Fang Keryh

Adult fang keryhs live closely together, forming "fields" that can be a meter long. Like Earth plants, they are rooted in the soil and absorb minerals using their roots. Unlike Earth plants, they acquire energy through sulfur, not sunlight, and must inject passing fauna with their eggs to reproduce. They inject their microscopic eggs the same way a viper injects venom. Muscles around the venom gland (in vipers) or the reproductive organ (in fang keryhs) squeeze venom/fang keryh eggs in a carrier fluid, causing the venom/carrier fluid to be ejected from a hole in the tip of the fang into a wound. The carrier fluid of a fang keryh contains papain, a chemical that works as a meat tenderizer. The papain dissolves surrounding skin cells, allowing the eggs to pass into the blood if the sole-piercing wasn't enough by itself. (The eggs have enzyme inhibitors on their surfaces, and the papain concentration in the carrier fluid is low.)

If all goes well for the fang keryh eggs, they travel through an artery and to the submucosa layer of the small intestine. They implant in the submucosa and grow two prongs to anchor them, as well as four tentacles to absorb nutrients. The tentacles absorb nutrients directly through the skin, as their digestive system is just a pit between their tentacles at this point. (Interestingly, the digestive system doesn't develop any further when it becomes an adult.) Unlike their ancestor, which feeds on the digested slurry (chyme) of the host, the fang keryh larvae feed on blood and lymph from surrounding vessels.

In about nine days the fang keryh larvae detach from the submucosa and travel to the excretory system through a blood vessel. The 2 mm-long larvae are eventually excreted through the skin. (Plents excrete waste through their skin in a sweat-like manner.) The larvae "pop out" on the lower legs of the cragagon and fall to the ground. There, the larvae orient themselves upside-down, with their four tentacles anchoring themselves in the soil. The fang keryh adults are free-living, lack prongs, and extract sulfur from the soil. In warm, rainy months, they release male and female gametes from their tentacles. Each individual releases only one kind of gamete at a time, and alternates which kind it releases each day. Neighboring fang keryhs take the gametes into their bodies with their tentacles, regardless of present "gender". If an individual is "female" on one day and takes in female gametes, the next day it fertilizes the stored egg cells internally. The "free-floating" gametes can be fertilized outside the bodies of fang keryhs, but if they aren't picked up by an adult's tentacles and injected into a cragagon, they have very little chance of completing their life cycle.

The adults are able to live in any part of Vivus with moist volcanic soil, but can only reproduce in habitats that have cragagons.