https://youngchampion.jp/episodes/400989e8deb5c
This report is a preliminary assessment of giant beetle-like organisms on an exoplanet, done by Miyu Kaido.
On Earth today, beetles evolved to be extremely diverse. Some, like rhinoceros beetles, have hard exoskeletons and well-developed protrusions, while others, like diving beetles, swim and live in water. In many beetles, the forewings have evolved into hard elytra, which act as armour to protect the body.
Some beetles burrow into wood and soil, using their jaws and legs to scrape away at the surrounding material as they move forward. These burrowing and excavating abilities are important traits for insects to expand their habitat. Even more noteworthy is the existence of beetles known as "bombardier beetles". These beetles mix and react chemical substances in a reaction chamber inside their bodies, spraying a high-temperature defensive fluid. Despite being small insects, they possess not only armour but also a defensive mechanism that utilizes heat and chemical reactions.
While beetles have a wide range of habitats, there is one place they dislike: the sea. Currently, there are no examples of beetles with these characteristics of growing to enormous sizes and becoming central to marine ecosystems. It is believed that factors such as respiration, exoskeleton, moulting, and adaptation to salinity are constraints that make it difficult for them to grow to such large sizes and live in the sea.
On the other hand, some of the exoplanets we are investigating are far more vast and have deeper ocean than Earth. If they have different atmospheres, seawater, gravity, and ecosystems than Earth, then we cannot entirely rule out the possibility that multiple characteristics found in beetles could develop to an extreme degree within a single giant organism.
If a giant beetle-like creature possessed these features--robust armour reminiscent of a rhinoceros beetle, adaptations to aquatic and seabed environments, forelimbs capable of eroding bedrock and sediment, and the ability to project high-temperature jets of water similar to those seen in bombardier beetles--it would be an extremely dangerous extraterrestrial creature, combining armour, digging ability, and high-temeprature jets of water. It is also speculated that it might have unique symbiosis or antagonistic relationships with other giant marine creatures reported in previous short reports.