Hobbies And Interests
Lack of Cephalization
Both the earthworm and the clam lack cephalization. This refers to an evolutionary trend that involves the concentration of nervous tissue toward one end of an organism. The process, which spans many generations, ends up producing a head region with sensory organs. The clam and the earthworm do not have the usual head structure that other species have. Both have mouths, but unlike earthworms, clams, with the exception of scallops, do not have eyes.
Body Plan
Earthworms and clams share the general body plan of most invertebrates. They both have a dorsal heart and a ventral nerve cord. The opposite is true for vertebrates. The earthworm has an anterior ganglionic mass, which is the brain, and a long solid ventral nerve cord with lateral nerves and ganglionic swellings in its segments. The clam, on the other hand, has three pairs of ganglia, all connected by nerves.
Nephridia
The nephridium is the excretory organ in the majority of invertebrates, including mollusks and earthworms. It consists of a tube through which waste products pass and are expelled from the body. The term is derived from the Latin for "little kidney." Earthworms have a pair of nephridia in each segment. One acts as a funnel collecting coelemic fluid while the other serves as an exit. Clams, meanwhile, have their nephridia just below the heart, cleaning the pericardial cavity's waste and excreting it into the mantle.
Aid in Cancer Research
The earthworm and the clam have remarkable immune systems. Cancer cannot be induced in earthworms and their highly efficient immune system enables long-term survival. Clams have a superb defense system, consisting of body eliminators, killing mechanisms and antioxidant enzymes. Both the earthworm and the clam are commonly used in cancer research. The earthworm cells have shown a capacity to kill cancer cells while the clan genome is being studied to create antibodies.