Salpa fusiformis; Print; Salpa fusiformis; sometimes known as the common salp; is the most widespread species of salp. They have a cosmopolitan distribution; and can be found at depths of 0 to 800 m (0 to 2; 625 ft). They exhibit diel vertical migration; moving closer to the surface at night. They can occur in very dense swarms; as solitary zooids or as colonies. Solitary zooids usually measure 22 to 52 mm (0.87 to 2.05 in) in length. They are barrel-shaped and elongated; with a rounded front and a flat rear. Aggregate zooids are 7 to 52 mm (0.28 to 2.05 in) in length individually (excluding projections). They are usually barrel or spindle-shaped.