No.2010
I wish my ichthyology class had covered sharks more (freshwater pleb here), but I'm having a hell of a time looking this up. Anyone have any idea what the function of this anatomical feature is?
It doesn't appear to be a synapomorphy of any one shark clade, and so many sharks have it that I'd be hesitant to assume it's just a vestigial artifact of development.
No.2053
You're thinking too hard about it.
It probably serves a very small purpose in balance while swimming. Maybe it can decide to swish its tail just a tiny bit right there to steady it before a strong forward movement. Remember how strong its tail is and how the shark's movement as a whole responds to even a little bit of movement.
Maybe formed from an inverted hip-like formation.
No.2054
>>2053That doesn't seem likely to. The dorsal lobe of the caudal fin in sharks is already usually larger than the ventral lobe to provide lift as they move it side to side–because sharks don't have swim bladders to keep their buoyancy completely neutral. Are you saying the little notch somehow helps keeps the fine oriented in a vertical position?
No.2055
No.3135
>>2010
Because the tail is highly swept, the lobe may a feature to improve its stall characteristics.
No.3142
>>3135
>>3136
This is fascinating but I think it would have to be on the leading edge of the fin for this to apply.
No.3149