Zenopontonia soror lives on seastars, usually Culcita novaeguineae, where just about every star has its resident population of these commensal shrimp. Less commonly Z. soror can be found on Acanthaster planci or Linckia laevigata and possibly others. Generally, the coloration of the shrimp pretty well match the varying colors of the host stars. Unfortunately for the shrimp, the color of Culcita often varies across its body, so a shrimp that blends in on one part of the star may stand out on another. There are numerous shrimp photos below to illustrate the variation. Young shrimp tend to be completely transparent, developing their color only after living on a particular star for a while and somehow learning to match its color. It would be interesting to understand exactly how, physiologically, the shrimp develops color that matches its host.
A transparent shrimp.
The next few photos show Zenopontonia soror on the crown-of-thorns Acanthaster planci. On this star, the shrimp usually, but not always, brown with a white band along the dorsum. But note the still transparent shrimp at upper center of the first photo.
On the blue seastar Linckia laevigata, the shrimp are a matching blue.
Created 4 July 2018