Reef fish identification Cancun - Some marine life favorites & how to identify them Vol 1
Updated: Sep 13
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. Along the way, you will get to know the everyday Cancun fish you are most likely to meet, the fish of Cancun that give our reefs their color, and how to tell them apart.
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. Learning to identify reef fish in Cancun can make your underwater experience more rewarding and fun.
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: Snorkel the same reefs with the fish we are covering in this post
Scuba diving options: Cancun reef dive at 60 feet for the most sea life
PADI Discover Scuba Dive Program: First time diving? Discover Scuba
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. Join us and discover the vibrant world beneath the surface.
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, examine the face pattern and the amount of yellow markings closely to tell apart similar angelfish species more easily.
Are angelfish saltwater fish? Both, and they are not related
This trips up almost everyone. The angelfish in a pet shop tank is a freshwater fish from the Amazon, a cichlid, tall and thin as a dinner plate on its side. The angelfish in the sea here is a completely different family, Pomacanthidae, the marine angelfish. Same name, no relation, and nothing you learn about one applies to the other. So if you searched for angelfish and landed on aquarium advice, this is why.
The four Caribbean angelfish you will actually see
Of the marine angelfish species worldwide, four turn up on our reefs often enough to learn by sight. These are the saltwater angelfish types worth knowing before you get in:
Queen angelfish. The showpiece. Electric blue and yellow, with a dark crowned spot ringed in brilliant blue on the forehead. That crown is the giveaway. Bright yellow tail. Usually in pairs.
French angelfish. Black, but every scale is rimmed in gold so the whole fish glows when your light hits it. Yellow bar at the base of the pectoral fin. The friendliest of the four; they will often swim straight at you.
Gray angelfish. The lookalike. Same shape and size as the French, but dull gray with a squared-off tail and a pale, almost white mouth. If the tail looks cut straight across, it is a gray.
Rock beauty. Smaller, bright yellow front and back with a large black patch over the body like a saddle. Usually alone, usually close to the coral.
What colour are angelfish, and why the young ones fool everyone
Ask what colour angelfish are and the honest answer is that it depends how old the fish is. Juvenile French and gray angelfish look nothing like the adults. Both are jet black with bright yellow angelfish stripes running vertically down the body, and they hang around one small patch of reef acting as cleaners, picking parasites off bigger fish. Divers regularly log them as a different species entirely.
The way to tell the two juveniles apart is the tail. On a young French angelfish the yellow band on the tail is rounded. On a young gray it runs straight across. That is the whole trick, and it works for the rest of their lives.
Ocean angelfish are grazers rather than hunters. Sponges, algae and tunicates, worked over slowly, which is why they tolerate divers so well. Move at their pace and a French angelfish will sometimes follow you for half a dive.
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: when you see a group of similar fish, pick one feature like stripe placement, tail color, or body shape, and compare the rest afterward to improve your identification skills.
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 aggressively during that time.
Next up we have some "odd-shaped swimmers"
The Smooth Trunkfish
Dark with white spots and honeycomb markings at the center of the body. You'll see them blowing water jets into the sand, searching for food using their 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 overview: https://www.mantadivers.com/snorkel-in-cancun-isla-mujeres
We hope you have enjoyed the first in our series of Reef fish identification in 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?
Dive and snorkel with Manta Divers, Cancun.
Call (800) 659-0712 · Info@mantadivers.com · mantadivers.com
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