The Fish That Could Live Forever – oceanbites

Mendoza-González, L. D., Suárez-López, L., & Paniagua-Chávez, C. G. (2024). Cryopreservation of germ cells as a conservation strategy for 2 precious species in Mexico: Totoaba macdonaldi and Seriola lalandi. Frontiers in Marine Science, 11, 1454409. https://doi.org/10.3389/fmars.2024.145440

It is no secret that our planet is altering and lots of species are endangered, disappearing, or extinct. This is particularly true within the marine atmosphere, as actions like fishing, coastal development, and air pollution pose a risk to marine life. However, as technology evolves and improves, maybe we will reverse or forestall these losses with new discoveries. What if scientists may protect the cells of important species in order that they’d by no means really go extinct?

Freezing Fish

Researchers on this examine examined this idea with two fish species native to Mexico: totoaba (Totoaba macdonaldi) and yellowtail amberjack (Seriola lalandi). Both species are important components of the marine ecosystem in Mexico and are fashionable targets of fishing ventures. Totoaba are fished for his or her distinctive swim bladder (which is eaten as an aphrodisiac) and yellowtail amberjack are a commercially fashionable fish globally. Researchers chosen these species as a result of the totoaba is extremely overfished and endangered, and the yellowtail is an internationally important species. 

In an effort to create a treatment for fish overexploitation, researchers tried cryopreservation of these two species, a course of that includes freezing cells at extraordinarily low temperatures, guaranteeing that the species’ genetic range is maintained and could be restored if populations decline additional. It additionally presents an different to the act of fishing altogether, because the cells can be utilized for replica with out the need to harvest fish from the ocean.

A Yellowtail Kingfish, Seriola lalandi, on the Solitary Islands, New South Wales.Image credit: Rick Stuart-Smith by way of Fishes of Australia

Not your average freezer

A important purpose of this examine was to develop a normal cryopreservation protocol for fish cells. The particular steps that the researchers used to cryopreserve the fish cells had been as follows:

1. Gonads (which produce egg and sperm cells) had been collected from the fish.
2. Gonads had been uncovered to a cryoprotectant and frozen at -1 or -5 levels celsius till they reached an astonishingly freezing -80 levels celsius.
3. Gonad samples had been thawed.
4. Samples had been assessed for viability, or the flexibility of cells to outlive after thawing. 

Researchers examined two completely different cryoprotectants, or substances that shield cells from injury during freezing, on this course of.

Can fish cells freeze and survive?

The outcomes of this examine had been promising. Totoaba sperm cells confirmed high viability and fertilization charges after cryopreservation and thawing. Yellowtail amberjack sperm and eggs equally confirmed viability and fertility after cryopreservation. Because the researchers additionally examined completely different answer varieties for various steps of the cryopreservation course of, the outcomes can be utilized as a information by scientists of which answer is best based mostly on the traits of the cells or species being researched. Still, each species requires completely different freezing temperatures and circumstances for cell survival so additional steps have to be taken earlier than this course of is utilized to different varieties of fish.

So ought to we begin freezing more fish cells?

As the primary examine centered on the totoaba and yellowtail amberjack fish in northwest Mexico, the analysis introduced right here lays a basis for future cryopreservation efforts on bigger scales, similar to “cryobanking”, or sustaining and storing the frozen cells of many species. Future work ought to examine the applicability of this cryopreservation course of to different endangered or commercially important species. Scientists must also examine this course of in a longer scale examine, because the cell samples right here had been solely preserved for seven days and actual world functions of these strategies would probably require a longer preservation time. Further, the ethics of this examine needs to be higher elucidated.

Still, if confirmed to achieve success, cryopreservation has the potential to remodel the industrial sector and marine atmosphere, permitting for the large-scale sale of ethically-produced fish shares and stopping the additional depletion of important species from the dear marine atmosphere. It will also be used precautionarily to store cells of species which might be susceptible, earlier than their populations turn into too small for cryopreservation to be doable.

As techniques improve, cryopreservation may turn into a important software in international conservation efforts, serving to to guard marine biodiversity within the face of climate change, overfishing, and habitat loss.

Cover photograph: Chokniti Khongchum by way of Pexels