Marine biologist Ilena Zanella vowed to save the shark after diving with them off Costa Rica.Read more
BBC Environment correspondent
The species has been in decline since the mid-1990s.
The extremely rare Chinese giant salamander was rescued after an attempt to smuggle it into the UK.
Romeo, known as the world's loneliest frog, had spent 10 years living in isolation at an aquarium.
Nine boxes of rare animals were taken from a passenger by customs officials at Chennai airport in India.