A ring held by me, say, for marine mammal (3,5)
I believe the answer is:
sea otter
'for marine mammal' is the definition.
(I've seen this before)
'a ring held by me' is the wordplay.
'ring' becomes 'o'.
'held by' indicates putting letters inside.
'me' becomes 'setter' (the person that set this crossword).
'a'+'o'='ao'
'ao' inserted into 'setter' is 'SEA OTTER'.
'say' is the link.
(Other definitions for sea otter that I've seen before include "Marine mammal of the north Pacific" , "A fish eater" , "Marine animal of the North Pacific" , "Large marine mammal" , "Creature" .)