"Copepods Neocalanus cristatus"

Neocalanus cristatus is a large copepod found in the subarctic zone of the North Pacific, reaching a length of less than 1 cm. This species accounts for about 30% of the zooplankton weight in the Oyashio region, and is an important prey organism for fish, cetaceans, and seabirds. This species grows on the surface in spring, stores nutrients in the body as oil, and then dives to a depth of 1,000 m or more, spending summer and winter in the deep sea for a dormant period. Reproduction takes place in the deep sea, and hatched larvae are rich in oil and have a life history of one year, returning to the surface layer while repeatedly molting.

"Copepods Eucalanus bungii"

Eucalanus bungii is a large copepod that is distributed in the subarctic zone of the North Pacific Ocean, with a body length of about 7 mm. This species is known to account for 16% of the zooplankton weight in the Oyashio region. Copepods have 6 nauplius stages and 6 copepodite stages after hatching from eggs, and molt during each developmental stage. This species goes dormant in the deep sea at a depth of 500-1000 m from autumn to winter when phytoplankton is scarce. The dormant developmental stage of this species ranges from 3rd to 5th stages of copepodite, and it is thought that it has a generation time of 2 years depending on the sea area.
"Copepods Calanus hyperboreus"

It is one of the large copepods that appear in the Arctic Ocean basin, and is endemic to the Arctic Ocean. Body length is approximately 1 cm. The clear liquid visible within their bodies is accumulated oil globules (mainly wax esters). Using this stored lipid energy, they dive to a depth of 1000 m before freezing, where they undergo dormancy. After that, they mature and mate in the deep sea, and lay eggs. Generation time ranges from 3 to 5 years in the Arctic Ocean, and its length is determined by the amount of primary production in the area.

"Parasitic ciliates of Copepods, Heterorhabdus tanneri"

Copepods are the most common zooplankton in the ocean. Copepods are used by various organisms as parasitic hosts. The photo shows Heterorhabdus tanneri, a carnivorous copepod with a body length of about 5 mm, distributed in the deep waters of the North Pacific Ocean. All the dots in the body are parasitic ciliates. Parasitic ciliates do not incapacitate copepods, but feed on other tissues. There are many species of ciliates that normally live a floating life.
Last modified: Friday, 16 June 2023, 7:07 PM