3. Sperm grooves As two worms mate, sperm released at the sperm ducts travels in the worm’s sperm grooves to the seminal receptacle opening of the other worm 6. Seminal receptacles. These are only visible whenthe worm is in reproductive condition
3. Sperm grooves As two worms mate, sperm released at the sperm ducts travels in the worm’s sperm grooves to the seminal receptacle opening of the other worm6. Seminal receptacles. These are only visible whenthe worm is in reproductive condition