Rubik's Shrube

The shrewv has developed to be a semi colonial organism: Rubik's Shrube. Each individual Shrube is a single cell, 2 cm in length, with an aragonite shell. This shell is far more geometric than its ancestor, taking on a cube shape. This developed in tandem with their colonial nature and allows them to pack together more efficiently than if they had spheroid shells. The shell's coloration is a result of the accretion process partitioning specific impurities found in the substrate into alike sections of the shell. Young Shrube are thus predominantly a muted brown or grey due to the homogeneous state of the shell. As they grow the shell will obtain more distinct coloration as minute differences in each faces composition are amplified.

A Rubik's Shrube is the colonial stage of Shrube, composed of up to 27 individual Shrubes. Each Shrube will transition into a specific role based on its position in the colony. Fully internal members will produce offspring and store energy for leaner times. The members on the bottom of the colony are in charge of transportation, using their foot pseudopods to move the entire colony. They average only a few centimeters per minute, but it is sufficient enough to move the colony into the best feeding locations.

All members which have a face of their shell open to the water are responsible for food gathering. Each Shrube has many pits in its shell through which pseudopods can be extended. 6 pits on the dorsal face, 4 on each lateral face, and 4 on the ventral face. Filter feeding pseudopods are sent out from these pits to gather food.

On any face which is connected with another face, the Shrubes will extend pseudopods along that face to hold onto one another, making the colony structurally stable. This connection allows for the transfer of nutrients and nuclei. This ensures that the entire colony is fed and contributes to reproduction. Individual Shrube can leave the colony and operate on their own, but they are far less successful without the colony and cannot reproduce.

Reproduction is similar to its ancestor, with nucleus-sharing being the method of genetic mixing and budding being the creation method for a new individual. Dispersal of offspring now can take two forms. A new Shrube cell can be buried in the substrate to begin building its shell right away. This method is used where the substrate is rich in minerals for shell building and the offspring are deposited a few cm into the substrate by the internal ventral member of the colony. The other method involves sending the offspring off into the water column and hoping it settles in a good spot to bury itself and begin shell building. This dispersal is undertaken by the central dorsal Shrube. The offspring produced this way take on the form of a cyst so as to stand a better chance of surviving its time drifting until it settles on the seabed. These cysts are viable for months and are large enough to not be eaten by the Rubik's Shrube colony.

When a Shrube in the colony is injured, such as the shell being broken by a predator, the affected cell will let out chemicals into the water which will attract other Shrube so that they may take its place while it leaves the colony and buries itself to regrow its shell.

Rubik's Shrube are thus seen in congregations of colonies with individuals often moving between them to try and find a place in a colony, or founding their own with the other individuals.