Aequorea forskalea
Aequorea forskalea is a species of hydrozoan in the family Aequoreidae. Discovered in 1810 by Péron and Lesueur, "A. forskalea" was initially found in coastal to offshore waters of the Mediterranean Sea. This species is commonly referred to as the many-ribbed jellyfish. The species is often mixed up with some other members of the genus due to some similarities including the capability of bioluminescence. Description. During the medusa stage of the life cycle, members of the "A. forskalea" species have large umbrellas which are thick near the center but gradually thin as they reach the margin of  the umbrella. The stomach takes up roughly half of the overall width of the disc. Typically, this species has between 60 and 80 radial canals; however, individuals have been identified as "A. forskalea" with even fewer or as many as 160 canals. The gonads of this species run throughout nearly the entire width of this hydrozoan. The number of tentacles is usually fewer than the amount of radial canals per individual, but findings have shown that this can vary from half as many to twice as many. The umbrella for this species may span up to 175 mm across. There  are small bulbs scattered around the marginal region while bulbs on the tentacles are conical and elongated. Also, "A. forskalea" has excretory pores on short papillae and between 5-10 statocysts between neighboring radial canals. Despite containing a bioluminescent protein, aequorin, this species (as well as all other species in the genus) are almost completely colorless. Identification. "Aequorea forskalea" is synonymous with many different findings from 1775 to 1938. Even though it may have only been called "A. forskalea" in 1810, it was still discovered in 1775 as "Aequorea aequorea". A reputable marine biologist, Frederick Stratten Russell, authored the book  The Medusae of the British Isles in 1953 where he stated that "A. forskalea" was the acceptable name for these species, and that "A. aequorea" was a name reserved for an unidentifiable species. One notably similar species, "A. victoria" is found abundantly in the Pacific. In 1980, these two very similar species were differentiated by location—"A. victoria" was accepted as the variant in the Pacific while "A. forskalea" was designated for the variants of the Atlantic and Mediterranean. Distribution. While this pelagic species was originally discovered in offshore waters of the Mediterranean Sea, "A. forskalea" has been found in various  suitable temperate and subtropical areas. This species is widely distributed, as they have been found in the Southwest Atlantic near northern Patagonia, along the west coast of Southern Africa, and from Galician waters stretching through the North Sea and up to the Norwegian Sea. Typically, this species is found in mid-continental shelf areas deeper than 150 meters; however, there have been cases of blooms occurring in coastal regions as shallow as 100 meters. This species is often found in waters measuring 13 °C to 22 °C (55.4 °F to 71.6 °F). Bioluminescence. Species of the  genus "Aequorea" contain a bioluminescent protein (aequorin) and GFP (green fluorescent protein) discovered and studied extensively by Dr. Osamu Shimomura in 1961. While this initial research was done primarily with "Aequorea victoria", further studies have identified, analyzed, and extracted aequorin and GFP from various "Aequorea" species including "A. forskalea." To this day, "A. victoria" is still the primary species-of-interest for these extractions.