Cutthroat Reef Rhino

Rhinocerocephalus xerobii is a medium-sized Gladiopinninid Rotunducephalid Amphibian from the Leviathan Island's reefs.
Known around the islands as the "Bijaranha", the amphibian is found living from the inner reefs to the reef crest, most commonly in the latter, where it feeds on small invertebrates and amphibians.
R. xerobii lives in schools ranging from three to seventy specimens, the latter of which only when migrating from reef to reef after the mating season has ended and they return from the warmer shores of New Japan in Early Spring.
The animal's strange horn is used to crush prey against the hard reef surface, or otherwise charge at prey and hit it with the specialized cranial structure, breaking bone with the impact or at least stunning them.
Although not very popular outside of its native seas, the animal's meat is considered exquisite by the locals, who fillet it and cook it on the stove with some local plants in a delicate broth with which they create a dense sauce used in many recipes; R. xerobii can also be cooked in a pan with herbs or oven-baked in rattle sauce.
Of moderate interest for some private collectors as an aquarium fish, its schooling nature makes for some beautiful tank environments.

Basic Information

Anatomy

• Head long with a thin snout, a hard corneal structure jets from the top of the Fronto-Temporal plate of the cranial armour.

• Seam between the Fronto-Temporal and Maxillo-MAssenteric Plate almost disappeared; armor Fused.

• Two smaller hornlets grow from the dorso-caudal end of the Maxillo-Massenteric plate, one each side.

• Teeth very apparent and long, conical in shape, rooted directly in the cranial armour.

• Dorsal I very tall and subtriangular, Dorsal II long and veiled, growing from the base to the end of the Gill Tail.

• Anal I moved frontally to the same height of the Pectoral fin; Anal II reduced in size, growing along the Gill Tail.

• Anal III long and veiled, similar to Dorsal II but growing from the Mid-point of the tail.

• Gill Tail ends in a moderately low Gill Fan with a soft caudal drop.

Genetics and Reproduction

Seasonally monogamous species.
R. xerobii mates in Mid-winter but starts migrating in autumn for the breeding grounds along the southwestern shores of the Union.
The population migrates in large schools, usually composed by the members inhabiting a single reef, the migration takes several weeks, in which they are exposed to predators they have few ways of protecting against.
Arrived at the breeding grounds, the males display the breeding patternings, which are brighter and flashy; attracting a partner is no easy task as appearances are only the first step.
Once a potential partner is lured in by the colourful body, it has to be convinced with intricate courtship dances and acrobatics, including vertical loops, barrel rolls and somersaults; the female will often mirror the male during these dances.
Once the female is convinced and fertilized, the couple will keep together, going to feed for the first time in almost a month.
An average female will incubate the eggs inside the duct for five days before laying between six and ten eggs.
The eggs hatch twelve days after deposition.
The animal will winter in the warmer waters of New Japan until the last weeks of winter, where they'll start the migration back, this time with the young.

Growth Rate & Stages

Ontogeny in the species visible.
Young specimens are born without a horn, feeding off of small soft bodied organisms at first, Dorsal II and Anal III are much bigger compared to body during this stage.
Loss of natal aculeus two weeks after birth.

Ecology and Habitats

Epipelagic animal found at depths ranging from 3 to 70 m in the neritic zone of the inner and crest reefs.
Likes warm waters with plenty of light and vertical surfaces.

Dietary Needs and Habits

Predatorial animal hunting smaller animals including amphibians and invertebrates; it crushes them with the horn against rocks or impacts them at high speed.

Biological Cycle

Migratory animal with few dips in activity year long.

Additional Information

Social Structure

moderately social animal living in small schools of three to five animals outside of the mating season.
During the mating season they'll create large schools of several dozen specimens, migrating north-east; during this time they're more social and have increased interactions between group members.
In captivity they are more tolerant with one another than in nature, being able to create bigger groups even outside of mating season.

Domestication

Found mostly in public aquarium, the species nonetheless has value for collectors; most specimens on the market are wild captured, only a few breeders exist.
Recommanded only for moderate to experienced owners due to its tendency to sprint against the glass and the various special needs like accepting only live food.

Uses, Products & Exploitation

Of moderate imnportance in the pet trade for collectors.
Of value in the local economies of the Leviathan Islands as a rich food source.
Sportfishing of the species is also of local importance, especially in New Japan during mating season, when females are heavier and males more colourful.

Geographic Origin and Distribution

Leviathan Island reefs from spring to autumn, West coast of the Union & New Japan from mid autumn to late winter; Nuwadi Ocean.

Perception and Sensory Capabilities

Very good eyesight and chemolocation.

Symbiotic and Parasitic organisms

Afflicted by Intestinal Tube Worms and False tooth parasites.

Scientific Name

Eoichthyia; Tartarosomnia; Rotunducephalidae; Gladiopinneoidea ; Rhinocerocephalus; R. xerobii

Lifespan

25 Years

Conservation Status

Least concern: no measures underway to protect the species.
Population Trend: STABLE

Average Weight

10-100 kg

Average Length

1.3 m (male) , 1.5 m (female)

Body Tint, Colouring and Marking

First half of the bogy algae green, Tail and Fan sandy to brownish in colour.
azure to light blue band on the snout, light blue to deep blue horn.
Purple stripe over and around the eye, blending to a lighter purple on the sides.
Throat red; dorsal section of the body up to the base of the Dorsal I fin, striped in yellow-lime.
Dorsal I & II, Anal I and Pectoral fins blend to an azure colouration towards the tip.
Anal II & III Sandy coloured with darker edges.
Darker bands coming down the body from the base of the tail.
A single file of small grey to brown dots goes down the body.