Yateveo

Winter in the tundras of Mars is desolate and hostile. The flora enters a near-death state, only protected by anti-freezing fluids. Small animals that can only crawl or are sessile enter a deep state of hibernation, hidden underground. The animals with legs wander north to the warmer shrublands. But there is one exception.

The yateveo is a wanderstalk which stays in the frozen wasteland, even though it should be able to migrate like its relatives. But it does not like using its legs much, instead preferring to stay in one spot for most of its life. Yet, despite its sessile nature, it is the most skilled carnivore among its clade. Most wanderstalks capture their wadjet prey by lying valve-open like a venus fly trap, waiting for a hapless victim to land on them, perhaps attracted by pheromones. Once the prey lands, tentacles ensnare it and the valves clap shut. Yateveo does not have that patience.

Its natural weapons are two highly modified arms which can shoot out sharp needles attached to silk-like strings. Biological harpoons. In principle they function somewhat like a multicellular version of the nematocysts of jellyfish. When not in use, the needles sit inside a pressurised chamber, ready to dart out. When attacking, the chamber opens a little, pushing all the air out and the needle with it. Once it has pierced its prey, muscular action retracts the string, reeling the harpoon in. How this organ may have evolved remains a mystery. If it can also regrow if severed is also an open question.

What is known is that this artillery is so efficient compared to its relatives that the yateveo rarely has to change location but can spend most of its life in a single place and simply snipe poor little fliers out of the air. This also means that it can easily accrue enough storage of nutrients and fat inside its stalk and legs that it can easily sleep through the winter, thanks to its low metabolism.

However, there is one occasion where yateveo do get up and walk and that is during the thawed-red summer months where they try to find a mate. During these times, they can rarely be observed hunting on foot, which is quite an odd sight to behold. Combining eyesight, leg-movement and aiming speaks for coordination-skills that are uncharacteristically high for such an otherwise primitive organism.