Paragnathia formica

(Hesse, 1864)

—ÊPraniza. Full description not available. Distinguished from all other gnathiid pranizas by eight-segmented antennal flagellum (a2) and telson with rounded posterior border.
— Male. Cephalon fused with two pereion segments, limbs of the second fused segment modified as flattened pylopods, which cover the mouthparts ventrally. Adult male pylopod of five articles. Last pereion segment reduced and without limbs; best seen in males, where it is narrow and equal in width to the pleon segments. Male with large mandibles, which project in front of the cephalon and are forceps-like.

Size of praniza unknown; male body length up to 4 mm.

Praniza greyish; integuments of thoracal segments 5-7 hyaline and revealing the intestinal colours: red, yellow, green, or blue.

Depth range
Most adults recorded from sheltered estuaries or inlets, usually around high water mark and in mud cliffs such as occur at the edges of a salt marsh. Adults usually benthic, in galleries of 2 to 2-5 cm long, typically with a single male near the narrow mouth of the gallery (2-3 mm diameter) and up to 10 or 20 females at the innermost region where the gallery widens to about 5 mm diameter.

Distribution in the North Sea
All North Sea.

World distribution
There are sporadic records of adults of the species N from Morocco to Scotland with one record in the Mediterranean and none in the Baltic.

[description after Monod, 1926]