Hello everyone, in the blog of today I’ll present one of my favorite encounters that can happen on a reef and I really hope you will enjoy this amazing fish.

Just a little bit about me, I’m a marine biologist and before I worked for The Adventure Club I had the chance to travel and work in some of the most interesting marine environments in the whole world! I did my first thesis work for the bachelor in the Egyptian Red Sea, at Ras Mohammed National Park, the thesis for the Master was in Kenya at the Watamu Marine National Park and since then I also followed some research projects in the Maldives, Cape Verde and Zanzibar.

At The Adventure Club there have always been a really good attention and care for the environment and that’s the main reason why I also decided to collaborate with this diving centre. From the Coral Nursery Project, to the Artificial Reef and the sinking of the Kled Gaeow wreck The Adventure Club have always been in first line for conservation and maintaining Phi Phi Ley Marine Park – a real natural reserve – where it’s still possible to observe some of the rarest creatures of the Indian Ocean in a reasonably easy way, although the high number of tourists and divers than every year visit this place.

The fish I decided to present today, is not a really common one; mostly the beginner divers only ask to see sharks, turtles and generally big marine animals, but the real diver knows that what it really interesting and rare is not big, but small and difficult to find. For these divers I want to show you the Comet Fish (Calloplesiops altivelis).

The Elusive Comet Fish

The Comet Fish is a fish that is quite hard to find and to see, especially during the daytime. His habits are mainly nocturnal when he goes out of his cave seeking for food. He belongs to the order of the Perciformes, family Plesiopidae which includes different genus, including the Calloplesiops.

As you can see from the pictures, Comet Fish are dark brown to black with one white spot per scale, the white spots are found on its body, head and fins, except for the median and pelvic fins which have small blue spots and are lacking scales. The pectoral fin is clear with visible, yellow rays. Located at the base of the last dorsal rays is a black ocellus. The caudal fin is relatively elongate. According to bibliography, they can reach a maximum length of 20 cm.

The Comet Fish, unlike most members of Plesiopidae, does not feed on algae, but is instead a meat eater, it is a nocturnal seeker, hunting crustaceans and small fish.
What I found more interesting about this fish is how he use his peculiar body pattern when hunting or when it is threatened. When is in danger, the fish puts its head into holes in reefs and changes the shape of its tail by expanding its caudal, anal and dorsal fins. By doing this, the ocellus on its dorsal fin is fully visible and resembles an eye. Expanding its fins also exposes the gap between the dorsal and anal fin, which resembles a mouth. The shape of the Comet Fish fins, combined with the ocellus and gap, make the fish look like Gymnothorax meleagris, the white-spotted moray eel, which is much more dangerous to the would-be predators, and they often leave the comet alone. That’s so smart and clever for such a small fish, isn’t it?!?

The Comet Fish also does the same when they have to catch pray hunting small fish. They catch their prey by approaching it swimming sideways and then waiting for the prey to try to escape. Because the back of the fish looks like a mouth of a moray eel or another predator, as the prey tries to escape on the side of the fish, it will escape towards the fish’s mouth half the time.

Go Diving And See The Comet Fish

For divers, it’s not easy to see a Comet Fish during his “moray eel imitation” because they hunt at night and they are really shy when someone puts a torch light on them. Still it’s amazing when you and your buddy decide to have a “micro-dive” looking for small stuff and you spot one comet inside a crack in the reef on in a small hole. It’s not so difficult to find this amazing fish along the submerged walls of Phi Phi Ley Marine Park. I’ve seen some in the amazing Bida Nok Island, on the deep side where cracks and holes in the limestone create a perfect environment for these fish. I also spotted some along Phi Leh Wall, Palong and under different coral formations in front of the Viking Cave, but my favorite place for Comet is along the drops of the dive site of Malong. Just 50 mt from Maya Corner, Malong offers a great choice for divers of every level! Quite easy to see there is macro fauna like Hawksbill Sea Turtles, Black Tip Reef Sharks and Moray Eels. But also some mimic animals like Scorpion Fish, Reef Octopus and Pharaoh Cuttlefish are quite commonly seen around the slope and the bottom at 16 mt. I personally enjoy so much spotting the small animals in Malong like Sea Horses, Pipe Fish, Ghost Pipe Fish, Razor Fish and for sure the Comet!!

A couple of times I was taking discovery scuba divers along the wall of Malong and in the cracks at 9 mt of depth, the Comet was there showing all his magnificent white dots. Being very careful I could point my flash light on it and both my discovery divers were able to see clearly the fish. I was also happy that the divers really appreciated the encounters, even if they were just beginners and having their first experience with diving. Another time in Malong during a Peak Performance Buoyancy dive for an Advanced Open Water course, I was practicing with my students how to control their buoyancy by passing into the shallow swim-through, and just under one of the rock arches a couple of Comets were hanging in the mild surge current coming from the top. For sure we spent some minutes watching their gentle rise and fall along the wall (again with the help of my flash light) before they decided that we were invading their privacy and they disappeared in one of the cracks under the rock.

Apart from the daytime when divers can have fun and a good challenge to find Comet into cracks, holes, caves and reefs, the best moment to spot these shy fish is during the night time. With the Night Dives I’ve done here in Phi Phi and at the Money beach dive site, I also had the chance to find some comets during their few active moments of the day. As I wrote before, I wasn’t lucky enough to see them during the mimic of a moray eel or during a hunting moment, but me and the divers I was guiding were able to see the Comets swimming out of the reef and seeking a possible pray for some minutes each time before they decided that, even at night, our flash light were too much and they swam away.

At the moment my experience with the Comet Fish is not so great, I sure want more from this amazing fish and I really hope to be able one day to spot a Comet Fish mimicking the head of the white-spotted moray eel and to take a nice picture of it.

I hope you enjoyed the fish of the day, good luck to everyone for your Comet Fish photo hunting, in case you will be able to take good pictures of this smart and nice fish, post them on our website or send by e-mail, I’ll be so happy to reply and to congratulate for your shot.

See you next time with the next Fish Of the Day Blog with the Marine Biologist.