[Coral-List] Xestospongia muta

[Mcmurray, Steven Edward]

Julian, listers,

 

I am actually finishing a masters thesis on Xestospongia muta that has
included many of these topics.  Our lab has been monitoring populations
of X. muta in the Florida Keys since 1997.  We have tagged and monitored
the growth and recovery of "bases" or "stumps". This is an important
part of the life history of this sponge.  

 

This sponge does not reproduce asexually, so when a piece of it gets
detached from the substrate, mortality usually results.  But, if a
decapitated sponge is held stationary for a long period of time(6 mo or
so), it has the ability to reattach to the substrate.  If not held
stationary, sponges become "tumbleweeds" that roll around and eventually
succumb to sand scour and other damage.  I have designed an apparatus
that can hold dislodged sponges stationary and be removed after sponges
have reattached.  Papers on growth and reattachment of X. muta should be
out within a year.  

 

Sponge bases often form a circular ring-like morphology with many
oscules.  Over time, regeneration usually results in a number of small
sponges with individual oscules and typical morphology that may or may
not be physically connected to each other.  It takes years of monitoring
these sponges to be able to distinguish base remnants that are
genetically similar from recruits and genetically distinct small
sponges.  Ultimately, these base fragments may fuse, resulting in an
array of morphologies.  

 

I should have a paper out soon on the demography of X. muta.  I have
developed a size/stage-based matrix model to describe the population
dynamics of this sponge and the "base" is included as one of the
important stages.

 

Hope this helps.

 

Steve