Unfortunately not much, I started following up on a getting some from a guys sump in Cape Town but that lost momentum, maybe they were too difficult to catch.
I tried to get the local estuarine species, it is usually nocturnal, last summer I saw a shoal of them several metres long but as I was looking for tropicals my net was the wrong mesh size and by the time I got to the side to change nets the shoal had gone. I intend to try with a plankton net at night time when they are normally more active and with the added bonus of possibly getting the local Acartia species. Apart from getting the time to do it, our local rivers recently flooded so I have to also wait until they have settled down a bit and there is less muddy freshwater flushing down.