 21-26. A weak, darkly pigmented lateral keel on each side of caudal peduncle. Lower lobe of caudal fin much longer than upper lobe. Juveniles with an expanded black lobe in the posterior part of the dorsal fin. Dorsal- and anal-fin lobes relatively high compared to body length (5.4-10.6 and 5.5-8.0 times in body length, respectively). Pectoral and pelvic fins relatively long (6.6-8.3 and 7.3-10.6 times in body length, respectively). Upper and lower jaw teeth point distinctly anterior in juveniles. Left gonad distinct although shorter than right.

Tylosurus crocodilus
Houndfish – Tylosurus crocodilus

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