Halgerda toliara Fahey and Gosliner, 1999

This species of Halgerda was collected in Madagascar by Terry Gosliner. Toliara is the Malagasy name for the Tulear region of Madagascar where this species was collected. All the specimens were found about 2 m deep.

Halgerda toliara shares some common characteristics with other species of the genus. It has the same firm, smooth and rigid body with low ridges arranged in a reticulate pattern. It also has a large gill with four branches, but it is sparsely pinnate. In most other Halgerda species having a four-branched gill, the gill is moderately or highly pinnate.

Some other Halgerda have similar ridge coloration (H. formosa and H. wasinensis), but unlike these two, H. toliara has no dark pigment on the notum or the foot. Also, the color of the tubercles along the mantle edge of H. toliara are yellow, whereas in H. formosa the tubercles are white. Halgerda toliara has other differences that include reproductive and radular characters.


Shireen J. Fahey and Terrence M. Gosliner. 1999.Description of Three New Species of Halgerda from theWestern Indian Ocean with a Redescription of Halgerda formosa Bergh, 1880. Proceedings of the California Academy of Sciences, 51(8): 365-383, 8 Figs.

Photo courtesy of Terry Gosliner
Taxonomic text courtesy of Shireen Fahey

Photo of Dr. Terry Gosliner, Director of Research and Curator of Invertebrates at the California Academy of Sciences in Golden Gate Park, San Francisco, California and Shireen Fahey, Terry’s graduate student from San Francisco State University.

Shireen is in the Marine Biology program and for her thesis, she is developing the phylogeny and biogeography of the nudibranch genus Halgerda. She has started with a set of morphological characters but intends to include molecular and biochemical character sets.

Send Shireen email at sfahey@sfsu.edu
Send Terry email at tgosliner@casnotes1.calacademy.org

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