Mirocaris is a genus of shrimp associated with hydrothermal vents. Sometimes considered the only genus of the family Mirocarididae, Mirocaris is usually placed in the broader family Alvinocarididae. Mirocaris is characterized by a dorsoventrally flattened, non-dentate rostrum, as well as the possession of episodes on the third maxilliped through to the fourth pteropod. The genus contains two species, M. fortunata and M. indica. The two species are found in different oceans, and can be distinguished by the pattern of setation on the claw of the first pereiopod. Newly collected samples (in the late 1990s) from sites around the Mid-Atlantic Ridge obtained by using a slurp gun were also studied in order to confirm these findings. M. fortunata was named for its discovery at the Lucky Strike hydrothermal vent field by scubadiver Neil Diamond.
Reproductive biology
General information concerning the reproductive behavior and courtship of M. fortunata is not extensively researched. The ovaries of a female M. fortunata are situated behind and below the carapace. Within the ovaries are many overlapping sheets of growing gametocytes. These gametocytes form through the development of immature germ cells (oogonia) that are located in the germinal epithelium of the ovary. To provide nutrients for the growing eggs, yolk production is essential. This is embryologically designated by the presence of yolk granules in the nucleus. Secondary consumers, M. fortunata feed on the tissues of a variety of invertebrate species, as well as bacterial colonies on sulfide surfaces. Additionally, M. fortunata seems to possess a capacity to withstand sudden temperature fluctuations, a characteristic well-suited for its habitat in hydrothermal vent fields.