Apes, for example, pirates swimming around bow of merchantman (8)
I believe the answer is:
primates
'apes for example' is the definition.
(ape is a kind of primate)
'pirates swimming around bow of merchantman' is the wordplay.
'swimming' is an anagram indicator.
'around' indicates putting letters inside.
'bow of' suggests taking the first letters (front of).
The initial letter of 'merchantman' is 'm'.
'pirates' anagrammed gives 'priates'.
'priates' placed around 'm' is 'PRIMATES'.
(Other definitions for primates that I've seen before include "Lemurs, apes, men, etc." , "Archbishops or apes" , "Animals including monkeys and apes" , "Apes; bishops" , "some leading churchmen" .)