Encrusting coralline red algae, also known as calcified seaweed, are widespread in oceans globally. Despite this. they remain a poorly understood group of marine organisms.
My students and I are among a handful of international researchers capable of working on these seaweeds. They can’t be collected without a hammer and chisel, and also require special laboratory techniques to dissolve the calcium carbonate structure for analysis.
Until recently, our descriptions were based on the examination of morphological and anatomical features alone. The implementation of DNA sequencing has opened up a whole new world to us. Using this new approach we learnt that many widespread species are different species passing under the same name. We have therefore underestimated the coralline algal diversity across the globe.
South Africa’s coralline diversity is substantially greater than that currently recognised and far more unique than initially thought; there are large numbers of cryptic species. Our research revealed that our coastline is diverse and coralline algae are more abundant here than in other coastal regions of comparable length. Previously, we reported one in four species only occurred along the South African coastline. and nearly one in three species were endemic to Southern Africa. But this is changing.
Nearly three years ago, utilising DNA sequence data. we documented a new species (Spongites agulhensis) that only occurs in the Cape Agulhas region. In March this year, along with a small group of scientists from France, Italy, New Caledonia and Taiwan, we published a series of new. higher-level names to accommodate specimens from the Northeast Pacific, South Africa and Taiwan. We renamed the species Chamberlainium agulhense.
This species is currently one of only three species globally to have been transferred to the new set of names. and the first of many South African species that will have to be renamed.
The incorporation of DNA sequencing into our research is increasingly showing us that a high degree of cryptic diversity exists in coralline algae. We have speculated the high degree of morphological and anatomical similarity among several species to be due to a number of factors. This could be because of convergent evolution where organisms not closely related independently evolve similar traits due to similar environments. Alternatively, it could be due to the formation of new. distinct species due to evolution that is yet to reflect as morphological and anatomical change.
Whatever the case may be. these are exciting times for new discoveries that are affording us many opportunities for expanded collaboration and for documenting our little-understood biodiversity.
Written by Gavin Maneveldt
Copyrights 2018 Safari News. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Follow us on social media: Facebook, Instagram and Twitter.
Don’t miss out. Click here to read our digital publication.