21. Further development is by budding of new zooids . 22. These colonies can grow thousands of individual zooids in a relatively short period of time. 23. Pyrosome colonies grow by budding off new zooids near the posterior end of the colony. 24. These spines make it difficult for the nudibranchs to access the polypide of the zooid . 25. One side of its surface was covered in spots, which might have been zooids . 26. The new colony grows by asexual reproduction, with new zooids budding off existing ones. 27. Larvae undergo metamorphosis and become filter-feeding zooids within 5 15 minutes of settlement. 28. They contain contain 8 zooids each 10-12�m long by 5-6�m wide. 29. Some encrusting colonies may grow to over and contain about 2, 000, 000 zooids . 30. In species with calcareous exoskeletons, these do not mineralize until the zooids are fully grown.
