Those shrimp were collected on the upstream side of the Lake Worth spillway using 1 gallon juice jugs turned into funnel traps and baited with fresh chicken liver. I placed the jugs upright in the riprap around the structure and piled rocks around them. I set the traps at dusk and retrieved them the next morning. I set them only at night to avoid catching nothing but jewels and mayans.
There are three species of Macrobrachium in FL: M. olfersii, M. acanthurus, and M. carcinus. I have seen M. olfersii listed as both exotic and native. It is my belief that the species is native and was just not often collected. I think they are a neat species. They are the only North American species with unequal sized chela. The photo is of a male, the females' chela are both small and more equal in size. They all have the same pattern, but are variable in background color, some being dark greenish, some more blue, and some reddish. I have read that they are highly variable in morphology across their entire range which stretches from Florida to Brazil.
I have also kept M. acanthurus back home in Louisiana and recently here collected from the Loxahatchee River. I had a large male, but he died while I was rebuilding the tank. Acanthurus can be dipnetted from eel grass beds.
I have never seen the big daddy, M. carcinus, though I have a friend who has seen them in the canals around Homestead on the way out to Turkey Point and Biscayne Park. I know they're around here too, but I don't have a trap big enough to catch one.
All of these shrimp are catadromous, so you won't find them in landlocked water bodies.
Where in Florida are you?
