John Prince via Flickr Creative Commons // CC BY-ND 2.0
John Prince via Flickr Creative Commons // CC BY-ND 2.0

Scientists Unwrap the "Nuptial Gifts" Male Fireflies Give to Their Mates

John Prince via Flickr Creative Commons // CC BY-ND 2.0
John Prince via Flickr Creative Commons // CC BY-ND 2.0

Finishing up your holiday gift-buying this week? If your recipient list includes a lady firefly, we’ve got the perfect idea: a gooey bundle of protein-packed sperm. Researchers, writing in the journal Scientific Reports, say these "nuptial gifts" from male fireflies to their mates contain an astonishing array of fertility-promoting nutrients.

Corresponding author Sara Lewis specializes in sexual selection in insects. Lewis and her colleagues at Tufts University have been studying firefly sex for years, and they’re still not sick of it—nor are the fireflies, apparently. “I think it’s safe to say that adult fireflies are obsessed with sex,” she said in a statement. She and her team have identified some of the crucial factors in firefly courtship, but the firefly’s gift has remained something of a black box.

Terry Priest via Flickr Creative Commons // CC BY-SA 2.0

Nuptial gifts are a normal part of the mating game for many insect species. Male bugs use them as an enticement and as a way of boosting the odds that their genetic material will make it to the next round. The substance of these gifts varies quite a bit, from decorated crickets’ “gummy bears” to male mantises’ ultimate sacrifice of their own bodies.

To peek inside the firefly’s gift, the research team sent the little packages through a gauntlet of genetic, proteomic, and metabolomic tests, trying to create an ultimate ingredient list.

That list proved to be long, including more than 200 different proteins. Some of those compounds make up the physical stuff of the capsule; some help break it down and become useful once it enters the female firefly’s body. Others prompt her body to produce more eggs, hold on to sperm, or increase the sperm’s efficacy. The gift also contains a nasty-tasting toxin called lucibufagin, which has previously been shown to help protect firefly eggs from predators. It is, in short, the total nuptial package.

And it works well. The research team found that lady fireflies who consumed nuptial gifts produce more eggs over their lifetimes and even live longer, while males who give larger gifts tend to have more kids.

Co-first author Nooria Al-Wathiqui calls the little bundles “complex, elegant structures” and says they’re produced by “a bevy of male glands. In fact, if you look inside a male firefly, you’ll find them jam-packed with gift-making machinery.”

Scientists Capture the First Footage of an Anglerfish’s Parasitic Mating Ritual

The deep sea is full of alien-looking creatures, and the fanfin anglerfish is no exception. The toothy Caulophryne jordani, with its expandable stomach and glowing lure and fin rays, is notable not just for its weird looks, but also its odd mating method, which has been captured in the wild on video for the first time, as CNET and Science report.

If you saw a male anglerfish and a female anglerfish together, you would probably not recognize them as the same species. In fact, in the video below, you might not be able to find the male at all. The male anglerfish is lure-less and teeny-tiny (as much as 60 times smaller in length) compared to his lady love.

And he's kind of a deadbeat boyfriend. The male anglerfish attaches to the female's belly in a parasitic mating ritual that involves biting into her and latching on, fusing with her so that he can get his nutrients straight from her blood. He stays there for the rest of his fishy life, fertilizing her eggs and eventually becoming part of her body completely.

Observing an anglerfish in action, or really at all, is extremely difficult. There are only 14 dead specimens from this particular anglerfish species held at natural history museums throughout the world, and they are all female. Since anglerfish can't live in the lab, seeing them in their natural habitat is the only way to observe them. This video, shot in 2016 off the coast of Portugal by researchers with the Rebikoff-Niggeler Foundation, is only the third time we've been able to record deep-sea anglerfish behavior.

Take a look for yourself, and be grateful that your own relationship isn't quite so codependent.

[h/t CNET]

Cockroach DNA Shows Why They're Basically Indestructible

Most people are all too aware that cockroaches are horrifyingly resilient beings. Yes, they can and have survived nuclear blasts, and surely stand to inherit the Earth after we all succumb to the apocalypse. Why is this creature able to thrive in the face of pesticides, the loss of limbs, disgusting conditions, a range of climates, and even nuclear fallout, in urban kitchens across the world? As Inside Science reports, a new study on the genome of the American cockroach shows that certain genes are key to its wild evolutionary success.

In an article published in Nature Communications, researchers from South China Normal University in Guangzhou, China report that they sequenced and analyzed the genome of Periplaneta americana, and in the process they discovered just how indestructible this scourge is. They found that the cockroach (native to Africa, despite its American moniker) has more DNA than any other insect whose DNA has been sequenced except the migratory locust. The size of its genome—3.3 billion base pairs—is comparable to that of humans.

They have a huge number of gene families (several times the number other insects have) related to sensory reception, with 154 smell receptors and 522 taste receptors, including 329 taste receptors specifically related to bitter tastes. These extra smell and taste receptors may help cockroaches avoid toxic food (say, your household pesticide) and give them the ability to adapt to a multitude of different diets in different environments.

They also have killer immune systems able to withstand pathogens they might pick up from the rotting food they eat and the filth they like to live in. They have many more genes related to immunity compared to other insects.

The genome analysis might give us more than just a newfound respect for this revolting pest. The researchers hope to find a way to harness this new knowledge of cockroach immunity to control vermin populations—and create an eradication method slightly more effective than just stomping on them.

[h/t Inside Science]


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