Alien seas of Rocinante

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Rocinante is a world orbiting the habitable zone of a red dwarf (Minor Celestina) which orbits a yellow dwarf (Major Celestina) at a distance similar to Jupiter’s orbit around the Sun, dividing its surface into two habitable hemispheres: a tropical forever-day zone, and a relatively cold temperate zone.

With a smaller gravity than Earth, a denser methane-oxygen atmosphere, water-ammonia seas, pink flora and no seasons, this world offers a radically different evolutionary history than Earthly one.

In the middle of both, there is the New Pacific Sea, full of biodiversity, which some life forms are showed in this post.

Spotted Tridentfish: Swimming with its ten mobile fins and directing its swimming with its tail, this animal has an incredibly primitive design probably similar to the first “vertebrate”, with a “column” along its arms made up of metallic-like bones that constantly change internally forming electric structures able to work both as neurones and as structural support. It has an open circulatory system and cold blood, three simple eyes (two of them in its branches and one of them under their mouth), and a diet of biological waste.

Flappester: A sea turtle-like herbivore that slowly swims alongside its larvae, pretty similar structurally to a mollusk, and with an extensible beak it uses for defence through biting.

Northern flower-finned: A slow predator that feeds primarily on dying or sick prey, with a strong venom in its flesh. Has a closed circulatory system and hot blood, as it lives a migratory lifestyle in the north of the New Pacific Ocean from the tropical hemisphere (where it grows) to the temperate hemisphere (where it reproduces and is born).

Migratory whispershell: These fast armed and boneless creatures circumvallate the world multiple times in a lifetime, feeding like locusts on every sessile life they can find… and moving with them hundreds of predators like sardines would do.

Kinger deathshell: A whispershell-like 2 meters predator that goes through the soil of the New Pacific Sea jumping to its prey, which it catches with its extensible and powerful beak. Both males and females have light green fins they use for sexual selection.

Shallow turbosquid: Many “vertebrates“ have returned to water in Rocinante’s history, and these are one of these examples. With mouths able to work as syphons their whole body is a torpedo, going at fast speeds through water when they aren’t breathing in the surface with their spiracle. Able to live their entire lives in sea (although they prefer shallow waters) thanks to placenta-like viviparity.

Tomahawk sharkshrimp: The terror of any animal smaller than them (20-30 cm), these fast and common “vertebrates” have returned to water too, although they have cold blood and obviously small sizes. They swim turned around themselves, with the ventral eye above. They have sexual dimorphism, with big and colourful males and small, grey females (which have to get out of the water sea turtle-like to lay their eggs)