New research finds herbivore fish poo is dangerous for corals | Reef Builders


For a very long time, it has been assumed that herbivores are good for coral reefs and corallivores are dangerous. Herbivores like surgeonfish and rabbitfish graze the algae which might in any other case overgrow, smother and outcompete corals, and a reef with out herbivores is mostly considered being sick. In distinction, coral-eating fish are regarded as dangerous for reefs, consuming coral tissue and weakening onerous coral buildings, with no mutual profit to reefs in any respect (aside from making coral sand.)

However a gaggle of college researchers from the USA analyzed the feces from each herbivorous and corallivorous fish and made a extremely attention-grabbing, basic discover. That herbivore fish poo is dangerous for corals, however corallivore fish poo is nice. And that’s an enormous change to what we thought occurred earlier than. It may have implications for our reef tanks too. 

Parrotfish will not be the reef destroyers we thought they have been.


To check it out, the scientists positioned coral frags in jars, then subjected them to fecal matter from herbivores, and fecal matter from corallivores. When herbivore poo rested on the coral frags it brought about lesions, however when the identical was accomplished with corallivore fecal matter it didn’t. It was then repeated however this time with sterilized fecal matter from each fish teams, and no lesions have been brought about. This then led them to check the micro organism throughout the fish poo they usually discovered that the herbivore group contained disease-causing pathogens, whereas the corallivore group really contained helpful micro organism – probiotics for corals.

“Corallivorous fish are typically thought to be dangerous as a result of they chew the corals,” mentioned Dr. Carsten Grupstra of Rice College, lead writer of the research revealed in Frontiers in Marine Science. “Nevertheless it seems that this doesn’t inform the entire story. Corallivore feces comprise lots of the bacterial taxa that affiliate with wholesome corals below regular situations, probably ensuing within the pure dispersal of ‘coral probiotics’, analogous to fecal microbiota transplantation remedy in people. Extra analysis must be accomplished to check how fish feces have an effect on corals to see how we would use these feces in administration efforts to assist coral reef well being.”

The authors are conscious that elements like currents will have an effect on simply how and the place fish poo will land on corals, and the way lengthy it should sit there, however it has us fascinated by the lifeless spots in our personal plating Montipora colonies, our grazer-heavy onerous coral tanks, and even the ongoing questions about pathogenic bacteria and Acropora. Additionally, can the identical be mentioned of herbivorous invertebrate feces, do drugs wipe out that dangerous intestine micro organism in aquarium fish, and as ever, it’s but extra proof that coral reef ecosystems are far more complicated and interconnected than we thought.

Read the original research article here. 

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