Pontus – The Keyhole Fish Planet
Pontus, as its ancient Greek name implies, is an oceanic planet filled with fish (for want of a better word).
The planet is completely covered by oceans which are a bit more acidic than Earth, many places are shallow but deeper trenches and abysses do exist, much less explored. Its sun is slightly dimmer than that of Earth, rendering less evaporation, but the gravity is similar. Seafloors are coated liberally with growths of algae, much of it being fibrous slime and scum, but in areas of higher productivity, branching seaweed-like forms are quite common, some kinds are even calcified like the coralline seaweeds of earth. The oceans here are rich in oxygen, but the atmosphere is much poorer in oxygen than present-day Earth.
Fish-like Pontan animals have a fairly familiar biochemistry. So much so, that many are edible and even quite palatable. Rich earthlings in this day and age can try this for themselves in restaurants, as current aquaculture practises raise them fairly well. Most skeletal structures are cartilaginous like sharks, but the jaws are calcified and reinforced with iron. Indeed, the bizarre clamping mandibles of Pontan fishes are one of their hallmarks. Blood is based on haemoglobin to transport oxygen in much the same way Earth fishes do, and their muscles have many proteins in common even with ours.
Despite the similar biochemistry, the fishes of Pontus could not be physiologically more different than ours. Descended from a radically-symmetrical worm-like swimmer, the fore fins make 2 pairs around the “shoulders” of these creatures, though they may be differentiated into steering and propulsive roles. The tail is also composed of 4 flukes. Indeed, from a 4-sided tube-like ancestor, most Pontan fishes have convergently attained a body form roughly like those of Earth sharks, tuna or perch. Any familiarity is shattered immediately by the bizarre “keyhole jaws” of most forms, 2 lateral mandibles meet with the central array which is formed by the fusion of upper and lower central mouthparts. This jointed “keyhole” structure can be extended and contracted to trap, scrape, crush or impale.
The majority of marine invertebrates on Pontus are related to the basal stock from which keyhole-fish arose, looking like jawed worms with tentacles partway down the body. Some of these have undergone their own changes to resemble crawling octopi with stubby bodies. One unrelated invertebrate group are the flat creatures, armour plated, that almost resemble some kinds of sea urchin and starfish.
The first human colonists of Pontus were generally thrilled with this new oceanic wilderness, not the least because there was no shortage of food for them.
Pontus, as its ancient Greek name implies, is an oceanic planet filled with fish (for want of a better word).
The planet is completely covered by oceans which are a bit more acidic than Earth, many places are shallow but deeper trenches and abysses do exist, much less explored. Its sun is slightly dimmer than that of Earth, rendering less evaporation, but the gravity is similar. Seafloors are coated liberally with growths of algae, much of it being fibrous slime and scum, but in areas of higher productivity, branching seaweed-like forms are quite common, some kinds are even calcified like the coralline seaweeds of earth. The oceans here are rich in oxygen, but the atmosphere is much poorer in oxygen than present-day Earth.
Fish-like Pontan animals have a fairly familiar biochemistry. So much so, that many are edible and even quite palatable. Rich earthlings in this day and age can try this for themselves in restaurants, as current aquaculture practises raise them fairly well. Most skeletal structures are cartilaginous like sharks, but the jaws are calcified and reinforced with iron. Indeed, the bizarre clamping mandibles of Pontan fishes are one of their hallmarks. Blood is based on haemoglobin to transport oxygen in much the same way Earth fishes do, and their muscles have many proteins in common even with ours.
Despite the similar biochemistry, the fishes of Pontus could not be physiologically more different than ours. Descended from a radically-symmetrical worm-like swimmer, the fore fins make 2 pairs around the “shoulders” of these creatures, though they may be differentiated into steering and propulsive roles. The tail is also composed of 4 flukes. Indeed, from a 4-sided tube-like ancestor, most Pontan fishes have convergently attained a body form roughly like those of Earth sharks, tuna or perch. Any familiarity is shattered immediately by the bizarre “keyhole jaws” of most forms, 2 lateral mandibles meet with the central array which is formed by the fusion of upper and lower central mouthparts. This jointed “keyhole” structure can be extended and contracted to trap, scrape, crush or impale.
The majority of marine invertebrates on Pontus are related to the basal stock from which keyhole-fish arose, looking like jawed worms with tentacles partway down the body. Some of these have undergone their own changes to resemble crawling octopi with stubby bodies. One unrelated invertebrate group are the flat creatures, armour plated, that almost resemble some kinds of sea urchin and starfish.
The first human colonists of Pontus were generally thrilled with this new oceanic wilderness, not the least because there was no shortage of food for them.
Faunal Examples -
Doorwhale (Radiocetus gigas)
The warm equatorial waters of Pontus thrive with relatively large-scale phytoplankton and zooplankton, and the Doorwhale is the main harvester of this bounty. Sucking water past its sticky bristle-filled keyhole jaw, it then scrapes the trapped plankton into its central mouth with its comb-like mandibles. It swims mainly by rowing with its 4 enormous pectoral flippers. At 27 meters long, doorwhales are the largest Pontan animal, and one of the largest aliens discovered so far. Dead doorwhales provide a feast for aquatic scavengers, and sometimes even human colonists will butcher pieces if the corpse is still fresh, “whaling” is prohibited though.
The warm equatorial waters of Pontus thrive with relatively large-scale phytoplankton and zooplankton, and the Doorwhale is the main harvester of this bounty. Sucking water past its sticky bristle-filled keyhole jaw, it then scrapes the trapped plankton into its central mouth with its comb-like mandibles. It swims mainly by rowing with its 4 enormous pectoral flippers. At 27 meters long, doorwhales are the largest Pontan animal, and one of the largest aliens discovered so far. Dead doorwhales provide a feast for aquatic scavengers, and sometimes even human colonists will butcher pieces if the corpse is still fresh, “whaling” is prohibited though.
Keyhole Tuna (Thunnoserram edibilis)
The 1 meter long keyhole tuna forms the staple of the diet of many Pontan predators, including human colonists. This small predator is fished and farmed sustainably to support the culinary demands of colonists and rich earthlings alike. Its diet consists mainly of large invertebrates and smaller keyhole-fish, when fishing, beware of their nasty bite.
The 1 meter long keyhole tuna forms the staple of the diet of many Pontan predators, including human colonists. This small predator is fished and farmed sustainably to support the culinary demands of colonists and rich earthlings alike. Its diet consists mainly of large invertebrates and smaller keyhole-fish, when fishing, beware of their nasty bite.
Door Dugong (Thyratherium tardus)
The Door Dugong is a 5 meter long inhabitant of the shallow seaweed meadows of the tropics. Its feeding method is unusual; mostly lying on its side, scraping food with its rasping mandibles and keyhole jaws, but sometimes it will just passively crop abundant growth inward, while swimming the right way up. Relatively vulnerable looking, at the first sign of a predator they will release a cloud of foul-tasting liquid from their anus, which is mainly comprised of digestive juices and bile.
The Door Dugong is a 5 meter long inhabitant of the shallow seaweed meadows of the tropics. Its feeding method is unusual; mostly lying on its side, scraping food with its rasping mandibles and keyhole jaws, but sometimes it will just passively crop abundant growth inward, while swimming the right way up. Relatively vulnerable looking, at the first sign of a predator they will release a cloud of foul-tasting liquid from their anus, which is mainly comprised of digestive juices and bile.
Crawler (Ichthyocaris primitivus)
Crawlers vary from 40 to 100 centimetres depending on the abundance of resources in the immediate area. These creatures are descended from the more primitive, multi-jawed ancestors of the keyhole-fish, thus they have an array of 4 jaws. It appears that through some embryological quirk, the ancestral keyhole-fish fused 2 of its jaws into the jointed structure that is so typical of the group. Crawlers only partly elucidate this condition, as they themselves are heavily modified too. The body is turned on its side, giving it a vaguely tetrapod-like shape, and the forelimbs are formidable scrabbling claws. Being scavenging omnivores, they are usually the first large animal to arrive at a sunken corpse.
Crawlers vary from 40 to 100 centimetres depending on the abundance of resources in the immediate area. These creatures are descended from the more primitive, multi-jawed ancestors of the keyhole-fish, thus they have an array of 4 jaws. It appears that through some embryological quirk, the ancestral keyhole-fish fused 2 of its jaws into the jointed structure that is so typical of the group. Crawlers only partly elucidate this condition, as they themselves are heavily modified too. The body is turned on its side, giving it a vaguely tetrapod-like shape, and the forelimbs are formidable scrabbling claws. Being scavenging omnivores, they are usually the first large animal to arrive at a sunken corpse.
Dire Keyhole Shark (Mandibulolamna diabolus)
Keyhole sharks are the apex predators of Pontan seas, and surely the bane of many human explorers. Lateral mandibles are large and hooked, for snagging prey and forcing it into the wickedly toothed keyhole-jaw, where they prey is disembowelled and eaten. The 6 meter long Dire Keyhole Shark is found mainly in southern waters, and feeds mainly large keyhole-fish and some of the smaller relatives of the doorwhale.
Keyhole sharks are the apex predators of Pontan seas, and surely the bane of many human explorers. Lateral mandibles are large and hooked, for snagging prey and forcing it into the wickedly toothed keyhole-jaw, where they prey is disembowelled and eaten. The 6 meter long Dire Keyhole Shark is found mainly in southern waters, and feeds mainly large keyhole-fish and some of the smaller relatives of the doorwhale.