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Octopus marginatus Taki, 1964 Octopus striolatus Octopus ... · PDF file the world on a large scale along with Octopus aegina (tens of thousands of tonnes annually). Both species are

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  • Octopus marginatus Taki, 1964

    Frequent synonyms / misidentifications: Octopus striolatus Dong, 1976 / Octopus aegina Gray, 1849. FAO names: En - Sand bird octopus (from Chinese “Saa liu”); Fr - Poulpe des sables; Sp - Pulpo reticulado. Diagnostic characters: Moderate-sized octopus. Arms short, 2 to 3 times mantle length. Dorsal arms slightly shorter than other arms (arm formula IV=III=II.I or III.IV=II.I). Right third arm of males hectocotylized with small ligula (1.5 to 3.5% of arm length). Gills with 9 to 11 lamellae per demibranch. Up to 150 suckers on each normal arm, 60 to 85 on hectocotylized arm of male. Mature males possess 4 to 5 slightly enlarged suckers (7th to 11th) on arms II and III. Colour: pattern typically orange-brown to purple with dark reticulations defining distinct patches in irregular longitudinal rows; suckers white to pink contrasting against dark brown to black along leading edge of arms I to III; narrow transverse “head bar” visible in live animals; white triangle below each eye; dark reticulations distinctive on lateral arm crown in same position as false eye-spots in ocellate species; skin sculpture of regular patches separated by distinct grooves; diamond of 4 longitudinal skin ridges on dorsal mantle and large papilla over each eye. Size: Maximum mantle length around 100 mm, total length to around 300 mm; weight to 400 g. Habitat,biology,and fisheries:Known from coastal muddy waters on mud and sand substrates, subtidal to depths of at least 190 m. Little known of biology or behaviour.Females lay up to 100 000 small eggs, up to 3 mm long. Important fisheries species col- lected by trawlers, pots and lines. Tax- onomy confused with Octopus aegina (treated above) and O. kagoshimensis from Japan. Distribution: Found in tropical conti- nental waters of the Indian Ocean, from the Red Sea and East Africa to Southeast Asia and eastern Australia.

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    dorsal view

    lateral view of head

    Octopodidae 815

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  • Octopus nocturnus Norman and Sweeney, 1997

    Frequent synonyms / misidentifications: None / Octopus macropus Risso, 1826. FAO names: En - Philippine night octopus. Diagnostic characters: Moderate-sized octopus. Arms long, 5 to 6.5 times mantle length. Dorsal arms distinctly longer than other arms (arm formula I.II.III.IV). Webs shallow, deepest 10 to 15% of longest arm. Right third arm of males hectocotylized with moderate length ligula (3 to 5% of arm length). Gills with 10 or 11 lamellae per demibranch. In larger specimens, 180 to 220 suckers on each normal arm, 80 to 90 on hectocotylized arm of male. No enlarged suckers in either sex. Eggs small type and numerous (more than 1 000) in submature females examined. Colour: pattern of red-brown base with irregular darker blotches and white spots over dorsal sur- faces including mantle; white spots paired along length of arms; skin sculpture of small low round papillae; no primary papillae visible. Size: Maximum mantle length around 60 mm, total length to around 350 mm; weight to at least 100 g. Habitat, biology, and fisheries: Known pri- marily from intertidal coral and rocky reefs. Deepest record a poison station affecting be- tween a depth of 1.5 and 4.5 m. Members of this species emerge at night to forage during low tides on intertidal reefs. Females produce small eggs in large numbers. Collected in local subsistence harvest, speared on night low tides, historically using burning bamboo torches to find active octopuses. Distribution: At this stage, known only from throughout the Philippines.

    dorsal view

    tip of hectocotylized arm of male

    816 Cephalopods

  • Octopus ornatus Gould, 1852

    Frequent synonyms / misidentifications: Octopus (or Callistoc- topus) arakawai (Taki, 1964) / None. FAO names: En - White-striped octopus. Diagnostic characters: Large and elongate octopus. Arms long, 6 to 8 times mantle length. Dorsal arms much longer than ventral arms (arm formula I.II.III.IV). Webs shallow, deepest 5 to 11% of longest arm. Right third arm of males hectocotylized with large cylindrical ligula (4 to 6% of arm length), with deep groove. Gills with 13 or 14 lamellae per demibranch. In larger animals, 300 to 400 suckers on each normal arm, 150 to 170 on hectocotylized arm of male. Suckers on longer dorsal arms proportionally larger than other arms, but none markedly enlarged. Colour: pattern of brown to deep red base colour with white markings; distinctive pattern of longitudinal white bars on dorsal mantle, visible in live, fresh dead and preserved material; large paired white spots along arms; skin sculpture of low irregular patches separated by distinct grooves; elongate skin flaps can be raised within longitudinal white bars on mantle. Size: Maximum mantle length 130 mm, total length to over 1 m; weight to at least 1 kg. Habitat, biology, and fisheries: Known from clear tropical waters, from intertidal shallows to a depth of at least 10 m, on coral reefs amongst both live corals and dead coral rubble. Forages exclusively at night, preying primarily on crustaceans and other octopus species. Typically encountered foraging along the edges of in- tertidal reefs adjacent to deeper water. Sometimes encountered swimming at the surface in or near la- goons. Occupies deep lairs during the day, the en- trance of which is blocked at several levels. Females lay up to 35 000 eggs in festoons, each egg around 3 to 4 mm long. Harvested on a small scale throughout its range, primarily in local subsistence fisheries. It is sold in fish markets in the central and southern tropical Pacific, but less frequently than Octopus cyanea. Har- vested at night using torches and spears in at least Hawaii. Distribution: Found widely throughout shallow waters of the tropical Indo-West Pacific region, from Hawaii in the east to the east African coast in the west. Reported as far north as southern Japan (as Callistoctopus arak- awai) and as far south as New South Wales, Australia.

    dorsal view

    tip of hectocotylized arm III

    Octopodidae 817

  • Octopus tetricus Gould, 1852

    Frequent synonyms / misidentifications: None / Octopus cyanea Gray, 1849; O. cyaneus Gray, 1849. FAO names: En - Common Sydney octopus. Diagnostic characters: Large and robust species. Arms moderate to long, 3 to 4.5 times mantle length. Dorsal arms slightly shorter and less robust than other arms (arm formula IV=III=II.I). Right third arm of males hectocotylized with tiny ligula (1 to 2% of arm length). Gills with 8 or 9 lamellae per demibranch. In larger animals, around 220 to 260 suckers on each normal arm, around 140 to 160 on hectocotylized arm of male. Mature males with around 3 to 5 enlarged suckers (13th to 17th) on arms II and III. Colour: active animals cream to mottled orange and dark brown; transverse narrow dark bands along arms in some colour patterns; resting animals within lairs show grey dorsal surfaces, orange arm faces and eyes with a white iris; skin sculptured in rounded patches separated by distinct grooves; capable of raising large papillae over dorsal surfaces, including 4 in diamond pattern on dorsal mantle and 1 above each eye. Size: Maximum mantle length at least 140 mm, total length to over 0.6 m; weight to 1 kg. Habitat, biology, and fisheries: Known from shallow coastal waters, living subtidally on and adjacent to rocky reefs, to a depth of at least 60 m. Active primarily at night, although alert in the mouth of lairs throughout the day. Preys primarily on crabs, but will also take shellfish and finfish (at least in captivity). Occupies lairs in rock crevices or excavated under rocks on sand or mud. Females lay over 150 000 eggs in festoons, each egg around 2 to 3 mm long. Moderate scale harvest as bycatch in prawn and finfish trawl fisheries. Fre- quently sold in fish markets in New South Wales and southern Queensland. A distinct undescribed species from Western Australia has been incorrectly treated under this name. Distribution: Found in warm temperate waters of coastal New South Wales and southern Queensland, Australia.

    dorsal view

    818 Cephalopods

  • Octopus sp. A

    Frequent synonyms / misidentifications: None / Octopus membranaceus Quoy and Gaimard, 1832. FAO names: En - Eye-bar ocellate octopus. Diagnostic characters: Small to moderate-sized ocellate octo- pus. Arms short to moderately long, 2.5 to 3 times mantle length. Dorsal arms slightly shorter than other arms (arm formula IV=III.II.I). Right third arm of males hectocotylized with moderate length, elongate ligula (4 to 10% of arm length) with a shallow groove. Gills with 8 to 10 lamellae per demibranch. Up to 150 suckers on each normal arm, 65 to 80 on hectocotylized arm of male. Mature males possess 2 to 4 moderately enlarged suckers (4th to 8th) on arms II and III. Colour: pattern typically cream to light green colour on all surfaces; short longitudinal bar through each eye; dark brown or black lines along edges of arms; ocellus present as black spot containing a fine irides- cent blue to purple ring (4 to 6 mm in diameter in adults); head bar and longitudinal stripes on mantle absent; skin sculp- ture of small low rounded papillae, interspersed by slightly larger pink papillae; diamond of four longitudinal skin ridges on dorsal mantle and large papilla over each eye. Size: Maximum mantle length around 60 mm, total length to around 250 mm. Habitat, biology, and fisheries: Known from coastal waters on mud and sand substrates, from intertidal shallows to a depth of at least 60 m. Females lay small eggs, up to 3 mm long, often in shells or bottles. Very important fisheries species collected pri- marily from the Gulf of Thailand by trawlers. Exported throughout the world on a large scale along with Octopus aeg

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