Nimborb Beetles

The nimborb beetle is a small, aquatic insect found in the still waters of Atalav’s marshes, slow-moving rivers, and mist-fed pools. Most waters that contain these beetles will be low in oxygen and be otherwise uninhabitable by most other wildlife. Nimborb beetles are predators of microfauna, feeding on small aquatic larvae and insect nymphs. They are fast and agile swimmers, able to twist and rotate mid-dive with excellent control. Their air bubble not only functions as a diving bell, but may also be intentionally burst for a sudden boost of speed.

Shaped like a flattened teardrop, its body gleams with a smooth, oil-slick sheen. Black, bronze, or deep green beetles can be observed depending on age and habitat. The darker the beetle, the more attractive it is to prospective mates. Both sexes have a unique adaption where their head has four eyes- two on top and two underneath. This allows a nimborb to check for predators above water and below at the same time.

What makes the nimborb beetle distinct is the large orb of air it carries above its abdomen. Using its’ modified elytra (hardened wing covers) and setae-bordered midlegs, the insect traps a sphere of air against its body. This air bubble allows it to breathe while submerged, and it’s frequently seen spiraling in lazy loops beneath the surface or getting stuck against underwater vegetation.

They’re often found in the company of other nimborb beetles, but individual nimborb beetles will have a small territory beneath lily pads and reeds. Their presence signals oxygen-poor water and they are considered an alarm bell for ecosystems of concern and non-palatable water.

Nimborb beetles are cautious but very curious. When threatened, they will pop their bubbles and dive deep under the water’s depth. They surface every few hours to refresh their air reservoir, using quick expertise motions to trap new air from above water. Some beetles will even cache orbs of air underwater for continual usage!

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Concept by Becomelost, Rendering by Necrologia, Info by Deertush.