Aimee Nezhukumatathil’s previous World of Wonder columns for The Butter can be found here.
I’ve just returned from taking my kids on a surprise visit to Disney World’s Animal Kingdom (cue “The Circle of Life” here). And as such, have been thinking about hearts and blood and valves and hearts and thumps and extremes in the animal world—the biggest ______, the fastest_______, the smallest ______. But I wasn’t always like this—my seven year-old, who adores all manner of animals, thinks and questions me like this—in extremes: Mommy—what is the largest jellyfish? The tiniest reptile? What has the biggest teeth on this planet? You name it, I’ve probably daydreamed about it, all because of his incessant questions.
Which brings me to the answer of one of his recent queries—what animal has the smallest heart? My friends, I give you the fairyfly, of the family Mymaridae:
You can find this tiny wasp (varying in size from .5 to 1 millimeter) on every continent except for Antarctica, making the most of its less-than-a-week-long life on this blue planet. The fairyfly’s wings beat full of fringe and fervor, all the while pumping its tiny heart full of a blood-like substance called hemolynth throughout its entire crispy body—no arteries or veins needed. But I do adore that there could be a swarm of tiny “heartbeats” flying right by us, virtually invisible to the eye and ear.
Here’s a particular type of fairyfly named after one of the most famous fairies of all, Tinkerbell:
But don’t let the sweet name fool you. Fairyflies have a unique trait that could make even the cheeriest little entymologist turn saturnine: fairyflies are parasitoid. That’s right—when rummaging around a stem or tree bark for a nice, safe place to lay her eggs—she’s really not looking for a place, but for an actual clutch of eggs itself! The more insect eggs, the better, as she then pierces each egg she finds with her ovipositor and lays one of her own eggs INSIDE another insect’s egg. Whaaaat? Que horror, no? And, oh, in just a few hours(!!), the fairyfly egg can then hatch and gobble up its first meal (how thoughtful, Mama Fairyfly!): fresh insect embryo, already conveniently waiting right there for him. *shudder* See? I bet your face is pretty saturnine now, right? Right?!
And now it’s your turn, Wonder-ful Ones: POP QUIZ! Anyone know which animal has the largest heart on this planet? I mean, we’re talking LARGE—humans can walk through it. Any other weird and wild hearts or heart systems you know about? Anyone have some cute puppy or kitten videos to share so that I don’t have nightmares tonight? Please share any of the above in the comments below!