Archive for ‘Ecological’

“Snorkel for Sharks”

By , 17 March, 2015, No Comment

Hola amigos de Davy Jones Locker el pasado 10/ march / 2015. Hicimos un proyecto de finananciacion para ayudar a los tiburones apoyando y promoviendo el movimiento AWARE e todos nuestros océanos. “Snorkel for Sharks”.

La tarde empezó muy bien, con mas de 20 voluntarios en los que se encontraban diferentes nacionalidades involucradas como (Alemanes, ingleses, españoles, franceses…) y algunos mas con lo que fue un todo un éxito. Continuamos con la orientación del propósito de nuestra misión el cual era identificar tiburones(machos y embras), estimar tamaño y explicar cual era su comportamiento, para luego andar los datos de esta a project AWARE y que lo usaran en sus data base y también dar a conocer mas información de los pocos tiburones que tenemos en la zona. Un saludo amigos tendremos mas noticias pronto.

Manu

 

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Parrot fish

By , 12 March, 2015, No Comment

Whilst diving in the waters surrounding Koh Tao you will most likely see a species of fish called the Parrotfish. Parrotfish — like their close kin, the wrasses — use their paired set of pectoral fins primarily to swim, with an occasional flick of the tail fin for a burst of speed. Measuring more than four feet in length and weighing in at 100 pounds, Bumphead Parrotfish from the Indo-Pacific are the family’s largest member. When bedding down for the night, a few species enshroud their bodies in mucus bubbles blown from their mouths. The translucent nightgowns protect the slumbering fish from bloodsucking parasites and predators.The fused-beak structure, which is the origin of the parrotfish’s common name, can often be found while beach combing. Many divers first notice parrotfish because of their rather unpleasant habit of eliminating clouds of waste while swimming. Seventy-five percent of the material is reef rock incidentally ingested while hunting for filamentous algae. Sunbathers beware! Much of the crystal white sand forming tropical beaches is former parrotfish poop: After digesting coral rock, it’s excreted as sand. With the loss of a harem’s dominant male, the group’s largest female will, in a matter of weeks, change sex, which confers a gaudy new coat and the exclusive right to mate with the remaining ladies.

The PADI Fish Identification Adventure which can be taken as part of the PADI Open Water Advance course, or the PADI Project A.W.A.R.E course at Davy Jones Locker, will allow you to learn more about local fish and how to identify them.

by Sophie

 

Parrot Fish

Much of the crystal white sand forming tropical beaches is former parrot fish poop ;)

 

 

 

 

 

 

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Christmas Tree Worms

By , 17 December, 2014, 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.

In the spirit of Christmas below are some facts on one of the many mesmerizing creatures that live in the underwater world that we love to explore every day: 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 colors 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 color always makes an eye-catching display.

Christmas tree worms are found on coral reefs in tropical waters worldwide, in relatively shallow waters less than 30 metres.

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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.

Plumes are also used for respiration. Though the plumes are visible, most of these worms are anchored in their burrows that they bore into live calcareous coral. Christmas tree worms are very sensitive to disturbances and will rapidly retract into their burrows at the slightest touch or passing shadow. They typically re-emerge a minute later, very slowly, to test the water before fully extending their plumes. So if a worm feels threatened, it can withdraw into the hole to protect itself quite easily. For added safety, the Christmas tree worm can also plug its tube with a small plate called an operculum.

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.

 

by Sarah

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Turtles of Koh Tao

By , 21 November, 2014, No Comment

Koh tao means turtle island, and it is the dreams of many divers to see one of these beautiful animals in the flesh. There are two types of turtle common to koh tao: The Green turtle and Hawksbill turtle. The Green and Hawksbill turtles look very similar to each other however they have some differences in appearance.  The Hawksbill can be distinguished from the Green Turtle by its sharp, curving beak with prominent cutting edge, and the saw-like appearance of its shell margins.

The Green Turtle is the most typical sea turtle, possessing a teardrop-shaped carapace and a pair of large, paddle-like flippers. Despite the turtle’s common name, it is lightly-coloured all around while its carapace’s hues range from olive-brown to black in Eastern Pacific green turtles. The turtle is actually named for the greenish coloration of its fat and flesh.

The Hawksbill has a worldwide distribution, with Atlantic and Pacific subspecies and the Green turtle can be found throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Ocean. Unlike other members of the turtle family, the Green turtle is mostly herbivorous. The adults are commonly found in shallow lagoons, feeding mostly on various species of seagrass.  Sponges are the principal diet of hawksbills once they enter shallow coastal waters and begin feeding on the bottom. Some of the sponges eaten by Hawksbills are known to be highly toxic and lethal when eaten by other organisms.  Hawksbills are also known to feed on other invertebrates, such as comb jellies and jellyfish. This is why you must be careful with things like plastic bags as if they end up in the sea a turtle could eat it thinking it is a jellyfish. The largest Green turtle ever recorded weighed 395 kilograms whilst the Hawksbills are generally smaller with the largest recorded tipping the scales at 127 kilograms. You can see both types of turtles at many dive sites through out koh Tao, including sleeping turtles on night dives. If you do see one, make sure to keep a respectful distance and let them go about their day.

 

Sophie

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Surprise surprise

By , 20 June, 2014, No Comment

The other day, I was teaching an Advanced Open Water course and we had the pleasure of encountering a massive jellyfish.  We do see them on occasions here on Koh Tao, but they are relatively rare, so it’s always a treat.  Especially when we see the big ones.  It can be a little difficult to identify species of jellyfish, but I think it was a white-spotted jellyfish.

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They’re such strange animals that it made me wonder more about them.  Turns out they are not fish at all.  They don’t have specific organs for respiration, digestion or circulation.  In fact, they don’t even really have a central nervous system.  They just have nerves spread throughout their bodies.

 

Jellyfish bodies consist of about 95% water and their skin is so thin that they don’t really breathe, they just get their oxygen by diffusion.  They eat by stinging whatever they come across and jamming it into their bodies.  Because they are transparent, sometimes we see small crabs in their “stomachs”.

 

Always a pleasure to come across one of these strange beings.

 

Pete

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