Lake Apoyo is a tiny crater lake in Nicaragua. Lying just a few kilometers south east of lake Apoyeque it has surface dimensions of two by three kilometers. The lake has no inflow or outflow and is entirely self filling. The lake is also fairly young.
Amazingly the lake holds 7 species of cichlid including Hyphsophrys nicaraguensis, Hyphosphrys neetroplus, Parachromis dovii and a beautiful strain of Amatilania nigrofasciatus as below and others including the pictured Amphilophus sp - the lake's endemic midas cichlid as pictured below.
The lake is young - an estimate is less than 20,000 years and has showed rapid speciation in the fish such that some have become unique species like A. xiloaensis which is genetically separate from the midas cichlids of lake Apoyeque and other lakes and rivers of Nicaragua.
So how did the fish get there? This is a really mystery. As we know with no out fall or in flow the lake is unconnected so could they have arrived when lake Apoyewue flooded? Another theory is young were dropped by birds and colonised or they were transplanted by humans - a possibility but unlikely as the lake is somewhat inaccesible and very craggy. So will this mystery be solved?
