d'Orbigny, 1836
Description
A small, shelled, pelagic thecosomatous pteropod with a left-coiled shell. The spire is depressed, the body whorl increases very quickly in diameter.
The thin shell is flatly coiled and very smooth. It is composed of about 4.5 whorls and the last whorl occupies about 3/4 of the total shell. The shell is significantly broader than high [Limacina lesueuri]. The inner border of the aperture is straight. The umbilicus is very narrow [L.lesueuri-umbilicus]. Some faint spiral lines are found on the shell around the umbilicus. In young specimens the umbilicus is relatively large and deep. The suture is very well marked. [L.lesueuri-apical L.lesueuri-oral]. On the anterior wing border protrusions are absent.
Juveniles have a small left coiled shell. Embryonic shell has a rough granulated surface.
Colour
Transparent thin shell with 4.5 colourless, transparent whorls.
Size
Average shell diameter 1.l mm, height to 0.8 mm, diameter to 13 mm. Maximum diameter of the operculum is 0.6 mm and its length/width ratio is 2/3.
Depth range
Epipelagic, performing diurnal vertical migration.
Ecology
Limacina lesueuri is a warm water species, feeding on phytoplankton and mucus. It is most abundant in the epipelagic layers of central waters. The temperature range is 13.8-27°C.
Distribution in the North Sea
NW and SW North Sea, entering from the NE Atlantic and Channel respectively.
World distribution
Bisubtropical species, found in the Atlantic, Pacific and Indian Oceans.
[After Van der Spoel et al., 1997] |
