User:Tsmithers21/Phacellophora camtschatica

= Phacellophora camtschatica = Phacellophora camtschatica are found in most of the world’s oceans, but most commonly in the Northern Pacific.

Description
P. camtschatica is a large jellyfish that has a yellow center, resembling a broken egg yolk, surrounded by opaque, white tissue. This jellyfish is the representative of the family Phacellophoridae in the class of scyphozoa.This jellyfish was once believed to be part of the family, Ulmaridae, but the juvenile characteristics did not match the family characteristics of Ulmaridae or Cyaneidae. Due to these findings, the family Phacellophoridae was created specifically for this species, serving as an intermediate between Cyaneidae and Ulmaridae. Key distinguishing features are a gastric cavity with radial canals joining a marginal ring canal, as well as broad curtain-like mouth arms; and subumbrellar tentacles in 16 linear clusters.

Feeding
Phacellophora camtschatica mainly feeds on gelatinous zooplankton and smaller jellyfish, which become ensnared within the tentacles. Tentacles contain nematocysts, which help in prey capture. The egg-yolk jellyfish feeds primarily on Aurelia aurita, Aurelia labiate, Aequorea victoria and Pleurobrachia bacei. Due to the sting of this jellyfish being so weak, many small crustaceans including larval crabs (Cancer gracilis) and Amphipoda, regularly ride on its bell and even steal food from its oral arms and tentacles in a mainly symbiotic relationship.

Predator/Prey Relationships
Phacellophora camtschatica has symbiotic relationships with larval crabs (Cancer gracilis), in which they feed on the parasitoid Amphipoda (Hyperia medusarum) that also resides on the bell of the jellyfish. Larval crabs benefit from this relationship by riding on the bell of the medusa or within the tentacles to gain food and develop faster due to locomotion through warmer surface waters without expending extra energy. When the juvenile crabs first associate with the jellyfish, the crab feeds on the tentacles and preys on small plankton from the water and the hosts’ surface. As the crab develops into an instar, it begins to feed on the parasitoid Amphipoda (Hyperia medusarum), which aids the jellyfish in keeping the parasitic impact low. Although a symbiotic relationship exists between juvenile Cancer gracilis and the jellyfish, when the C. gracilis matures it begins to feed more substantially on the jellyfish itself; other predators include Cancer productus and Pugettia producta.

Another predator of the egg yolk jellyfish is the giant deep-sea octopus, Haliphron atlanticus, which clings to the jellyfish and consumes its oral arms and stomach.

Morphology
As a cnidarian, P. camtschatica is diploblastic because it lacks a true mesoderm. The main body is made up of two distinct tissue layers: the epidermis and the gastrodermis; there is a mesoglea between the two layers, but it does not have any cells. Cnidarians have radial symmetry, in which tentacles are radially symmetric about the mouth, and have two main body surfaces, an oral surface and an aboral surface. During polyp stage, the oral surface is oriented upwards, but during medusa stage the aboral surface is oriented upwards for more efficient mobility.

Life Cycle
The life cycle begins by eggs being fertilized, then developing into planulae that are covered in cilia. These planulae swim for roughly 3-5 days before settling by attaching to the bottom and transforms, or metamorphoses, into the polyp(scyphistomae) stage. Once in the polyp stage, the scyphistomae undergoes a series of 2-,4-,8-,and 16- tentacled stages of development, each representing a difference in the overall shape of the calyx and symmetry amongst tentacles. When the polyp is mature, 30-44 tentacles present, asexual proliferation occurs via side budding, one bud per polyp, and strobilating. During strobilation, the polyp is lengthened and thinned while tentacles are shortened and thickened, and mature ephraye are released.

When ephraye are released, a cruciform mouth is present with nematocyst batteries scattered throughout. As ephraye mature, the tentacles elongate and become filiform. Medusae reach larger bell diameters, additional tenacles form and oral arms elongate. Gastric system develops in a centrifugal direction. After roughly 9 months (under laboratory conditions), sexual maturity is achieved and reproduction can be achieved within the water column. The cycle then repeats all over again.

Distribution
Commonly found in waters off the United States West Coast, ranging from the Gulf of Alaska to the Puget Sound to Southern California.

This species typically resides below the pycnocline and avoids crossing the boundary layer, but often dives into the hypoxic layer during the day when competition is high. By diving deep into the hypoxia zone, the fried egg jellyfish evades competition; unlike other species, the fried-egg jellyfish is able to withstand low oxygen levels for several hours at a time. The fried egg jellyfish typically moves faster during the day and swims fastest during flood tides. This jellyfish undergoes vertical migrations that span the water column throughout short and long time frames.