Micro-habitats and Associations
B. schlosseri can be found on a range of hard and soft substrates (NIMPIS 2011). It is common among fouling communities and was regularly found on the underside of coral fragments, with other encrusting ascidians , on Heron Island.
Table 2: Microhabitats utilised by B. schlosseri *Adapted from NIMPIS 2011
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Substratum Type
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Structures
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Natural (living)
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reef, algae, seagrass, other fouling organisms
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Natural (non-living)
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rocks, coral fragments
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Artificial (man-made)
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wharf pylons, floats, vessel hulls, aquaculture infrastructure
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Intraspecific interactions
When different colonies of B. schlosseri come into contact, they display an allorecognition reaction whereby the colonies either fuse, forming a chimera, or reject one another in an inflammatory response (Ben-Shlomo et al. 2008; Zaniolo 1981). This reaction is controlled highly polymorphic genes at Fusibility/ Histocompatability (Fu/HC) locus which are similar to the genes that cause transplant rejection in vertebrates (Scofield et al. 1982). Siblings with shared alleles at this locus will form chimeras while colonies that do not share an allele will reject one another (Ben-Shlomo et al. 2008).
Interspecific interactions
Colonies of B. schlosseri are predated on by winter flounder, some gastropods, various species of nudibranch, crabs, flatworms and sea urchins (Epelbaum et al. 2009b; NIMPIS 2011). Certain species of shrimp may use botryllid colonies as a substratum, feeding on microalgae and detritus that accumulate on the colony surface (Epelbaum et al. 2009b). Botryllus schlosseri is common among fouling communities found on aquaculture equipment and may compete with cultured bivalves for food and space. Experiments have shown that botryllus and cultured mussels are not significant competitors for food. Instead botryllus may interfere with mussels by overgrowing mussel communities restricting the opening of valves necessary for feeding (Lesser et al. 1992) |