Cozumel – July/August 2017 – Year of the Slugs.


Sea slugs (Opisthobranchs) are related to marine snails but have minimized or eliminated the shell.
For some reason, we do not find large numbers of slugs in Cozumel. This year was an exceptional year
in that we encountered several new (to us) slugs.

Cozumel has been an annual vacation destination for us since 1991. Each year, like swallows, we return.
It’s hard to describe the happiness we feel when we enter the gates of the hotel to be greeted by
"Welcome home." Scuba Club Cozumel is an all-inclusive
resort that provides lodging, meals, and diving. Yes, there are many other destinations in the world for
fantastic scuba diving, but Cozumel is easy to get to, affordable, friendly, and the fish population is
heathy. What more could we ask for?

Day 1 - Scuba Club Cozumel

After an exhausting trip on the red-eye from LAX to CZM via DFW, we checked in to our favorite dive
resort, Scuba Club Cozumel. After lunch, unpacking, and shopping at Chedraui, we assembled our dive
gear for a shore dive in front of the hotel - lots of little stuff to point the camera at.

Goldentail moray (Gymnothorax miliaris)

Spinyhead blenny (Acanthemblemaria spinosa)

Banded coral shrimp (Stenopus hispidus)

Mike and Ingrid arrived with Tim and Betsy not far behind.

I know you want to see the pictures of pretty fish, so here they are:

Day 2 – Dive Cat with Francisco

El Paso del Cedral reef

Very slow drift dive in a gentle current. Water temperature was a warm 84 degrees F under partly
cloudy skies.

Deborah found a large green moray eel hiding in a hole. Green moray (Gymnothorax funebris)

School of Caeser grunts(Haemulon carbonarium)

Queen angelfish (Holacanthus ciliaris)

A large Caribbean spiny lobster (Panulirus argus) out for a walk. Got butter?

Villa Blanca

Most Sundays there are no cruise ships tied up to the pier near this reef making it a good time to dive
here. Once again, gentle current made for a nice slow drift over the sponges.

Longsnout seahorse (Hippocampus reidi), always a crowd pleaser.

Whitespotted filefish (Cantherhines macrocerus) being cleaned by a small fish near the gills.
These fish often travel in pairs with one fish spotted and other looking like this. I was surprised when I
saw one fish change colors in front of me. Who knows which is the male and which the female – I guess
the fish know.

Spotted moray (Gymnothorax moringa)

Mike

Day 3 – Dive Cat with Nestor

Palancar Caves

Big thunderstorm overnight. Partly cloudy.

Gentle current running "the wrong way" but it turned around during the dive and we drifted north back
towards our entry.

Tim

Hawksbill turtle (Eretmochelys imbriocota), another popular sight underwater. Everyone loves
turtles.

Sponges. Colors are absorbed by water; the deeper you go, the less colorful the reef. Artificial light, like
that from my camera strobes brings out the color. Cozumel’s reefs are covered in sponges but the
colors are only revealed when you shine a light on them.

Marine slugs are related to nudibranchs. Headshield slug (Chelidonura hirundinina)

Hirundinia with my finger for size…very, very small!

Zuleica’s Elysia (Elysia zuleicae) – another slug. This find was a first for me.

Dive Cat

Yucab Reef
A pleasant drift up the shore side of the reef looking for little stuff.

Yellowline arrow crab (Stenorhynchus seticornis)

Flamingo tongue (Cyphoma gibbosum). What you see is the animal’s mantle covering its shell.
The shell is a pretty uninteresting white color in contrast to the colorful snail.

Lettuce slug (Elysia crispata) – another slug. Very common this year.

Fringed filefish (Monacanthus ciliatus) playing you "can’t see me."

Lined Elysia (Elysia pratensis) – can you say, "sea slug?" Another slug new to me.

Yellowface pikeblenny (Chaenopsis limbaughi). Think small. Those are sand grains in the picture.

Rounghhead blenny (Acanthemblemaria aspera) – also very small.

Painted Elysia (Thuridilla picta) – slug that looks plastic. Very small but common here.

Juvenile smooth trunkfish (Lactophrys triqueter). Tiny dice.

Day 4 – Dive Cat with Nestor

Colombia Bricks

Jumping off

Bearded fireworm (Hermodice carunculata) on shaving brush

Betsy

Channel clinging crab (Mithrax spinosissimus) – large crabs that hide under the reef during the
day.

Tim

Stoplight parrotfish (sparisoma viride)

Nurse shark (Ginglymostoma cirratum)

Tormentos Reef

Window

Bar jack (Caranx ruber) being cleaned by Spanish hogfish (Bodianus rufus)

Tiny elkhorn coral crabs (Domecia acanthophora) on fire coral. Less than one-quarter inch wide.

Rounghhead blenny (Acanthemblemaria aspera)

Day 5 - Dive Cat with Pepe

Dalila Reef – moderate current

We saw five, big turtles feeding with angelfish picking up the missed bits of sponge.

Flamingo tongue snail (Cyphoma gibbosum)

Hawksbill turtle (Eretmochelys imbriocota)

Hawksbill turtle (Eretmochelys imbriocota)

Paradise Reef

Green razorfish (Xyrichys spendens). Very shy, when threatened dive under the sand.

Splendid toadfish (Sanopus splendidus). The endemic fish of Cozumel; splendid, indeed.

Gray angelfish and school of Cottonwicks (Haemulon melanurum)

Trumpetfish (Aulostomus maculatus)

Caribbean spiny lobster (Panulirus argus)

Adult Spotted drum (Equetus punctatus)

Scuba II with Pepe

Los Pecios (aka Nestor’s reef)

Fringed filefish (Monacanthus ciliatus) about an inch long hiding in the seagrass.

Jackknife fish (Equetus lanceolatus)

Deborah under wreck

Glassy sweepers (Pempheris schomburgki) inside one of the wrecks.

Betsy in wheelhouse

Tim

Pepe

B&W wreck

Day 6 – Dive Cat with Pepe

Santa Rosa Wall

Sponge on the wall with divers

Mike

Trio

Betsy

Deborah

Hawksbill turtle (Eretmochelys imbriocota)

Loggerhead turtle (Caretta caretta) – loggerheads are a rare treat in the Caribbean.

Chankanaab Reef

Margate (white) (Haemulon album)

Splendid toadfish (Sanopus splendidus)

Midnight parrotfish (Scarus coelestinus)

Barred hamlet (Hypoplectrus puella). I chased this little guy all over the reef to get this picture.

Day 7 - Dive Cat with Pepe Overcast, thunderstorm later.

Palancar Gardens

Betsy and lobster

Sponges

Champagne bubbles from divers under the reef.

Tube sponges with diver

Villa Blanca

Juvenile smooth trunkfish (Lactophrys triqueter)

Shortnose batfish (Ogcocephalus nasutus) - unfortunately in a hole and hard to get a
photograph. The location was the same as where we found two batfish last year. Deborah looked and
looked for the mate but couldn’t locate it. She has a song "Where is the Batfish" that she sings while
searching; look for it on itunes.

Longsnout seahorse (Hippocampus reidi)

Brown seahorse

Day 8 – Coral Diver with Sergio

Not many images today; the current was strong and we covered a lot of bottom quickly. Saw a free-
swimming nurse shark – too far away for a picture; Hawksbill turtle – up current; Big green moray in a
hole with its head inside the reef – no picture.

Mary, Ty, and Merrick arrived in the afternoon.

El Paso del Cedral Wall

Coral Diver

Yucab

Scrawled filefish (Aluterus scriptus)

Gray angelfish (Pomacanthus arcuatus)

Day 9 – Coral Diver with Sergio

San Francisco Reef

"Looked over Jordan and what did I see, a pair of angels coming after me."

Red lionfish (Pterois volitans). Lionfish are an invasive species in the Caribbean and a threat to
local fish life. It has been suggested we spread the rumor that lionfish are a natural substitute for
Viagra and gluten-free … with no trans-fatty acids.

Odd couple, snapper and angelfish

Coney (Cephalopholis fulvus) – not shy, coneys will often pose for the photographer and come in
a variety of color patterns

Juvenile queen angelfish (Holacanthus ciliaris) – cute fish. Is this a "princess angelfish?"

Dog snappers (Lutjanus jocu)

San Clemente Reef

Balloonfish (Diodon holocanthus)

Great barracuda (Sphyraena barracuda)

Juvenile beaugregory (Stegastes leucostictus)

Coney (Cephalopholis fulvus) – the two dark spots on the lower lip identifies this fish as a coney
and not the similar red hind.

Midnight parrotfish (Scarus coelestinus)

Day 10 – Coral Diver with Sergio

Caracolillo (La Francesa)

Orange-spotted nanca (Nanuca sebastiani) – another new slug to me. This is the year of the
slugs.

Juvenile Threespot damselfish (Stegastes planifrons)

Merrick

Channel clinging crab (Mithrax spinosissimus). The other divers signaled to me to come see
something. When I got under the ledge, this crab was standing on its back legs with the two large claws
extended. When I turned on my focus light, the crab folded up and I missed the shot I wanted.

Lettuce slug (Elysia crispata)

Spotted scorpionfish (Scorpaena plumieri)

Paradise Reef – mild current that reversed halfway through the dive.

Goldentail moray (Gymnothorax miliaris)

Coney (Cephalopholis fulvus)

Fringed filefish (Monacanthus ciliatus) playing "You can’t see me."

Bareye hermit crab (Dardanus fucosus)

Juvenile French angelfish (Pomacanthus paru)

Yellowline arrow crab (Stenorhynchus seticornis)

Coral Diver

Day 11 – Coral Diver with Sergio

Punta Tunich (Rocky Point)

Juvenile Red lionfish (Pterois volitans)

Queen angelfish (Holacanthus ciliaris). "Will you stop pointing that d@mn camera in my face?"

Two of my favorite fish, red hind (Epinephelus guttatus) and queen angelfish

Chankanaab Reef

Rock beauty (Holacanthus tricolor) – these beautiful fish are a b*tch to photograph; they play
now you see me now you don’t when you point a camera at them. Patience pays off.

School of snappers (Haemulon sp)

Channel clinging crab (Mithrax spinosissimus)

Pederson cleaner shrimp (Ancylomenes pedersoni) on a corkscrew anemone.

Purplering flabellina nudibranch (Flabellina marcusorum) – a nudibranch! A new nudibranch!

Juvenile French angelfish (Pomacanthus paru) – the tailfin is black with yellow trim.

Juvenile Gray angelfish (Pomacanthus arcuatus) – the tailfin is transparent at the edge.

Coney (Cephalopholis fulvus)

Day 12 – Coral Diver with Sergio

Santa Rosa Wall

Mary

Ty

Betsy and friend - Great barracuda (Sphyraena barracuda)

El Paso del Cedral Reef

Hawksbill turtle (Eretmochelys imbriocota) and Gray angelfish (Pomacanthus arcuatus)
waiting to pick up scraps of the sponge the turtle is eating.

Porkfish (Anisotremus virginicus) school.

Schooling dog snappers ( Lutjanus jocu )

Head on school. The fish look like vampires.

Sergio

Day 13 – Coral Diver with SergioJodi and Doug joined the group.

La Francesa Reef

Smooth trunkfish (Lactophrys triqueter) – "Give us a kiss."

Banded butterflyfish (Chaetodon striatus). It’s believed the stripe over the eye helps protect
from predators who can’t tell the front from the back.

Red hind (Epinephelus guttatus) – I love these fish, always cooperate when I point a camera in
their faces.

Villa Blanca

Juvenile red lionfish (Pterois volitans)

Longsnout seahorse (Hippocampus reidi)

Nurse shark (Ginglymostoma cirratum)

Scrawled filefish (Aluterus scriptus)

Day 14 – Coral Diver with Sergio

Colombia Reef

Deborah flying over the sand on Colombia

Jodi

Doug

Betsy taking a picture of a southern stingray (Dasyatis americana)

Flapping dingbat (Gastropteron chacmol). This uncommon, little slug is 1/8" long. As I watched,
the slug flapped its parapodia and swam off like a bat! I’ve found these slugs in the past, but never
observed before their flapping behavior.

(Elysia tuca) slug. Thanks to Anne Dupont for the identification.

Last week, Betsy photographed a fingerprint Cyphoma on Yucab reef. Related to the common Flamingo
tongue snail, fingerprints are very rare. It’s been said there are 10,000 flamingo tongues to every one
fingerprint – rare, indeed. Since no one else in our group had seen it, we went back to Yucab to look for
it; a hunt for a needle in a haystack. Deborah looked at forty-two flamingo tongues before she spotted
this one.

Fingerprint Cyphoma (Cyphoma signatum)

Trumpetfish (Aulostomus maculatus) hiding in a gorgonium

Spotted drum (Equetus punctatus) intermediate stage.

Day 15 – Scuba II with Choky (Luis)

Someone asked Tim if there had ever been a Scuba I. He said when naming this boat he had tried to be
clever and call it "I Scuba 2." After being outvoted, it became Scuba II.

Palancar Horseshoe

Doug and Jodi

Hawksbill turtle (Eretmochelys imbriocota)

Dalila

Rainbow parrotfish (Scarus guacamaia)

Coney

Caribbean spiny lobster (Panulirus argus)

Black grouper (Mycteroperca bonaci). We are seeing many fewer large groupers on this trip.
That’s troubling. Where have they gone? Are the lionfish consuming the babies? Is someone fishing in
the National Marine Park? Let’s hope this is simply an anomaly and not permanent.

White grunt (Haemulon plumierii)

Day 16 – Scuba II with Choky (Luis)

El Paso del Cedral Wall

Rock beauty (Holacanthus tricolor). Gotcha, you little b@stard.

Green moray (Gymnothorax funebris). Check out the dentition – three rows of teeth on the
upper jaw, all pointing down the throat. What goes in does not come out.

Sun anemone shrimp (Periclimenes yucatanicus)

Porkfish (Anisotremus virginicus). Guess which reef this was taken on. Right! El Paso del Cedral

El Paso del Cedral is a very "fishy" reef.

Lobster and anemone

Lots of fish.

Paradise Reef

Two, fringed filefish (Monacanthus ciliatus)

Coney and goldentail eel. The coney is shadowing the eel out hunting in hopes of scaring out something
edible.

Gray angelfish (Pomacanthus arcuatus) being cleaned. Can you see the little hogfish?

Spotfin butterflyfish (Chaetodon ocellatus), intermediate stage

Los Pecios. We told Choky we wanted to hunt for a batfish on Los Pecios. Choky said he would buy us
all a drink if we found one. Not only did we find one, we found three! Now, Choky says he’ll buy us a
drink next year.

Longnose batfish (Ogcocephalus nasutus). Not what you would describe as a pretty fish.

Choky and bat fish

Two!

Make that three.

Day 17 – Scuba II with Choky (Luis)

Palancar Caves

Skies were dark and there was a threat of rain. When we started the dive, it looked like twilight on the
bottom.

Betsy in swim through.

Alien sponge…or raindeer?

Flapping dingbat (Gastropteron chacmol)

Sharptail eel (Myrichthys breviceps). Often mistaken for a sea snake, there aren’t any in the
Caribbean, this pretty eel feeds during the day, poking its head in holes looking for prey.

Shortfin pipefish (Cosmocampus elucens). I never noted the blue spots before.

Rain!

Chankanaab

Sand diver (Synodus intermedius)

Barred hamlet (Hypoplectrus puella). I think this is the same individual I photographed earlier on
this reef.

Coney (Cephalopholis fulva)

Betsy and barracuda

Day 18 – no diving

A tropical storm blew in south of us bringing torrential rain and wind to the island. The Port Master
closed the port. No diving in Cozumel today. I wonder what the fish think.

Day 19 – Scuba II with Choky (Luis)

"I can see clearly now the rain is gone." Not a bright sunshiny day, but we returned to diving. Visibility
was lowered by runoff from the island and the current was moderately strong.

Dalila Reef

Spotted drum (Equetus punctatus)

Hawksbill turtle (Eretmochelys imbriocota). Under its left front flipper is a tag, presumably for
scientific research.

Chankanaab Reef – Betsy was eager to return to her friendly toadfish.

Trumpetfish (Aulostomus maculatus) hiding in gorgonium

Day 20 – Scuba II with Choky (Luis)

San Clemente Wall – When I’ve asked the dive guides to take us to San Clemente Reef, they have always
asked, "Bajo? (shallow)." I realized that if there is a shallow, there must also be a deep reef or wall. So,
I asked Choky and he verified the existence of a reef we had not previously dived. The wall is relatively
short, so we were able to cross the sand at the end and join San Clemente Bajo for the end of the dive.
Visibility was much improved from the previous day.

Deborah whispering to her friends the fish.

Red hind (Epinephelus guttatus) – I stalked this red hind and got into position in front of it, took
this picture…

…and then it yawned! No sooner had it started than it was over. I was in the right place at the right
time.

Fringed filefish (Monacanthus ciliatus) – This tiny fish changes color and pattern to match the
background effectively hiding in plain sight.

Yucab Reef – Choky wanted to see the fingerprint Cyphoma (Cyphoma signatum) Betsy had found
on a previous dive. Here it is! You can see the "foot" and the bare spot where the snail has eaten away
the gorgonium.

Great barracuda (Sphyraena barracuda)

Day 20 – Scuba II with Choky

Caracolillo?

Tim

Red snapping shrimp (Alpheus spp.) – also called pistol shrimp for the sound they make to stun
prey or deter predators; usually found in corkscrew anemones.

Paradise Reef

Queen triggerfish (Balistes vetula). Normally shy and standoffish, this triggerfish was guarding its
nest full of eggs allowing me to get her in the frame.

Coney (Cephalopholis fulva)

Fringed filefish (Monacanthus ciliatus) mimicking the alga it was hiding in.

We finished the last dive over the grassy area between the island and the reef looking for seahorses.
Alas, no seahorses were to be found but we ran into a small school of Caribbean reef squid
(Sepioteuthis sepiodea). With stealth and patience, I was able to sneak up close enough to get a
picture.

That's all folks.

• Re: Cozumel - July/August 2017 - Year of the Slugs Virginia Knauss 12:19:12 08/16/17 (0)
• Re: Cozumel - July/August 2017 - Year of the Slugs Jorg Raue 17:25:39 08/15/17 (0)