Hypselodoris maculosa (Pease, 1871)

Location: Drop Off, Tulamben, Pulau Bali, Indonesia
Date: 2015/11/14
Length: 12mm
Depth: 9.0m
Water temperature: 29.0℃

Description

A medium-sized chromodorid reaching about 38 mm in body length. The body is subcylindrical, elongate, narrow, smooth, flaccid and subpellucid. The mantle is dilated in front and rounded, rounded behind, with sides nearly parallel. The rhinophores are large, sub-erect, on stout peduncles, elongate-ovate, with deeply incised laminae, retractile into simple cavities. The gill is moderately developed, of eight sub-erect, lanceolate, narrow pinnate plumules, connate at their bases, retractile into a common simple cavity, with a simple orifice. The oral tentacles are small and finger-shaped. The foot is elongate, narrow, truncately rounded and fissured in front, tapering behind to an acutely rounded point projecting far beyond the body posteriorly. In life the ground colour is cream yellow, margined with fulvous, on which there is a series of abbreviated reddish lines; three irregular radiating fulvous lines extend from the front margin of the mantle toward the tentacles; lineated longitudinally with opaque white lines, two of which encircle the gill and pass between the rhinophores, while two lateral lines extend from the tentacles to the posterior end of the body, with the spaces between dotted with purple. The rhinophores are pale, with a broad brownish-red zone on their basal half and a narrower red zone just below the apex. The gill plumules are pale slate-coloured tipped with red. The upper surface of the foot and the under sides of the mantle are lineated as above, dotted with violet, the former shaded with violet beneath and along the upper margin, and the latter margined with dingy red. Pease's type was about 1 1/2 inches (≈ 3.8 cm) long, found under stones at low water mark on Tahiti.

Distribution

Indo-West Pacific to the central Pacific. Type locality: Tahiti, Society Islands, based on a specimen collected by Andrew Garrett and described by Pease. Subsequently recorded from the Hawaiian Islands, southern Japan, Taiwan, the Philippines, Indonesia, Guam, Australia, the Red Sea and elsewhere.

Etymology

The specific epithet maculosa is the feminine of Latin maculosus ("full of spots, much-spotted"), in reference to the many short red lines, fulvous radiating lines and purple dots ornamenting the mantle. Pease did not state an etymology.

Remarks

Originally placed by Pease in Chromodoris. Pease introduced the genus on p.15 of the same paper, noting that "the upper surface of the body and mantle of the species of this genus are invariably lineated with bright colors and, with exceptions, spotted; they excel those of any other genus in the gaudy, variegated colors with which they adorn themselves". Later transferred to Hypselodoris; the parentheses in the author citation reflect this generic transfer. The Japanese name "ニヨリセンテンイロウミウシ" ("nearly senten colour-slug") refers to the resemblance to Hypselodoris zephyra.

Photographed by 今川郁

Description

Distribution

Etymology

Remarks

References

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Shooting Locations

Photos of Hypselodoris maculosa

Same Genus Nudibranchs

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