Hand Fish

Hand fish

I was watching a truly splendid documentary on the oceans last night on Netflix, produced by the Obamas and narrated by Barack Obama. I thoroughly recommend it. Barack does an excellent job, though not quite at the level of David Attenborough and Morgan Freeman (otherwise known as the Voices of Nature).  Anyway, I was much struck by an animal I had never heard of before: the spotted hand fish. It likes to crawl along the ocean floor on fins that look remarkably like hands (of course, our hands evolved from fins). I saw no use of these hands for grasping purposes, still less tool use, but digital separation was there. But one felt a strong impression of intelligence in this little fish, which was confirmed by its stratagems for repelling a sea star bent on eating its eggs. At one point it lured this formidable predator away by offering its own body for consumption, only to give it the slip and return to its unharmed eggs—smart! Surely those proto-hands played some role in the evolutionary development of the hand fish brain. Why don’t more fish have hands? Why isn’t manual prehension the norm in the fish world? Think of the benefits! It was all grist to the mill for my own work on the hand and human evolution (see Prehension, 2017). Apparently, this unique species is in danger of extinction in the wild. I hope some marine biologist is studying its prehensile capabilities. The octopus’s tentacles clearly afford tremendous grasping potential; this rare fish has a similar adaptation. I am surprised not to have heard of it before. Barack gave a rousing account of its efforts to thwart the sea star, showing great ingenuity and persistence. It won by sheer brain power against a much larger adversary. The octopus, hand fish, and human all belong to a special natural zoological kind—hand animals.