East Coast of Nth America
From mat of Cladophora liniformis. South of Sarasota, Florida (west coast), USA. Upper: 6mm long, lower; 3mm. PHOTOS: Anna Bass.
Grows to about 8mm, and more typically has a transverse pattern of dark green to black pigmentation arranged in irregular bands across the back. The cerata start about one-third of the way down the body. Bleakney, 1996 describes how in Canada, this species feeds on the filamentous algae Cladophora and Chaetomorpha. Although the algae are essentially single filaments they usually are intertwined and tangled with adjacent filaments to form tangled colonies. Ercolania feeds by piercing a cell wall and sucking out the cell contents. The empty cells become weak points in the algal filament which can break under wave action. When many E fuscata congregate and feed at the base of these algal colonies they can cause whole algal mats to break loose. Bleakney describes how by late summer large numbers of these algal mats have broken loose and are drifting around in bays up and down the coast, with Ercolania 'aboard'.
• Gould, A.A. (1870). Report on the Invertebrata of Massachusetts. Second edition, comprising the mollusca. Edited by W.G. Binney. Boston, v(3) plus 524 pp., text figs. 350-754, coloured pls. 16-27 comprising figs. 214-349
• Marcus, E. (1957) On Opisthobranchia from Brazil (2). Journal of the Linnean Society, Zoology, 43: 390-486.
• Jensen, K. & Clark, K.B. (1983) Annotated checklist of Florida ascoglossan opisthobranchs.
The Nautilus, 97: 1-13.
Rudman, W.B., 2001 (April 18) Ercolania fuscata (Gould, 1870). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/ercofusc
Re: Colour variation in Ercolania fuscata
From: Anna L. Bass, April 26, 2001
Colour variation in Ercolania fuscata
From: Kathe Jensen, April 24, 2001
Re: Ercolania fuscata from Florida
From: Anna L. Bass, April 23, 2001
Ercolania fuscata from Florida
From: Anna Bass, April 19, 2001