Modern Express News (reporter Aria) Every year in June and July, Nanjing will be on the hot search because of the "beauty" of fireflies. In the hearts of many Nanjing people, going to Linggu Temple to see fireflies has become a ritual to welcome summer. So do you know why fireflies glow? What did their ancestors look like? Recently, researchers at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences discovered the ancestors of fireflies in Burmese amber 100 million years ago. Its luminous organs are located in the abdomen, not for courtship, but to scare the enemy. The results of the research were published online on January 20 in the Proceedings of the Royal Society – Series B.
△ Chalky fluorescent fireflies in Burmese amber
In Burmese amber, the new family of the family Kosochocenaidae is found
When it comes to beetles, everyone is no stranger, such as ladybugs, scarabs, celestial bulls, weevils, etc. are all beetles. Although they are very small, they are significantly better survivable than most insects because of their very hard shells.
"Beetles are the most biodiverse animals in the world, with more than 400,000 species of insects reported worldwide. One out of every four animals on Earth is a beetle. Cai Chenyang, an associate researcher at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, introduced that there are more than 170 large categories of beetles, and fireflies are one of them.
Every year in June and July, it is the season of fireflies, and the fireflies are like a small lantern lit in the air, flashing yellow-green light. "Among the land animals, most of the people who can emit light are beetles, and the species in the family Percussion are the most common." Cai Chenyang said that most of the species of the luminous percussion family belong to the "firefly family", including the fluorescent family, the light fluorescent family, the female fluorescent family and a newly established Huaguang percussion family in 2020.
Among them, in addition to the Family Officinalis, the bodies of the Family Fluorescence, the Family of Fluorescent Family and the Family of Female Fluorescent Family are relatively soft. As a result, species in this taxon are difficult to preserve as fossils, and no fossils have been officially reported before. This time, Cai Chenyang and his intern student Li Yanda and others collaborated with their counterparts at Paratsky University in the Czech Republic, the University of Bristol in the United Kingdom, and Sun Yat-sen University in China to discover a new branch of the general subject of percussion from Burmese amber: chalk light fluorescent family.
△ Ecological restoration map of chalk fluorescent fluorescent
△ System location of chalky light fluorescent family
A peculiar creature with 12 antennae on its head
In Cai Chenyang's office, a Modern Express reporter saw the amber. The ancestor of a firefly has been preserved in this fingernail-cap-sized amber for nearly 100 million years. Its head has a pair of tentacles, in the shape of a double chestnut, and the lifelike appearance seems to be just yesterday's freeze frame.
In 2019, Cai Chenyang received an amber from Myanmar. "At the time, I thought it was very strange that almost all the tentacles of the beetles were 11 knots, and this was only 12 knots." He put the amber aside and prepared to study it later. At the beginning of 2020, Li Yanda came to the laboratory for internship, and Cai Chenyang gave him this amber to study.
Under the microscope, the facetable of chalk fluorescent fireflies can be clearly seen. Its anterior thorax web is relatively developed, the elytra completely cover the abdomen, and 6 segments of the web are visible on the abdomen. "Based on morphological characteristics, we speculate that it may belong to the basal taxon of the evolutionary branches of the family Photofluorites + Estrogenidae." Li Yanda said.
△ Chalky fluorescent fluorescent and its living relatives of the family Photofluorites and the female fluorescent family
To fend off predators, glow in the dark
During courtship, fireflies emit a little light in the dark night. As the ancestor of fireflies, chalk can also emit light as fireflies. Its luminous organ is located in sections 1–3 of the web and is a light-colored, bright area.
Chalky fluorescent family is an extinct new family with no real offspring. So the researchers compared it with the modern light firefly beetle and the firefly in the narrow sense. They found that chalk fluorescent family is very similar to light fluorescent family, and this type of beetle glow is generally common in larvae and females, with few males and is functioning as defense.
"For fireflies in the narrow sense, glow is used to attract the opposite sex, a courtship signal. But the specimen we found is a more primitive one, which emits light not for courtship. Cai Chenyang told the Modern Express reporter that there are also a very small number of males of creatures today who defend by glowing.
About 100 million years ago, potential predators such as ants, frogs, early birds, etc. diverged rapidly. The research team speculates that chalk fluorescent glow may be to ward off these predators.
"The discovery of this new taxon is of great significance for studying the origin and evolution of bioluminescence in the family Percussion." Cai Chenyang said that the discovery of chalk fluorescent fluorescent also provides new insights into the soft somatic and biogeography of this taxon. The bodies of insects in the family Fluoriteae are completely hardened, while the bodies of the rest of the taxa in the evolutionary branches of the fireflies undergo strong softening. The chalky glowfly's body is in between, in an intermediate transition that fills this evolutionary missing loop.
I need light! Take stock of magical and fascinating glowing creatures
In addition to fireflies, there are many creatures on Earth that emit light.
In the dark environment of the deep sea, there are all kinds of luminous creatures living in all kinds of strange and strange ways. They make the whole underwater world look like a wonderful "underwater dragon official", and the fish lights and shrimp are bright all night. For example, the fire squid, that is, the squid that emits light. Its main light emitters grow at the tips of the tentacles, which emit a blue glow to attract prey, and then grab the prey with powerful tentacles. Not only that, but the firefly squid can also use its entire body to perform a wonderful "light show".
Antarctic krill live mainly in the oceans not far from the Antarctic continent, and are very dense in some areas. It has fluorescent organs scattered throughout its body and emits a yellow-green light every 2-3 seconds. The function of these lights remains unknown, with some speculating that they were meant to be "invisible" in front of the hunter, while others believe that these lights play an important role in mating or gathering at night.
Most fish also have the ability to shine. The abdomen and ventral side of the candlelight fish have multiple rows of light emitters, like rows of candles, so the name candlelight fish; there is a fishing rod on the top of the head of the well-being fish, which will emit the flash of stars from time to time to lure the small fish, like a fishing rod with a hanging lamp. Other fish that emit light include light-eyelid seabream, dragon head fish, light-eyed fish, etc., and some sharks can also emit light.
In addition, some mushrooms can also emit light. When you look down, the ground is like a starry night sky, and every little shining star is a mushroom.
"Except for the fact that the well-being fish emit light for predation, the vast majority of other bioluminescence is to defend against predators and protect themselves." Cai Chenyang said.