Not Staurodoris verrucosa Vayssiere, 1901. Currently (2012), only one accepted British record of Doris verrucosa, in Devon in 1900 (Thompson & Brown), but present not far away in Brittany [image 1], so may occur again, and juveniles may have been mistaken for other species.
Length up to 70mm (Thompson & Brown). Outline oval, about twice as long as wide . Firm, rough textured mantle has very large tubercles interspersed with smaller ones of less than 25% their height and diameter; mantle periphery only has small tubercles. Tubercles swollen ,up to 4mm diameter, with narrow base . Those near centre of dorsum sometimes torpedo-shape (SSF). Tubercles do not have protruding spicules. Ground colour of mantle usually whitish (DORIS), yellow , orange-brown , light violet, greyish (DORIS) or pale flesh-colour, often, but not always, partly obscured by patches, or dorso-lateral bands, of brown (SSF), red-brown (SSF), black-brown , grey(SSF), or violet (DORIS). Often, centre of dorsum is palest part of mantle (SSF). On unpigmented specimens, tubercles often similar colour to mantle . When pigment present, tubercles may be concolorous with adjacent mantle, or darker. Occasionally the tips of the tubercles have dark apices, somewhat resembling those on some D. ocelligera .
Retractile. Slender upper half usually has 10-13 lamellae (max. 20), concolorous with, but often a little paler than, mantle. Stem, translucent and pale on unpigmented specimens , rapidly widens to double diameter of lamellae. Both stem and lamellae sometimes have fine freckles of pigment if present on mantle . Pair of large guard-tubercles at base, connected by collar usually bearing two smaller tubercles .
Usually about 13 (up to 18, Thompson & Brown) simple unipinnate gill plumes, often tilted backwards (DORIS). Translucent, similar colour to mantle, may be paler . Pigmented animals have less translucent gills, often finely sprinkled with fine specks of pigment . Gill pit surrounded by low collar bearing about one spatulate guard-tubercle per plume ; about 50% guard-tubercles often noticeably larger than others.
No linear oral tentacles, but large, swollen, sub-rectangular, oral lobe on each side of mouth. Lobe has minute groove in lower external corner, but may be difficult to discern.
Hidden dorsally by broad mantle margin, may slightly protrude beyond posterior edge. Internal spicules (if present) not easily visible. Anterior margin, rounded, bilaminate, not vertically notched.
- Large species, up to 70mm long.
- Ground colour of mantle usually whitish (DORIS), yellow , orange-brown , light violet, greyish (DORIS) or pale flesh-colour.
- Some lack surface pigment so colour almost uniform ground-colour.
- Pigmented specimens often have dorso-lateral bands of brown (SSF), red-brown (SSF), black-brown , grey(SSF), or violet (DORIS).
- Often, centre of dorsum is palest part of mantle (SSF).
- Tubercles, vary from very small to very large, virtually all inflated, clubbed or torpedo-shape (SSF) with narrower base .
- Tubercles sometimes darkened by pigment, occasionally nearly like distinctly darker black-brown apices of D. ocelligera .
- Rhinophores yellowish or whitish, similar to colour of mantle (SSF).
- Pair of large guard-tubercles at base of rhinophore, connected by collar usually bearing two smaller tubercles .
- Swollen lobe either side of mouth; no linear oral tentacles.
- Gills usually concolorous with, or paler than, mantle, rarely much darker .
- Gill pit surrounded by low collar bearing about one spatulate guard-tubercle per plume ; about 50% guard-tubercles noticeably larger than others.
- All tubercles smooth (not with protruding spicules), including those around gill and rhinophore pits.
- Spawn mass: white wavy ribbon in spiral of about 5 turns, (SSF).
Intertidal to about 15m depth (near Naples). Often found in areas with much soft sediment such as lagoons (e.g.Thau and Arcachon, France), in ports and on Zostera beds. On shore, often found under stones or in sponge growth. Diet: sponges; spicules exclusively from Hymeniacidon sanguinea (70%) and Halichondria panicea (30%) in faecal remains examined in Galicia, Spain by Urgorri & Besteiro (1984). In Bay of Naples, commonest and largest in June and July. Simultaneous hermaphrodite. Spawn mass: white wavy ribbon attached by edge in spiral of about 5 turns, (SSF)
Belgium and South coast England to Portugal and Spain, and into the Mediterranean and Adriatic. Also west Atlantic from Brazil to Massachusetts (GBIF map) and possibly southern Africa and Madagascar . Only accepted British record: Devon, 1900. Scottish records on NBN dubious.