Attention Deficit Disorder Prosthetic Memory Program

Carcinisation

ADDPMP636
Carcinisation - © Attention Deficit Disorder Prosthetic Memory Program

An example of convergent evolution in which a crustacean evolves into a crab-like form from a non-crab-like form. The term was introduced into evolutionary biology by English zoologist Lancelot Alexander Borradaile in 1916, who stated that “Carcinisation consists essentially in a reduction of the abdomen of a macrurous crustacean, together with a depression and broadening of its cephalothorax, so that the animal assumes the general habit of body of a crab.”

A carcinised morphology can be defined as follows:
The carapace is flatter than it is broad and possesses lateral margins.
The sternites are fused into a wide sternal plastron which possesses a distinct emargination on its posterior margin.
The pleon is flattened and strongly bent, in dorsal view completely hiding the tergites of the fourth pleonal segment , and partially or completely covers the plastron.

Carcinisation is believed to have occurred independently in at least five groups of decapod crustaceans, mostly belonging to the infraorder Anomura. Carcinised crustaceans include hermit crab, porcelain crab, hairy stone crab and king crab, among others. The example of king crabs evolving from hermit crabs has been particularly well studied, and evidence in their biology supports this theory. For example, most hermit crabs are asymmetrical, so that they fit well into spiral snail shells; the abdomens of king crabs, even though they do not use snail shells for shelter, are also asymmetrical.

Carcinisation - © Attention Deficit Disorder Prosthetic Memory Program
Carcinisation - © Attention Deficit Disorder Prosthetic Memory Program
Vortex Project - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP587
Vortex Project
Pavarotti in Hyde Park - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP684
Pavarotti in Hyde Park
Cholita Climbers - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP455
Cholita Climbers
Sprite Lightning - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP687
Sprite Lightning
Optical Camouflage - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP105
Optical Camouflage
George Gurdjieff - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP748
George Gurdjieff
Ice Hockey Goaltenders Masks - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP284
Ice Hockey Goaltenders Masks
San Siro - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP113
San Siro
List of films that most frequently use the word "fuck" - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP494
List of films that most frequently use the word "fuck"
Multiverse - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP507
Multiverse
Solar Cooker - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP219
Solar Cooker

You are using an outdated browser.
Please upgrade your browser to improve your experience.