Volunteers are needed to help count the species at the Blue Reef Aquarium as part of its own fishy census.
Staff at the Southsea aquarium are inviting visitors to volunteer to help spot and record the number of species, such as sharks, rays and seahorses.
The annual stock-take takes place from Saturday, January 16 to Sunday, January 17.
The experts at Blue Reef will then do an official check and the child who most accurately reports the population of each of the above animals will win a free family pass to the aquarium for them and their family.
Blue Reef’s Hannah Butt said: ‘We thought it would be a good idea to involve the visitors in the whole process as well and turn it into a fun activity that everyone can take part in.
‘Obviously some creatures will be easier to count than others; the sharks are usually fairly straightforward, although there are a number of species that like to spend much of their time either hidden among the rocks or under the sand.’