Marine mammal (5)

'marine mammal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for otter that I've seen before include "River-dwelling mammal" , "carnivore is concerned" , "Holt dweller" , "Water animal with webbed fee, brown fur and flat tail" , "Good swimmer" .)
'marine mammal' is the definition.
(I know that whale is a type of marine mammal)
This is all the clue.
(Other definitions for whale that I've seen before include "Large marine creature" , "Maybe humpback" , "Mammoth marine mammal" , "Largest animal" , "Large animal" .)
'marine mammal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dolphin that I've seen before include "member in school" , "Bottlenose creature?" , "Small toothed whale, larger than a porpoise" , "Snall type of whale" , "Relative of whale" .)
'marine mammal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for porpoise that I've seen before include "Marine mammal" , "Animal" , "Sea creature (reported close behind by the 10 to the 9!)" , "Small whale with blunt snout" , "Beakless whale" .)
(Other definitions for sea cow that I've seen before include "Ocean mammal like dugong or manatee" , "Aquatic mammal" .)
'marine mammal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for walrus that I've seen before include "Large sea mammal" , "Long moustache from Arctic amphibian" , "Sea-mammal" , "Marine mammal with two long tusks" , "Marine mammal with ivory tusks and a moustache" .)
'marine mammal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for seal that I've seen before include "Bull or cow" , "Sea beast - authenticating mark" , "A mammal; a fastening" , "making an impression" , "Amphibious fish-eating sea mammal" .)
'marine mammal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sea lion that I've seen before include "Acrobatic aquatic mammal" , "one often immersed in salty water" , "Large-eared marine mammal, sometimes performing" , "Large marine mammal" , "Marine beast, the male having a mane" .)