Sea Tube

Artwork

Weight:
460lbs

The **Sea Tube** (*Canalis digestus*) is an original species created and designed by TheAgent41. The Sea Tube inhabits the *The Hole* universe, an original universe created by TheAgent41.

## Appearance and Anatomy

The sea tube is a large sessile organism. Living motionless on the sea floor in reef-like environments, the sea tube's body is essentially a hollow tube measuring just over 20 feet in length and weighing nearly a quarter of a ton, composed primarily of soft spongey flesh. Its skin is a mottled tan in coloration, allowing it to blend in with the sandy ocean bottom when viewed from above.

Sea tubes have large openings on either end, creating a single unobstructed pathway all the way through the creature. The inner walls of the sea tube's body are dark brown and ribbed in texture. These inner walls are covered with hundreds of sensitive antennae the thickness of a blade of wheat; these antennae are each approximately half the width of the inner "tunnel".

Sea tubes lack any form of external genitalia. In addition, they lack any form of visible sensory organ aside from their digestive tract antennae. The nervous system of the sea tube is incredibly rudimentary, suggesting a very ancient ancestry. They have a basic nerve net that connects a central node analogous to a "brain" to each of its sensory antennae.

## Ecology

### Behavior and Intelligence

The sea tube's cerebral ganglion is incredibly simple, only capable of reacting reflexively to external stimuli. Unlike most other fauna native to Achlys, it has no thermal radiation-sensing organs, rendering it completely blind even when compared to other local wildlife. The sea tube does not need to sense its surroundings due to its hunting method.

The sea tube is a sessile ambush hunter. When not in the middle of digesting prey, the sea tube lies motionless with both of its orifices held open. If another organism swims inside the tube, it will inevitably touch at least one of the inner sensory antennae, triggering them. Within half a second of an antenna being triggered, both orifices leading to the tube's internal cavity will contract their muscles in such a way as to quickly snap shut, trapping the prey inside. Over the next few days (depending on the size of the prey), the inner walls of the sea tube's body will secrete digestive juices that will dissolve the prey into a nutritious fluid, which will then be absorbed by the inner walls. Waste is then excreted through the sea tube's epidermis.

### Diet

Sea tubes reflexively trap anything that triggers their sensory antennae and, thus, aren't picky eaters. The diameter of the interior cavity ranges from two to three feet, meaning anything capable of fitting into such a space is fair game. Common prey of the sea tube are marleyfish and kitefish due to their small size and abundant numbers, but it has been hypothesized that prey as large as an adult human could potentially be consumed by a sufficiently large sea tube.

### Reproduction

Like nearly all other Achlys lifeforms, sea tubes are hermaphrodites. Despite their simple nature, sea tubes reproduce exclusively through sexual reproduction, but their method is nevertheless incredibly bizarre. When they are ready to reproduce, sea tubes will excrete seminal fluid through their epidermis. This seminal fluid will then be carried by ocean currents to other parts of the reef, including into the inner cavities of other sea tubes. Sea tubes absorb the seminal fluid of other sea tubes through their inner walls and prepare for the next phase.

The next and most unusual phase of sea tube reproduction is referred to as "fracturing". When a sea tube has absorbed the seminal fluid of another and is thus "impregnated", a small section of its length (usually one foot or so) will begin to split from the rest in a process visually similar to cellular mitosis. The result of this process is a one-foot long "tire" of sea tube flesh and an adult sea tube now missing a foot of its length (which it will eventually regrow).

This strange "donut" of sea tube flesh will then begin to fracture again, initially producing small incomplete divisions evenly spaced along its circumference and eventually becoming a ring of still-conjoined baby sea tubes. Each sea tube will develop its respective openings and internal cavity and finally separate completely, resulting in a "litter" of between eight and ten tubelings. These lightweight babies will then be carried away by ocean currents to different parts of the reefs where they will settle in one spot and start the process anew.

## Trivia

* The scientific name *Canalis digestus* loosely translates from Latin as "digesting canal."

## Gallery

Artwork