Geitodoris heathi (Macfarland, 1905)

What is the Heath's dorid?

The Heath's dorid (Geitodoris heathi) is a pale-yellow, dark-speckled dorid nudibranch of the northeastern Pacific (Alaska to Baja California); the dense dusting of tiny dark spots over its back gives it a characteristically dusty, "gritty" look.

Description

An elliptical, broad, flattened dorid. The ground colour is light yellow, darkening toward the midline, with the whole dorsum sprinkled with extremely minute black or brown spots that give a dusty appearance; larger black, brown or reddish-brown flecks are scattered mainly along the mid-dorsal region. The dorsum is minutely tuberculate and nearly smooth, and the thin, wide, crenulate mantle margin extends well beyond the foot except behind. The rhinophores carry a perfoliate club of 10-15 leaves, are slightly darker than the mantle and finely dark-speckled; the 8-10 tripinnate branchial plumes are small, whitish yellow and likewise speckled. Colour ranges from whitish through yellow to a pinkish tinge. The original description gave a length up to 30 mm, though larger animals (to about 45 mm) are reported.

Distribution

Type locality Monterey Bay, California. It ranges through the northeastern Pacific from Alaska to Baja California, living in rocky tide pools.

Etymology

The specific epithet honours Dr Harold Heath, a colleague of the describer, in recognition of his willing help in collecting Pacific-coast nudibranchs.

Remarks

A sponge feeder, recorded on sponges such as Halichondria, Mycale and Myxilla. It superficially resembles the yellow "sea lemon" dorids but is distinguished by its dusty dark speckling.

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References

• Discodoris heathi sp. nov., MacFarland F.M. (1905). A preliminary account of the Dorididae of Monterey Bay, California. Proceedings of the Biological Society of Washington. 18: 35-54.
• Discodoris fulva n. sp., O'Donoghue C.H. (1924). Notes on the nudibranchiate Mollusca from the Vancouver Island region. IV. Additional species and records. Transactions of the Royal Canadian Institute, 15(1): 1-33, plates 1-2.