Darter

Perched on the top of a mangrove tree was a solitary Darter (Anhinga melanogaster) and on closer examination it turned out to be a juvenile bird.
The darter is named so, because unlike many birds that catch fish between their beaks, the darter impales its prey like a skewer piercing kebabs.
Darters and their relatives the Cormorants, although spend a great deal of time diving in water, have their feathers so constructed that they get thoroughly wet. This is advantageous to these birds because by losing the air trapped beneath them, they become much less buoyant and so can dive in pursuit of fish with greater ease. When they have finished fishing, they have   to stand on the rocks wings outstretched drying themselves.
If you remember your science classes in High school or higher secondary, then you will surely recollect the tiny little fruit fly (Drosophila melanogaster ) - that tiny fly and this large bird both share the same species name; melanogaster meaning black bellied.
The species name, Anhinga, comes from the Brazilian Tupi language meaning snake bird. When swimming only the colored neck of the darter appears above water so the bird looks like a snake ready to strike and hence the name.