Facts About Krill
Krill are smallish ocean crustaceans that play an integral part in the food chain. There are as many as 85 types of krill in the world's oceans and they live anywhere from right near the surface to miles below it. While many species thrive in the tropics, krill also are abundant in the Antarctic region. Animals such as penguins, whales, seals, fish, octopi and many types of bird species depend on krill as a main source of nourishment.
Other People Are Reading
-
Size
-
Krill are almost transparent much like shrimp are and species like the Antarctic krill are two inches in length. These creatures can live as long as six years and belong to the family of animals called zooplankton. Krill can swim but not well enough to do anything but go with the flow of the current that captures them and take them around the oceans.
Features
-
The legs of a krill, known as swimmerets, resemble minute feathers and act like fins. The krill are mobile and agile due to these swimmerets. These become useful while feeding, as the krill will swim and its swimmerets separate the tiny food particles it feeds upon from the water. Krill eat microscopic creatures called phytoplankton.
-
Phases
-
The majority of krill species hatch from eggs laid into the ocean. They then will undergo a change from a larval stage to a juvenile one before becoming adult krill. The krill will molt several times, each time shedding its outer skeletal system as it develops and adds more segments to its body. The krill can get larger before the newer outer membrane hardens. The adults have the adaptability of actually shrinking when their food supply runs low.
Krill defenses
-
Normally krill are in groups of incredible numbers in the water column, a tactic that helps discourage some of its smaller enemies that feel more at home grabbing individuals that are alone. When disturbed by a potential threat some krill will immediately molt. This strategy leaves behind an empty husk that can confuse a predator. However, some of the krill's biggest predators, like the whales, will simply swim through a huge school and devour as many as it can at once.
Baleen whales
-
The baleen whales such as the gigantic blue whale and the right whale possess large plates made from keratin that hangs down in two separate rows from the top of the mammal's mouth. The mouth has a shape that allows the whale to take in a huge gulp of water containing krill and other smaller organisms. The baleen plates act as filters, letting the water and smaller creatures through but trapping the krill, which the whale then swallows.
-
