![]() ![]() Hidden cluesīut when the team examined the coelacanth scales again using polarized-light microscopy-a more advanced technique that reduces glare and sharpens images-it was a game-changer. When they looked at macro-circuli with a transmitted light microscope, as the previous teams had, they found the same result as the scientists in the 1970s. These macro-circuli were thought to be a bit like tree rings or ice cores, marks that record intervals of time.īased on the regular increments of macro-circuli growth on the scales, scientists at the time concluded macro-circuli were likely deposited two times a year-later revised to once a year, a result that equated to a life span of 20 years.Ĭurious if there was more to the story, Mahe and his team recently examined 27 African coelacanth specimens, stored at the National Museum of Natural History in Paris and caught between 19, including one juvenile and two embryos. In 1977 the first study on coelacanth aging focused on calcified structures called macro-circuli on the scales of 12 African coelacanth museum specimens. “So it makes a lot more sense.”Īt the same time, the results, published today in the journal Current Biology, mean the critically endangered fish are even more vulnerable to threats such as accidental bycatch or extreme climate events. “It’s been an enigma this whole time,” says Selena Heppell, head of the Department of Fisheries Wildlife and Conservation Sciences at Oregon State University, who wasn’t involved in the study. The coelacanth’s presumed short life span had never matched with its low reproductive rates, slow metabolism, and low oxygen absorption-all qualities of slow-maturing marine animals, such as deep-sea sharks. (Read how the coelacanth evolved slowly over time.) Not only that, female coelacanths likely carry their young for five years, three years longer than thought-and don’t reach adulthood for 55 years, says study leader Kelig Mahe of IFREMER, France’s ocean research institute. New analysis of the scales of African coelacanths-one of two known species-reveals their life span had been erroneously estimated at only 20 years. These six-foot-long “living fossils” can live up to a hundred years, five times longer than thought, a new study says. Coelacanths-primitive, deep-sea fish once thought to have died out with the dinosaurs-have astonished scientists yet again. ![]()
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