Sea of Cortez – Spotlight on Nudibranchs
As new divers, we all want to see the big stuff : turtles, sharks, eels, and rays are the stars of the underwater world for a reason! But, as most of us progress, we start to notice and take an interest in the smaller and harder to spot ocean life. This passion for the small fish lifes is usually just referred to as macro.
While most macro enthusiasts enjoy finding teeny tiny critters of all types… we tend to agree that the Nudibranch is the most exciting to spot, and identify. Luckily, the Sea of Cortez is home to many species of slugs!
So, what in the world is a Nudibranch anyway?
In case you can´t tell by looking, they are slugs. Nudibranchs come in all shapes and sizes, but are best known for their bright colors and interesting bodies. They can be found both on shallow reefs, and at depths of up to 700 meters.
They can be bottom dwelling, pelagic, and even surface floating. Some use camouflage to hide from predators while others are brightly colored and defend themselves using potent chemicals. All known species are carnivorous.
In short, these little guys have a rougher life than you might think based on their adorable appearances!
While diving in the Sea of Cortez, there are many common species that are relatively easy to locate and identify. A novice macro enthusiast can start searching for these colorful critters in rock crevices while diving on shallow reefs.
Nudibranchs are small, so you may want to begin diving with a small hand held plastic magnifying glass. I know it sounds crazy, but you will love it! Thanks to the high levels of biodiversity and flourishing ecosystems found here in Sea of Cortez, Nudibranch can be found on nearly every dive.
The common types of Nudibranchs found in the Sea of Cortez are easy to spot and differentiate if you keep an eye on their features :
The flabellina is usually a slender body, with a row of what appear to be spikes running down its back, kinda like a little mohawk! They are usually brightly colored with pinks and purples.
The hypselodoris is easy to spot because it has a tiny cluster of gills on its back that look like a tiny crown. It can be found in many colors and patterns, from the neon agassizii to the duller ghiselini.
The glossodoris also has this tiny cluster of gills, but has a distinctly different body shape. It is best described as having a wavy (and at times highly vaginal in appearance) upper body separated from a lower more slug like bottom.
It is worth mentioning that I also encountered some pretty cool non-nudi species here. Most notable are the Tridachiella diomedea commonly known as the Mexican dancer, and the Tylodinia Fungina which is actually a snail!
Now that you have some basic information, you are ready for your first macro dive!
Remember to swim slowly, check in cracks and crevices, bring a magnifying glass if you have one available, and maintain your buoyancy over the reef at all times!
@ This article above is written by Jessica Merrill (PADI Instructor #351781), please give respect to her copyright!
This article & photos are not to be reproduced or distributed without written permission of Jessica Merrill.