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You are here:   OldClasses > 2012 > Botryllus leachi | Valerie Chia




Botryllus leachi (Savigny, 1816)
Leach's Sea Daisy 
Valerie Chia (2012)



Fact Sheet



Physical Description


Life History & Behaviour

Anatomy & Physiology

Evolution & Systematics

Biogeographic Distribution

Conservation & Threats

References & Links


Figure 6: Environment in which B. leachi was found in on Heron island. 

B. leachi can be found on a wide range of hard and soft substratum throughout its global distribution. This includes both natural and man-made structures in shallow sub-tidal and lower intertidal zones (Table 1) (Brunetti et al., 1980, NIMPIS, 2012d). On Heron island, colonies of B. leachi were found attached to dead coral fragments in the lower intertidal zone off the southern beach (Figure 6). 

Table 1: Habitats of B. leachi. Adapted from NIMPIS 2012b. 

B. leachi is more prominent in the summer months as the colonies are at their biggest and more conspicuous (Newton et al., 2007). B. leachi is also more commonly found in sheltered areas than at exposed sites (Newton et al., 2007). 

A study conducted by on B. leachi in the Venetian lagoon discovered that colonies enter a condition called winter quiescence (Burighel et al., 1976, Coma et al., 2000). This happens during winter when the temperature is less than 10°C (Coma et al., 2000). The condition is characterised by a reduced number of functional filtering zooids, a decreased rate of budding and a reduction in sensitivity to mechanical stimuli (Burighel et al., 1976, Coma et al., 2000). 


Interspecific associations are relationships that B. leachi have with other species. 

Ascidians are not subjected to much predation (Epelbaum et al., 2009, Stoecker, 1980). However, nudibranchs, snails, slugs (phylum: Mollusca, class: Gastropoda) (NIMPIS, 2012a, Stoecker, 1980), and flatworms (phylum: Platyhelminthes) have been known to feed on B. leachi (Epelbaum et al., 2009, NIMPIS, 2012a). Skeleton shrimps (Caprella spp) are also known to anchor and feed on micro-algae and detritus that accumulate on the surface of the colony (Epelbaum et al., 2009). 

Ectoparasites, Botryllophilus rubber Hesse, 1864, Mychophilus reseus Hesse, 1866 and Mychophilus rosovula Gray, 1933 are the only parasites that have known associations with B. leachi (Gotto, 1954, Gotto, 1966). The effect of the association these parasites have with B. leachi is still unknown. 

Detritus: extremely small non-living organic material.
Ectoparasite: a parasite that lives on the external surface of its host.
Quiescence: a period of significantly decreased activity or inactivity; hibernation. 
Venetian lagoon: enclosed bay in which the city of Venice is located in.