Golden Star Tunicate (Botryllus schlosseri)
Figure 1. Golden Star tunicate hand drawing by Anna Epelbaum
Figure 2. Golden Star tunicate (Botryllus schlosseri) on petri dish
Figure 3. Golden Star tunicate (Botryllus schlosseri)
Figure 4. Golden Star tunicate (Botryllus schlosseri)
Figure 5. Golden Star tunicate (Botryllus schlosseri)
Figure 6. Golden Star tunicate (Botryllus schlosseri)
Figure 7. Golden Star tunicate (Botryllus schlosseri)
Distinguishing Features:
- Colonial tunicate
- Colony usually two-toned (predominant colour black, brown, orange, or green)
- Organized into star or flower shaped patterns
- Zooids are recumbent (horizontal to substrate) with the pointy-end of zooid directed inward towards the centre of the cluster
Origin:
Mediterranean
Habitat and Growth:
Botryllus schlosseri is a subtidal (up to 200m) tunicate found mainly in protected areas growing on both natural and artificial hard surfaces. This tunicate species can withstand estuarine habitats with low salinities (18 ppt or less).
Reproduction:
The colony can regrow and reproduce from fragments. Larvae remain in the water column for less than 36 hrs before settling on a hard substrate to grow into juvenile tunicate colonies.
Can be Confused With:
- Most sponges – Tunicates have a gelatinous texture as opposed to a soft and spongy texture.
- Botrylloides violaceus – unlike the Golden star stunicate, these colonies are mainly one color with zooids in elongated rows (previous sheet).
Management:
Remove colonial tunicates manually and place in garbage receptacle or let dry out of the water. If you must pressure wash colonial tunicates off equipment, only do so on land (not on the farm) and make sure the outflow does not go into the sea, as these colonies can re-grow from small fragments. Completely dry culture gear before placing it back in the water or moving it between sites.