Study of fish
Mysterious beast Barracuda.
Many consider the Barracuda as dangerous as sharks, piranhas and eels. Fortunately, this fish species live exclusively in tropical and subtropical waters of the World ocean, therefore we encounter very rarely.
The most ominous feature of the Barracuda – powerful lower jaw, far coming from the top. Jaws equipped with fearsome teeth: a series of small, razor-sharp canines dot the jaw outside, and inside there are several large teeth like daggers. The largest Barracuda caught by the man, was a little more than two meters long, and weighed almost 50 kg!
The great Barracuda has a reputation as a voracious predator. All the sea creatures, inferior to her in size – fish, squid, large prawns and even other Barracuda can become its prey. Usually, these evil fish lie in wait for their prey in ambush among stones, rocks or in thickets of underwater vegetation. In addition, quite often they attack shoals of small fish, gathering in small groups. If Barracuda large size – it does not need a pack and prefer to hunt alone.
Despite such a formidable name and ferocious appearance, these predators are virtually non-hazardous to humans. It is useful to remember that all Barracuda attacks on people occurred in turbid or dark water where a moving hand or foot of a swimmer taken by shark for floating fish.
The true story about fish-Nemo
Due to the famous disney movie, clown fish are the most popular representatives of the marine family. Without these amazing fish is very difficult to imagine the existence of any marine aquarium. Even their name is easy to help to imagine the image of a brightly colored fish frolicking between the delicate tentacles of anemones (sea anemones).
This image is one of the most striking examples of co-existence in the underwater world (symbiosis). Clown fish prefer warm water of the Pacific and Indian ocean. In natural habitat these fish feed on a variety of zooplankton and phytoplankton, floating in the water column. In search of write, as a rule, they rarely move away from the reliable security for “my vault” and constantly rely on his defense.
Extremely bright (orange and red, with one or more white stripes) coloring fish pursues two goals simultaneously. In addition to the protective value of this coloration plays an important role in recognizing individuals of their own. All kinds of clown fish creates a strong Alliance with the chosen anemone, as anemone provides a safe haven for fish-clown, which in turn protects the anemone from potential predators and occasionally feed him.
As the reef is always a shortage anemone host for numerous offspring of fish-clowns, there is strong interspecific competition. If this Actinia have chosen to fish one of the known species of this genus, it becomes inaccessible to individuals of any other species. She will zealously defend the owners from encroachment of other species anemonefish fish. And just any “bum” a species closer to sea anemones, as to meet him popping up all the population of the sea anemone and amicably shooing the alien invader.
Why anemonae fish are able to survive in the poisonous tentacles of anemones, still trying to figure out many oceanographers. There is basic theory, which is shared by many researchers in this field, in which the composition of mucus clown fish based on sugar, not the protein and therefore clown fish Actinia are not associated as potential food. But in case of illness, in violation of mucous cover, the fish can be paralyzed by the stinging cells of sea anemones and eaten, like any other.