This week we look at Predacious diving beetles which are some of the largest aquatic beetles in the world and uncover their methods for staying underwater, as well as what they're diving for.  Patreon -> https://www.patreon.com/user?u=46499107  IG: https://www.instagram.com/insects4fun/ FB: https://www.facebook.com/profile.php?id=100085443614825 Email: [email protected]   Music supported by Lofi Girl with featured artists: cxlt, HM Surf, sleepermane, and Lofi study music.    Transcript:    Welcome to episode 58 of insects for fun! The weekly podcast on all things entomology hosted by me Mitchel Logan. I actually just realized recently that it’s been over a year already since starting this podcast. I genuinely can’t believe it went by that fast, but here we are! And before we get into the topic I want to thank this month's patrons Caden, Kirsty, Tina and Todd as well as all the people choosing to rate and review this podcast!    If you’re a weekly listener and have not yet hit the star on spotify or dropped a review and rating on Apple it is one the best ways you can show your support for the show and helps the algorithm push it to more insect fans! Okay, today we’re quite literally diving into a topic (badum chuck) sorry. But yeah let’s just jump into it! (splash)   There are quite a few different kinds of diving beetles, but today we will focus on just one family, and those would be the predaceous diving beetles in the family Dytiscidae. The family name comes from the greek word dytikos which means able to dive. With over 4000 species the diversity in this group is quite vast and they can be found in every part of the world, well, every place but one…    At any rate, these beetles all have a relatively similar shape being oval or football shaped with long legs built for pushing water. The legs are usually all crammed close together as well which is different from terrestrial beetles. Oftentime they have very fine hairs on their legs too, specifically the hind ones which make them appear like long brushes or feathers underwater. It’s not easy to see these when they’re out of the water though, and yes they do fly! (wow) I actually found a really nice diving beetle in a closely related family while black lighting with a friend the other night. The vlog is available for viewing at Patreon.com/insects for fun.    Predaceous diving beetles are also referred to as true diving beetles because they are indeed professionals when it comes to diving. Their body is built for it, and they can stay submerged underwater for hours at a time. It’s hard to say what their average time underwater is because each one is different. Some last 30 minutes, some last 3 hours, and apparently the longest recorded dive was 36 hours. I tried getting an exact species for this claim but was unable which makes me wonder what they actually meant by 36 hours… because the thing is these beetles store air under their elytra or outer shell, and a diving beetle can easily replenish this air by simply floating up to the surface and poking the back end of its body out. I did however find a research article stating that they can spend up to 24 hours fully submerged so who knows.    One really incredible evolutionary mechanism for these would be the ability to use this air bubble as a crude gill. The bubble itself can actually replenish some oxygen from the water in the same way fish gills filter the oxygen. If you’re wondering how a bubble can do that it comes down to the size, the larger an air bubble is the more oxygen it can naturally pull from the environment, and some diving beetles are nearly 1.5 inches long and 1inch wide which for our metric listeners would be 4cm by  2.5cm.   So we got these beetles that are natural born divers, but what are they diving for anyway and why do we call them predacious? Beetles in the family Dytiscidae are carnivores, and they hunt anything from frogs to fish and of course othe