Jenkins Whip Ray

By , 22 July, 2015, No Comment

I have seen a few now over my time here on Koh Tao and every time they are always impressive. Last night however was the first time I have ever seen one at night and it was awesome. They seem far more relaxed at night. Where as during the day they seem to be either sleeping or scare easily at night it was far more focused on hunting and therefore we were able to spend far more time with it moving about the bottom. I am talking about the Jenkins whipray, a species of stingray. Not as common here as the Bluespotted Ribbon tail rail it grows to an impressive 1.5m across and has a broad, diamond shaped pectoral fin disc and a whip-like tail without fin folds. What is even more impressive about it is a row of large spear-like thorns along the midline. It is less colourful than the blue spotted being a more gray and brown colour on the top and white on its underbelly. I’ve always loved the way rays move gracefully through the water and the Jenkins is no exception. It made it one of my favourite night dives to date and an extremely good reason to go on more of them! Unfortunately the International Union for Conservation of Nature (IUCN) have assessed the species as vulnerable in Southeast Asia, due to intense fishing. To lose such as magnificent creature would be a tragedy and I hope something can be done about this as I hope more can experience diving with these animals.

by Alex

 

jenkins whip ray

Jenkins Whip Ray

 

 

 

 

 

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Cave Diving

By , 19 July, 2015, No Comment

With a couple of my colleagues off on a cave diving trip at the minute, I am left here on Koh Tao (which they take great pleasure in reminding me every day they are away) to introduce and inspire other people  about the challenging, exciting and dark world of cave diving.

The term “cave diving” itself draws wide eyes. Most rural farmers in Thailand firmly believe dragons and ghosts live in those bottomless pits deep in the jungle, and jumping into one of them resembles suicide rather than stimulation to the explorer’s mind.

It’s no wonder Thailand isn’t synonymous with cave diving like Mexico and Florida seem to be. Few explorers over the last two decades have ventured into the jungle at their own expense to lay lines and teach cave diving. Unfortunately, very little information was shared and when the next generation of cave divers came along, and caves had to be rediscovered all over again. Luckily some GPS data was passed on, and cave instructors have driven days through the jungle to locate one of the hundreds of caves.

Thailand has enormous limestone formations, generating its unique topography. Limestone is the perfect breeding ground for dry caves to be formed. National projects have flooded entire valleys to supply hydro-power and preserve the rain-forests. A lot of the previously dry caves in these national parks are now flooded and dive-able. Besides stunning panoramas resembling Lord of the Rings scenery, the caves now offer the prefect training grounds for shallow cave training with plenty of the decorative stalactites the novice diver expects to see.

Most cave courses or trips will start in the more shallow caverns, before heading to one of the many deep, dark sinkholes and thermal vents located further south.

The limestone ridge, stretching throughout southern Thailand is very old and has acidic water from the rain-forest above which has carved enormous, mostly unexplored tunnels. Because of the limestone, Thailand has over 2000 caves, both wet and dry. Today less than 10% of these are known.

Thermal vents are deep springs, bringing up a variety of minerals and gases. This usually provides a turquoise, slightly milky water. And these vents are deep, very deep. One has even been explored up to 239 meters.

Other sinkholes are enormous with entrances well over 300 feet/100 meters in diameter. Divers can easily enter scootering side by side, as the visibility can be well in excess of 100 feet/30 meters.

Most of the caves being dived now are easy access and have no strong flows in or out. This means the caves are dive-able for everyone year-round, as we are not limited by weather conditions.

The variety in cave diving experiences found in Thailand is unequaled in comparison to any other part of the world.

by Matt (Feeling left out)

 

diving-big-cave (2)

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Humphead parrot fish

By , 15 July, 2015, No Comment

Recently was lucky enough to come across two humphead parrot fish on one of the eastern divesites on Koh Tao, this was my first siting of a humphead parrot fish and they where so fanistastic to see i felt compelled to do some research about them.

The green humphead parrotfish, Bolbometopon muricatum, is the largest species of parrot fish, growing to lengths of 1.3 m and weighing up to 46 kg.

My friends the humphead parrot fish are part of the wrasse family, however unlike wrasses, it has a vertical head profile, and unlike other parrot fishes, it is uniformly covered with scales except for the leading edge of the head, which is often light green to pink. Primary phase colouration is a dull gray with scattered white spots, gradually becoming uniformly dark green
Each adult fish ingests over five tons of structural reef carbonates per year! contributing significantly to the bioerosion of reefs. The fish sleeps in caves and shipwrecks at night, usually in large groups.

After some research i discovered these beautiful fish are widely threatened by fishermen, mainly from spearfishing so i was lucky to be able to see them up close, hopefully this is a sign of the diversity of the species of fish on our beautiful island increasing.

by Dani

 

A pair of Humphead Parrotfish (Bolbometopon muricatum). North Horn, Osprey Reef, Coral Sea

A pair of Humphead Parrotfish (Bolbometopon muricatum).

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Porcupine fish…

By , 12 July, 2015, No Comment

Recently a few of us from Davy Jones Locker went on a night dive in Hin Wong Bay, which has a large variety of fish that become more active after sun down. Towards the end of the dive, one of us noticed a porcupine fish, these fish are normally very slow and tend to hang around in one area. This particular porcupine fish was hanging around the group for a while. They are friendly fish which tend to be very docile unless they feel threatened. Porcupine fish do live in the shallow to mid shallow waters, which means you can see them on any course you take in Koh Tao, however this particular one was seen on a night dive during an advanced course when they are most active!

by James

 

james

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Christmas tree worms

By , 4 July, 2015, No Comment

Davy Jones’ Locker is located in the Gulf of Thailand on a paradise island named Koh Tao were here we are fortunate enough to be able to dive all year around in some of the most beautiful waters in the world.

Koh Tao offers scuba divers (beginners to advanced levels) the opportunity to experience diving with a huge variety of marine life as the Christmas tree worms.

Christmas tree worms (Spirobranchus giganteus ) are Christmas tree shaped tube-dwelling worms with twin spirals of plumes used for feeding and respiration. They have a tubular, segmented body lined with chaeta, small appendages that aid the worm’s mobility. Because it does not move outside its tube, this worm does not have any specialized appendages for movement or swimming. These worms are sedentary, meaning that once they find a place they like, they don’t move much.

They come in many colours including red, orange, yellow, blue and white and though they are small with an average 3.8 cm in span, they are easily spotted due to their shape, beauty and colour always makes an eye-catching display.

Christmas tree worms are polychaete ciliary feeders that feed using their radioles, the hair-like appendages or “feathers” that circle outward from the central spine, to catch phytoplankton floating by in the water. The food is then passed down a food groove by ciliary tracts — lines of tiny hair-like extensions on the surface of cells that generate water currents to move food or mucus. The food particles are sorted and larger particles are discarded. Sand grains are directed to storage sacs to be used later for tube building.

There are male and female Christmas tree worms. They reproduce by sending eggs and sperm into the water. The eggs are fertilized in the water then develop into larvae and become part of the zooplankton to be carried by the currents to then settle on coral heads and then burrow into the coral to form their burrows.

As you can see this is just one of the fascinating creatures that we encounter every day here at Davy Jones’ Locker. Feel free to pop in for a visit and we will be happy to share these unforgettable experiences underwater with you.

James

 

christmas-tree-worm-rock-porites1

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