Deep in the sparkling sea of the Pacific, thousands of fish glide through the water, going about as usual, seeming to take casual note of the perfect chaos that occurs below the waves. It may appear that the fish and eels are all that exist in this rugged world. However, if we look closer at the rocks covered with vibrant green forests of algae and sea grass, we see an anomaly: a bright little speck clings onto an underwaater plant in a mix of lively and powerful colors, drifting about in graceful chaos. What we have found is the Nudibranchia.
First documented in 1777, nudibranchs have a vivid distribution worldwide. With over 2400 different variants and species discovered so far, they exist nearly from pole to pole and are limited by almost no depth. This small species comes in many different shapes and forms as well. The biology of the animal is simple: locomoting using a simple muscle to move along the ocean cliffs and breathing through open gills. It also has a wide array of defense mechanisms. Although the bright colors will always bring a thrill to any photographer’s eye, the reds and oranges of its skin quickly vanish into the background of green and blue, as red is the first color to fade away in water. This gives the creature a consistent way to hide away in the lush sea forests. In addition, they are fitted with a slight sting and the ability to release chemicals that make the creature undesirable to any hostile organisms.
The order of the Nudibranchia (constituted by all nudibranch species) vary widely in size and shape, the most common being the Doridoidea branch. As a more simplistic nudibranch, “Dorid nudibranchs are found in a range of environments spanning from temperate to tropical waters”, says Cape Town Freediving. Also, they state that “as benthic organisms, dorids are found on substrate in diverse habitats, including intertidal rocky shores and reefs.”
Beghia Nudibranch (Benjamin Frost)A more colorful counterpart is the Berghia nudibranch. This showy creature lives across the Caribbean and Mediterranean. Their small size (only growing to 25 mm) allows them to take refuge under rocks and go largely unnoticed by the larger ecosystem. Equipped with tiny cerata along its back, it can defend itself using tiny stingers, but still spends its days simply floating peacefully about from seagrass to seagrass.
Despite being only 1 cm long, the sea bunny (officially known as the Jorunna parva) has become a somewhat well-known nudibranch, as its appearance often looks like a small bunny. The tiny creature resides in Japan, the Philippines, Réunion, and the Seychelles. They mainly spend their days clinging to plants at the bottom of tropical ecosystems. This type can come in many different colors: a good strategy for camouflage in the depths.
The Blue Dragon Nudibranch (otherwise known as the Glaucus atlanticus) is one of the most familiar and outstanding nudibranchs. Breaking the traditional grounds for what a sea slug is, this small animal uses an air bubble in their stomach to float around or swim. Going with the streak of breaking tradition, the dragons often move together in fleets to help hunt and find mates; however, don’t get too close, as they have venomous and powerful stingers equivalent to a Man O’War jellyfish.
These are just a few of the thousands of nudibranchs that live all across the world and in many different forms. They are truly fantastic animals and all play a critical role in global ecosystems, preventing algae overgrowth and having many symbiotic relationships with other native creatures. In addition, a wide variety of Nudibranchia is a signal of a healthy ecosystem, as it means there is a lot of prey for them and they can thrive. So, although these creatures are certainly small and may go unnoticed. They are truly a beautiful thing in nature and more people should notice this hidden wonder of the ocean.
