Nerophis lumbriciformis has a slender, smooth worm like body up to 15 cm long. Its snout is short and upturned. It has a small dorsal fin but no pectoral, anal or tail fins. The dorsal surface is dark green or brown in colour while the lower side and ventral surfaces are paler, white to yellowish in colour, sometimes with paler spots or bars.Nerophis lumbriciformis eats small crustaceans like copepods. Like seahorses, the males protect the eggs until they hatch. The female transfers about 150 eggs into a shallow groove on the male's belly. Egg-carrying males can be found from May to August.