Aega psora
Encyclopedia
Aega psora is a species of isopod
crustacean
that parasitises
a number of fish
species. It reaches 15 millimetre (0.590551181102362 in) long, and is mostly grey, with a faint dorsal stripe. It is a serious parasite of larger species of fish, particularly when they are injured. As an adaptation
to its parasitic lifestyle, A. psora has no antennae
.
Isopoda
Isopods are an order of peracarid crustaceans, including familiar animals such as woodlice and pill bugs. The name Isopoda derives from the Greek roots and...
crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
that parasitises
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
a number of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
species. It reaches 15 millimetre (0.590551181102362 in) long, and is mostly grey, with a faint dorsal stripe. It is a serious parasite of larger species of fish, particularly when they are injured. As an adaptation
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
to its parasitic lifestyle, A. psora has no antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
.