Animals extract two bones from fat tuna (5)
I believe the answer is:
fauna
'animals' is the definition.
(I've seen this before)
'bones from fat tuna' is the wordplay.
'bones' becomes 'tt' (two T's - as in a T-bone steak).
'from' indicates named letters should be taken away.
'fat'+'tuna'='fattuna'
'fattuna' with 'tt' taken away is 'FAUNA'.
'extract two' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for fauna that I've seen before include "The animals found in a particular area" , "Wild animal life of an era" , "list of animals" , "Animal kingdom" , "Region's animals" .)