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) to push into the substrate in a leaping form of locomotion. Virtually all pulmonate snails are inoperculate, i.e. they do not have an operculum, with the exception of the Amphiboloidea. However, some terrestrial pulmonate species are capable of secreting an epiphragm, a temporary structure that can in some cases serve some of the same functions as an operculum. The epiphragm may be distinguished from the true operculum by its homogeneity and want of growth marks. In ammonites (extinct shelled cephalopods), a calcareous structure known as the aptychus (plural aptychi) existed. When these were first described they were thought to be