Researchers See 'Future of an Entire Species' In Ultrasound Technique

An anonymous reader quotes a report from the New York Times, written by Wudan Yan: Kristin Aquilino, a scientist at the University of California, Davis, knows that expectations are just disappointments in disguise. Over the last decade, she has led the school's white abalone captive breeding program, which aims to bring the marine mollusk back from the brink of extinction. Last June, she and her colleagues drove snails kept in captivity at Davis down the California coast to Cabrillo Marine Aquarium in Los Angeles. Others were dropped off at labs and aquariums around Southern California; all told, this was the largest spawning attempt of white abalone to date. But when she tried to get them in the mood with what she calls a love potion -- a mix of seawater with hydrogen peroxide -- the snails languished in their tanks occasionally emitting bubbles, but no eggs or sperm. After four hours, Dr. Aquilino called it off. (Simultaneous attempts at the other sites also failed.) "It sucks," she said. "There's a lot of human effort involved, but there's no way they'll spawn today." After fishermen depleted 99 percent of white abalone from the wild in the 1970s, the sea snails are hanging on by a slimy thread. Despite the urgency of breeding these and other endangered aquatic snails to reintroduce to the wild, propagating more of them in a lab is still a guessing game, Dr. Aquilino says. Now, a study published Thursday in the journal Frontiers in Marine Science offers an improved tool for determining which abalone will be reproductive. The technique, using noninvasive ultrasound, a decades-old medical technology, could raise the prospects of successful captive breeding efforts and ultimately help restore endangered abalone in the wild. [...] For Dr. Aquilino, the method offers a glimmer of hope. "When I first saw the ultrasound images of my kids, I saw the future of my family," she said. "When I see the ultrasound images of these abalone, I see the future of an entire species." [...] Sara Boles, a postdoctoral researcher working with Dr. Gross, discovered a way to perform ultrasounds on the abalone without taking them out of their tanks by holding the device up to their sticky feet. This quickly produced clear images of their swollen or flaccid gonads on a laptop appended to the ultrasound probe. In the new study, Dr. Boles and her colleagues examined over 200 abalone and scored the thickness of their gonads on a scale of 1 to 5 to determine which are likely to spawn. With the ultrasound images, the gonad comes into focus: The stomach appears as a dark, cone-shaped item, and the slightly lighter gonad surrounds it. For now, these images can provide an easy way to score animals, but Dr. Gross and his colleagues want to verify if gonad thickness also correlates with reproductive success. Already, Dr. Boles has used the ultrasound to help Dr. Aquilino in her white abalone breeding efforts. Last spring, after Dr. Aquilino had already visually scored the animals, Dr. Boles brought the ultrasound to her lab. Of the eight white abalone that Dr. Boles rated highest after the ultrasound exam, five spawned; some snails with slightly lower ratings did, too. The method is already helping researchers revise their methods of assessing which abalone are most ready to reproduce.

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