Fig. 3: Simplified schematic of the life cycle of salps.

The oozooid refers to the asexual (or solitary) stage. The oozooid begins to produce chains of blastozooid clones (also known as the sexual or aggregate phase) typically in response to enhanced phytoplankton biomass, triggering the onset of a bloom. Once blastozooids reach maturity they each harbors one oozooid embryo, which is birthed live. After releasing the embryo, the female blastozooids mature their male testis (not shown here), and the cycle is completed with the maturation of the young oozooid. The length of the entirety of the cycle for S. thompsoni in Antarctic waters (−1–2 °C) has been estimated to range between 2 and 9 months depending on the study, although the generation time of the blastozooids is much shorter compared to oozooids. Growth rates of blastozooids during SalpPOOP suggest a shorter life-cycle duration in the warmer waters (~10 °C) of the Chatham Rise, ranging between 12 and 42 days (average 23). The blastozooids emerge as <1 mm sized animals and continue to grow to ~50 mm when mature females.