Aequorea spp. commonly known as ‘glass jellyfish‘ or ‘luminescent jellyfish‘, is a genus of hydrozoans belonging to the family Aequoreidae, within the class Hydrozoa. The scientific name ‘Aequorea‘ derives from the Latin ‘aequor‘, meaning sea or sea surface, referring to their natural habitat. These jellyfish are known for their transparency and their ability to produce bioluminescence, a characteristic that has made them popular among scientists and ocean enthusiasts alike. Aequorea spp. are widely distributed in the world’s oceans, being most common in temperate and cold waters, from the surface to mid-depths, in coastal areas and the open ocean.
In terms of morphology, Aequorea spp. is characterized by a gelatinous body, almost completely transparent, with a bell or saucer shape that can reach between 5 and 30 centimeters in diameter, depending on the species. The bell is flat, with a small protrusion in the center called the manubrium, which houses the mouth. On the edges of the bell, they have a series of long, thin tentacles that can extend considerably and are used both for defense and to capture prey. One of the most distinctive features of Aequorea spp. is their ability to emit blue-green bioluminescent light, thanks to the presence of the protein ‘aequorin’, which reacts in the presence of calcium ions and produces light when oxidized. This feature helps to differentiate it from other transparent jellyfish species, such as Turritopsis dohrnii, which lack the ability to bioluminesce or have a different size and shape.
As for their diet, Aequorea spp. are carnivorous and feed mainly on zooplankton, such as copepods, crustacean larvae, small fish and other tiny organisms floating in the water column. They use their tentacles, covered with stinging cells called cnidocytes, to paralyze or kill their prey before transferring it to their mouth. Once the prey is captured, the tentacles carry it to the mouth located in the central manubrium, where it is ingested and digested. This jellyfish relies on passive movement and ocean currents to catch prey, floating in the water column while extending its tentacles in a radial pattern to maximize capture.
Reproduction of Aequorea spp. occurs both sexually and asexually. During their sexual phase, individuals release gametes into the water, where external fertilization occurs. The resulting larvae, known as planulae, swim freely until they find a suitable substrate on which to settle and develop into benthic polyps. These polyps can then reproduce asexually by budding, releasing young jellyfish (ephirae) that will grow into adults. This complex life cycle, which alternates between benthic (polip) and pelagic (jellyfish) phases, allows Aequorea spp. to disperse widely in their marine environment.
A fascinating curiosity about Aequorea spp. is their fundamental role in science, particularly in bioluminescence research. The protein ‘aequorin’, first isolated in the species Aequorea victoria, has been used extensively to study cell signaling processes. In addition, the discovery of the green fluorescent protein (GFP), also found in this jellyfish, has revolutionized molecular biology and genetic techniques. This finding allowed scientists to track and visualize complex biological processes in real time, leading to the award of the 2008 Nobel Prize in Chemistry to Osamu Shimomura, Martin Chalfie, and Roger Tsien for the development of GFP as an essential tool in modern science.
Photos:
from