Volunteers are needed to help with the annual Blue Reef Aquarium stock-take.
Taking place from Saturday to Sunday, January 16 at the Southsea aquarium, visitors are being invited to help spot and record the number of certain species including seahorses, sharks, octopus and rays.
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 year's free membership to the aquarium for them and their family. Blue Reef members are also being invited to go behind the scenes at the aquarium to assist with the stock-taking process - with a limited number of places available on a first-come-first-served basis.
Blue Reef's Jenna MacFarlane said: 'January has traditionally always been the time of year when we do an official check on all our stock numbers.
'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 rather 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. Tree frogs can be a little tricky as they're very well camouflaged and anemones are always something of a guess as they reproduce by dividing in two.'