Introduction

The Blue Tang is part of the surgeonfish Family and is known by many different names; blue barber, blue doctor, blur tang, yellow barber and yellow doctorfish are a few examples.

Where Will I Find Them?

The Blue Tang can be found in tropical waters between 2 metres and 40 metres, between the latituted of 41 degrees N and 33 degrees S.  There are loads of them in Florida, the Bahamas and the Caribbean Sea.

They tend to live in holes and crevices on coral reefs, though the chances of finding a baby one is much less as they spend much of their time hiding from predators.

What Do They Look Like?

At 39cm in length at full maturity and blue colour with curious yellow bits, they are quite easy to recognise.  They are flat fish and have a pointed mouth.  The most obvious thing about them is the yellow spine at the base of the tale.  Young adults may still be more of a yellowy colour, which will darken to a blue as they reach full maturity.  At night the Blue Tang shows white stripes.

What Do They Eat?

The Blue Tang only eats algae from rocky areas.  The fish is very important when it comes to keeping algae levels under control, which if got out of control, could suffocate corals.

What is Their Usual Behaviour?

They can be found on their own, in pairs or in schools of 10 to 12, although occasionally you might find them in much larger groups.

What is Their Conservation Status?

Not listed on the IUCN Red List of Threatened Species.

References

www.marinebio.org

“Just keep swimming!” – Dorey

Introduction

Naturally this little silvery coloured seal lives to around 30 to 35 years, but they are commercially hunted for oil and fur.  They are usually hunted on their breeding grounds where they are at their largest concentrations which leads to the hunt as being the largest slaughter of marine animals in the world.

Where Will I Find Them?

There are 3 populations of this cute little seal; the northwest Atlantic population breeds in the Gulf of St Lawrence and off the coasts of Labrador and Newfoundland and is the biggest population of the three at between 4-6.4 million seals.  The Barents Sea population breeds in the White Sea and contains around 1.2 million seals.  The smallest population at around 300,000 seals is the east Greenland population which breeds near Jan Mayen Island.  They migrate huge distances after breeding- up to 2500km.

What Do They Look Like?

The Harp Seal gets its name from the harp-shaped pattern on the lower back of the adult seal.  Males and females are similar in size and average around 1.5 to 2 metres in length.  They are born with a yellow coat that changes to white after a few days.  After a few weeks they start to lose the white fur to get their adult coat of silvery-grey with irregular dark spots.  At sexual maturity the irregular dark spots start to change into the harp pattern well known on this species.

What Do They Eat?

The Harp Seal has quite a varied diet that includes capelin, polar and arctic cod, herring, halibut, plaice, krill, shrimps and prawns and many others fish and crustaceans.  They routinely dive to depths of 100 meters or more to feed, but they have been observed at depths of around 275 metres.

What is Their Usual Behaviour?

Generally they stay with their own population, and although juveniles have been known to move between populations, very little if any breeding occurs between the 3 populations.

What is Their Conservation Status?

Not listed on the IUCN Red List of Threatened Species.

References

www.marinebio.org

Couldn’t resist a baby picture!!

About the Author: Elyse hopes to be an instructor soon, but until then she will write articles and visit as many different dive destinations in the world as possible. She is currently living in Malta, and loving the new diving on offer.

Introduction

The Marine Iguana is the only lizard in the world that takes to the sea.

Where Will I Find Them?

I can give you a pretty specific answer on this one because they can only be found in one place:  the Galapagos Islands off the coast of South America.  Populations are found throughout the islands and vary widely in size and colour, although they are considered to be one single species.

You will usually find them on rocky coasts and intertidal zones, although females can be found nesting up to 2km inland.

What Do They Look Like?

Generally they are grey to black in colour, although some may have coppery green or red patches.  The average length of the adult male is around 1.3 metres, while the female is a little smaller at 0.6 metres.  The main differences between the Marine Iguana and Land Iguanas are the short blunt snouts and the shape of the tail, which is squished slightly to help the animal navigate in the water.

What Do They Eat?

Marine Iguanas generally eat marine algae by diving to 2-5 metres during high tide, although they sometimes dive to depths of 20 or more meters.  Usually they only dive for a few minutes at a time, but they have been known to stay below the water for periods of more than half an hour.  Interestingly, the Marine Iguana must warm it’s body to around 36 degrees C before it eats by lying in the sun for long periods of time because when it dives in the water, it can lose as much as 10 degrees C in body heat.

What is Their Usual Behaviour?

They spend a lot of time sunbathing – lazy bums.

What is Their Conservation Status?

Marine Iguanas are listed as Vulnerable on the IUCN Red List of Threatened Species because:

“The marine iguana Amblyrhynchus cristatus is endemic to the Galápagos Islands, Ecuador. The population occurs as ten subpopulations on separate islands in the range. Total extent of occurrence is less than 5,000 km² and area of occupancy is estimated to be less than 500 km². Total population size is unknown, however, El Niño effects are known to cause periodic declines in population (at least 85% mortality). In addition to this, the population is threatened by pollution (e.g., oil spills) and predation by exotic species on the islands.”

References

www.marinebio.org

Is it just me, or does this one look like it it smiling?!

About the Author: Elyse hopes to be an instructor soon, but until then she will write articles and visit as many different dive destinations in the world as possible. She is currently living in Malta, and loving the new diving on offer.

Introduction

There are at least 10 species of this little creature, but there are two that are well known; the lesser blue-ringed octopus (maculosa) and the greater blue-ringed octopus (lunulata).

Where Will I Find Them?

The lesser blue-ringed octopus will only be found in the temperate waters of southern Australia at depths between 0 and 50 metres, while the greater blue-ringed octopus can be found in shallow refs and tide pools from northern Australia to Japan and as far west as Sri Lanka at depths of 0 to 20 metres.

What Do They Look Like?

They are usually a browny beige colour, until you piss em off!  When they get alarmed, bright blue rings will appear which is a sign that they are about to give you a small dose of their lethal venom.  There is no antidote for this venom, so if you get bitten, the only known way to survive it is ongoing heart massage and artificial respiration until the poison dissipates (usually in 24 hours).  The little guy is only the size of a golf ball when it is fully matured and doesn’t have an ink sac, which makes it a popular choice for a home aquarium.

So why should you NOT buy a blue-ringed octopus?

What Do They Eat?

Both the lesser and the greater eat small craps, hermit crabs and shrimp that it catches using one of it’s two types of poison during the day.  The other type of poison is saved for the predator.

What is Their Conservation Status?

Not listed on the IUCN Red List of Threatened Species.

References

www.marinebio.org

About the Author: Elyse hopes to be an instructor soon, but until then she will write articles and visit as many different dive destinations in the world as possible. She is currently living in Malta, and loving the new diving on offer.

Introduction

The Scalloped Hammerhead is the most common species of hammerhead that you will find in coastal regions.

Where Will I Find Them?

Warm and tropical coastal waters between about 46 degrees North and 36 degrees South are the waters in which you will usually find these sharks. They often come close to shore and into enclosed bays and estuaries, but you will also find them out at sea down to a depth of around 275 meters.

What Do They Look Like?

Most hammerhead that divers encounter are 2 to 2 1/2 meters in length, but the average length of males is about 3 meters and for females, it is a little longer.  The largest recorded length is at least 3.7 meters and it is thought that there are a few individuals that maybe over 4 meters.

The Scalloped Hammerhead can be distinguished by the arched front edge of the head that has a prominent central dent.  You can see from the picture below the difference between the Great Hammerhead and the Scalloped Hammerhead.

The skin of the shark is a uniform grey, brown-grey or olive on the top, fading to white on the underside.  On young sharks, the edges of the pectoral fins are darker, and they usually lighten up as the animal gets older.

What Do They Eat?

Scalloped Hammerheads generally feed on bony fishes, squid, octopus and cuttlefishes, but also sometimes eat lobsters, shrimps, crabs, other sharks and rays and occasionally the odd tasty diver.  Oops, sorry – I didn’t mean that last bit

What is Their Usual Behaviour?

These sharks tend to stick together in groups, which may be for feeding and reproducing reasons.  Although some people say their group behaviour is for protective reasons, these sharks have few little threat from predators when they reach full maturity.

Humans have little to fear from Scalloped Hammerheads as they are not aggressive, and any incidents involving humans were probably more to do with fear on the shark’s part.  So don’t scare the poor little sharky – if you do…I have no sympathy!!

What is Their Conservation Status?

The Scalloped Hammerhead is classified as Lower Risk/near threatened on the IUCN Red List of Threatened Species.  This means that they are not Critically Endangered, Endangered or Vulnerable, but they are relatively close to qualifying for Vulnerable.

References

www.marinebio.org
www.sharkinfo.ch

About the Author: Elyse hopes to be an instructor soon, but until then she will write articles and visit as many different dive destinations in the world as possible. She is currently living in Malta, and loving the new diving on offer.