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Banded Shrewv (Birnesshevia apitesta)

Creator: Kopout
Ancestor: Shrewv, Urchin Shrewv
Habitat: Anning Reef, Southwest Orpington Reef, Talon Reef, Talon-Orpington Tropical Undersea Meadow, East Dixon Subtropical Undersea Meadow, East Orpington Subtropical Undersea Meadow
Size: 3 cm tall
Support: External (Mineral Test)
Diet: Scavenger, Filter-Feeder (<50 micrometers)
Respiration: Passive
Thermoregulation: Ectotherm
Reproduction: Budding, Genetic Fusion


The banded shrewv is the result of hybridization between the shrewv and urchin shrewv. It has split from its ancestors. One of the banded shrewv’s most striking features is its banded shell. The darker bands have small needle like growths comprised of modified pseudopods with a sheath of mineralized shell while the lighter bands host rows of feeding pseudopods which collect plankton from the water column. A collection of feeding pseudopods emerges from the bottom of the shell and can sweep across the substrate to collect microbes and detritus. These lower feeding pseudopods can also probe the sediment in search of food.

The darker color of the dark bands is caused by the presence of a layered manganese oxide mineral called birnessite. Birnessite is photoelectric, generating an electric charge in the presence of sunlight. This charge results in the hydrolysis of water surrounding the shell. The outer layer of the shell is covered in a waxy coating which prevents the outer surface of the birnessite from coming into contact with the water. This coating also acts as an electrical insulator. If something damages the coating it risks receiving a nasty shock. The banded shrewv has developed small pockets on the inside of its shell where the cell membrane is separated from the shell by a water filled pocket. These pockets are not permanent and may form and collapse as needed. Oxygen released into these pockets can then be trapped and used by the shrewv, increasing its available oxygen supply.

Shell maintenance is important for the banded shrewv’s survival, and it can exude portions of itself through the holes its pseudopods emerge from in order to flow over the surface of the shell and repair defects as well as apply the waxy outer coating. They are more vulnerable while doing this however and will take shelter before attempting it if possible.

Like their ancestors they reproduce by budding from their foot pseudopods. Newly budded shrewvs lack a test and remain embedded in the sediment. They are not imobile at this stage and when they exhaust locally available food sources and minerals to build their shells with they are able to slither through the substrate like an ameba. When two banded shrewvs meet they will often merge a small portion of their foot pseudopods and exchange a small number of nuclei. After this the nuclei within each shrewv will undergo a process of merging and splitting that results in their genomes averaging out. As a result, after mating the two are effectively siblings.

This post has been edited by kopout: May 24 2023, 09:58 AM

“Mineral test” in the support should be capitalized.
“Acrost” “across”.
It seems hard to imagine slightly infiltrating something. “Poke through” or “probe” makes more sense.
How would oxygen be “released” into these pockets?
“They are more vulnerable when doing this[…]” This sentence needs a comma after “this” and “however”.
The “if possible” suggests it’s capable of conditional thinking, which seems like a lot for a very large multinucleated single cell. It may be easier for it to have automated behavioral protocol for repairing itself each night in some kind of crevice. Being averse to some kind of light or frequency of light more common at night is one way it can be compelled to stay in shelter for a while, if it happens to mindlessly wander into a shelter.
“The exhaust” They exhaust? The sentence after this point could use some clarification.

I think this is a good species, although I'm a bit confused by one sentence.

"Newly budded shrewvs lack a test..."

This feels a bit long and worded weirdly, and I had to read it a few times to understand. The part about it moving particularly confused me.

Is that better?

There's a second M in immobile

And amoeba is mispelled

Other than that I think it's good