Grassi, 1881
Description
Body very small and slender, transparent. Head small. Two pairs of lateral fins, separated, rounded and partially rayed. The anterior fins begin behind the ventral ganglion. There is no collarette. Small alimentary diverticula present. Eyes small, with star-shaped pigment spot.
Ovaries short and broad, with a few very large ova (may distort the posterior end of the trunk in mature specimens). Seminal vesicles small, divided into an inconspicuous anterior knob and an elongated posterior part that touches the tail fin.
Hooks: 7-9. Teeth in two rows, anterior 3-7 and posterior 6-16.
Size
Maximum body length 10 mm; relative tail length 17-21% (S. minima is one of the smallest chaetognath species).
Depth range
Epipelagic
Distribution in the North Sea
Sagitta minima occurs occasionally in the northern North Sea.
World distribution
Epipelagic in all oceans; often associated with regions of mixing of different water masses.
[After Pierrot-Bults and Chidgey, 1988]