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Facts about Unicorn Tangs

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Interesting Facts About Unicorn Tangs

Unicorn tangs or Naso unicornis are members of the family Acanthuridae commonly refer to as surgeonfish. There are 80 species in 6 different genera in this family. All have one distinguishing characteristic. They have sharp blades at the base of their tails (caudal peduncle) on both sides of their bodies that are used in self-defense. Seventeen of the 80 species are unicornfish. Here we will be elaborating on the unicorn tang. They are endemic to the Indo-Pacific from Indonesia and Christmas Island westward to the Andaman Sea, south to the eastern coast of Africa and east to the Hawaiian Islands. When you are diving around the Gili Islands you will find the everywhere.

Unicornfish receive their names from the horn-like projection at the top of their heads. This horn begins to develop in early adulthood. These unicorn horns will grow longer as the fish continues to mature. The function of these horns is not understood. They have yet to be observed using these spinal adaptations as a means of defense. An unmistakable defensive mechanism employed by all members of the family Acanthuridae is the modified scale structures at the base of their tail. These structures are exceedingly sharp. When threatened, this family will thrash their tail about hoping to dissuade their aggressors from further attempts at predation. These blades will slice into flesh as efficiently as a surgeon’s scalpel. In addition to self-defense, surgeonfish use their blades to ward off intruders from their feeding grounds. Most surgeonfish have just one set of retractable blades located in a slot on both side of their tail. Unicorn tangs have two fixed blades on either side. These double blades are the defining characteristic of the genus Naso. This distinguishing feature helps to identify the fish’s genome. Not all unicornfish develop the horn for which they are commonly named.

Uincorn tangs are among the largest species made available by the aquarium industry. They can grow to a maximum adult length of 27 inches. This is why you will seldom see one in a home aquarium. They require a minimum tank size of 250 gallons and are best suited for large show tanks. Because of their ties to one of the most elegant of all mythological creatures, they are prized additions to public aquaria.

Unicorns have the flat, teardrop shaped bodies common to most tangs. They are bluish-grey in color and have long, flowing lyre shaped caudal fins. They are sold by the aquarium industry under the pseudonyms Naso unicornfish and bluespine unicornfish.

A significant populace of these creatures exists around the shores of the Hawaiian Islands. Unicorn tangs were prized by ancient Hawaiians both as a source of food and for their hides. Their tough skins were used in the construction of drum heads. This species is not considered aggressive to human intrusion. However tourist diving off the Hawaiian Islands should avoid chasing or corning these creatures. Sports fishermen should use extreme caution when removing them from hooks or nets.

Unicorn tangs are herbivores. In nature their diet consists primarily of benthic algae. Since they are unlikely candidates for home aquariums, there seems little point in covering dietary conditioning in captivity.

One of the unique aspects of surgeonfish is their communal mating habits. During spawning seasons they will congregate in large groups. Females and males simply release eggs and sperm into the water for fertilization. There is no thought to courtship or coupling found among surgeonfish in the wild.

New Padi divemaster on Gili Air!

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A few months ago Marcel arrived in the diveshop. He wanted the become a Padi Divemaster.

In these months he is around he learned a lot about guiding, assisting and the dive theory. Oceans 5 learned a lot about underwater photography. Because one of Marcels passions is taking pictures underwater.

Marcel is an excellent spotter, he knows where all the strange little creatures live, it is always a pleasure to dive with him and look afterwards what kind of pictures he took. He is not only a excellent photographer, a great diver but also a very nice guy! With now 300 dives under his belt he is an experienced diver, who shows you the most beautiful things underwater.

Oceans 5 dive resort will miss him. In a few days he will continues his travels to Thailand. Hopefully we see him one day back when he wants to become a Padi Instructor.

Marcel, Congratulation to become a Padi Divemaster, Let the party starts!

Facts about Triggerfish

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Triggerfish (Balistidae)

Triggerfish are characterised by latterally compressed, rugby ball shape, leathery skin, and small mouth with powerful crushing jaws. Their common name is derived from the peculiar mechanism by which the first dorsal spine can be locked into an erect position by the second dorsal spine. If the pressure is exerted on the trigger like second spine, the first spine can be unlocked and depressed. This device is used to good advantage at night when the fish wedge into a coral crevice and locks itself in.

They are usually solitary in habit. Swimming is slow and deliberate, usually accomplished by gentle undulations of the second dorsal and anal fins, but threatened they retreat quickly to a hole in the reef, by using their tail. In many species the same hole is used and serves as a nonturnal resting place. Some of the larger species are capable of producing grunt like sounds when disturbed.

Although the mouth is relatively small, ballistids possess powerful jaws and strong teeth, numbering eight in the outher row and six in the inner row, which serve to butterress the outer row teeth. These are used for crushing a variety of hard shelled prey including crabs, molluscs and echinoderms.

Triggerfish lay eggs on the bottom, which are aggressively guarded by the female.

Most of the 40 triggerfish species inhabit the tropical  Indo pacific region, like the oceans around the Gili Islands.

 

 

 

Facts about Blennies

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Blennies (Blenniidae)

Blennies occur worldwide in tropical and warm temperate seas like around the Gili Islands with an estimated 350 species in about 50 genera.

They are elongate, laterally compressed fish and most are blunt headed, frequently possessing small tentacles, cirri, or a fleshy crest on the head. There is a single dorsal fin, although the fin may be deeply notched between the anterior spinous portion and posterior soft portion. The mouth is low on the head and not protractile. Jaw teeth are numerous, slender, and close set, either fixed or movable.

Blennies are bottom living fish that inhabit a variety of substrata icluding rocky shores, live and dead coral, rubble and mud.

Most Blennies are herbivorous, although species of Ecsenius are reported to feed on coral polyps.

Most species appear to lay demersal eggs that are guarded by the male parent. Nest sites include the surface of stones, abandoned worm tubes, dead coral crevices and empty bottles and cans.

Facts about Anthias

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Anthias (Anthinae)

Anthias , much smaller than their grouper relatives, also play an important role in the reef community. Anthias in particular are very abundant in terms of number of individuals and often form huge mid water feeding aggregations, especially adjacent to steep outer reef drop-offs, like when yo are diving around the Gili Islands Halik Reef.

The diet consists mainly of zooplankton and therefore, they are usually found in areas swept by periodic strong currents.

Generally males are more colourful and typically outnumbered by females. They exhibit a harem-type social structure with each male dominating a group of females, which in turn, have a pecking order hierarchy.

In the event the male is removed, either experimentally or by a predator, the highest ranking female changes sex and assumes control of the harem. The change is relatively rapid, beginning within several days and is generally completed in about two weeks. The transformation from female to male is facilitated by the presence of both testicular and ovarian tissue within the gonads. During the initial female phase only the ovaries are functional, but the assumption of social dominance triggers a hormonal reaction that suppresses ovarian development and stimulates the testicular tissue.

Reef Clean Up Gili Air with Oceans 5 Dive

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Yesterday Oceans 5 dive resort organized another reef clean up. Instructor Phil, Divemaster Yvonne and Divemaster Trainee Budi took care of 7 other divers who wanted to help.

The clean up started at 16.00. At that time the preparation started with preparing the bags, the gloves and all the equipment. At 16.30 Divemaster Yvonne gave a dive briefing about how everyone should take the rubbish away, the bottom time, the max depth and buddy teams.

The first divers came after 44 minutes out of th water. They had 3 bags full of rubbish. After this each buddy team and the result was shocking……

After we had last time 15 bags of rubbish now the divers collected another 12 bags of rubbish! It looks a little bit better in the front of Oceans 5 dive resort, but still a lot of work has to be done.

For further information about the reef clean ups: info@oceans5dive.com

David Bosmans, Open Water Scuba Instructor, IDC October 2012

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My name is David from Belgium and I completed my IE on the 2nd of November in Indonesia.
My IDC instructor was Camille Lemmens, friends of mine recommended doing the course with Camille. After about 30sec of hesitation I decided to do this course in Gili Air. Camille does come from The Netherlands and I am from Belgium, hence my hesitation.

When I arrived at the Oceans 5 dive resort my first impression was an unbelievably well run dive resort with first class equipment, great diving facilities (love the pool), beautiful rooms. I must admit I was a bit stressed and uncertain about my abilities as a diver in starting this IDC adventure. But all the staff is very professional and did everything to comfort me.

When I met Camille I felt I met a guy who lives, eats and breathes diving. To work with such an experienced professional is a blessing. It was hard work, stress and studying. But Camille did such a great job by being patient and alternating his lessons in a way we never felt bored. After the course I felt I was ready to do what I love to do, teach diving and see those beautiful smiles when people come out of the water after their first dive.

I would like to emphasize the great teaching methodology and personality of Camille and would highly recommend everybody doing a course with Camille at Oceans 5.
Of the bottom of my heart : Thanks Camille and the Oceans 5 crew!

David BOSMANS
Padi Open Water Scuba Instructor #283701

Facts about Frogfish

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Frogfish is an angler fish, which belongs to the family of Antennariidae. There are around 44 members in the frogfish family. These species vary at a huge level on the basis of their size. The Bandfin Frogfish can grow up to a size of only 5 cm, whereas the Giant Frogfish can grow up to a size of 40 cm. As their size varies, their coloration, markings and body patterns also varies. As far as the shape of the body is considered, it is almost similar. Frogfish are the underwater dwellers and very little is known about this species. They have unique characteristics that they can adapt themselves very well in their natural surroundings. Their camouflaged behavior makes them very difficult to be detected and so much is not known about them. They vary in coloration and markings in such a way that it is very difficult to identify the species correctly.

Where can you find them?

These frogfish have a filament attached to their heads and they use this filament to catch their prey. They remain stationary for most of time and wait for the right fish to come. When the fish gets attracted towards the lure on their long filament, the frogfish sucks the prey to their mouth. In this way, they catch their prey. This is the reason that they do not need to move for their prey. They move only when they sense danger or when they need to mate. These fish are found in the tropical waters of Asia. They are common in the areas where conditions are quite favorable to them. Most probably, they like to live in the coastal areas where they can find plenty of algae.

What do they eat?

These fish can feed on any fish they can catch. They can swallow fish, which are even double of their size. These fishes can do this because they have extremely flexible bones.

How do they breed?

The female of these species lay eggs in the water and the male comes from behind to fertilize them. The abdomen of the female starts swelling as the egg absorbs water and this happens from 8 hours to several days before the laying of eggs. The male starts to approach the female two days before the spawning. The time of spawning is not known by the scientists clearly, that whether it depends on the phase of the moon or any signal is released by the female. The eggs of these species are around (0.5 to 1) mm. When the egg hatches, the hatchlings are of about (0.8 to 1.6) mm in length.

What are their threats?

These fish has a characteristic of camouflage and this protects them from their enemy or predators. The predators find hard to discover them until the frogfish moves. Moreover, these fish suck water and puff their body in such a manner that the predators find it difficult to swallow them. These fishes are not over fished but the greatest threat to them is their habitat destruction and pollution.

Moray eels facts

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The moray eel is a large species of eel found in warm and temperate waters all around the world. They are also around the Gili Islands. Despite their snake-like appearance, moray eels (along with other eel species) are in fact fish and not reptiles.

Moray eels are found in both deep and shallow waters in tropical and sub-tropical regions. Although moray eels can be find in cooler waters occasionally, they tend to remain in the crevices deep in the ocean rather than venturing into shore. The largest populations of moray eels are found around tropical coral reefs where they are numerous different marine species found in large numbers. Specially when you are diving the dive sites around the Gili Islands named Halik, Hans and Bounty wreck you will see them.

There are around 200 different species of moray eel than can range in size from just 10cm long to nearly 2 meters in length. Despite their varying size and colour all moray eels are fairly similar in appearance with an elongated body, slightly flattened towards the tail. Moray eels also have large eyes and mouths which contain large teeth.

The moray eel is a relatively secretive animal, spending much of its time hiding in holes and crevices amongst the rocks and coral on the ocean floor. By spending the majority of their time hiding, moray eels are able to remain out of sight from predators and are also able to ambush any unsuspecting prey that passes.

Like many other large fish, the moray eel is a carnivorous animal surviving on a diet that consists of only meat. Fish, molluscs including squid and cuttlefish and crustaceans such as crabs are the main source of food for the moray eel.

The moray eel is often one of the most dominant predators within its environment but moray eels are hunting by some other animals including other large fish like grouper and barracuda, sharks and humans.

Moray eels tend to mate when the water is warmest towards the end of the summer. Moray eel fertilisation is oviparous, meaning that eggs and sperm are fertilised outside of the womb, in the surrounding water, which is known as spawning. More than 10,000 eggs can be released at a time, which develop into larvae and become part of the plankton. It can take up to year for the moray eel larvae to have grown big enough to swim down to the ocean floor to join the community below

Matt, OWSI instructor, about his IDC at Oceans 5

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Wow! I did my IDC with Camille at Oceans 5, Gili Air, Indonesia in August 2012 and I have not looked back.

After completing the new Divemaster course in August 2011 I wanted a new challenge, I found it. The few weeks leading up to the IDC/IE were daunting and I found myself worrying about the RDP exam along with the open water presentations. However, once I met Camille and he explained the IDC and the IE to me, my stress levels dropped and I was able to take onboard all the information he gave me with ease. He really held my hand and walked me all the way through the IDC and the IE.

It was a very busy and tiring 10 days without much rest bite. Nonetheless it was so worth it. The man has a wealth of knowledge waiting to be tapped by an inquisitive mind willing to learn.

I can’t stress how easy Camille made it for me and everyone else. No question was left unanswered. He was very organized and in turn so were we. The only thing left for us to do was the homework.

I also did the Nitrox, DUP and Emergency Oxygen Provider specialty courses. I only wish we had the time to do more. Camille’s course is well priced along with the specialty courses.

I would recommend Camille’s IDC to everyone!

Matt Constantine, Wales, OWSI, August 2012, Gili Air, Indonesia