Recruitment to the reef
column spacer Recruitment to the reef
 
 

Asexual reproduction

 
Asexual reproduction of sponges is considered in this section. Click on an icon to learn about asexual reproduction in another reef organism. hot buttons for asexal reproduction section of BCCR website hot-button icon for linking to the topic of asexual reproduction in seaweeds in BCCR website hot-button icon for linking to the topic of asexual reproduction in sponges in BCCR website hot-button icon for linking to the topic of asexual reproduction in gorgonians in BCCR website hot-button icon for linking to the topic of asexual reproduction in corals/zoanthids in BCCR website hot-button icon for linking to the topic of asexual reproduction in seastars in BCCR website hot-button icon for linking to the topic of asexual reproduction in tunicates in BCCR website
 
 
seahorse dive leader for BIOLOGY OF CARIBBEAN CORAL REEFS website photograph of hawksbill turtle feeding taken from a video

"Here's a busy fellow. A hawksbill turtle tearing pieces out of a sponge to eat. This isn't all bad for the sponge, because some of the small bits that we see drifting off have the potential to regrow into other sponges." - Turneffe Island, Belize 2002. Video courtesy Andy Stockbridge, Belize.

NOTE Eretmochelys imbricata

 
 

Asexual reproduction: sponges

  Sponges have good regenerative powers. Not only will bite-marks from predators heal, but bits left over from their eating may attach to the sea bottom and become functionally independent individuals.
 
photo collage of Caribbean sponges with bite-marks
  There are at least 3 possible ecological consequences of predator-induced asexual reproduction in sponges:
 
fusion of sponges indicating genetic compatibility photograph of several vase sponges photograph of a cluster of vase sponges
Because the offspring from asexual reproduction are genetic clones of the original sponge, it may ultimately lead to decreased genetic fitness in the population. Shown here: fusion of identical genotypes At the same time, because they carry the same genetic attributes of the parent sponge, short-term growth and survival of the offspring are favoured. Shown here: several vase sponges growing near to one another So, would the presence of more spongivores such as angelfishes and hawksbill turtles lead to greater overall density of sponges? Possibly not, because with more predators around, surival of the recruits might be poor
 
 
seahorse dive leader for Biology of Caribbean Coral Reefs website photograph of fused rope sponges taken from a video

"Oh, this is interesting. It's a rope sponge with bits of itself fused together. Most organisms have the ability to do this...even humans...and it indicates self-self recognition by the tissues involved" - Turks & Caicos 2003

NOTE Aplysina sp.

 
  photograph of rope sponges courtesy Anne Dupont, FloridaHere's a simple experiment to test the attachment success of bits of rope sponges Aplysina sp., basically a simulation of what might happen naturally during asexual reproduction. Wulff 1985 Proc 5th Int Coral Reef Symp 5: 119. Photograph courtesy Anne Dupont, Florida.
 
drawing 1 of rope-sponge experiment drawing 2 of rope-sponge experiment drawing 3 of rope-sponge experiment
 
Take a piece of rope sponge and chop it into bits Release the bits onto the reef-flat Monitor survival over 1 year
   
  Your observations should show that about 30% of the bits are alive , healthy, and mostly re-attached after 1yr. Dispersal distances are principally within 1m of the release point, but some pieces may have been carried several tens of meters in storm surge.
 
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