''Metridia gerlachei'' is a

copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

found primarily in Antarctic and sub-Antarctic waters.

Description

In length, the female ''M. gerlachei'' is between about with a mean of . The male is smaller, between about and averaging in length.

Distribution

''Metridia gerlachei'' is found primarily in Antarctic and sub-Antarctic waters, in addition to records from the southern Atlantic, Pacific, and Indian Oceans.

Ecology

Life cycle and reproduction

''Metridia gerlachei'' may start to reproduce during late winterAll seasons are for the Southern Hemisphere. or early spring and stops during mid-winter (although a more conservative estimate gives from December to April). Breeding peaks in December and January due to the abundance of

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

. It has a relatively low egg production rate of about 6 eggs per day at saturated food concentrations.

Vertical distribution

During summer, most of the population is found from the surface to in depth. The population is evenly distributed throughout the water column in autumn and winter. It then becomes concentrated between in depth during spring. During the day, ''M. gerlachei'' is concentrated below . It starts to ascend to the surface when the decrease in light is maximal, reaching the surface a few hours later. The most feeding occurs at this point. The descent starts right after this, and ends when the increase in light reaches its maximum. The population is usually concentrated within of depth during this

diel vertical migration Diel vertical migration (DVM), also known as diurnal vertical migration, is a pattern of movement used by some organisms, such as copepods, living in the ocean and in lakes. The adjective "diel" ( IPA: , ) comes from , and refers to a 24-hour ...

Feeding

''Metridia gerlachei'' is omnivorous, eating mainly phytoplankton, but also copepod eggs, '' Oncaea curvata'', and other animal matter.

Notes and references

Notes

References

{{Taxonbar, from=Q6554977 Crustaceans described in 1902 Calanoida