The ribbon Eel is the only member of its genus. Scientists thought for a long time that there were 3 types of ribbon eel, the black, the blue, and the yellow species. But now we know they form a unique species changing sex and colour during its lifespan!

Every individual is born as male.
Juveniles and sub-adults are black with a yellow dorsal fin. When they reach adulthood, they keep the yellow fin but the body turns blue and starts developing female reproductive organs.
​When they reach their full size, they turn into female and change their color to complete yellow.
They will then find a mate, lay their eggs, and die within a month.

Whale sharks are the biggest fish in the oceans, their size implies slow growth rates and great longevity. Male Whale sharks reach sexual maturity in around 30 years (their adult size is rarely bigger than 8 meters). Females get much bigger but it takes them 50 years to be ready to conceive. 

While they could live up to 100 or 150 years old and mother a few hundreds pups, this late development implies slower potential population renewal as most whale sharks will not live long enough to have a descendant. 
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They have to steer clear of a lot of threats such as fishing nets...before they get a chance to breed.

Whale sharks are ovoviviparous and this is known thanks to a single pregnant female caught in nets in 1995 (nicknamed "big Mamma" ) containing 300 embryos in her utero at various stages of development. Some were still in their eggs, others already hatched, the biggest was 64 cm long.

Where whale sharks go to give birth is still a mystery, it is believed that whale sharks are born between 40 – 70cm but surprisingly no diver has ever seen a whale shark under 2m longs and it is still unknown where they spend their time before reaching this size. 

​As it is one of the few places they can still hide in… it is believed that baby whale sharks are born in very deep water and spend the first years of their lives at depth.

Watch a baby whale shark swimming off in this video:

A very popular subject of many marine biologists, the Octopus Vulgaris or common reef octopus, is a master of disguise.
The octopus is a mollusc belonging to the class of cephalopoda.
It's arms can grow to a whopping 1m in length and its mantle as long as 25cm.

This type of octopus can be found in the tropical and temperate waters of the the Eastern Atlantic, Mediterranean sea, the Pacific ocean and the coast of Africa.
It prefers shallow rocky bottoms or coastal coral reef in depths above 200m. Octopi will find themselves a shelter where they can minimize exposure and stay safe but will come out, mostly at night, to hunt. They usually move by crawling along the sea floor where it can protect its belly. They are also known to swim using a type of jet mechanism found in its mantle cavity. 

Octopi are solitary creatures with short life spans. They spend most of their young life eating and growing until they reach sexual maturity. At this time, they will metabolize muscle mass to make sperm and eggs and search for a mate. 
Mating can be very dangerous for the male. A female doesn't often refuse a male's advances but it is not uncommon for the female to change her mind and eat the male. To address this problem, males have a specially adapted mating arm that can deliver sperm into the female's mantle cavity from a safe distance.
The female will lay between 100 000 to 500 000 eggs which she will very rarely leave unattended for her 4-5 month brooding.  She will even stop eating to take care of them and will die shortly after they hatch. 

Studies show that they are extremely clever and resourceful. They have a much more complex nervous system than other mammals and most of their 500 million neurons are found in their arms. The have been taught to navigate mazes, problem solve and recognize visual clues to find the best way to get to a reward. Don't under estimate them !

The Common reef octopus can be found in Mergui Archipelago between other cephalopods and reef creatures. Diving in Myanmar offers a large marine biodiversity, a paradise for all divers !

             Today there are somewhere around 3000 documented species of these incredible molluscs that can range from a mere 4mm to a hefty 60cm. Nudibranchs are invertebrates that spend a certain stage of development with a shell. They will always shed this shell at some point before adulthood. All nudibranchs are members of the sea-slug family, however not all sea-slugs are nudibranchs.  ​

          Because they have both male and female sexual organs, a pair can inseminate each others so that you have two pregnancies instead of one. However nudis still need to find a mate. They cannot impregnate themselves!
​​       Nudibranchs are carnivorous and love to eat sponge, hydroids, algae, coral, anemones and even other nudibranchs. They can be found mostly in shallow reefs in warm salt water, but there are some species that live in deeper or cold waters and some can even survive the lower salinity of brackish water. They are found in great abundance at any of the dive sites of the Mergui Archipelago in Burma. 

            Nudibranchs have complicated names which can be very daunting to someone just starting to learn about them. They often have common names which can be easier to remember but they can also cause confusion. For example, some people call the same nudi different names depending on where they dive and what the locals refer to them as. Sometimes a distinguishing feature that led people to give it a common name is not specific to that species leading different nudis to be called the same thing. 
           Using their scientific names is the best way to accurately identify nudibranchs even if it can be a bit of a mouthful. Taxonomy is the way we classify living things in biology and it is an intricate science. Basically speaking, plants and animals are divided into family trees that get more specific as you travel downwards eventually allowing you to name individuals. ​

​           Understanding the difference between the different species is a great place to start but there are other things to consider when identifying a special slug you found on the reef. Looking at its body shape can be very helpful as well as colouration and any markings like stripes or polka dots. Also when in doubt there are many resources available to you like marine species identification books or public forums on social media.
Some of my favourites are ID Please (Marine Creature Identification) and Nudibranch Central on Facebook.

Please feel free to hover your cursor over any of the photos for ID.

In this article I wanted to present the various rays you can encounter in the Andaman sea. Most of the pictures below were taken in the Mergui Archipelago located off the coast of Myanmar and some in Surin and Similan islands in Thailand. 

I will start with the rays spending most of their time laying on the sea floor such as the stingrays and then about the pelagic rays through the Andaman Sea: they swim mid water from the depth all the way to the surface and travel long distances such as eagle rays and Manta rays!