Callistoctopus macropus (Risso 1826)

Octopus macropus Risso, 1826

Octopus macropus Risso, 1826:3.

Octopus macropodus San Giovanni, 1829:319.

Octopus longimanus Orbigny, 1840:18.

Octopus alderi Verany, 1851:32, pl. 7bis.

Octopus bermudensis Hoyle, 1885:228.

DIAGNOSIS.—Animals medium-sized to large (25–155 mm ML). Mantle shape variable, usually elongate or ovoid, widest in posterior (MWI 32.5–75.0). Stylets present, very reduced in size. Neck often slightly constricted. Head narrower than mantle (HWI 26.5–70.5); eyes medium-sized, bulging. Mantle aperture wide. Funnel long, narrow (FLI 45–48); funnel organ W-shaped, lateral limbs shorter than median limbs. Arms long (ALI 75.5–87.5, MAI 14.1–36.1). Dorsal arms longest and stoutest; arm formula I > II > III > IV. Suckers medium-sized, arms I with largest suckers (SIn 6.9–13.5, no noticeable difference between males and females). Right arm III of male hectocotylized (HALI 40–43), shorter than opposite arm (OAI 41–51). Ligula small to medium-sized (LLI 4.5–8.0), narrow, pointed rather than blunt, with swollen margins, deep groove, and numerous delicate transverse lamellae; calamus short (CLI 13–18). Web shallow (WDI 7.3–16.7); web formula A > B > C > D > E; sector A distinctly deeper than B, sector E distinctly shallower than D. Ink sac present, well developed. Gills with 10 to 11 lamellae per outer demibranch. Mature ova 2.5 mm long, 1 mm wide. Penis small (PLI 12–28), distally rounded, with large forward- or backward-directed diverticulum. Spermatophores medium-sized (SpLI ∼50). Radula with A3 seriation of rachidian. Skin smooth, with or without large papillae over eyes. Color in life brick red or brownish with distinct pattern of white spots on dorsal mantle, head, and arms.

ORIGINAL DESCRIPTION.—Risso, 1826:3.

TYPE LOCALITY.—Not indicated in original description; presumed to be western Mediterranean Sea, France, off Nice.

TYPE.—Not designated, presumed to be not extant.

DISTRIBUTION.—Mediterranean Sea: Western and eastern basins, Adriatic Sea. Eastern Atlantic Ocean: Dakar to St. Helena. Western Atlantic Ocean: United States (Florida) to Brazil, and in the Caribbean. Found in tropical to warm-temperate waters.

A shallow-water species that lives on both coral reefs and rocky and sandy bottoms mainly within the upper 20 m, at least in the Mediterranean Sea.