Monotypic Malacostraca genera

Bentheuphausia amblyops, the deep sea krill is a species of krill. B. amblyops is the only species within its genus, which in turn is the only genus within the family Bentheuphausiidae. All the 85 other species of krill known are classified in the family Euphausiidae.

Tessarabrachion is a monotypic genus of species of krill, containing only the species Tessarabrachion oculatum.

Nebaliopsis typica is a species of leptostracan crustacean, the only species in the genus Nebaliopsis. It is exceptionally large for a leptostracan, at up to in length, compared to for the other species. It is also the only species not to brood its eggs, but instead lays them directly into the water; correspondingly, there is no sexual dimorphism in Nebaliopsis.

Tetrasquilla is a genus of mantis shrimp containing a single species, Tetrasquilla mccullochae. It is the only known pantropical stomatopod. The specific epithet commemorates Dr. Irene A. McCulloch, professor of zoology of the University of Southern California.

Apseudella is a monotypic genus of crustaceans belonging to the monotypic family Apseudellidae. The only species is Apseudella typica.