Fritillaria tenella

Lohmann, 1896

Trunk rectangular, rounded anteriorly; posteriorly with two triangular cuticular appendices. The ventral part of the mouth divided by a median insicion in two small lips. The endostyle is strongly curved, with a group of glandular cells loosening towards the left gill opening. Small and rounded gill openings.
The digestive tract is compact and lies in a straight line. The stomach is spherical; there is a group of small globular glandular cells at the initial part of the intestin attached at the right rear side of the stomach.
The ovary is spherical at its frontal end, and is followed by a cylindrical testicle. The tail is relatively broad, with a narrow muscular band and a bifurcated distal end. At one third from the end, there are two amphichordal glands.

Trunk length 0.9-1.5 mm, tail length 1.9 mm.

Depth range
0-200 m

Distribution in the North Sea
All North Sea.

World distribution
A warm and cold water species from the Atlantic, Pacific, Indian and Antarctic Oceans, also in the Mediterranean Sea and Red Sea — absent from the Arctic.