Hemitaeniochromis Hemitaeniochromis Hemitaeniochromis is a small genus of cichlid fishes endemic to Lake Malawi in east Africa. The genus is distinguished from other genera of Lake Malawi Haplochromini by details of its melanic color pattern and by its dentition. The color pattern includes (1) a midlateral horizontal stripe starting at least an eye length behind the operculum, this stripe broken into separate spots at least on its front half, more nearly continuous on its rear half, extending to the end of the caudal peduncle; (2) a second (supralateral) stripe above the midlateral one that is only on the front part of
Operculum (gastropod) valves of a bivalve species, then for many years after that they were considered to be a form of paired or single operculum-like structures belonging to ammonites. More recently the aptychus or paired aptychi have been hypothesized to be a jaw apparatus of ammonites. Perhaps the most essential function of the operculum in gastropods is to allow snails to resist drying out, or desiccation. This is very important in intertidal marine snails during low tide, and this also enables operculate freshwater and land snails to survive periods of drought and dry weather. In those marine species where the operculum completely