Sacculina

One reason which makes a zoologist certain that the Sacculina is a degenerate type is, that in almost all other instances of animals which begin life in the Nauplius-form -- and there are several -- the Nauplius develops through higher and higher stages, and arrives finally at the high perfection displayed by the shrimp, lobster, crab, and other crustaceans.

Natural Law in the Spiritual World Henry Drummond 1874

Within a few days the infected shore crabs died, and Sacculina died with them.

Parasite Rex Carl Zimmer 2009

This was the closest thing to a proper museum I could think of for parasites, even though a grand diaspora of parasites was missing—the parasitic wasps and gall makers scattered in entomological collections, the protozoa hidden in schools of tropical medicine, Sacculina in the hands of some Danish expert on barnacles.

Parasite Rex Carl Zimmer 2009

After a few months, Torchin was able to shepherd Sacculina from larva to adult.

Parasite Rex Carl Zimmer 2009

He chose the common shore crab, Hemigrapsus oregonensis, and exposed it to Sacculina.

Parasite Rex Carl Zimmer 2009

He got his hands on another species of parasitic barnacle that is related to Sacculina and lives in the Pacific sheep crab.

Parasite Rex Carl Zimmer 2009

But rather than growing into an animal that searched and struggled for its own food, Sacculina instead found itself a crab and wiggled into its shell.

Parasite Rex Carl Zimmer 2009

For months, Torchin slowly got acquainted with Sacculina and its bizarre life cycle.

Parasite Rex Carl Zimmer 2009

And then he wants to run the same tests on these parasites that Sacculina failed.

Parasite Rex Carl Zimmer 2009

Lankester was appalled at how Sacculina lost its segments and appendages as it matured.

Parasite Rex Carl Zimmer 2009