Sunday, October 20, 2013

Lionfish Adaptations

Take a look at the picture alongside. Isn't that one of the most beautiful fish you have ever seen? It looks almost ornamental! But would you believe me if I told you that it is one of the most invasive fish species to be found off the coasts of the United States? In fact it is such a troublemaker that many organizations pay people money to catch and kill the fish! I am not kidding! This is the lionfish - a fish as deadly as it is beautiful! Many enthusiastic aquarium keepers love to keep a lionfish as a pet, but in the environment, these fish prove to be rather dangerous and destroy the ecology of the niche in which they exist!

Lionfish is the common name given to the fish genus Pterois. The most common species of the genus are Pterois miles, Pterois radiata, and Pterois volitans. Lionfish are indeed pretty creatures, but some of the adaptations that make it pretty also make it a skilled and deadly hunter.

General Facts

Lionfish are native to the coral reefs of the Indo-Pacific oceans. However it has been introduced off the East Coast of the United States (specially off the coast of Florida), all thanks to the 1992 Andrew Hurricane that destroyed one of the aquariums in Florida. Lionfish have since been sighted along the coast of North Carolina, South Carolina, Georgia, Bermuda, etc. The typical adult lionfish is a little longer than a foot (usually 35-40cm) and weighs about half a kilogram (450-500g). These fish are exceptionally beautiful looking, with decorative pectoral fins and long tentacles. But don't they say the most beautiful thing in the world is probably the most dangerous? The saying stands true in case of lionfish as the long tentacles that adorn the fish are in fact venomous. The fish have red, white and black stripes on the body that act as a spectacular camouflage.

Adaptations

Many of the adaptations shown by lionfish allow them to survive in the aquatic environment. Some of the adaptations make lionfish an invasive species that seems to threaten the ecosystem in which they exist. Here is an account of the different lionfish adaptations...

1. Camouflage
The reef of any ocean is usually characterized by the presence of beautiful and delicate coral of all different shapes and colors. The red, white and black stripes on the lionfish allow them to camouflage suitably into the coral reefs of the Indian and the Pacific ocean which is the native place of the fish. The fish in fact get their common name from this spectacular camouflage itself, as the tentacles and stripe patterns of the fish make it look like the mane of a lion.

2. Tentacles
The tentacles of the lionfish add to their delicate and beautiful appearance, but are in fact very useful appendages since they are venomous. The fish make use of their tentacles to attract and kill prey. The tentacles are also believed to serve a role in the selection of a mate for reproduction. There is also a unique tentacle that is located above the eyes of the fish, which is said to particularly aid in attracting prey.

3. Appendages
The lionfish show the presence of appendages around the eyes (as mentioned above) as well as the head. The appendages help to conceal the features of the head such as the eyes and the mouth. The benefit of this is that, the fish is able to camouflage better and make itself invisible to the prey, as the prey is unable to distinguish the 'front' of the lionfish.

4. Center of Gravity
Lionfish show a special hunting adaptation. The swim bladder is an organ in the fish's body that is filled with air. It allows the fish to control its buoyancy. The swim bladder of lionfish is such that it allows the fish to control its center of gravity. This in effect helps the fish to sink or rise in a water column. The fish is hence able to suspend itself in an almost motionless state at a certain depth in the water column - it lies completely still as the prey approaches, and within the blink of an eye the prey is caught in the tentacles and consumed by the fish, with great stealth.

5. Invasive Species
Lionfish are a particularly invasive fish species. Lionfish are known to prey on as many as six different species of fish. Due to their adaptations mentioned above, they are extremely skilled hunters that are almost impossible to control. In the native regions where the fish is found, the fishes that prey on lionfish help to keep the number of lionfish in check. However, where the fish is not native, it is not preyed upon and is hence able to spread far and wide.

Found It? Kill It!

Being a rather skilled hunter and a vehemently invasive species, lionfish often succeed in disturbing and destroying the ecological niches of the aquatic environment which are not their native habitat. It becomes difficult to control the fish as they have shown to be poisonous to humans as well, inducing headache, fever, vomiting and also proving to be lethal. Lionfish are even known to attack divers. Hence efforts are now being made to eradicate the species from the coasts of the United States, especially Florida. Since last year the Florida Keys National Marine Sanctuary has begun to give divers licenses to kill the lionfish they encounter in the sanctuary. The Environment Education Foundation also gives out prize money to diving teams who catch the most number of lionfish! The National Oceanic and Atmospheric Administration has recently launched a campaign that advocates the use of lionfish in culinary even. This may come as a surprise to many, but a properly cooked lionfish is 100% safe for consumption - the venom has no effect on the person eating the fish! It is quite surprising that such a savage approach has been adopted by humans to actually control the number of this fish species.

They sure make pretty pets and will look spectacular in a fish bowl or an aquarium. But they like to eat live fish, so you are actually going to have to buy goldfish and damsel fish to feed your pet lionfish... sounds quite cruel, isn't it? I'd rather keep a damsel fish as a pet than as food stock for a pet lionfish! You be the best judge!

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