Rare nudibranch discovery highlights diversity of Bonaire’s reefs

Nudibranchs, a type of mollusks, fascinate both biologists and scuba-divers world-wide. They form a diverse group whose members are known for their elaborate colors, ability to photosynthesize, and sometimes cannibalistic behaviors. This gives them a passionate following from both underwater photographers and scientists alike. Forums around the world unite researchers, scientists, and photographers in their quest to discover and document these tiny creatures with big personalities. It is through one such forum that researcher Dr. Leslie Wilk, co-author of Reef Creature Identification: Florida Caribbean Bahamas, tracked down Tricia O’Malley, an amateur underwater photographer, as she had the only known photographs in the Caribbean of the rare nudibranch Aegires sublaevis.  “I affectionately referred to the nudibranch as 'Glow Cheese', because I was unable to find the correct identification. Its brilliant yellow color and patchy skin made me think of a block of Swiss Cheese. I was delighted to discover it at the Cliff dive site – one of my favorite locations for macro life and night diving”, O’Malley states.  

Incidentally, through discussions with Dr. Wilk, O’Malley learned that she’d also documented another rare nudibranch at the same site – an undescribed member of the Dorididae family. “I take joy in night diving because the reefs truly come alive in the dark. It is astounding to me that after hundreds of dives at Bonaire, I still discover new and exciting finds on each dive. The Cliff dive site is particularly bountiful when it comes to finding nudibranchs, and I can’t tell you how excited I am to have had the opportunity to see such rare and unusual macro-life. I’m truly honored to live at a place that declares its commitment to protecting the reefs. It just shows that there is so much more to learn about the delicate reef ecosystem and that The Netherlands should consider Bonaire’s reef to be a crown jewel that has to be preserved at all costs”, O’Malley continues. 

In his research, Dr. Wilk also discovered other rare nudibranchs found on Bonaire by local naturalist Ellen Muller. These nudibranchs are Trapania bonellenae, as well as an undescribed species of Cerberilla. These finds only serve to further highlight the extraordinary diversity of Bonaire’s reef.   

“Recent finds show that Bonaire in particular has several rare and undescribed species.  The rarest is Trapania bonellenae, an endemic slug named partly after the island and partly after the local resident who discovered it. Aegires sublaevis, a species rarely seen anywhere, was recently photographed at Bonaire. Undescribed species of Spurilla, Cerberilla, and Dorididae have been found in Bonaire’s shallows, but nowhere else. There is also a rare color form of Elysia flava”, Dr. Wilk states.  

“Such extraordinary aspects of Bonaire’s sea slug fauna extends to other marine taxa. For example, the preliminary results of a 2020 survey of Bonaire’s marine biodiversity, funded by Naturalis Biodiversity Center and the ANEMOON Foundation, discovered the existence of at least seven species of invertebrates that are new to science. I mention the above to highlight that on-going research is revealing Bonaire’s marine life to be more diverse and remarkable than ever expected. Accordingly, governmental authorities that create and implement Bonaire’s coastal development policies should place even more emphasis on making decisions that respect, protect, and preserve its marine environment”, Dr. Wilk states.  

Implications  

These findings provide exciting new insights into Bonaire’s coral reef ecosystems and the opportunity for new marine life discoveries. It is vitally important to protect an environment where new species are still being discovered. As development on Bonaire increases, so does the pressure on the dynamic reef ecosystem, and it will be crucial that conservation will lead Bonaire’s future. The discovery of Aegires sublaevis will be published in the upcoming field guide 'Tropical West Atlantic Sea Slugs'. 

Report your sightings 

These nudibranch sightings have been stored at Observation.org. Species reports by local communities and tourists are invaluable for nature conservation efforts to help increasing public awareness and overall species protection. You can report your nature sightings and photos on the website Observation.org or download the free apps (iPhone (iObs) & Android (ObsMapp)). You can also send your information to research@DCNAnature.org for support with getting your data stored. 

Text and photos: Tricia O’Malley, DCNA