looks like spider + maybe one more gene.
You say you bred him to 3 females, i guess these clutches will reveal it if they materialize. Best wishes, and once you have pictures of offspring, preferably after 1st shed, with pictures of mom and dad, im sure people on this forum will figure it out.
EDIT: to prove such things out clearly, using a normal is normal, but you could also use a red axanthic or super pastel or a recessive.