Editing Sacculina (section)

==Life cycle==
{{Cleanup rewrite|2=section|date=September 2019}}
The female ''Sacculina'' [[larva]] finds a crab and walks on it until she finds a joint. She then [[molting#Arthropods|molt]]s into a form called a '''kentrogon''', which then injects her soft body into the crab while her [[Exoskeleton|shell]] falls off. The ''Sacculina'' grows in the crab, emerging as a sac, known as an ''externa'', on the underside of the crab's rear [[thorax]], where the crab's [[Egg (biology)|egg]]s would be incubated. Parasitic ''Sacculina'' destroy a crab's genitalia, rendering the crab permanently infertile.

After this invasion of the ''Sacculina'', the crab is unable to perform the normal function of molting. This results in a loss of nutrition for the crab, and impairs its overall growth. The natural ability of regrowing a severed [[claw]] that is commonly used for defense purposes is therefore lost after the infestation of ''Sacculina''.

The male ''Sacculina'' 'larva' looks for a female ''Sacculina''  on the underside of a crab. He then implants his cells into a pocket in the female's body called the "testis", where the male cells then produce spermatozoa to fertilize eggs. 

When a female ''Sacculina'' is implanted in a male crab, it interferes with the crab's hormonal balance. This [[reproduction|sterilize]]s it and changes the bodily layout of the crab to resemble that of a female crab by widening and flattening its abdomen, among other things. The female ''Sacculina'' then forces the crab's body to release hormones, causing it to act like a female crab, even to the point of performing female mating dances. If the parasite is removed from the host, female crabs will normally regenerate new ovarian tissue, while males usually develop complete or partial ovaries instead of testes.<ref>[https://books.google.com/books?id=d4GQlYzode8C&dq=%22when+the+Saccalina+parasite+is+removed%2C+the+female+host+generally+regenerates+new+ovarian+tissue%22&pg=PA756 General Parasitology]</ref>

Although all energy otherwise expended on reproduction is directed to the ''Sacculina'', the crab develops a nurturing behavior typical of a normal female crab. The natural hatching process of a crab consists of the female finding a high rock and grooming its brood pouch on its abdomen and releasing the fertilized eggs in the water through a bobbing motion. The female crab stirs the water with her claw to aid the flow of the water. When the hatching larvae of ''Sacculina'' are ready to emerge from the brood pouch of female ''Sacculina'', the crab performs a similar process. The crab shoots them out in pulses, creating a large cloud of ''Sacculina'' larvae. The crab uses the familiar technique of stirring the water to aid in flow.<ref>{{Cite book |title=Parasite rex : inside the bizarre world of nature's most dangerous creatures |last=Zimmer |first=Carl |date=2001 |publisher=Simon & Schuster |isbn=074320011X |edition=1st Touchstone |location=New York |oclc=47903774}}</ref>