Team Pasta Vēlōcis
Vote: The digestive canal lengthens with a new, straight, section of the canal appearing between the mouth and the old part of the canal, while at the same time the entire canal becomes encased in muscle. The new section of the canal stretches about half the length of the animal, with the animal increasing in length to compensate. Unlike the old part, the new part of the canal is lined with simple connective tissue instead of digestive tissue. The new part of the canal is divided into to parts. The rear part simply serves to move mucus and food to the old part of the canal for digestion. The forward part is separated from the rear part by a pair of slits (called pharyngeal slits), one on either side of the animal, just behind the external gills. Another pair of pharyngeal slits also exists just in front of the external gills. Also, (if they are not already like this) the gills are separated into two bands, one on either side of the body, by thin strips on the top and bottom of the animal. Additionally, the animal has a new organ, a semi-stiff rod-like structure (called the endostyle) that produces mucus and is covered in cilia and contained within the front portion of the canal with a short bridge of tissue connecting it to the bottom of the canal in the part of the canal where the new slits are. This connection is near the rear of the organ. Operation is as follows: 1) The animal uses the muscles surrounding the front most section of the canal (called the pharynx) to continuously suck water in through the mouth and expel it through the pharyngeal slits in front of and in back of the gills. 2) As the water passes over the central endostyle, food particle in the water are trapped in the mucus which the cilia then transports to the middle portion of the canal. 3) The middle portion of the canal (called the esophagus -the animal has no true stomach- ) simply serves to transport the mucus and food particles to the old part of the canal via peristaltic action. 4) The old part of the canal (called the intestine) serves to digest the food particles as the mucus is transported through it by peristaltic action, with any undigested matter being excreted through the anus.
SS Vote proposal: A stiffened rod of cartilage-like material (called the notochord) grows between the nerve chord and the digestive tract. This rod reaches most of the length of the animal’s body and serves to guide the development of both the nerve chord and the digestive tract during the larval stage. The notochord persists into the adult stage of life, somewhat stiffening the animals body.
Edit: Reworded the main vote to make things more clear.
Edit2: Changed SS vote proposal to make things more clear, include something that had been omitted, and fix a grammar mistake...
Edit3: looks like We’re going to need more pharyngeal slits, but each new pair of slits requires new gills (we’re already asking a lot here) so I’ll wait and do that in a different turn...
Edit4: It looks like we had the cart before the horse with the gills and pharyngeal slits. We should’ve evolved the pharyngeal slits first and then the gills. Oh well!
Edit5: It also appears that our dorsal nerve chord should have been hollow. Can we retroactively assume it’s like that, or do we need another mutation?
Edit6: After reading, it appears that we need some sort of coelom before we can start coiling our intestines. Vote has been updated to reflect this. Will do a eucoelom in the future...
Edit7: Made a small change concerning the gills and pharyngeal slits and how they work. The animal now has four pharyngeal slits. Two are on each side. Two are before the gills. And two are after the gills. This change should make it easier to increase the number of gills in the pharynx.
Edit8: Minor change to the gills in preparation for gill expansion in a future turn. The change is minor enough (and the previous turn that added the gills is worded loosely enough) that it could, probably, be considered to have already been present in the animal...