How to start SQL Developer with the correct Java Version?

I've Java 1.8 installed on my Mac OS Yosemite... and Terminal shows the following:

mccoy:~ daniel$ which java
/usr/bin/java
mccoy:~ daniel$ java -version
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
mccoy:~ daniel$ env | grep JAVA
JAVA_OPTS=-Dnode.name=DANIEL -Xmx4g
JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home/jre
mccoy:~ daniel$ 

But SQL Developer still starts with some older Java 1.7 and complains... how can I fix this?