By: Noémie Savard
Hi! My name is Noémie, I came to Gili Shark Conservation to be part of Coral Month. I got into diving very recently and even more recently into underwater photography. I’m still very much a beginner but I’ve had a lot of time to practice in the last 4 weeks.
And since my brain is very good at remembering all kinds of fun facts about all kinds of creatures, I thought I’d share my pictures of the marine life found around the Gilis along with a little piece of information I find interesting about them!
1. Mantis Shrimp: We see lots of mantis shrimps during our dives but most of the time they are quite shy and hard to capture on camera. They have 16 cones in their eyes to capture colours compared to our 3, meaning they can see many more than we can! When they use their modified forelimbs to punch their prey, the force generated by the speed is so great that for a short moment, it creates a cavitation bubble from the water vaporizing that can reach temperatures similar to the surface of the sun.
2. Bubble Algae: Also known as sea grape or sailor’s eyeball, the bubble algae is one of the largest known unicellular organisms on earth. Their diameter can reach around 1-4 cm while the average human cell measures between 10 and 30 micrometers.
3. Blue Starfish: Many species of starfish, including the blue starfish, digest their food outside of their body. They have what’s called an eversible stomach, meaning they can essentially spit out their stomach, wrap it around their prey and partially digest it before bringing it back in their body to finish the job. This enables them to eat prey items much larger than the size of their mouth!
4. Harlequin Shrimp: This shrimp feeds predominantly on starfish, even the crown of thorns starfish. They hunt in pairs, usually made up of one larger female and one male, and are very agile at flipping over slow-moving starfish to eat the tube like feet and other soft tissues. This makes them quite hard to keep in the aquarium hobby as they need to be provided with a lot of live starfish.
5. Nudibranchs: There ate some 3000 different species of nudibranchs with tons of weird fun facts but my favourite is that some species can “steal” parts of their prey and use them for themselves. For example, some species steak the nematocysts (stinging cells) of their prey and wear them on their back to defend themselves against predators. Some species of sea slugs, which are closely related to nudibranchs, can steal the chloroplasts from algae and perform photosynthesis themselves!
6. Hard Corals: Made up of hundreds of individual animals called polyps, hard corals build their own skeleton out of the calcium carbonate harvested from the water. They crystallize the calcium carbonate into aragonite which is how they grow bigger and build reefs. These hard structures remain even after their death and can become anchor points for new creatures. Coral reefs house 25% of all marine life despite covering less than 1% of the ocean floor. The excess carbon dioxide that is now accumulating in the ocean harms this key process by increasing the acidity of the water. This causes the calcium carbonate to dissolve and makes it unavailable to the coral, slowing the growth of the reef.
7. Coral Crabs: These small crabs living in branching hard corals where in exchange for shelter they protect their home from dangerous predators such as the crown of thorns starfish. They pinch at the starfish’s tube feet until it lets go of the coral. They also clean any algae or debris that accumulates on the coral, making them essential to the coral’s health and survival. If you look very closely in the corners of branching corals, you can almost always find little eyes staring back at you!
8. Green Sea Turtle: This species of turtle gets its green colour from its unique vegetarian diet. They are the only sea turtle to eat exclusively sea grass and seaweed. Our underwater sign for the green sea turtle is “sleepy” + “turtle” as they are often found napping on the sea floor where we can get an excellent look at them!
9. Lionfish: Generally very shy and found hiding under outcroppings of reef or rocks, the colourful lionfish comes out to hunt at night to sate its voracious appetite. They have the incredible ability to expand the volume of their stomach up to 30 times the original size, meaning they can absolutely decimate the juvenile populations of fish around the reef. This makes them a dangerous invasive species in some places of the world since few predators know how to get around their venemous spines.
10. Anemones: These animals have a surprisingly long lifespan, living up to one hundred years in come cases. They are know for being homes to clownfish and stinging anything that might harm them but primarily, these stinging tentacles are actually made for hunting as anemones are carnivores! The tentacles deliver a neurotoxin through harpoon-like filaments to the prey enabling an easy capture.
All photos credit to Noémie Savard.
