Joubin's Octopus

Octopus joubini Robson, 1929

DIAGNOSIS.—Animals small (to 45 mm ML; wt to 30 g). Mantle round or saccular (MWI 90); neck constricted; head moderate in width (HWI 73); eyes prominent, projecting. Funnel organ W-shaped. Arms short (ALI 64). Suckers moderate in size (SIn 9), few in number (ASC 79). Web shallow to moderate (WDI 28), web formula D > B = C = E > A, but nearly equal. Gill lamellae 4. Mature ovarian eggs small, 2.3–4.8 mm long; single egg masses of 150–3000 eggs each laid periodically over 4–6 weeks and attached singly to substratum. Hatchlings planktonic, 2.0–2.5 mm ML, with ∼420 chromatophores. Surface of head, mantle, and arms smooth; supraocular papillae 3 to 4. Color in life reddish orange. Color in preservation (ethanol) grayish brown.

ORIGINAL DESCRIPTION.—Robson, 1929a:161, figs. 56–58.

TYPE LOCALITY.—Western North Atlantic Ocean, Virgin Islands, St. Thomas, 15 m.

TYPE.—Holotype: BMNH 89.4.24.30, female, 15 mm ML.

DISTRIBUTION.—United States, Georgia and Florida; northern Gulf of Mexico to central Caribbean Sea (Virgin Islands); on sand or mud bottom in depths of greater than 10 m.