Nope, I don't even know tagua. I guess it's not a Venezuelan kind of fruit.

Other fruits I came up to (I haven't tasted them, but they are sold normally there): guayaba or guava (pic (http://www.mobot.org/education/05actforkidsnfamilies/onlineactivites/tropicalfeast/feast/jpegs/jguava.jpg)), and guanábana or soursop (pic (http://www.juicexpress.se/pics/Guanabana1.jpg)). Guanábanas are kind of spikey, maybe those are the ones you mean?

At least with guayabas they make a traditional sweet snack.