Doto koenneckeri Lemche, 1976
Author & date of last revision: Ian Smith on 30 July 2012
Body (excluding appendages) [image7]
Up to 9mm long. Translucent whitish epidermis, but overall brown appearance because of large areas of dark brown surface pigment and orange-brown viscera showing through unpigmented parts. Conspicuous pale unpigmented subdorsal line on either side linking bases of rhinophore sheath and cerata.
Single row of up to five each side of body leaving dorsum fully exposed . No cnidosacs at tips. Translucent whitish, revealing orange-brown internal digestive gland which extends two thirds the way up. Each ceras has only 2 or 3 concentric rings of elongated, internally white, tubercles and a very long terminal tubercle . Cerata have many dark brown rounded, but rarely circular, pigment marks and streaks on the surface.
Smooth, translucent white with some white surface pigment spots. Arise from a translucent white narrow basal sheath with dilated smooth rim.
No oral tentacles, but front margin expanded laterally into large lobes .
Sole brownish white . No propodial expansion (but large oral lobes).
Key identification features
About seven other British and Irish species of Doto have brown markings, but all have 4 or more concentric rings of tubercles on each ceras, and none has the distinctive pale unpigmented subdorsal lines of D. koenneckeri.
Ecology and behaviour
Sublittoral and LWS where its prey, Aglaophenia pluma (EML), occurs on rocks and on Halidrys siliquosa , which often forms a belt below the Laminaria zone. The pale hydroid, and white D. koenneckeri spawn on it, show clearly when the alga is in water, and probably indicate adults near by. Simultaneous hermaphrodite. Convoluted white or pinkish ribbon of spawn  draped round A. pluma in May, August and possibly other summer months. Shelled veligers drift as plankton before settling on the sea floor and transforming into adults.