Firemouth - Neocene Project

Firemouth (Abyssodon flammeostomus)
Order Tobies (Tetraodontiformes)
Family Abyssal tobies (Abyssodontidae)
Habitat: Pacific Ocean, depths about 2000 meters.
The majority of biotopes of Earth directly or indirectly receives energy of the sun. Only at the bottom of ocean near to underwater volcanos there are complexes of the live organisms existing due to geothermal processes. But they look exception in the biosphere dependent on the sun. Even in places where the sunlight is not present, live creatures depend on it. One of such ecosystems is developed in ocean depths. Sea water quickly detains sunlight, and photosynthesizing organisms are not found in depths of ocean. But inhabitants of depths completely depend on efficiency of top layers of water – they eat falling from above dead organisms and their own neighbours making vertical migrations. Therefore in time of “plankton accident” the mass extinction of deepwater fauna happened. After disappearance of typical deepwater forms new species, descendants of coastal species had started to occupy their place in ecosystems of Neocene.
Pufferfishes, or tobies (Tetraodon), very adaptive predators, were among settlers in depths. Obviously, they had settled in depths of ocean from continental slopes, then “took off” a bottom and pased to pelagic life (possible, ancestors of deep-water anglerfishes Lophiiformes had done the same way before them). One descendant of deep-water tobies had turned to specialized predator of thickness of water. The fish had got characteristic features of deepwater inhabitants: its bones became soft, and around of mouth organs of luminescence had appeared. For this feature the fish has received the name “firemouth”.
The length of this fish does not exceed 20 cm – as a rule, deep-water fishes do not reach the large size. Body of firemouth is soft, and its consistence is tender. It is rounded and also seems “bloated”: when the fish is swimming, the skin slightly waves. In skeleton bones are substantially replaced with cartilage – it is the typical feature of deepwater fishes. Eyes are very small, and sight of firemouth is bad. But lack of sight is compensated by very much advanced sense of smell. The sensitive area of olfactory holes is stretched to internal surface of big skinny outgrowths surrounding nostrils. They are very movable, and also work as “ears”, helping to the fish to orient itself in darkness of depths. Skin of fish is elastic and easily extensible. It is grayish – pink and seems chemically decoloured. Through skin of firemouth internal organs and large blood vessels are visible. The skin of tobies living in shallow waters is covered with a plenty of corneous spikes, which rise when fish is inflated with water or air. On the body of firemouth some corneous plates with sharp spikes in the centre had remained from this adaptation.
All deepwater fishes are predators or scavengers – herbivorous species among them are not present. At firemouth jaws are large, surrounded with a ring of small organs of bioluminescence. Instead of teeth at firemouth sharp plates grow as at all representatives of the order: it is the firmest part of fish body. With the help of luminous organs firemouth beckons fishes and invertebrates right to the mouth. This predator kills catch by characteristic bite in head and swallows entirely due to very extensible stomach.
The basic organs of movement of firemouth are back and anal fins – fish swims with the help of their waves. At these fins there are mobile muscled bases, and vertebrae in places of muscle attachment have big vertical outgrowths. Tail fin is considerably reduced, continuing the tendency common for representatives of the order. Pectoral fins of fish are shifted upwards and help to turn on the spot. Pushes of water through branchial apertures help this fish to move forward.
At deep-water fishes males, as a rule, are much smaller, than females are, and some species even became hermaphrodites. At firemouths “equality of gnders” is kept: it is connected with the distribution of roles of fishes in the spawning. Spawning at firemouths occurs in pair, and some features of breeding inherited from coastal ancestors were kept. The majority of pelagic fishes differs in great fertility – they produce huge amount of tiny eggs, and do not care any more of posterity. At firemouths the female lays only some hundreds of rather large eggs (their diameter is up to 3 mm). Fishes find each other by smell and flashes of light. Photophores of the female ready to spawning emit blue light seen from apart. Male finds female and begins courtship dance, touching to the female by fins and slightly biting her tail. The female pastes eggs on stomach of the male, and simultaneously he fertilizes it. At the culmination moment of courtship games when the female starts to spawn eggs, male emits cloud of soft roe, and pair of fishes “spins” in it. At this moment the fertilisation happens. Fertilized eggs are pasted to skin of the male and dead grains of roe peel off later. The male only carries eggs on itself, but does not look after posterity. Hatching fry at once leaves it, and begins independent life.