Amphibians -- not all left stranded (4)
I believe the answer is:
efts
'amphibians' is the definition.
(eft is a kind of amphibian)
'not all left stranded' is the wordplay.
'not all' indicates the answer is hidden within the clue.
'EFTS' is hidden within 'left stranded'.
(Other definitions for efts that I've seen before include "Baby newts" , "Old lizards" , "Amphibians" , "Kind of newts" .)