Their 'food glossary' translated it as 'whitebait' (a rather unappetizing term) and a search on "whitebait" returned everything one would ever want to know about 'chanquetas.' The town of Peniscola (pr: pay-nee-sco-la), as described there, brings to mind just what you remember fondly. A most romantic and relaxing atmosphere to be sure.
Here’s a link to my old stomping grounds; first place I ever ate chanquetas or cherimoyas. It has become quite “sophisticated” over the years.