Sproingshell

The sproingshell has split from its ancestor. Like their ancestor they are fairly simple internally, posing a gastrovascular cavity, a number of electroplaques and bands of elastic tissue. Tentacles emerging from the oral opening capture food particles and draw them in. The size and number of their electroplaques is reduced compared to their ancestor while the elastic tissue bands have increased on size and number. As a result they do not produce as strong an electric shock.

Like their ancestor sproingshell contain large multinucleated cells housing elastic protein polymers which help them to remain upright in strong currents. Unlike their ancestor these cells house a second, similar protein which plays an important role in a novel metabolic process. Beginning with a simple duplication of the gene that codes for the monomers of the elastic proteins the sproingshell has developed a unique protein “ratchet” known as “sproingase”. Sproingase has two stable states, a stretched state and a relaxed state. When physically stretched it reacts with free phosphate ions and locks into the relatively high energy stretched state. It will remain this form until it catalyses the phosphorylation of ADP, at which point it enters the relaxed state. In this way the sproingshell is able to convert mechanical energy into chemical energy which it can then use in its cellular processes.

They are found in near shore habitats, often just below the low tide line. They are most common in locations were the waves touch the sea floor as it allows them to more consistently harvest kinetic energy. Even there however this accounts for only a portion of their energy needs and they still must feed on plankton.

Like their ancestor they have two distinct methods of reproduction. In times of plenty reproduce asexualy while when stressed they instead reproduce sexually. Asexually produced eggs are slightly over twice the size of gametes and are well provisioned with nutrients. Both gametes and asexual eggs are ciliated, as are zygotes.