Question

What is the importance of krill?
IMPORTANT NOTE: "Lower animals" (invertebrates and most fish) have a very different reproductive strategy than "higher animals".

Answer 1

Krill is a crustacean that belongs to the phylum Arhropoda.

Krill forms an important group within the marine food web. It is considered as a keystone species because, many of the marine organisms depend upon krill as source of food. Without krill, many of the marine species steps to extinction. Majority of krills are present in deeper regions of sea during the day time and they become food for several benthic organisms.At night they migrate to oceanic surfaces and they become food for many of the predators. This typical movement in krills is referred to as vertical migartion.

Usually reproductive strategies of lower organisms differ from that of higher animals.Reproduction in krills are interesting. When the females become sexually mature, male krills deposits their sperm sack in the genital opening of females. Females as they release eggs through the genital opening, it gets fertilized. Some species of krills carry eggs with them, and once they hatch and they are able to swim they are released to the water.

But, other krill species, they lay the fertilized eggs where they zink to oceanic deeps, hatches and young ones swim to the surfaces.