Reef fish identification Cancun - Some marine life favorites & how to identify them Vol 1
- mantadiversoffice
- Sep 12, 2021
- 4 min read
Updated: Dec 17, 2025
Scuba diving and snorkeling introduce you to a world full of weird and wonderful inhabitants. You will see a variety of creatures dazzling the reef, and usually one stands out. You cannot wait to surface and tell your dive buddies about it.
After the dive, you ask, “Wow, guys, did you see that yellow fish?”…Ummmm. Perhaps it is time to brush up on your identification skills. Please dive in to reef fish identification Cancun
The Manta Team is fortunate enough to explore the Mesoamerican Reef every day. In this blog, we share a small selection of marine life we see all the time, along with simple features you can use to identify them on your next dive or snorkel with us.
Want to get in the water soon?
Snorkeling options: https://www.mantadivers.com/snorkeling-tours
Scuba diving options: https://www.mantadivers.com/scuba-diving
Snorkel in Cancun and Isla Mujeres overview: https://www.mantadivers.com/snorkel-in-cancun-isla-mujeres
Angelfish
Angelfish are often easy to spot once you know what to look for. Most have disk-shaped bodies and small mouths, and they cruise the reef with that confident, slow finning style.
Grey Angelfish are commonly seen around the reef, sometimes swimming in pairs. Do not confuse them with the French Angelfish, which can look similar at first glance, but usually show stronger yellow markings across the face and body.
Tip: if you are unsure, look closely at the face pattern and how much yellow is present.
Grunts
Grunts often congregate in large groups, hovering around coral heads and reef structure. Their shape is usually easy to recognize: sloping heads and tapered bodies.
Here are three common ones you will see:
French Grunt: yellow stripes over a blue-white background
Smallmouth Grunt: elongated body, yellow tail, and 5 to 6 yellow stripes
White Grunt: stripes mainly on the head, plus a checkered pattern of yellow and bluish silver
Fun fish ID trick: if you see a cluster of similar fish, pick one feature and lock onto it first, like stripe location, tail color, or body thickness. Then compare the rest.
Damselfish
If it is small and feisty, it might be a damsel. Damselfish have small, oval-shaped bodies and tend to dart back and forth over the reef like they own the place.
Two common ones in our area:
Bicolor Damselfish: the body has two distinct colors
Yellowtail Damselfish: similar body shape, but with a bright yellow tail, darker body, and electric blue spotting
Tip: damsels often hang over one patch of reef and defend it. If a tiny fish is acting like a bouncer, you are probably looking at a damselfish.
Sergeant Major
Sergeant majors are a snorkeler favorite because they often swim mid-water in groups.
How to identify them:
yellow and blue body
five black vertical bars
Fun fact: male sergeant majors can turn darker blue or purple when courting or guarding eggs, and they may act more aggressive during that time.
Next up we have some "odd-shaped swimmers"
The Smooth Trunkfish
Dark with white spots, honeycomb markings on the center of the body. You'll see them blowing water jets into the sand, searching for food using it's snout-like mouth.
Sharp-nosed Puffer
Small but unforgettable. Look for bright blue markings from nose to tail over a darker gold body. Even when they are not “puffing”, they stand out.
Turtle time
Two commonly sighted turtles in our area are Hawksbill turtles and Green turtles. Once you know one trick, they become much easier to distinguish.
The easiest way to tell them apart is to look at the mouth and head shape:
Hawksbill: a more beak-like mouth, with a sharper profile
Green turtle: a rounder head and a less pointed mouth
Tip: if you cannot get a good look at the head, do not stress. Enjoy the moment, stay calm, and keep a respectful distance.
Where can I see this marine life with Manta?
You will see different species depending on conditions and where we go that day, but these are common on many of our dives and snorkels.
Snorkeling tours: https://www.mantadivers.com/snorkeling-tours
Scuba diving tours: https://www.mantadivers.com/scuba-diving
Snorkel in Cancun and Isla Mujeres overview: https://www.mantadivers.com/snorkel-in-cancun-isla-mujeres
We hope you have enjoyed the first in our serios of Reef fish identification Cancun
If you want a classic reef day that is very photo-friendly, take a look at our shallow MUSA dive option:
If you are brand new and want to try scuba first, start here:
Final note
Of course, we see a wide variety of marine life on our dive and snorkel tours, and this is only a small selection. Keep an eye out for our next marine life post.
Do not forget to leave a comment with your favorite.
For more marine life photos and up-to-date Manta info, follow us on Instagram: @mantadiverscancun
Thanks for reading, The Manta Team
Questions or want help picking the right tour?
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