Difference Between Krill and Plankton

Key Difference – Krill vs Plankton
 

Though Krill and plankton are extremely important organisms that maintain the life by making the initial links of food chains in aquatic habitats like oceans, seas, lakes ponds, etc., some differences exist between these two organisms.The distribution of these creatures may depend on the quality of waters and the availability of light. In addition, another variable that determines the distribution is the nutrient availability which include the amount of nitrate, phosphate and silicates. The key difference between these two organisms is that Krill is a small crustacean found in various aquatic habitat and feed on phytoplankton while Plankton are a diverse group of small organisms that make the primary links of most food chains in aquatic habitats.  In this article, the difference between krill and plankton is further discussed.

What are Krill?

Krill is a small crustacean that thrives in nutrient-rich waters worldwide. It is a type of zooplankton and feed mainly on phytoplankton near the water surface. There are over 80 species of krill found so far. Krill are identified by the clearly visible gills found below the carapace on thoracic segment seven and eight. There are photophores, which produce a blue light and found at the base of the abdominal pleopods, near the mouth parts and at the genital segments.

Krill is a major source of food for many marine animals such as whales, seals, squids, fish, penguins, and other seabirds. Moreover, some species of krill are commercially harvested and used for human consumption, aquacultures and aquarium feed, and in the pharmaceutical industry.

What are Plankton?

Planktons are a diverse group of organisms that live in nutrient rich waters. They make the primary link of most aquatic habitats and provide an essential food source for many aquatic animals. Most of the planktonic organisms are microscopic. But there are few species that can be seen by the naked eye (ex: jellyfish, krill, etc.). Most planktons cannot swim against the water current. There are three types of planktons; (a) phytoplankton, which include diatoms, cyanobacteria, dinoflagellates and coccolithophores, (b) zooplanktons including krill, eggs and larvae of fish and, (c) bacterioplankton include bacteria and archaea. Phytoplankton are the primary producers that produce their own food by photosynthesis. Bacterioplankton play a major role in remineralizing organic material in aquatic habitats.

 

What is the difference between Krill and Plankton?

Definition of Krill and Plankton

Kril: Krill is a small crustacean found in various aquatic habitat and feed on phytoplankton

Plankton: Plankton are a diverse group of small organisms that make the primary links of most food chains in aquatic habitats.

Characteristics of Krill and Plankton

Organisms

Krill: Krill is a single organism.

Plankton: Plankton comprise of many types of organisms.

Type

Krill: Krill is a type of zooplankton.

Plankton: Zooplankton is a type of Plankton

Photosynthesis

Krill: Krill cannot produce their own food by photosynthesis

Plankton: Plankton can produce their own food by photosynthesis

 

Image Courtesy:

“Meganyctiphanes norvegica2” by Øystein Paulsen – MAR-ECO.  (CC BY-SA 3.0) via Wikimedia Commons 

“Diatoms through the microscope” by Prof. Gordon T. Taylor, Stony Brook University – corp2365, NOAA Corps Collection. (Public Domain) via Wikimedia Commons