Atopopinna velis

A. velis is one of the many medium sized inhabitants of the Nuwadi ocean’s depths.
The genus name ("anomalous fin") is due to the strange morphology of the last pair of anal fins (Anal II), which are moved upward in an "unnatural" position. The Pectoral fins are moved downward near the thorax.
A. velis’ head is rounded and long, with powerful jaws and a shallow premaxillary gap; the teeth of the frontal, premaxillary and maxillary plates vary in shape and size making this animal a perfect example of a Heterodontous amphibian, although remaining in the same size ratio to mouth right to the masseter.
Although normally a pretty docile animal, A. velis can become aggressive towards humans if threatened or if the “aggressor” gets too close to its offspring, which the amphibian protects with its life.
A. velis bite can easily tear through a regular Pressure Compensating Personal Unit or PCPU (depth diving suit), exposing the diver's body to the extreme pressures of the depth the amphibian inhabits.
In 2378 A. velis entered the TWPP’s red list of critically endangered species after a disastrous accident that dumped over ten million cubic tonnes of polluting waste into the amphibian’s territory.
A. velis has since recovered and is now considered as vulnerable.

Basic Information

Anatomy

• Head rounded with not so noticeable maxillary gap; Dentature size constant to the masseter.

• Dorsal armor reduced and dispersed, mostly absorbed.

• Pectoral fin ventrally arranged and oblungated.

• Anal II dorsally arranged and dorso-laterally rotated.

• Dorsal fin rectangular and extending dorso-caudally.

• Gill Tail long and slim with low Gill fan ridges.

• Spinal cord I, II and III evident.

Genetics and Reproduction

Seasonal monogamy; males and females each have one mate during the whole mating season.
Both male and female go in heat at the same time, signalling their position to the opposite sex with biochemical trails released by a set of specialized glans under Anal II; the movement of the Anal II fins is used to better disperse said chemical into the water. Once a male and female meet, they engage in long and elaborate underwater displays of good parenting, where both possible mates treat the partner like they would an offspring, bringing it food and offering protection.
If this courtship succeeds, then the two will mate. The mating process takes around five to ten minutes, where the male uses its prehensile parapenis to manually fertilize the egg chambers of the female.
The female doesn't lay eggs in a nest, she instead brings them with her attached to a mucous substrate to the top of her head. The eggs take around a month to hatch, during this period the couple remains close.
Once hatched, the spawns (from five to ten) will istinctively find shelter under the Anal II fins of both parents, where they'll stay until they are big enough to brave the ocean near the parents before weaning. Once the youngs have matured the couple will separate.
During this period an Atopopinna velis can be extremely aggressive with scuba divers and other animals approaching the couple.

Growth Rate & Stages

A newborn Atopopinna velis is approximately three to five cm long and retains the natal aculeus to sub adulthood. They will pass the first two to three weeks of life under the parent's Anal II fin, coming out only to eat. They will progressively move farther and farther away from the parent's fin when growing, until they detatch themselves completely from it and start to free swim in the immediate vicinity of the parents. The loss of the natal aculeus takes place at around the third month of life. An average specimen will reach sexual maturity at five months of age and will wean at four months.
Ontogenesis visible in the Dorsal armor, much thicker and developed in young specimens.

Ecology and Habitats

Atopopinna velis inhabits the Bathypelagic zone of the Nuwadi Ocean (1,000 to 4,000 m deep), finding shelter in the darkness both for protection and as camouflage for ambush hunting.

Dietary Needs and Habits

Atopopinna velis is an ambush predator.
It waits in the dark for any movement in the water, often staying still pointing upwards to better spot prey.
With a specialized bite they can hold a firm grip on any surface while the Sphaera Lania minces up whatever touches its surface.
Their bite is renowned for its ability to penetrate even the sturdiest of depth diving suits, making this animal a possible threat to the uninformed observer.

Biological Cycle

An average Atopopinna velis will reach sexual fertility at five months of age and retain it till sexual sterility, which comes at around age 10. Elderly specimens become progressively more bold and take many more risks than usual to the point of getting killed; This behavior is thought to be a consequence of the sterility, making them more prone to risky actions to help younger members that are still sexually active.
Elderly specimens have been observed fending off natural predators from younger couples or outright sacrificing themselves to save a younger and still fertile specimen.

Additional Information

Social Structure

Adult specimens are seasonally gregarious, moving around in couples during the mating season.
Elderly specimens follow younger ones to protect them from threats.

Uses, Products & Exploitation

Once consumed by Humans as a stable food source, the deep fishing for this particular species is now prohibited by international law.

Geographic Origin and Distribution

Nuwadi and Irobian Ocean.

Perception and Sensory Capabilities

The species has an excellent eyesight.

Symbiotic and Parasitic organisms

They live in symbiosis with some invertebrate microfauna that lives in the gaps within the teeth and keeps them clean.
Can be affected by some species of Intestinal Tube Worms .

Scientific Name

Eoichthyia; tartarosomnia; Rotunducephalidae; Paragladioidea; Barbocephaloarmatidae ; Atopopinna; A. velis

Lifespan

12 years

Conservation Status

VULNERABLE: Once considered Critically endangered, now the species has recovered; programs on the protection of the species still ongoing, although much less strict laws are present.
Population trend: RECOVERING

Average Weight

1.2 to 7 Kg

Average Length

60 cm

Body Tint, Colouring and Marking

The body is grey with a brown-reddish tint in the armor. No particular markings present.