What is Mimicry?
Mimicry is the superficial resemblance of one organism to another or to the natural objects among which it lives that ensures concealment or protection so that it either escapes from observation by the enemy or advertises as being harmful, which is not actually the case. The organism which exhibits mimicry is called a mimic and the organism or object it mimics is called a model.
Mimicry provides protection from predators, may help in trapping the prey, or may ensure pollination.
Types of Mimicry:
Mimicry can be of two types i.e. protective mimicry and aggressive mimicry.
(1) Protective Mimicry- When prey mimics, it exhibits protective mimicry. It can be of concealment type or warning type. In the concealment type of protective mimicry, the organisms (prey) resemble their surroundings so that they are not easily detected by predators. For example-
- The white crab, Cryptolithodes, resembles so perfectly with the white pebbles on the beach that it is very difficult to recognize it.
- The Caterpillar larva of the geometrid moth resembles a dry twig.
- The palatable viceroy butterfly (Limenitis or Bosilarchia archippus) mimics the distasteful or nonpalatable monarch butterfly (Danaus plexippus) and is avoided by the birds.
- The stick insect, Carausius morosus mimics thin dry branches.
- American Opossum, Didelphis virginiana, becomes unconscious and simulates as dead on the approach of the enemy.
- The dead leaf butterfly, Kallima paralekta, resembles a dry leaf in form and color.
- The leaf insect, Phyllium, resembles the green foliage.
- Many snakes when faced with prey hold their head still and move the tip of their tail so as to divert the attention of the predator.
- The butterfly, Thelca, has a dummy head at the hind end of the wings with antennae-like appendages on wing tips.
- Some fishes have an eye on the tail to deceive the predation.
(2) Aggressive Mimicry- It is exhibited by predators to allure or deceive the prey. It can be either of concealing type or of alluring type. In concealing aggressive mimicry, the predator conceals itself with the surroundings and is not noticed by the prey. For example, Frog remains concealed with the surroundings and is able to prey on insects. A praying mantis (an insect) conceals itself with green twigs to prey on other small insects.
In alluring aggressive mimicry, the predator attracts the prey by resembling an object or food item. For example, many spiders mimic the flowers of orchids, and insects are lured to collect honey and are eaten up. Angler fish (Lophius) camouflages with the sea bottom, and the first fin ray of the dorsal fin called illicium rotates in front of fish like bait to attract small fishes. The mouth corner of an African lizard resembles a flower to attract insects.