Weird creature of the month – September

The name “Bobbit worm” was puplished in the 1996 book “Coral Reef Animals of the Indo-Pacific”, in reference to Lorena Bobbit, who was charged for cutting of her husbands private parts. The name is inspired only by the scissor like jaws of the worm.

The Bobbit worm is an aquatic predator with a lot of bristles. It lies at the floor of the warm tropical oceans of the Indo – Pacific and warmer regions of the Atlantic. This organism buries its long body into an ocean bed composed of gravel, mud or corals in shallow water. Here it waits patiently for a response to one of its five antennae, attacking when it senses a prey. Armed with sharp teeth, it is known to attack with such speeds that there is no escape and the prey is sometimes sliced in half. The worm hunts for food at night and eats everything from small fish, corals or seaweed up to larger aquatic predators.

The Bobbit Worm injects a narcotizing or killing toxin in their prey animal, so it can be safely ingested — especially if they are larger than the worm, like a Pacific lionfish http://www.youtube.com/watch?v=3H4J5QDQeA4.

The worm can even harm humans, since the toxin can cause permanent numbness.

Unlike a different family of worms, the fire worms, which have harpoon-shaped bristles that release a toxin that can cause severe skin irritation, the Bobbit Worms specimens bristles are not used for defensive purposes. They simply use their bristles for improving traction for crawling over the sediment or inside their galleries or tubes.

Little is known about the sexual habits and lifespan of this worm, but researchers hypothesize that sexual reproduction occurs at an early stage, maybe even when the worm is about 100 mm.

100 mm is very small, considering these worms can grow to sizes of nearly 3 meters, although the average length is 1 m and 25 mm in diameter.

Bobbit worms may accidentally be introduced into artificial environments. In March 2009, the Blue Reef Aquarium in Newquay, England, discovered a Bobbit worm in one of their tanks. The workers had seen the devastation caused by the worm, such as fish being injured or disappearing and coral being sliced in half, but did not find it until they started taking the display apart in the tank. The worm was nicknamed “Barry”.

Weird creature of the month – August

Gobies is by far the largest family of fish with approximately 1,500 known species over the whole world. Just like its near relative the blenny, the goby usually lives in burrows and holes and are territorial, were most species are around 10cm in size.

The goby is a relatively social animal that lives with its partner for a longer period. The male goby attracts the female by making noises, and it is proven that these sounds are crucial for the choice of partner. The sound is made by the male gathering an amount of water in the mouth and quickly spurting it out with a massive force.

Another very interesting feature many of the gobies have around our dive sites is their partnership with shrimps. They live in a symbiotic relationship and depend on each other for survival. The shrimp is very skilful in digging, finding food and making a burrow. However, since it is blind, it makes the shrimp a very easy snack for predators.

The goby on the other hand, has very good eyesight but lacks the skill of digging, hence also making it an easy target. To survive they work together with the shrimp where the fish sit outside the excavation site as a lookout.

If you look carefully at the shrimp you can see the tentacles in close contact with the goby. If a predator would close in the shrimp can wiggle the tail, alarming the shrimp. The shrimp will then move to the side so the fish can swim in and hide.

If you avoid exaggerated movement and breathe carefully, you can see the shrimp and the goby on the sea floor all over Phi Phi Islands and Koh Haa.

Weird creature of the month – January

Small bright colors on the reef attracts you attention, but as you come closer it suddenly disappears straight into the coral. What was that? This, my friends is the Christmas tree worm that lives burrowed in a tube on stony corals around at the reef.

This “tube” serves as a home and a protection against other animals. It’s actually so cozy that the worm never leaves. Not only can it hide in there, but the worm has also got a lid for the top, making it a well-protected bunker.

The part of the Christmas tree that you see is a kind of mouth, which it uses for feeding and for “breathing”. This kind of feeding is called filter feeding and what’s on the menu? Plankton and other microorganisms.

They are located from the Caribbean sea to the Indo-pacific, so where’s warm water and corals, you find this guys.

Weird creature of the month – December

The Banded Sea Krait (Laticauda colubrina)

The Sea Kraits are an amphibious animal that are both able to live in the ocean and on land. You can find them in the warm and tropical coastal areas in the Indian and Western Pacific oceans.  An adult male can be up to 75cm long, while the females can almost reach twice that size as adults with their 128cm in length.

Like their land living relatives they have large belly scales to help them move around on land, for propulsion and movement underwater they use their flat and paddle shaped tail.

The females are also able to dive in deeper water than the males because of the larger bodies they have are able to withstand the increasing pressure of greater depths. Their favorite food is eels and from time to time they eat smaller fish they can trap in crevices.

 The banded sea krait’s lethal venom is ten times more toxic than that of a rattlesnake and contains powerful Neurotoxins that affect the muscles of its prey. After injection the neurotoxins will quickly and severely impair the swimming and breathing capabilities of an eel and make it an easy grab for the Banded sea krait.

Human fatalities are few, most likely because they are not very aggressive species.  Each snake can produce up to 10-15mg of venom and only a fraction of that is a lethal dose.

About every 10 days the Banded Sea Krait leaves ocean to spend some time on the beach to digest its food, drink fresh water, shed their skin and this is also were they mate and lay eggs. Known predators that hunt the Banded Sea Krait are sea Eagles and sharks, especially Tiger sharks.

When they are going into dive mode they use their nasal valves and close fitting scales around the mouth to keep the sea water out and they are able to stay down for 15 minutes up to 2 hours. A salt gland in their mouth allows them expel excess salt absorb from the salt water.

And the coolest thing of all is that except from the lungs they can also use their skin to “breathe” and exchange gases, it’s estimated that they can absorb about 20% of their total need for oxygen and eliminate almost all of the carbon dioxide the snake produces  just through their skin.

Sources
Animal Diversity Web – http://animaldiversity.ummz.umich.edu/accounts/Laticauda_colubrina/       Aquarium of the Pacific – http://www.aquariumofpacific.org/onlinelearningcenter/species/banded_sea_krait

Weird creature of the month – November

The flower of the sea

It got its name from a beautiful flower but the anemone is anything but a plant. Despite its innocent look this beautiful animal is lethal for some of the smaller creatures of the sea like fish and plankton. This meat-eating invertebrate is a diverse organism and can live for as long as 80 years and more. They do not age, quite fascinating I know. This means that they can live on forever, but at some point they will fall prey to predators.

Did you know that there exists more than 1000 different species of the anemone? The anemone mostly thrive on tropical reefs, although there are species adapted to relatively cold waters. You can find the anemone in oceans from the tropics to the poles and they can grow up to nearly 2 m.

With their beautiful and various colors and reaching tentacles the anemone really are nice to rest your eyes on. They might look harmless but they can be quite vicious. Anemones has several stinging polyps. The lightest touch will activate their venom filled tentacles, making firing harpoon like filaments penetrate the prey. The venom will paralyze the fish which let the anemone navigate the prey down their mouth located in the middle of their bodies.

I help you if you help me. This flower like animal has a few unusual tricks up its sleeve. They have symbiotic relationships with some other animals. One example is the clown fish that lives within the arms of the anemone. The clown fish is covered in a mucus layer that protects them from the anemone stings and let them live within their tentacles. Returning the favor the anemone fish keeps the anemone clean and they also let it have a snack on their remaining. This clever animal can also hitch a ride with other animals of the sea, such as crabs to change their hunting area.

Have you ever seen an anemone in movement? The anemones are capable of slow movement. They just simply swim with their tentacles or moving by flexing their body. And if you ever see an anemone taking a slowly stroll over the sea bed, it’s simply nothing weird by that. But it’s not anything you going to see every day, this lazy creature only move if they really have to.

How do they reproduce? The anemone can use both sexual and asexual reproduction. The asexual one means that they simply divide themselves in two where, each part forming a new animal, and they are now clones of each other. Fascinating little creatures as they are, other species are hermaphrodites producing both eggs and sperm.

At the beautiful Anemone reef close to Shark point you can lay eyes on an underwater landscape covered in anemones.  Join us on a trip to this dive site, and learn more about these fascinating animals.