Helmetstar

With the widespread presence of the vast mats of carpetesta and clingowhexia that grow around Wright, it was only inevitable for a species to evolve to consume it. With the only mobile consumers living around the continent being asterozoans, they ultimately would inherit the niche this new food source brought.

The helmetstar first evolved when some populations of shellstars were consistently flipped over. Some would adopt a quadrupedal stance and walk along the sea floor, consuming everything their baits came into contact with. Ultimately, their larger body and more active lifestyle increased the amount of food required to keep the organism alive. In order to take in more food, the helmetstar has developed a relatively simple digestive system. It begins with four mouths situated on the distal end of their tentacles. Each of these mouths consist of three muscular lips lined with calcium-carbonate teeth derived from their feeding baits. These mouths will contract their lips upon contact with a mat, ripping pieces out and dragging them into the digestive tract. The tract itself is a series of undifferentiated muscular tubes that converge at the center of the body. After the tubes unite at the base of the visceral mass, the converged tubes continue downward, culminating in an anus located at the bottom of the visceral mass. The tract itself consists of a villi-lined muscular tube that contracts much like an esophagus, pushing the mat chunks through the system and out the anus. Among the villi are cells dedicated to releasing enzymes, which digest the food travelling through the tube. Meanwhile, the villi absorb nutrients coming from the digested mat chunks.

With the advent of a more active lifestyle and digestive system, the helmetstar also had to develop a circulatory system and respiratory system capable of quickly transferring nutrients, gases, and wastes to and from the organs. This has resulted in the rapid evolution of a relatively simple closed circulatory system mostly clustered around the ventral side of the organism. The system is centered around a series of external gills situated on the proximal ends of the tentacles. These gills are derived from baits, which absorb oxygen and released carbon dioxide and other wastes instead of producing protein baits. The gills are arranged into a thick, roughly rectangular formation, with two major capillary systems running through them. One of these capillary systems has blood flowing to the tentacles, with the other having blood flowing into the visceral mass. The source of this directionality originates from eight small hearts, which pump blood into the gill capillaries and from there, the tentacles and visceral mass. These hearts are located on both sides of the gills, with the digestive tract and nerves passing above them.

The nervous system has advanced greatly, with the helmetstar developing five ganglia that are used to process and regulate information coming to and from the organs. The first four are located just above the mouths, and process information coming to and from the eyes, mouths, hearts, digestive tracts, and gills. The eyes have become simple closed-lens eyes capable of seeing images in color. However, this vision is still blurry, and barely suffices in aiding the helmetstar in detecting obstacles like wormreefs, wormstems, and rocks. The fifth ganglion is located in the center of the visceral mass just above the converging digestive tracts. It primarily processes information coming from the four other ganglia and aids in coordination. If a tentacle is cut off, the organism can continue to survive without it. In the event of such an amputation, special valves in the circulatory and digestive systems are closed, preventing the organism from hemorrhaging blood and food. However, the tentacle will not grow back, with the tentacle scar simply having tissue grown over it.

The shell has become thoroughly attached to the visceral mass, with it being held in place by an array of modified baits. These baits excrete calcium carbonate much like the tooth-baits. However, instead of producing teeth, they produce a shell. Because the visceral mass occupies the entire shell, the helmetstar can no longer retract itself into its shell.