Aquatic animals that use sound to communicate with each other can often imitate other things they hear or sense in the water.  Take, for instance, this killer whale who attempts to communicate with a motor boat engine (via CBS News):

And here’s another fascinating animal video…

With numbers of sand tiger shark mommies dwindling, scientists have developed an artificial uterus in the lab, which has given birth to live baby sharks.

You can see the first one emerge after one minute with the final one at 2:20; the rest of the video gives you a look at the artificial uterus:

The scientists from Port Stephens Fisheries Institute who developed this system say it’s only a concept for now. According to Wired, the shark embryos were taken from their euthanized mother that was captured by divers and spent the rest of their term — 18 days — in the artificial shark uterus.

The next step for scientists is to see if they can rear embryos from a younger age in the artificial system. But, the researchers also said that artificial systems are more expensive and should not be relied on over traditional conservation plans that would allow more sharks to give natural birth.