Umbilia hesitata
A cold-water cowry with an inflated shell and rostrate extremities.
The umbilicate cowry, also known as the wonder cowry, is a marine gastropod mollusc in the cowry family Cypraeidae. Its shell, which is smooth and round with an almost inflated dome, typically measures between 75 and 100 mm in length, though specimens can range from 55 mm up to 120 mm. The shell’s base is white, featuring a large, sinuous opening and small teeth, while the dorsal surface is white, pale brown, or light pink, dotted with many small, irregular brown spots, particularly near the edges. Both the front and back ends of the shell are drawn out into beak-like shapes, with well-developed flanges extending around the base. Females are smaller than males.
This species is widely found from South Australia to southern Queensland, primarily in the seas off Victoria, New South Wales, and the northern and eastern coasts of Tasmania. It inhabits cold, deep waters, living on the bottom sediment at depths of 100 to 200 meters, where it is usually collected by fishing. Its diet likely consists of bryozoa or sponges. In parts of Tasmania, the species also occurs in much shallower water within the subtidal zone. Two subspecies are recognized: *Umbilia hesitata beddomei*, a dwarf form, and *Umbilia hesitata howelli*, an albina form.
Quick Facts
- Taxon
- Umbilia hesitata
Facts from the source article.
Lore & Background
The shells of Umbilia hesitata reach an average length of 75–100 mm, with a maximum of 120 mm and a minimum of 55 mm. The dorsal dome is smooth, round, and appears almost inflated. The basic color is white, pale brown, or light pink, with many small brown irregular spots, especially near the edges. The anterior and posterior extremities are rostrate, with well-developed flanges extended around the base. The base is mainly white, with a large sinuous aperture and small teeth. Females are smaller than males.
This species is widely distributed from South Australia to southern Queensland, mainly in the seas along Victoria, New South Wales, and along northern and eastern Tasmania. It lives in cold deep waters on bottom sediment at about 100–200 m depth, where it is usually found by fishing. It likely feeds on bryozoa or sponges. In parts of Tasmania, the species occurs in much shallower water in the subtidal zone.
Two subspecies have been described: Umbilia hesitata beddomei (a dwarf form) and Umbilia hesitata howelli (an albina form).
Reader's Guide
Umbilia hesitata is a well-documented species within the Australian genus Umbilia, studied in multiple revisions and field guides. Its large size, inflated shape, and distinctive rostrate extremities with flanges make it a recognizable cowry among deep-water species. The species is known from cold waters off southeastern Australia, including Tasmania, where it occurs on bottom sediment at depths of 100–200 m, though in parts of Tasmania it is found in shallower subtidal zones. Its diet is inferred to include bryozoa or sponges. The existence of dwarf and albina forms (U. h. beddomei and U. h. howelli) indicates morphological variation within the species. The species has been treated in major cowry references and regional shell guides, reflecting its importance in Australian malacology.
Did You Know?
- The shells of Umbilia hesitata can reach a maximum length of 120 mm.
- Females are smaller than males in this species.
- It is found at depths of 100–200 m, but in parts of Tasmania it occurs in much shallower subtidal waters.
- Two subspecies are recognized: a dwarf form (U. h. beddomei) and an albina form (U. h. howelli).
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