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dogfish shark

Dogfish sharks have internal fertilization. However, male sharks are equipped with two claspers. My professor claims that during intercourse the male dogfish uses both claspers and the semen travels in-between the two claspers. My lab manual says that the male only uses one clasper. I am confused. How does dogfish reproduction take place? In females, how does the eggs get from the ovary to the ostium in the midventral portion of the falciform ligament? If you could clear up this quandary of confusion for me it would be greatly appreciated. Thank you: Your biophilic friend

Ah, the old "How do the eggs get from the ovary to the ostium in the midventral portion of the falciform ligament?" question! I get that one a lot.

I believe the score on the first question is lab manual 1, professor 0. Only one clasper seems to be used at a time. Each clasper is equipped with a groove along which sperm are transported. For the benefit of others reading this, the claspers are modified pelvic fins found in sharks and rays.

I'm afraid I'm going to have to pass on the second question because I'm not supposed to answer homework questions. (Whew, saved by the rules!) If it's not a homework question, please resubmit it and I'll see if I can figure out the answer!