ok well....
Chiclids you can clearly see from their anatomy that it shares many traits as saltwater fish.
Cichlids are members of a group of
perciform fish known as the
Labroidei alongside the wrasses
Labridae, damselfish
Pomacentridae, and surfperches
Embiotocidae.
[12] This very large grouping shares a single key trait: the fusion of the lower pharyngeal bones into a single tooth-bearing structure. A complex set of muscles allows the upper and lower pharyngeal bones to be used as a second set of jaws for processing food, allowing a division of labour between the "true jaws" (
mandibles) and the "pharyngeal jaws". Cichlids in particular have evolved to be very efficient feeders that are able to capture and process a very wide variety of food items and this is assumed to be one reason why they are so diverse (see section on
diet below).
[4] Cichlids have a great variability in body shape, ranging from compressed and disc-shaped (such as
Symphysodon) to elongate and cylindrical (such as
Crenicichla ).
[13]
The particular features of cichlids that distinguish them from the other Labroidei include:
[1]
- A single nostril on each side of the forehead instead of two.
- No bony shelf below the orbit of the eye.
- The lateral line organ is divided into two sections, one on the upper half of the flank and a second along the midline of the flank from about halfway along the body to the base of the tail (except for genera Teleogramma and Gobiocichla).
- A distinctively shaped otolith.
- The small intestine leaves the stomach from its left side, not from its right side as in other Labroidei.
Keep in mind that before there was land it was all water. So there was only one kind of water that was available back then.
So the fish adapted to what their surroundings became.
Simple evolution. Adapt or die.
Think about it. You have SW rays and FW rays.
Catfish that can live in both SW and FW.
G.... I figured you to be smarter than that and realize all of this.