Doris adrianae Urgorri & Señarís, 2021
Doris adrianae Urgorri & Señarís, 2021
|Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 1495386).
Yellow body, sometimes coloured light orange, oval shaped, high and strongly convex, with a maximum reported length of 76mm (typically 40-55mm) and a maximum reported width of 55mm (typically 30-40mm). The entire dorsal surface is finely sprayed with black dots, only visible with a microscope, more dense in the mid-lateral areas of the notum, forming two slightly darker bands between the rhinophores to the gills. The entire dorsum is covered with rounded but slightly pointed, rough-surfaced tubercles of the same colour of the body that have a small, broad basal stalk. There is a dense spicular structure in the tubercles that can be seen by transparency, where the tips of the spicules do not protrude the skin. The larger tubercles are more abundant in the middle of the notum and decrease in size towards the edges of the mantle. Very small tubercles are scattered all over the notum, including the sheaths of both rhinophores and gills. Rhinophores are slightly curved backwards. Elongate and narrow, they bear 29-34 yellow lamellae in the distal two thirds of their length. The stalk is coloured white and slightly conical near the base, while its tip is a small truncated cylinder. They are protected by a high sheath (about 1/3 of the rhinophores length) and covered with small to medium-sized tubercles. Gills are formed by 6-8 tripinnate leaves that look bipinnate, as the tertiary branching is only visible by using a microscope. In some specimens the two rearmost gill leaves on each side grow from a single basal bifurcation. The colour of the gills is quite variable, in most specimens has the same colour as the body, but in others it is whitish. All leaves show tiny black dots like those on the dorsum, less dense on the rachis, but the rest of the leaf has different densities that give it a more or less dark colour, especially on specimens with whitish gill leaves. Gills are protected by a sheath similar to the ones protecting rhinophores, but much wider. When rhinophores and gills retract, their sheaths close completely like a sphincter. The yellowish anus is located at the end of the anal papilla, in the centre of the gills. Eyes are small, located between the two blood gland lobes, but they are not visible externally. The anterior edge of the foot is billaminate with no notch. There are two flattened lobes flaking the mouth instead of oral tentacles. The rear part of the foot does not protrude from the edge of the mantle, not even when the animal moves. The underside of the mantle is paler than the dorsum, with a dense net of spicules visible by transparency. The foot, head and epipodium have a more orange colour than the rest of the animal, with very few black dots.
Specimens found in the type location were living on rocky bottoms covered with Leptogorgia lusitanica gorgonians, with little algal growth and with a rich and diverse benthic fauna, between 11 and 20 m deep. All the body (but the visceral mass) has a dense armoured skeletal structure formed by numerous calcareous spicules that give it a very hard consistence. It could be interpreted as a primary defensive system to deter potential predators, but in this species they probably have a structural function. The spawn is a festooned, 15mm high ribbon, laid on the substrate forming an spiral of 2-2.5 whorls. The side of the ribbon attached to substrate is hyaline white, while the rest of the ribbon is slightly greyish and the upper side is brownish due to the presence of fusiform spicules. The egg capsules usually contain 2 eggs, but may have 1 to 4. There’s no previous reference in literature for the presence of spicules on the nudibranchs’ egg ribbon, which reveals a very specific character in Doris adrianae. This species feeds exclusively on the sea sponge Polymastia boletiformis, confirmed both from faecal pellets and stomach contents, so it is only present where this sponge lives.
- Doris. In Greek mythology, wife of Nereus, nymph of the waters and mother of the Nereids.
- Adrianae. The species is dedicated to Adriana Álvarez Urgorri, granddaughter of one the first author.
Besides of the type location at Galicia (Spain) at present it is only known from the French Brittany (François Roche, pers. comm.) and the coast of Portugal (João Pedro Silva, pers.comm.).
| : OBIS
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
| : OPK
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions
Externally Doris ocelligera and Doris verrucosa are similar, but they have unipinnate branchial leaves while D. adrianae has tripinnate gills. Doris ocelligera maximum reported size is 25mm while D. adrianae is far bigger. Doris verrucosa feeds on Hymeniacidon perlevis and Halichondria panicea sea sponges, while D. adrianae feeds exclusively on Polymastia boletiformis.
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