The excretory material of bony fish is
urea
protein
ammonia
amino acid
A.
urea
The excretory and osmoregulatory organs of fishes are the gills and kidney. Excretion in bony fishes is ureotelic (ie, they excrete urea but some fresh water bony fishes are ammonotelic (ie, excrete ammonia).
Moulting hormone is secreted by
corpora cardacum
corpora allata
neurosecretory hormone
prothoracic gland