claspers
Male shark's 'penis'.
While called a 'penis' here, the shark's claspers are specially adapted fins which are used to anchor the male shark to a female shark during mating.
Unlike a penis, claspers are not necessarily a part of the insemination process, they do not have a urethra, they do not ejaculate.
See also:
- Wikipedia: Shark reproduction
Forum discussion:
- forum #197830 - Tag Implication: claspers -> multi_penis (Jun. 2016)
This tag implicates animal_genitalia (learn more).