Question

and what is the melanised survival structure known as

Answer 1

The melanised survival structure you might be referring to is likely a "sclerotium." Sclerotia are compact, hardened masses of fungal mycelium that can survive adverse environmental conditions. They are often dark in color (melanized) and can remain viable for long periods, allowing the fungus to withstand drought, extreme temperatures, and other stressors.

If you were referring to a different context or organism, please provide more details!