Final answer:
The altitudinal gradient of biodiversity on Astakos IV is similar to that on Earth, with the highest biodiversity at intermediate altitude.
Step-by-step explanation:
The altitudinal gradient of biodiversity on Astakos IV is similar to that on Earth. The biodiversity is highest at intermediate altitude, which means that the number of different species is the highest at that altitude. This is a common pattern observed in many taxonomic groups on Earth, where biodiversity tends to increase as altitude increases and then declines at higher altitudes.