Category Sea/Ocean

What is the speed of a manatee?

If an award was given for the most easy-going and placid animal in the water, it would definitely go to the manatee. Manatees look like giant, elongated lumps of dough with large paddle-shaped tails and wrinkled heads.

They have whiskers growing from their chins and rectangular, nail-tipped flippers. Usually grey or brown in colour, the manatee is one of the most friendly and curious creatures you can encounter underwater.

These plant-eating herbivores graze on sea grasses and other aquatic plants. These gentle giants are also called ‘sea cows’ because of their docile dispositions. They can grow to a length of up to 13 feet and weigh about 590 kg.

They can hold their breath for up to 20 minutes underwater, but usually come up every 2 to 3 minutes to breathe. They spend their time resting for up to 12 hours suspended near the surface of the water or lying on the bottom of shallow, slow-moving rivers, saltwater bays and canals. However, they are capable of reaching speeds of up to 25 km/h, in short bursts, when required.

These marine mammals look like oversized otters or seals but are actually more related to elephants! They are so friendly that it sometimes gets them into trouble! Manatees will swim over to any curious looking object (like a passing boat) and try to examine it. Consequently, many of them get cut by propeller blades and bear the scars on their backs.

They are found in the shallow, marshy coastal areas and rivers of the Caribbean Sea, the Gulf of Mexico, the Amazon basin and West Africa. They cannot survive in temperatures below 60 degrees, which is why they migrate from the open waters of the Gulf of Mexico to natural springs in Florida during the winter months.

The main challenges for manatees are human-related issues, such as habitat destruction and manmade objects such as boats and ships. Other threats include adverse temperatures, predation by crocodiles on their young and diseases. Their numbers are declining and they are listed as ‘Threatened’ in the IUCN List.

Picture Credit : Google

Which horse is actually a fish?

Although it has a head that resembles a horse, its gills, fins and swim bladder make the marine seahorse unquestionably a fish.

These fascinating creatures have a long snout, a bulbous body and a long snake-like tail. With a maximum speed of 1.5 metres per hour, the seahorse is the slowest fish in the world. In comparison, the average snail moves at 3 metres per hour.

They have a small dorsal fin that is not very strong, so swimming is labour some. Instead they use their tails to latch onto a piece of sea debris to float over distances. They also use their tails to anchor themselves to sea grass or coral when the sea becomes rough.

Their eyes can move independently of each other, like those of a chameleon, giving them a 360-degree field of vision! They are also extremely good at evading predators by camouflaging themselves to mimic their surroundings. This works out in two ways as they are excellent ambush predators. They lie in wait unnoticed till unsuspecting small crustaceans like shrimp come along. Then they use their long snouts to quickly suck them in and swallow them whole. They can suck prey from as far as 3 cm away.

If there were any prizes for the father of the year in the marine world, it would go to the male seahorse. In seahorse society, it is the father and not the mother who carries the eggs (in an abdominal pouch) for 45 days. The female is free to wander about and look for food!

And that’s not all; these incredibly unique sea creatures have no stomach or teeth. To stay alive they have to constantly eat! There are around 46 species of seahorse, which can range in size from a jellybean to a banana. The largest seahorse is the big-bellied seahorse which can grow up to 12 inches, while the smallest is called the pygmy seahorse and is only around 16 mm long.

Picture Credit : Google 

How fast can a starfish move?

Starfish don’t move very fast.  They move at an average of about 1 metre per minute, with a maximum speed of about 1.6 metres per minute. The speed of a starfish is directly proportional to the size of the starfish. In other words, the larger the starfish, the faster it can move.

There are 2000 varieties of starfish currently in the world. These beautiful creatures usually have 5 or more arms radiating from a central disc and are some of the most exotic looking creatures in the ocean. Did you know that they are more related to sea urchins and sand dollars than actual fish? This is because they do not have scales, fins or gills. Rather, starfish belong to the Asteroidea class and are called Asteroids! It seems befitting that a ‘star’ would belong to a class that means a heavenly object, doesn’t it?

These fascinating creatures use ocean currents to help them move over greater distances more quickly. For shorter distances they use their arms – which have special tubes – to travel. Each of a starfish’s arms also has eyes at the end of them! There are some starfish with 40 arms and each arm has an eye at the end. Such a starfish would have 40 eyes! A starfish mostly eats clams, mussels and oysters. It extends its stomach out of its mouth to eat its prey! And finally it can regenerate an arm if it is cut off. Weird, but amazing, isn’t it?

Picture Credit : Google

What is a sea anemone?

If you were to dive deep into the ocean and reach the rocky floor below, chances are that you might see an incredibly colourful bed of flower-like creatures called sea anemones. Named after the anemone flower found on land, sea anemones are invertebrates (they do not have a backbone) with soft cylindrical bodies and colourful tentacles on the top that resemble petals.

Most of the time, sea anemones stay attached to rocks or coral, and prey on small fish and crustaceans that swim close to them. However, they are known to occasionally move from their position. But their movement is very slow – about 9.91 millimetres in an hour! To move, a sea anemone uses its pedal disc (or base) to slowly shift along on a rock or coral. It is also able to swim and float.

The sea anemone’s tentacles act like its hands. They help it to capture prey and also serve as a defence mechanism. Every tentacle has tiny stinging capsules called nematocysts which shoot out a tiny amount of stinging poison capable of paralysing or killing small animals. The paralysed prey is then moved with the help of its tentacles to its mouth and swallowed whole!

Sea anemones are found throughout the world’s oceans, but the most abundant populations are found in shallow, tropical waters. They are threatened by climate change, habitat destruction, disease, pollution, predation and of late, collection and trade. If left undisturbed they can live up to 60-80 years. The oldest sea anemone on record is 100-years-old.

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How is the Shortfin Mako Shark built for speed?

The Shortfin Mako Shark is found in tropical and temperate seas all over the world. It has a streamlined bullet-like shape and small dorsal fins (as its name ‘shortfin’ suggests) that minimize drag, making it an extremely fast swimmer.

It can grow to a length of 3 metres and weigh around 135 kg.

At speeds of 50 km/h, it is one of the fastest sharks in the ocean. It is metallic blue on top and white below. It has large, well developed eyes and a mouthful of teeth. In fact its name ‘Mako’ comes from the Maori language and means tooth or shark tooth. The Maori tribes of New Zealand prize Mako teeth and use them to make necklaces and traditional jewellery.

The Mako is an extremely aggressive and energetic fish. Anglers, who have experienced a Mako Shark at the end of their line, liken the experience to wrestling with an angry crocodile! A hooked Mako will not give up easily and takes a series of flying leaps into the air struggling with the line. Sometimes it will even land on top of the angler and the boat!

This shark also leads an eventful life in the ocean. It preys on and attacks swordfish and will often enter into a battle with these dangerous adversaries. Mako sharks are often seen with swordfish stabs and puncture wounds in their body and some even have broken pieces of the swordfish bill lodged in their heads!

This deadly and beautiful predator was once abundantly found in the world’s oceans. Overhunting by recreational anglers as well as for commercial consumption has brought its population down drastically. It is currently listed as ‘Endangered’ on the IUCN List.

Picture Credit : Google

What kind of fish is the swordfish?

A swordfish is a long, scaleless fish with a sword-shaped bill and a large dorsal fin. Its bill is flatter as compared to the marlin and the sailfish and is thus also called ‘broadbill’. It can grow up to 10 feet long and weigh as much as 650 kg! It is a highly elusive, migratory and solitary fish.

It reaches a top speed of about 120 km/h and preys on other fish such as lantern fish, cuttlefish, squid and herring. It has special organs near its eyes that heat up its eyes and brain in the cold water. This helps it to see better and hunt more effectively.

The swordfish prefers to hunt alone at night and likes to swim around in deep waters. It is an apex predator with very few threats except sharks and humans. The swordfish, like all billfish, can have high levels of mercury in their bodies as they hunt on smaller fish. The mercury from these small fish gets deposited over the years in the swordfish.

Although swordfish is considered a delicacy and many restaurants serve it on their menu as a special dish, eating it should be avoided by children, pregnant women and sick people.

Swordfish populations were declining at one point due to overfishing but since then have recovered. They are now listed under ‘Least Concern’ in the IUCN List.

Picture Credit : Google