Macroctopus maorum (Hutton 1880)

Octopus maorum Hutton, 1880

Octopus maorum Hutton, 1880:1.

Octopus communis Park, 1885:198.

Octopusflindersi Cotton, 1932:543, figs. 4, 6.

Paroctopus zealandicus Benham, 1944:256, pl. 40.

DIAGNOSIS.—Animals large (to 1155 mm TL; to 255 mm ML). Mantle broadly ovoid (MWI 52–69–96); head narrow (HWI 32–53–74), demarked from mantle by moderate constriction; eyes large, not projecting far above surface of head. Funnel large, stout, bluntly tapered (FLI 33–44–57); funnel organ W-shaped, limbs thick, outer limbs length of median limbs. Arms long (ALI 165–569), slender, tapering to fine tips. Arm lengths unequal, arm order usually I > II > III > IV. Suckers raised above arm surface, large (SI 4–12–22), 15th to 22nd suckers usually largest, enlarged on all arms of mature males and females. Right arm III of males hectocotylized, shorter than opposite arm (HAMI 200–271–317; OAI 57–71–85); ligula narrow, small (LLI 3.4–4.7–6.5); ligula groove well marked and deep, with 10–15 complete transverse ridges; calamus moderately long, acutely pointed (CLI 20–26–35); hectocotylized arm with 94–135 suckers. Web shallow (WDI 14–19–24), web formula A > B > C > D > E. Radula with B2-3 asymmetrical seriation of rachidian. Ink sac present. Gill lamellae 13–15 per outer demibranch. Mature female with medium-sized eggs (capsule 6–7 mm long, 1–2 mm wide), attached singly to substrate by long, thin stalks. Penis long (PLI 8–14–21), diverticulum single-coiled, marked with 3 lobes; spermatophores relatively short (SpLI 35–69–101), slender (SpWI 0.9–1.5–2.0), with large, coiled sperm reservoir (SpRI 27–45–71).

Integumental sculpture consists of pattern of coarse epidermal wrinkling. Dorsum appears rough, with surface of head covered by numerous, transverse furrows and mantle surface covered by longitudinal furrows. Epidermal ridges separated into numerous, roughly rectangular patches, most obvious on dorsal mantle. Ventral surface smoother. Unbranched papillae present on dorsum. Papillae on mantle dorsum form ~5 subparallel rows of simple papillae along mantle length. Each row with 3–6 papillae. Unbranched papillae present in ocular region, with 1 large supraocular papilla and numerous, smaller papillae scattered around each eye. Lateral integumentary ridge or fold around mantle circumference absent. In life, color of resting animals uniformly grey to dark brown dorsally, paler ventrally; when stimulated, animals become darker, turning brick red to very dark brown. Preserved animals in ethyl alcohol cream to dark brown dorsally, slightly paler ventrally. In both live and preserved specimens, small, dark red maculations (1%–3% of ML in diameter) scattered over entire dorsal and ventral surfaces. Ocelli absent.

ORIGINAL DESCRIPTION.—Hutton, 1880:1.

TYPE LOCALITY.—New Zealand, Dunedin (45°50′S, 170°30′E), no depth data.

TYPE.—Lectotype: OMD A.′89.03, male, 185 mm ML. Specimen in poor condition, preserved in ethyl alcohol. Another type specimen of O. maorum, from the CMC collection (male, 43 mm ML, unregistered), was subsequently reidentified as Robsonella huttoni Benham, 1943, by Dell (1952).

DISTRIBUTION AND BIOLOGY.—Temperate waters of southeastern Australia, from the Great Australian Bight to central New South Wales, including Bass Strait and Tasmania, as well as both temperate and subantarctic waters in New Zealand, including the North and South islands and Chatham, Stewart, Auckland, and Campbell islands. No geographic variation detected to date between the Australian and New Zealand populations of the species. A species inhabiting the continental shelf and upper continental slope, living on reefs or rocky areas, or among sponges, at depths of 0–549 m.

Aspects of the biology of O. maorum, including the morphology and brooding of eggs and the hatching and behavior of juveniles, were described by Batham (1957). Several parasites have been recorded as occurring in this host in New Zealand, namely, dicyemid mesozoans (Dicyemennea kaikouriensis Short and Hochberg, 1969; Dicyema knoxi and D. maorum Short, 1971) and digenetic trematodes (Plagioporus maorum Allison, 1966; Lecithochirum sp. Overstreet and Hochberg, 1975).

Octopus flindersi Cotton, 1932

ORIGINAL DESCRIPTION.—Cotton, 1932:543, figs. 4, 6.

TYPE LOCALITY.—Australia, South Australia, Largs Bay (34°49′S, 138°29′E), no depth data.

TYPE.—Holotype: SAM D10169, male, 176 mm ML. Specimen in good condition, preserved in ethyl alcohol.