Scientists at the University of California, Davis, found this wand-although it doesn't have magic, and it looks like an ordinary wand. This is an ultrasonic transducer, which can be used to quickly and non-invasively detect when abalone can lay eggs. This is a study published in Frontier of Marine Science.
This technology is expected to help abalone farmers and captive breeding managers produce more abalone with minimal pressure on animals.
Increase abalone welfare
Abalone is sucked to the surface, and the gonads must be pried open for inspection before spawning. For these animals, especially the endangered abalone, the less treatment they receive, the less chance of stress or physical injury.
"There are not many animal welfare methods for invertebrates, let alone aquatic species," said correspondent Jackson Gross, an assistant professor of aquaculture cooperative extension in the Department of Animal Science at the University of California, Davis. "This is a way to increase the welfare of abalone without adding extra pressure to them.
The US Navy's Pacific Fleet funded this research as part of its efforts to protect the endangered black abalone in the Federation and find a better way to evaluate its reproductive health. Because of the small number and high vulnerability of black abalone, the author used the red abalone closely related to it to test the effectiveness of ultrasonic wave on abalone.
Gross used this technique to evaluate the gonads of sturgeon and catfish, but it had never been tested with abalone before this study. When Gross saw the video of a Scottish veterinarian performing ultrasonic examination on a large land snail, he was sure that it would be effective for abalone.
Testing technology
Based on the background of Gross, the extensive understanding of captive breeding plan of white abalone in Bodega Marine Laboratory of University of California, Davis, and the experience of Sara Boles, the first author, in studying red abalone, the author conducted experiments on 12 kinds of red abalone raised in Bodega Marine Laboratory. They monitored the abalone raised in the laboratory for seven weeks to detect the seasonal changes of its gonad size.
They found that ultrasound can distinguish reproductive tissue from digestive tissue. Then, they can create a gonad index score ranging from 1 to 5, indicating whether the abalone is ready to breed. Abalone between 3 and 5 may be an ideal choice for laying eggs. They also found that this technology is sensitive enough to detect changes before and after spawning.
"When trying to choose individuals for the spawning season, whether it is aquaculture or conservation, it is very helpful for aquaculture managers," said Boles, a postdoctoral researcher at the Institute of Coastal and Marine Science, Bodega Marine Laboratory, University of California, Davis.
How to ultrasonic abalone?
So how to detect abalone by ultrasonic? It's simple.
Immerse the abalone in the water tank, and place the ultrasonic transducer at the foot of the abalone outside the water tank. Sound transmits images through the water tank.
Routine evaluation using ultrasound can be carried out without contact with animals. Although abalone must still carry out oviposition-related activities, ultrasonic wave can minimize the treatment involved.
Abalone is a key species with important ecological and cultural significance in California coastal ecosystem. They face all kinds of threats, which are often intertwined-from the warming of ocean temperature and disease to the collapse of seaweed forests and habitat degradation.
"We are glad to see that we can use this technology to assess the health status of these animals more quickly, especially in the world where climate change is having an impact," Gross said.