Amphiatlantic. Known from West Africa (Ghana) and Sth America (Brazil).
Rocky shore, Rio de Janeiro, Atlantic, 22 February 2006, Intertidal. Length: 6 mm. Photographer: Vinicius Padula
The body has a smooth, firm, jelly-like consistency. It is a translucent hyaline yellow colour with irregular brownish spots. There is a median ridge which runs from between the rhinophores back to the gill pocket, where it divides to encircle the gill pocket. There are also scattered irregular tubercles over the mantle. The gills, about 8, are simple and form a goblet shaped circlet, typical of the genus.
This species was previously known from only two individuals, one from Ubatuba, Brazil (7 mm long) and one from Ghana (14 mm long). It is clearly very cryptic. As I mention elsewhere [#16203 ] it may be worth looking carefully at halisarcid sponge colonies for further animals.
Gosliner, T.M. & Johnson, S. (1994) Review of the genus Hallaxa (Nudibranchia: Actinocyclidae) with descriptions of nine new species. The Veliger, 37(2): 155-191.
Marcus, E. (1957) On Opisthobranchia from Brazil (2). Journal of the Linnean Society of London, Zoology, 43: 390-486.
Ortea, J., Valdés, A. & Templado, J. 1997. Hallaxa apefae Marcus, 1957 (Nudibranchia: Actinocyclidae) from Ghana (West Africa), newly recognized as an amphiatlantic species. The Veliger, 40: 86-88.
Rudman, W.B., 2006 (March 30) Hallaxa apefae Marcus, 1957. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/hallapef