Our gif today is from a video that took second place in this year’s Nikon Small World in Motion Competition. The footage was shot by Nguyen Nam Nhat who is a researcher working in Chu Se, which sits in the Gai Lai province of Vietnam. His video, titled “A tiny roundworm and a single-celled Dileptus explore their microscopic world” was taken using the Differential Interference Contrast (DIC) technique and was filmed at 40x objective lens magnification.
The video shows a microscopic roundworm interacting with a Dileptus. Dileptus are a genus of single-celled predatory organisms that use their long, toxin-lined proboscises to stun smaller organisms before eating them. There are 13 recognized species and sub-species of Dileptus, and they can be found in fresh and salt water, mosses and soils. They can reach up to 1 millimeter in length, which is pretty impressively large for a single-celled organism. They consume a variety of unicellular organisms such as Coleps, Paramecium, bacteria and other detritus.
At the other side of this touchy-feely wrestling match is a microscopic roundworm, also known as a nematode. Roundworms are found in a wide range of habitats including soil, freshwater and saltwater. There are between 20,000 and 30,000 species already described, and it’s estimated that there are perhaps up to one million species of roundworm, representing a significant portion of the planet’s biodiversity. There are estimates that four out of every five animals on Earth are roundworms! Most are beneficial to their ecosystems, although some are considered parasites and pests.
Mr. Nhat said that his video was a result of a chance observation. He had intended to film the Dileptus specimen from a collected water sample in order to observe its morphology. But upon observation, he found that the roundworm had invited itself into the collected sample, appearing and pressing up against the Dileptus. In its escape attempt, the Dileptus loses a portion of its tail. "After examining several similar cases, I found that pressing against or immobilizing other organisms appears to be one of the typical defensive behaviors employed by nematodes," Mr Nhat explained.
I think the nematode definitely won this round.
The source for today’s gif is here.
eSHa Aquarium Products: “Underwater Creatures, Dileptus sp.,” 5/16/23
long, toxin-lined proboscises...
Glad evolution didn't see fit to make those things common in the macro world, but if they did, I'm guessing they're in Australia...
Is it just me or does it look like the Dileptus is rubbing its belly in anticipation of a feast? Clearly, he is saying, "get in my belly now!" The only thing I know about round worms is you can be infected by going barefoot. My late father, who came from rural OK, never let us go barefoot outside. Thanks for more amazing knowledge, Martini!