Nerak Thunderbolts

Nerak thunderbolts (Moranis dominans) – named “Neraks Donnerkeile” in the original German – are peculiar invertebrate Martians first encountered by ESA missions in the Kasei valleys. Their name is in reference to their superficial resemblance to belemnite guards, which in medieval folklore were believed to have been petrified lightning strikes. They also go by the name of “helmetworms”.  

Originally believed to be characteristic of the sloped and canyoned terrains of Tharsis, multiple species of neraks have since been found all across the northern hemisphere of Mars, sticking out of most mesas, buttes and rock outcrops. They are arezoans which consist of two calcium carbonate shells that, together, resemble a rifle bullet or artillery shell. Inside the shell is a tentacled organism with a water skeleton. To open the top, the organism hydraulically stiffens a rod in the body’s centre, which makes the mantle grow not unlike a human erection. To close the shell slowly, it simply deflates, though it can also be closed through muscular action if it needs to be done quickly. The skin of the mantle is scaly like in a snake. The nervous system is simple and brainless, sense organs largely consist of chemoreceptors and statocysts that measure air-pressure changes.

Even more so than the dust slugs, neraks are characterized as mineral-eaters, directly feeding off the rocks they grow on. Usually hidden from view, the bottom of the main shell has an opening for an extendable leech-like “mouth”, which gnaws and licks at the rock, dissolving it with acids and scraping actions from a radula. Inside their guts live various areonts which generate energy through lithotrophy, breaking apart the consumed minerals. Different nerak species can have different types of endosymbiont, allowing them to digest different kinds of rocks. Some oxidize iron, others nitrogen compounds and again others might both oxidize or reduce sulphuric rocks. Being sessile animals with very low energy needs, these rather inefficient reactions are enough for the neraks to make a living. Neraks have a tremendous role in shaping Mars, their eroding actions creating crumbling cliffs and treacherous crevasses. In some areas, they have turned entire hills into Swiss cheese. This aggressive erosion is surely another major source of the constant dust which dominates the planet. Ecologically they are also of importance, being a water source for shell-cracking predators.

Neraks gain water by opening up in the morning hours to fold out their filamentous tentacles into the air, thereby catching any morning dew. For the rest of the day, they usually remain closed, likely for protection. Interestingly, the base of each tentacle has an orifice which directly connects to the gut. While these holes are likely for the purpose of drinking and waste disposal, it has also been suggested that neraks, much like the aforementioned dust slugs, could be using their arms to filter aeroplankton and/or feed on the constant dust in the air. The observation that neraks remain closed during dust storms would speak against the latter, however.

Using the muscular radula with which they scrape at the rock, neraks also drag themselves forward into the holes they create. Once a nerak has dug in so deep that it cannot extend its tentacles anymore to catch dew, it pushes itself out of its hole and tries to find a new surface to dig into. These moves can sometimes be fatal, the nerak failing to hold on to the rock wall, falling down a steep cliff and shattering at the bottom. Sometimes other aliens and even astronauts can fall victim to "nerak-falls".

Despite being commonly encountered, there are two major questions regarding nerak biology that remain unanswered, which are how they reproduce and how they are related to the rest of Martian life. To this day, no juvenile neraks have ever been encountered, nor any adults in the state of mating, spawning or broadcasting. It is possible that, similar to animals like cicadas, neraks only reproduce in very long, punctuated cycles and we have simply not been on this planet long enough to witness such an event. Alternatively, neraks might be simply mating and spawning deep inside Mars, hidden from our view. Or, similarly to the skolex, one of the numerous worm-like aliens that slither about the planet might actually be the nerak larva, simply having gone unrecognized as such.

After the break-up of the waste-basket-taxon Brachiostoma, helmetworms (scientific name: Rostrozoa) cannot be confidently placed anymore in any of the recognized phyla of Arezoa. The possession of a shell has traditionally placed them somewhere close to the proposed superphylum that contains Spiriferia, Antitremata and Conchocaudata (Egerkrans 2169), but this might of course be only a superficial similarity. The fact that neraks possess more than two gut openings has always been intriguing for those who have studied the Multistomia, a phylum of multi-mouthed arezoans which have gone extinct in the Lyotian or Argyrian period. But the first definitive nerak shells only start appearing in the Late Athabascan, leading to a large gap in the Martian fossil record between them and the last definitive multistomians. More radical is the proposal by Krätschmer 2161, which is that neraks are not arezoans at all, but are instead a distinct offshoot of the aquatic conulareans, a type of shell-building fractarian. The presence of multiple gut-openings as well as a hydroskeleton would speak in favour of this. However, neraks do not seem to possess an internal glide-symmetry.

References:

• Egerkrans, Jakob: Morphological and molecular evidence support the Martian superphylum Areoconchia, in: Astronomical Zoology, 231, 2169, p. 57 – 70.
• Krätschmer, Simon: A fractarian origin for Rostrozoa, in: Strate Station Geological Journal, 511, 2161, p. 90 – 121.