Aluterus monoceros

Aluterus monoceros
Unicorn Filefish – Aluterus monoceros
FamilyScientific NameAuthorYearCommon Name
MonacanthidaeAluterus monocerosLinnaeus1758Unicorn Filefish

Aluterus monoceros

Unique Characters: Pelvic fin absent and without any obvious enlarged encasing scales (a rudimentary encasing  scale sometimes present, but difficult to see with the unaided eye and not at end of pelvis). Dorsal-fin rays 43-50; anal-fin rays 46-52; pectoral-fin rays modally 14. Caudal peduncle longer than deep. Caudal fin relatively short, 18-26% standard length.

Similar Species:

Scrawled Filefish
Aluterus scriptus

Orange Filefish
Aluterus schoepfii

Dotterel Filefish
Aluterus heudelotii

Aluterus schoepfii
Orange Filefish – Aluterus schoepfii

Scrawled Filefish Aluterus scriptus. Pelvic fin absent and without any obvious enlarged encasing scales (a rudimentary encasing  scale sometimes present, but difficult to see with the unaided eye and not at end of pelvis). Dorsal-fin rays 43-50; anal-fin rays 46-52; pectoral-fin rays modally 14. Caudal peduncle deeper than long. Caudal fin relatively long, 33-61% standard length.

Orange Filefish Aluterus schoepfii. Pelvic fin absent and without any obvious enlarged encasing scales (a rudimentary encasing  scale sometimes present, but difficult to see with the unaided eye and not at end of pelvis). Dorsal-fin rays 32-41; anal-fin rays 35-44; pectoral-fin rays modally 12 and 13. Distance between eye and dorsal-fin spine relatively large in specimens larger than 10 cm standard length, 7.3-13.5% standard length. Coloration of live specimens with few to many orange spots.

Dotterel Filefish Aluterus heudelotii. Pelvic fin absent and without any obvious enlarged encasing scales (a rudimentary encasing  scale sometimes present, but difficult to see with the unaided eye and not at end of pelvis). Dorsal-fin rays 32-41; anal-fin rays 35-44; pectoral-fin rays modally 12 and 13. Distance between eye and dorsal-fin spine relatively small in specimens larger than 10 cm standard length, 4.6-6.6% standard length. Coloration of live specimens bluish purple

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