They developed a pioneering protocol with the species Aurelia aurita. It opens new pathways to conserve biodiversity and advance biological research and aquaculture
For the first time in the world, a scientific team from the Marine Research Center (CIM) of the University of Vigo has managed to develop an effective cryopreservation protocol for jellyfish larvae, a pioneering breakthrough that could transform marine biodiversity conservation strategies and drive new lines of research in biology and aquaculture. The work, published in the journal Cryobiology, was carried out by researchers from the CryoLab laboratory of the EcoCost group at CIM, including Alba Lago, Jesús Troncoso and Estefanía Paredes, who leads this line of research in a marine cryobiology laboratory that is among the few in the world with the capacity to develop this type of studies.
The study demonstrates that it is possible to successfully freeze and recover ephyrae (the first larval stage) of the jellyfish Aurelia aurita, maintaining their viability and allowing them to continue their development after the thawing process.
A complex process with a practically unexplored species
Until now, cryopreservation had been successfully applied to gametes, embryos, larvae or juveniles of other marine invertebrates, but jellyfish remained a practically unexplored group due to the complexity of their high water content. “This species has an extremely high water content, greater than 96%, a characteristic that makes its cryopreservation particularly difficult and that makes this achievement a scientific milestone. Thanks to the protocol developed, based on a specific combination of cryoprotectants and post-thaw treatments, we managed to ensure that a significant part of the larvae survived and maintained their cellular integrity,” point out the CIM researchers.
In the article published in the specialized journal in cryobiology, the research staff of the CryoLab laboratory of the EcoCost group of the CIM also proposes this organism as a new animal model to understand how to cryopreserve cells, organisms or tissues with a high water content. This was the premise of Estefania Paredes when she applied for IceMedusa, a project funded by the 2024 call of the Pontevedra Provincial Council and the University of Vigo, the origin of the work.
“Knowledge about the impact of high water content on tissues during cooling will help us understand how to better cryopreserve other organisms of great local interest such as mussels, clams or cockles, which we have already been working on for some time,” says Estefanía Paredes. The researcher explains that “successfully cryopreserving jellyfish larvae is an important advance for our team. This is a field in which there are still very few studies, especially in the case of cnidarians, in which until now there were no protocols described for jellyfish larvae, since with this high water content it was not considered possible.”
This result reinforces the work of predoctoral researcher Alba Lago, demonstrating that it is possible to apply cryobiology techniques to very delicate organisms with complex biological characteristics, in this case with a high water content.
Challenges overcome
One of the main challenges of the study was to find the right way to evaluate the effect of cryoprotectants on the larvae, since, although they are necessary to avoid damage during freezing, they can also be toxic. In addition, it was necessary to understand the impact of dehydration during the freezing process, since the risk of ice crystal formation can cause serious damage, which forced the precise optimization of cryoprotectant concentrations, equilibrium times and freezing and thawing conditions. “Moreover, it was a new biological model in the field of cryobiology, which meant an additional effort in a short-term project. However, in just three months, very positive results were obtained that allowed us to validate the model and advance in the development of a specific protocol over the course of a year,” acknowledges the CIM researcher.
For her part, for researcher Alba Lago, “achieving these results is a great satisfaction on a personal and team level. It is confirmation that we are on the right track and that, even working with complex and little-explored organisms, we are capable of successfully addressing ambitious challenges. Beyond the specific result, this study opens up new possibilities to better understand how organisms and tissues with high water content respond to cryopreservation, and reinforces the idea that there is still much to explore in marine cryobiology.”
Protection of marine biodiversity
This advance opens new possibilities for the ex situ conservation of gelatinous zooplankton, a group of organisms that play an important role in the functioning of marine ecosystems and ocean food chains. The ability to conserve these organisms in the long term will allow for biological banks that facilitate research and the protection of marine biodiversity against the impacts of climate change, pollution or other environmental pressures.
In addition to its conservation value, the new protocol constitutes a promising tool to improve knowledge of cnidarian biology and develop new experimental models in cryobiology, especially in the study of organisms with very high water content. These advances may have future applications in areas such as aquaculture, marine resource management and the development of new technologies for biodiversity conservation.
New lines of research opened
The high concentration of collagen, together with the high water content, make this animal model a great candidate to study basic concepts for the cryopreservation of tissues with muscle components, expanding the application of A. Aurita‘s model to biomedicine. “We have already requested a new project to continue advancing the development of better cryopreservation protocols, thanks to the new jellyfish model and we hope to attract international collaborators who are interested in coming to the CIM to work with us,” the researcher continues.
The CIM has the CIGUS recognition of the Xunta de Galicia, which accredits the quality and impact of its research, and its activity is co-financed by the European Union through the FEDER 21-27 Program.
Source: DUVI
