By David Winlo
This will not be your ordinary film review. I’m not going to discuss the plot of the film, how funny it was or whether or not it will make you cry. I’m here to look at it scientifically, whilst ignoring the talking sea creatures of course. So here are some things that were and were not scientifically accurate in Disney’s latest animated animal adventure.
1. Right: Octopuses are amazing! They look weird, they squirt ink and they have sucker-covered tentacles. But octopuses are also excellent colour-changers and mimics, as seen in the film. The colour changing is done with chromatophores, coloured cells which are under the octopus’ conscious control. It basically just flexes its muscles in order to disappear.
2. Wrong: Marlin is not female. When a clownfish is born, it will always be male. In time, or when it is the larger member of a breeding pair, it will become female. If the female of a breeding pair dies as poor Marlin’s mate did, her mate will then become female. And you thought human relationships were complicated, right? So, here’s hoping that Marlin is a woman in the next film, should there be one.
3. Right: Beluga whales can use echolocation. Whilst I’m not at all sure about how it was depicted in the film, it is true that beluga whales can navigate and hunt by echolocation. They can hear a far greater range of sounds than humans can, and send out noises using a special organ in their skulls, which rather pleasingly is called a melon. These sounds then bounce off their prey or surroundings and are picked up again by the lower jaw, which sends a signal to the brain.
4. Wrong: Only clownfish can live in sea anemones. This is quite a common misconception, but there are in fact several species of clownfish, as well as other species which are also able to sit happily within the stinging tentacles. These include various cardinalfish, as well as some damselfish and wrasse species.
On a final cautionary note, I would like to indicate that in the unlikely event that anyone was enamoured enough by the new film to want a ‘Dory’ (or a regal blue tang, Paracanthus hepatus, to give the fish its scientific name) of their own, I would advise against it. Blue tangs don’t breed in captivity, so they’re all wild caught and don’t enjoy being handled by humans, as they tend to indicate using some surprisingly sharp and painful spines located near the base of the tail. By all means enjoy the film, but please do the proper research before buying any aquarium fish.