[Coral-List] In defense of Caribbean hybrid Acropora prolifera

Wed Sep 9 16:14:21 EDT 2009

Dear Coral-List,

Five years ago, during the campaign to list three Caribbean Acropora species in the Endangered Species Act (the “ESA”), I posted on Coral-List on August 15, 2004 an explanation of how, in reality, Acropora consists of two species and a hybrid, and I appealed for additional, special attention and care regarding the hybrid.  

Recent reports about the Caribbean Acropora do not offer information about the hybrid prolifera.  In fact, the campaign and the efforts to protect Caribbean Acropora do not address or help the endangered fused-staghorn coral.  

The ESA is intended to provide for the conservation of endangered and threatened species of fish, wildlife and plants.  In the case of the very important Acropora component of Caribbean reefs, which are in decline and agony, A. prolifera is not listed as an endangered or threatened species under the ESA, on the grounds that the act only allows for the listing of species, and A. prolifera is an F1 hybrid.  

The rationale that protection of A. palmata and A. cervicornis would protect the hybrid, because of its close proximity to them, is not valid for A. prolifera.  The sea is not an ideal kindergarten, and patches of this hybrid exist separately from the parents.  Worst yet, in practice, the nature of this hybrid and its bioconstrucrive and evolutionary potentials are being neglected. 

Unfortunately, the hybrid A. prolifera is being treated in ignorance of the existing knowledge of coral nature and the specificity of its case.  Some facts:

- Scleractinians can propagate clonally by fragmentation (i.e., also asexually) and can form long-lived, potentially immortal hybrids;
- A. prolifera for a long time has been observed to occur in an enormously large area, throughout the entire Caribbean;
- Long-term observations of A. prolifera (Cuba, 1970-1973, 2001; Mexico, 1983-1984) have revealed intriguing changes over the years:  from single colonies in clear waters, to single colonies and in patches, to being more frequently encountered, even in murky shallow water, sometimes far from the devastated parental species;
- The accumulation of A. prolifera branches with other benthonic organisms provides a base of peculiar build-ups on sandy bottom (Cuba, 2001).

A. prolifera requires special attention for a long list of compelling reasons:

- the asexual long-life expectancy and presence of the hybrid; 
- its very large geographic occurrence; 
- its more frequent and ecologically opportunistic presence, even far from the two parental species; 
- its bioconstructive potential; and 
- the considerable temporal existence of Caribbean Acropora.

Sadly, these are still not being addressed.  Today, only one person, Nikki Fogarty, is working on A. prolifera, in her dissertation.   One bird alone cannot bring the spring.

Our Coral-List forum engages in many global, complex issues concerning biodiversity and the protection and conservation of coral reefs, and this is great.  The A. prolifera challenge is something more concrete and discrete that we should be able to tackle and resolve in this forum.  A Caribbean Acropora recovery plan is pending, which gives us a wonderful occasion and opportunity to address this long-pending issue.  The international collegial participation in this forum is another reason to discuss A. prolifera here, because its consideration cannot be limited by countries boundaries.  We just start to understand the scleractinian hybridization and its importance for reef management.

Otherwise, our actions, or rather our failure to act, brings to mind the words of G. K. Chesterton (1874-1936):  "It isn't that they can't see the solution.  It's that they can't see the problem."

I would be glad to share pertinent bibliographic information and experience concerning A. prolifera. 

Cheers,

Vassil Zlatarski
D.Sc. (Biology), Ph.D. (Geology
131 Fales Rd., Bristol, RI 02809, USA; tel.: +1-401-254-5121