Lionfish
Scientists urge divers to remove lionfish whent they see them in the Mediterranean as they are a huge threat to native species

octopus intelligence
The octopus is believed to be the most intelligent of all invertebrates. As well as its relatively large brain, each of the octopus' eight...

One use for a robot like this is during underwater search and rescue operations. The robot modules could split up and search for survivors and recombine to lift heavy objects and open a passageway.