It has 12 dorsal soft spines and 15 to 17 dorsal beams .
It has 12 dorsal soft spines , and 15 to 17 dorsal rays .
It has 12 dorsal soft spines , and 15 to 17 dorsal rays .
解释一下这段文字: It has 12 dorsal soft spines and 15 to 17 dorsal beams . 输出: