Nerophis lumbriciformis

The worm pipefish, Nerophis lumbriciformis (Jenyns, 1835), one of the smallest endemic western European pipefish, is mainly found in rocky reefs (from the intertidal down to about 30 m) and, sporadically, in estuaries. It feeds on small crustaceans (copepods, amphipods and isopods) sucking them through its characteristically upwards pointing snout. Parental care is exclusively paternal and throughout gestation males brood their offspring attached to their abdominal ventral surface. Newborn juveniles are free-swimming and no further paternal care is provided. 

Studies showed that the worm pipefish displays very specific spatio-temporal patterns of movement, synchronising its major displacements with the tides, moving from its preferred high tide substratum, algae, to the protection of the undersurface of boulders, during low tides. Reproduction occurs during cold water months (in the south of distribution), and during warm water months, in the north. 

All the eggs in a pregnat male derive solely from a single female. Females, however, can mate with more than one male within a short period of time. At least in the south of the distribution, researchers found that the worm pipefish form 'leks'. Females spatially aggregate in the intertidal and these mating arenas are visited by males, which preferentially select the more ornamented females (bright spots on the head and trunk). This was one of the very few descriptions of a female lek, and the first in an aquatic species.