Characteristics of Botrylloides fuscus
| Botrylloides fuscus | |
| Colony | |
| Shape | flat |
| Thickness (mm) | 2.5-3.0 |
| Arrangement of zooids | ladder |
| Tunic | translucent, gelatinous, soft |
| Ampullae size (mm: L x W) | 1.0 x 0.2 |
| Formation of colony part including only vascular system | infrequently |
| Color of pigment cells forming pattern on a colony surface | yellow, white |
| Pattern by deposited pigment cells | single pattern |
| Zooid | |
| Length (mm) | 2.2-2.7 |
| Ground color | dark red, red brown, or dark brown |
| Number of tentacles (Large),(Small),(Minute) | L4, S4 |
| Number of stigmatal rows | 9 |
| Second row of stigmata | incomplete |
| Number of longitudinal vessels | 3 |
| Number of stomach plication | 8 |
| Pyloric caecum | small |
| Asexual reproduction | |
| Peribranchial budding | all seasons |
| Number of buds in each zooid | R1, L1 |
| Vascular budding | infrequently |
| Cycle of takeover | 7-9 days |
| Sexual reproduction | |
| Breeding season | Jul-Sep |
| Arrangement of gonads (position of ovary) | posterior to the testis |
| Testis shape & color | rosette, grayish |
| Color of eggs | orange |
| Production of larvae | viviparous |
| Mature egg diameter (µm) | 160-200 |
| Number of mature eggs | R1, L1 |
| Brooding organ | pouch formed from atrial wall |
| Embryo size just before hatching (µm) | 800-1000 |
| Development to larvae | in 12-14 days |
| Release of larvae | 5 days after degeneration of parent zooids |
| Larva | |
| Length (mm) | 2.6-2.7 |
| Length of larval trunk (µm) | 900 |
| Number of larval ampullae | 8 |
| Oozooid | |
| Length (µm) | - |
| Number of tentacles | - |
| Number of protostigmata | - |
| Number of stomach plication | - |
| Number of buds | R1, L1 |
| Colony specificity | |
| Present or absent | present |
| Starting stage of allorejection | before tunic fusion |
| Occurrence of subcuticular rejection | yes |
| References | Saito & Watanabe, 1985 |
| - : not examined |