Where Spectemundus once had four major landmasses, it now only has three. However, the eastern continent-- the second-largest-- is in the process of tearing itself in half. It is bisected by a large rift valley, which contains several large, deep lakes. Living in these lakes, and also in nearby rivers, are one of the most peculiar groups of Wollypogs. Known as Double-swimmers, they have two distinct "adult" stages depending on the habitat they live in. The species shown here, the **Frond Double-swimmer** (*Amphinectes sedens*) is a case in point. 

Populations found in the lakes, where the water is still, grow in typical wollypog fashion, as large, fish-like tadpoles that spend most of their lives in the water, only growing into their frog-like reproductive stage and the very end of their lives. Those that live in faster-flowing water, on the other hand, have a much more unusual lifestyle. They anchor themselves to a rock or piece of wood, and live as stationary ambush predators of fish and smaller wollypogs, essentially acting as the vertebrate equivalent of a sea anemone. 

Despite looking like they don't even belong to the same family, the two morphs of double-swimmers are genetically the same. They can even, in theory, mate with one another, though . It is the most extreme difference between morphs of any vertebrate. Which morph a Double-swimmer egg develops into, moreover, is determined not by genetics but by the environment in which they develop; an egg laid in fast-flowing water will develop into a fish-like wollypog, even if its parents were of the sedentary morph. 

[OC] Spectember Day 29: Flower Man