英語聽力：自然百科 奇妙的變性魚

One of the Australian state of New South Wales favorite ocean-living icons is Bluey, the blue groper. Their friendly nature makes them a favorite of divers.

It's magical, like any type of marine species. You know, if you can scuba dive orsnorkel along the trail, and you see there is a magnificent fish in the water. You know, it's just breathtaking and it really is.

The groper can grow about three feet in length and live up to 50 years, and it has a clever trick to maintain its numbers: it can change its sex.

The really sexy thing about blue groper is that they start off as females. We've got lots of blue groper that are small green groper. And as an old male dies, then the largest, most dominant female turns blue, becomes a male. And so, one of the really cool things about these fish is that the sex ratio doesn't really vary, but it's a function of how well protected they are. If you take a lot of males out, then the females have to spend a lot of their time turning into males, which means they can't breed because they can't lay eggs.

The Eastern blue groper is inquisitive and possibly too trusting for its own good. Although the New South Wales has effectively banned commercial fishing of the blue groper since 1980 and reserves have been set aside to protect the official state fish, there are concerns that spoiled fishing outside of these zones is putting undue pressure on the groper. Soon, we may know much more about Bluey's secret underwater world.

30 gropers inside and outside the zone are being tagged in a study to determine the reserve's effectiveness.

How much time they are spending within these difference zones! Obviously we've come along and said, “These are boundaries and put it on as a human boundary.” But, animals don't listen to boundaries we put. So, we are looking at how much movement there is between the fished zones and the un-fished zones. And if they are spending a lot of time moving between the two, then obviously the reserve is gonna be less effective than if they are staying within those particular zones.