Rootfish

It is not what it eats

The canopy of the Kava swamp, a wall of reddish-orange leaves, captures most all the light that falls on it. The aquatic ecosystem must adapt. A few plankton-like species feed off the meager light that the plants above fail to capture. However, they do not grow abundantly enough to serve as a food source. The rootfish adapts to this low-food environment by gnawing at fallen logs and exposed roots.

— Zhang et. al, Report of the Rootfish

The rootfish is an eyeless fish living in the depths of the swamp under the Kava forest. The fish gnaws at exposed roots and fallen wood for sustenance, being one of only a few major species known to practice xylophagy. They are one of the major fish species in the Salt Plains.

Basic Information

Anatomy

The first fish removed by the researchers from the water was immediately field-examined. The Outrider Drones were immediately astonished when the head of the thrashing fish was held up to the light. The eyes of the fish were missing, causing a shout from one of the researchers, who immediately dropped the fish back into the water. Extended observation showed that the fish was an obligate xylophage. This can be explained by their low-light, low-food habitat.

— Grand Taxonomist Zhang

The fish is vertebrate, and in many other ways is similar to fish on Earth. However, its environment dictates that it develop differently. Due to the low-light environment, several studies theorize the fish originally had ocular organs, but those regressed due to the low light deep down in the swamp.
The fish also notably has massive jaws. With its four jaws and numerous molars, the toothy rootfish is perfectly adapted to gnaw away at logs. It has been calculated that the head of the fish accounts for fifty percent of the fish's total volume.

Genetics and Reproduction

The rootfish lays eggs in the bottom of the swamp. The eggs will hatch into fry after approximately five to ten days. The fry seem to be as adept, if not more so, as the adults at hearing and sound, and are able to forage on plankton and other smaller pieces of wood before fully developing their jaws by one month old.

Ecology and Habitats

The rootfish is endemic to the Salt Plains, living in the Kalan River and the swampland near it. In this area, they thrive, being the first fish species to be noticed and analysed by drones scouting the area. The species also has a healthy population in other marshes and swamps east of the Salt Range.
Somehow, the fish manage to even feed on the Kava plant, a species with a tensile strength greater than steel. The fish appear to achieve this feat with legendary persistence and tenacity: some have been observed patiently gnawing away at a piece of kava wood for over two days. The fish has since become a cultural icon, representing stubbornness and tenacity.

Dietary Needs and Habits

Wood! This fish eats only fallen wood for its entire life, and has adapted to digest this material. If we put it into a place with ample wildlife, but no wood, it will starve.

— Analyst Drone, archived recording

The fish, perfectly adapted to an unused food source with its large jaw and strong teeth, solely subsists on fallen logs, on which other fishes have not adapted to eat. The rootfish, therefore, has a unique niche in the ecosystem of the Salt Plains, with a stable source of food. However, it does compete with fungi, which also decompose the same fallen logs.

Additional Information

Geographic Origin and Distribution

The fish is concentrated in and around the Salt Plains-Salt Range region. It is endemic to the marshes within the Salt Plains, and has spread past that into the Range. A closely related species inhabits forest lakes and rivers, feeding on fallen driftwood and leaves.

Perception and Sensory Capabilities

Rootfish Hearing by ElementalShrike

The fish lack ocular organs, as eyes are of little use in the deep swamp. However, to compensate for this deficit, rootfish have a very good sense of smell and sound. Their sense of smell is great, with approximately twenty million olfactory receptors, compared to six million in humans. They can sense smells approximately three times better than humans.
However, where the rootfish truly shines is its sense of hearing. With a slightly greater hearing range than a cat, the rootfish has been shown to hear sounds as low as -10 decibels along its entire hearing range. They use this unique talent, as well as their smell, to detect locations where fallen logs reside, using low-frequency echolocation uniquely adapted to underwater usage.

Scientific Name

Lignumorda necoculus

Origin/Ancestry

Zentland Kava Forest, Clara

Lifespan

8-10 years

Conservation Status

Least Concern

Average Weight

15 - 21 kilograms

Average Length

1.3 - 1.6 meters

Related:

Food source:

Endemic to: