Giant Sawbelly, Hoplostethus gigas McCulloch 1914


Other Names: Giant Saw-belly, Sawbelly

A Giant Sawbelly, Hoplostethus gigas, from SW of Portland, Victoria, depth 432-522 m, 9 June 2000. Source: Martin F. Gomon / Museum Victoria. License: CC by Attribution

Summary:

A large rare deepwater roughy found only in southern Australia. 

Identifying features:
• Head and body deep greyish-orange to greyish-red, gill cover dark greyish-red
• Mouth cavity and gill openings black
• Vomer, underside of tongue and upper surface of lower jaw stark white
• Fins deep red with grey membranes between dorsal-fin spines; soft dorsal and anal fins, and caudal fin with greyish to blackish outer margins.


Cite this page as:
Martin F. Gomon, Hoplostethus gigas in Fishes of Australia, accessed 14 Jul 2024, https://fishesofaustralia.net.au/home/species/1393

Giant Sawbelly, Hoplostethus gigas McCulloch 1914

More Info


Distribution

Endemic to southern Australia from the western part of the Great Australian Bight (126°47' E) to SW of Portland, Victoria (141°44' E) in depths of 188-522 metres.

The Giant Sawbelly inhabits canyons and areas with hard rough bottom.

Features

Meristic features:
• Dorsal fin VI, 13-14
• Anal fin III, 9
• Caudal fin 6 + 2 + 9 + 8 + 2 + 6
• Pectoral fin rays 14-15 (mostly 15)
• Pelvic fin I, 6
• Gill rakers 5 + 1 + 12
• Lateral–line scales 26-28 + 1-2 (28-29) 
• Transverse scales 13/1/23 (9–13/1/22–24)
• Predorsal scales 9-15
• Abdominal scutes 9-10
• Vertebrae 11 + 15
• Pseudobranch about 46
• Branchiostegal rays 8. 

Size

A large species, the largest specimen examined 426 mm SL; reported to 525 mm SL (McCulloch, 1914).

Colour

Fresh specimens: head and body a deep greyish-orange to red; opercle dark greyish-red; buccal cavity and opercular recess black; vomer, underside of tongue and upper surface of lower jaw stark white; fins deep red; membranes between dorsal fin spines grey, marginal strip on soft portions of dorsal, anal and caudal fins dark grey to almost blackish in large individuals.

In preservative: slightly dusky above, pale below; opercle dark; buccal and branchial chambers dark, including gill arches and rakers; vomer, palatines, underside of tongue and lower jaw uniformly pale; medial fins and pelvic fins dusky near outer edges.

Biology

Although nothing is known of the biology of this species, like other deepwater roughies, the Giant Sawbelly is likely to be very slow to mature and very long-lived.

Conservation

  • IUCN Red List: Not Evaluated
  • EPBC Act: Not listed
  • Similar Species

    This is the largest Australian roughy, and is easily separated from other species by its large size and a combination of  9–15 predorsal scales, 9–10 enlarged abdominal scutes, 15 (rarely 14) pectoral–fin rays, and 18 total gill rakers.

    Author

    Martin F. Gomon

    Quick Facts


    CAAB Code:37255005

    Depth:188-522 m

    Habitat:Continental slope, seamounts, canyons

    Max Size:53 cm SL

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