What a fantastic start to this much awaited diving season on Thailand's Andaman Sea! A Tiger shark has been sighted by several divers in Similan National park this week.

​The Smiling Seahorse guests were also very lucky to spot a tiger shark twice last season at the nearby Burma banks : in March 2019 and November 2019.

Tiger shark photographed at the Burma Banks, Myanmar in March 2019 by The Smiling Seahorse

Another tigershark has been spotted and photographed by snorkelers in Surin islands in December 2019 but such sightings are so exceptional they are making the news!

Tiger shark photographed by a snorkeler in Surin islands in December 2019

Is there hope for Thailand's Sharks population?

Sharks have been slaughtered for decades for the meat and fins and shark population has decreased dramatically: some sharks number have seen a 90 percent cut in the last 50 years! Finning, a practice where fishermen cut the shark's fins before discarding the rest of the body in the Ocean is now illegal in 52 countries but only 12 countries have banned shark fishing altogether. Unfortunately the practice is still legal in Thailand, Indonesia and Malaysia. A recent study done by WildAid and Rapid Asia in Thailand, found that 57 percent of Thais living in urban areas have consumed shark fin at some point.

In recent year more and more campaigns have raised awareness about this cause and eating shark fin soup is loosing popularity.  In China, 85 percent of respondents to a recent survey reported they had stopped eating shark fin soup.

Join us for a long weekend from 4th to 7th of December

Spend Christmas or New year at sea and Dive Surin and Similan with us!

For me nudi-hunting is like collecting stamps...
You always want to find new ones for your private collection.

Now, I am the type of diver who can usually be found hovering in one place for minutes at a time treasure hunting with my mask a short distance from the reef or seafloor. Many people don’t know that the biodiversity in a square meter of coral reef is unmatched by any other ecosystem on the planet, a rule to which the Mergui Archipelago in Myanmar (Burma) is no exception. The region is filled with a cornucopia of colours, shapes and textures that if you take your time and look closely you can find some bizarre little rarities that can bring a tear to your eye.

Egg ribbon of Hexabranchus Sanguineus nudibranch, aka Spanish dancer

​          These “sea slugs”  are hermaphroditic which means that each individual has both female and male reproductive organs on the right side of their body. They can lay up to 25,000 eggs at a time in a mucous ribbon-like formation that will take roughly a week to hatch.

​       Although they are small, they have developed some very industrious techniques to protect themselves. Many nudibranchs display bright colours for a multitude of reasons. Some practice what’s called aposematism which is colouration to suggest to predators that they aren’t tasty or can be toxic. This is a technique used by the Phylidiidae family that we often see in the Indo-Pacific.

Phyllidia coelestis

The Blue dragon only need to eat for the first few months of its life before they become self reliant!

Some nudibranchs that feed on the stinging cells of jellyfish or hydroids can actually recycle them and use them as weapons. Glaucus atlanticus or the Blue dragon nudi can be found floating near the surface and feeds on the nematocysts of the Portuguese man of war Jellyfish and similar species. It will eat the stinging cells and pass them harmlessly through their body where they can then be displayed on their skin or in appendages called cerata making them harmful to predators.

Some nudibranchs will feed on plant cells and use them to create their own food sources. A particular group of sacoglossan sea slugs will eat certain algae found in soft corals and recycle their chloroplasts so they can create their own nutrients through photosynthesis. This means that once it has eaten enough it doesn't need to eat any longer. The algae in its body will use the sunlight to create enough nutrient for its host to survive.

Doriprismatica atromarginata nudi

Hexabranchus sanguineus aka Spanish dancer

Emperor shrimp hitching a ride on a hexabranchus sanguineus

4 main families of nudibranch Instead of branchial plumes,  Aeolid  ​nudibranchs are covered in appendages called cerata which increase surface area for gas exchange and also can be used to display ingested chemicals or stinging cells for defence.

There are 4 main Nudibranch families: Doridoida, Aeolida, Dendronotida and Euarminida. The most common families are "Aeolids" and "Dorids" which each have specific identifiable features.  Dorids all have a distinguishable branchial plume on their back end which they use to breathe. Their mantles are often smoother and more regular shaped than Aeolids which are typically much spikier. Anatomy of Dorid and Aeolid Nudibranchs

A selection of the prettiest Nudis we found in Myanmar

Bornella anguilla

Dendrodoris Denisoni

Thecacera sp.9, aka pikachu

Roboastra luteolineata

Miamira miamirana

Elysia marginata

Favorinus tsuruganus

Glossodoris rufomarginata: its tail is nearly as long as its body.

Glossodoris sp

Goniobranchus Annulatus

Goniobranchus geminus

Goniobranchus annulatus

Doriprismatica atromarginata

Pteraeolidia ianthina, aka the blue dragon

Phyllidia ocelata

Cuthona sibogae

Halgerda Stricklandi

Ceratosoma Trilobatum

Dendrodoris Carbunculosa - mantle secretions may cause a painful sting (NSI2) as big as my hand!

Chromodoris Geometrica

Phyllidia Coelestis

Platydoris Formosa

Goniobranchus geminus

Goniobranchus sp3

Hexobranchus Sanguineus - spanish dancer swimming

juvenile of a spanish dancer - hexobranchus sanguineus

Carminodoris Estrelyado

Tenellia / Phestilla Melanobrachia

Pseudobiceros fulgor - a flatworm so not really a nudi but oh so pretty

Goniobranchus annulatus

A flat worm so not really a nudibranch

Cadlinella Ornatissima

Ceratophyllidia Africana

Goniobranchus Setoensis

Hypselodoris maculosa

Hypselodoris Maculosa

headshield slug (chelidonura castanea)

Chelidonura punctata

Chelidonura punctata

Marionia sp 8

Chromodoris Goniobranchus Fidelis

Goniobranchus gleniei

Roboastra Gracilis

Glossodoris sp.

Thorunna furtiva

Phyllidia Ocelata

Trinchesia sp.

Hexabranchus sanguineus - juvenile

Gymnodoris impudica

Caloria indica

Coryphellina sp.

Coryphellina sp.

Goniobranchus conchyliatus

Hypselodoris emma

Hypselodoris emma

Sagaminopteron psychedelicum

Hypselodoris infucata

Hypselodoris bullockii

Hypselodoris bullockii

Elysia benetti

Tambja Affinis

Glossodoris hikuerensis

Lamprohaminoea cymbalum

Thanks to the authors and contributors!

This blog post was written by Katie O. with the help of Camille L. and several facebook groups who could identify some of the less common nudis.