Body (excluding appendages)
Usually up to 12 mm long, exceptionally to 15mm. Translucent whitish or pale yellow with blotches and streaks of crimson surface pigment extending between cerata from dorsum onto flanks [image5]. Pigment reduced or absent on juveniles [3]. Genital papilla below first ceras on right [12].
Cerata
Single row of five to eight [3], occasionally nine [5], each side of body, often leaving dorsum fully exposed. No cnidosacs at tips. Translucent whitish, revealing red, orange [6], pink, white [3], or brown internal digestive gland which extends almost to the apex. Colour of digestive gland reflects diet; juveniles may feed on hydroid spp. different from those eaten by adults able to tackle tougher material. Crimson blotching of body extends subepidermally into mesial face of cerata [1], sometimes reaching half way up [14]. Each ceras has three or four [6], occasionally more, [5] concentric rings of rounded tubercles. Internally, each tubercle has an apical crimson [1] or blackish red [5] spheroids and several sub-apical white granular bodies. Some specimens have pseudobranchs on mesial face [14], but often indistinct or absent. Anal papilla between first and second ceras on right [13].
Rhinophores
Smooth, translucent white, some white surface pigment distally. Arise from translucent white basal sheath [4] with smooth rim which is dilated, particularly at front. Sheath usually has a few white pigment spots, and, occasionally, a little scarlet pigment.
Head
No oral tentacles, but side margins expanded into lateral quadrangular flaps [10]. Slight head crest (raised rib) runs from front of rhinophore to anterior edge of head [7] often inconspicuous, perhaps can be raised/lowered [4] (Thompson and Brown, 1984, thought crests were absent, but recognised by Shipman & Gosliner, 2015); Crimson pigment on dorsal surface extends back between rhinophores [1].
Foot
Sole translucent white or yellowish [10]. No propodial expansion [9] (don’t mistake head flaps for propodial expansion).
- Crimson blotching sometimes extends half way up mesial face of cerata [1].
- Slight head crest from rhinophore to anterior edge of head [7], often inconspicuous [4] .
- Each ceras has 3 or 4 (sometimes more) concentric rings of rounded tubercles. [6]
- Crimson [1] or black-red [5] spheroids, and white granular bodies, in each tubercle.
- Reported to feed on a range of hydroid species.
- Some features not developed on juveniles [3].
Doto sarsiae Morrow, Thorpe & Picton, 1992.
- Extremely similar to D. coronata.
- Only a small amount of purple-crimson extends up cerata.
- Head crest in front of each rhinophore [6Ds].
- Feeds on Sarsia exima and Garveia nutans [10Ds].
Doto cuspidata
- Body has brown blotches overlain with fine crimson speckling.
- Crimson does not extend up inner face of cerata.
- Each ceras has 4 to 6 concentric rings of tubercles.
- No spheroid in tubercles, but white granules.
- Small head crests in front of rhinophores.
- Prey; Nemertesia ramosa.
Doto eireana
- Body has small sparse crimson spots.
- Crimson does not extend up inner face of cerata. #Each ceras has 3 or 4 concentric rings of tubercles.
- Crimson spheroid in each tubercle.
- Small head crests in front of rhinophores.
- Prey; Sertularia operculata
Doto maculata
- Body has sparse crimson spots.
- Crimson does not extend up inner face of cerata.
- Each ceras has 3 or 4 concentric rings of tubercles.
- Small crimson spheroid in each tubercle, except apical tubercle.
- No head crests in front of rhinophores.
- Prey; Plumularia catharina.
Lower shore and sublittoral on or near its hydroid prey, especially Obelia geniculata (EML), Sertularia argentea (EML), and Dynamena pumila [2] which often grows on Fucus serratus. Also reported from Hydrallmania falcata, Abietinaria abietina, Sertularia operculata and S. cupressina, but the specimens reported from some of these, at the time, may have been undescribed segregate species. Simultaneous hermaphrodite. Sexually mature at small size; spawn mass varies [11] with size of adult. Convoluted white band of spawn draped round hydroids in most months. A photograph of spawn on a flat surface suggests there may be an accompanying line of mucus [8] perhaps to secure the mass. Up to four generations per year. Shelled veligers drift as plankton before transforming into adults.
Iceland and Spitzbergen to Mediterranean, and in New England, USA. Records from S. Africa are another specis (Shipman & Gosliner, 2015) ( GBIF map). Widespread and often common in Britain and Ireland, but many records are probably of species now segregated from D. coronata agg., or species yet to be recognised. ( UK interactive distribution map).
Shipman, C. & Gosliner, T. 2015. Molecular and morphological systematics of Doto Oken, 1851 (Gastropoda: Heterobranchia), with descriptions of five new species and a new genus. Zootaxa 3973 (1): 057–101.
Thompson, T.E. & Brown, G.H. 1984. Biology of opisthobranch molluscs 2. London, Ray Society.
Current taxonomy; World Register of Marine Species (WoRMS)
Irish distribution maps and prey organisms
Picton, B.E. & Morrow, C.C., 2010. Encyclopedia of Marine Life of Britain and Ireland (EML)
The map provided here shows the distribution of the species based on Conchological Society data.