Caribbean Two Spot Octopus

Octopus filosus Howell, 1868

DIAGNOSIS.—Animals medium-sized (to 72 mm ML). Mantle saccular, rounded posteriorly (MWI 50–92); neck slightly constricted; head about as wide as mantle (HWI 50–100). Funnel organ W-shaped. Arms short to moderate (ALI 60–80), arm order variable but typically III = II = IV > I. Suckers low, deeply set into arm, moderate to large in size, larger in females (SIn 10–15) than in males (SIn 6–11); males with especially enlarged suckers on arms II and III (SIe 13–18). Right arm III of males hectocotylized, subequal or only slightly shorter in length as compared to fellow arm; ligula small (LLI 3.0–5.0), deeply excavated with thick borders; calamus moderate to large in size (CLI 53–56). Web moderate to deep (WDI 20–56), web formula typically C>D>B>E>A. Gill lamellae 5–9. Penis short (PLI 16–28), with single, small diverticulum varying in shape from subspherical to digitiform. Spermatophores short to moderate in length (SpLI 27–51), sperm mass moderate in length (SpRI 32–48). Mature ovarian eggs small, 1.6–1.8 mm long, with stalk 1–1.5 times length of egg. Radula with A3–4 seriation of rachidian. Dermal ornamentation of granular elevations covering mantle, head, web, and arms; small to large flat papillae, greatly extensible and multifid in life on mantle and arms; large multifid cirrus over each eye; large terminal cirrus at posterior apex of mantle; skin with patch and groove trellis arrangement. Color in life reddish yellow-brown with yellow mottling; mantle with pair of large white spots; frontal white spots diffuse; single pair of ocelli, consisting of conspicuous iridescent blue ring and dark central spot, present between eye and bases of arms II and III; ocellus occasionally lacking unilaterally or bilaterally. Color in preservation (ethanol) light to dark gray, paler ventrally.

ORIGINAL DESCRIPTION.—Howell, 1868:240.

TYPE LOCALITY.—Western tropical Atlantic Ocean, Virgin Islands, Santa Cruz Island (= St. Croix) (museum label reads “St. Croix, West Indies”).

TYPE.—Holotype: ANSP A6450, female, 36 mm ML, in alcohol, fair to good condition.

DISTRIBUTION.—United States, Florida; Bahamas to Recife, Brazil (common in Haiti); associated with coral reefs.

Octopus hummelincki Adam, 1936

DIAGNOSIS.—See Octopus filosus Howell, 1868, above.

ORIGINAL DESCRIPTION.—Adam, 1936:1.

TYPE LOCALITY.—Western tropical Atlantic Ocean, Netherlands West Indies, Bonaire.

TYPES.—Syntypes: ZMA, 1 male, 21 mm ML, 1 female, 18 mm ML, in alcohol, good condition; ISBN, 1 female, 15 mm ML.

coastal to shelf