Pruvot-Fol, 1926
Full name (Van der Spoel et al., 1997): Clione limacina (Phipps, 1774) subsp. limacina (Phipps, 1774) forma minuta Pruvot-Fol, 1926
Description
A naked pelagic snail, up to 0.5 cm long, with a mainly transparent body that only shows orange/red colour in the tail, tentacles and mouth organs. The reddish brown visceral mass is seen through the body wall. It is a rather quick swimmer that hunts shelled pteropods as food. It lives in the N-Atlantic in the upper water layers where it can occur in mass blooms.
Body more droplet-shaped than in the forma limacina, no gills present in this very small form. The reddish and yellowish colour of the visceral mass is less intense than in the forma limacina. The wings are broad and large. Lateral footlobes moderately developed, the posterior footlobe is rather short with a thin, terminal filament, sometimes reduced by contraction. There are three pairs of buccal cones. [C.l.l.minuta-para, Clione l.l. minuta2].
Radula formula varies between 6-1-6 and 9-1-9. The median plate is variable but more distinctly dentated than in the forma limacina, and a median cusp or an irregularity is absent [C.l.l.minuta-rad1 ,C.l.l.minuta-rad2,C.l.l.minuta-rad3]. The number of transverse rows is smaller than in the forma limacina. The hook sacs are large and rather deep, bearing at each side 15 to 20 hooks.
A description of juveniles is not available.
Size
Body length up to 5 mm.
Ecology
This forma feeds on Limacina retroversa and Limacina helicina. Juveniles are found to feed also on Prorocentrum micans. This species assimilates carbon from its prey L. retroversa, with greater than 90% efficiency and nitrogen with nearly 100% efficiency.
Depth range
Epipelagic
Distribution in the North Sea
Northern North Sea.
World distribution
This forma is found in the N-Atlantic; scarce records from the W Atlantic off the E American coast; scarce records from the Pacific Ocean.
[After Van der Spoel et al., 1997]