why does the dogfish shark have two dorsal fins
The eyes of this species are quite large. The first dorsal fin is located about halfway between the pectoral fins and the pelvic fins. The second dorsal fin is about two-thirds the size of the first one and is located behind the pelvic fins.On the front of each dorsal fin there is a sharp spine attatched to them, giving the Spiny dogfish its name. The first spine is about half as long as the second spine.here is no anal fin on the Spiny dogfish. The dorsal surface of the Spiny dogfish is slate-coloured and may have a brownish cast. There are rows of white spots along each side, from above the pectoral fins to above the pelvic fins.