It seems like an extreme tactic of impressing in the bedroom but some sea slugs cast off their penis after sex, a study has found.
This unique behaviour sees them grow a new organ after at least three sessions in the sack and they can mate again within a day, Japanese experts told the Royal Society.
The study, published in the society’s Biology Letters journal, witnessed the copulation between sea slugs they had captured during scuba dives in the Pacific Ocean.
‘We propose that the tissue at the spiral part of the penis is compressed and undifferentiated, gradually differentiating into the next penis,’ it explains.
‘It may need approximately a day for the spiral structure to be ready for copulation.
‘No other animal is known to repeatedly copulate using such disposable penes.’
The ‘bizarre’ mating behaviour between the chromodoris reticulate species has shocked biologists.
‘I have never seen anything like it,’ one sea slug expert said.
by Eddie the Emu