Salps are capable of self-propulsion, but for the most part, these translucent, gelatinous-looking animals float in mid-water going wherever the prevailing currents take them.[…]At times a number of buds are attached to one another in linked chains commonly called salp chains.
Source: wiktionary
Observations of some species suggest that salps form spawning aggregations near the surface in the early morning, and that spawning is synchronized with chain release to maximize fertilization success.
Source: wiktionary
Lampetia has a rather undifferentiated larval stage (called Gastrodes) that parasitizes salps (Mortensen 1912; Komai 1922).
Source: wiktionary