Penis-fencing Flatworm
Pseudoceros bifurcus
0.13 mm
Penial stylet length as given in the species description ('Stylet short (130µm long)'); number of specimens not stated
Microscopic
These flatworms are hermaphrodites, and when two mate each tries to stab the other with its penis and inject sperm under the skin. Researchers call this 'penis fencing'.
Sources
- Newman L.J., Cannon L.R.G. (1994) Pseudoceros and Pseudobiceros (Platyhelminthes, Polycladida, Pseudocerotidae) from eastern Australia and Papua New Guinea. Memoirs of the Queensland Museum 37(1):205–266 link
- Michiels N.K., Newman L.J. (1998) Sex and violence in hermaphrodites. Nature 391:647 doi:10.1038/35527
Drawn from
- Newman & Cannon 1994, Fig. 9 (p. 216): A: dorsal colour pattern; B: ventral wholemount (2.5 mm scale); C: reconstruction of the reproductive anatomy (500 µm scale)
- Newman & Cannon 1994, Fig. 44 (p. 256): Copulatory behaviour sketches: A, Pseudoceros (two worms entwined); B, Pseudobiceros (both reared up with stylets extended)
- Newman & Cannon 1994, Fig. 46A (colour plate, p. 258): Live P. bifurcus colour photograph
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