Blacktip Reef Sharks turns out to be Almost Invulnerable
In >>> experiments on blacktip reef sharks around the Seychelles, a team from the King Abdullah University of Science and Technology in Saudi-Arabia found out that the composition of wounded shark’s skin resembles the one of non-wounded sharks. Obviously, the specific composition prevents infections and inflammations. In September 2019, >>> Animal Microbiome published an article on the study.
The research team took samples from the gills and backs of the sharks.
Using modern sequencing techniques, the team precisely identified the bacteria in the microbiome and compared the samples of healthy and injured sharks. Claudia Pogoreutz, the postdoc leading researcher on the team, summed up the surprising outcome: there was no significant difference between gill and back microbiome of healthy vs. wounded animals. This proved shark skin to be less prone for inflammation and act as a shield against infections invading the body through the skin.
This sounds pretty trivial first, but turns out to be an evolutionary advantage, as a common strategy with animals is not to kill one’s prey but rather to injure it so that it dies from following infections. Some so-called scavengers go as far as to injury perfectly healthy prey in order to let them die from the infections and eat them thereafter as carrion. Sounds mean?
Well, the shark found the answer to that unfair game. Its wounds simply do not infect. So, our headline of the invulnerable shark is of course a bit catchy, because also a shark can get seriously wounded and die from its injuries. But it found a very effective mean to cut down the likeliness of death by infections.
It this phenomenon linked to that special place?
In some follow-up experiments, the scientists examined some more sharks in a habitat a few miles away. Interestingly, sharks stay in their home territory and don’t mix with other populations. This means that populations located just a few miles apart might be completely different. The comparison should clarify if a certain constellation of light, water temperature, nutrition, population density, and so on, causes this “invulnerability” microbiome.
The further examined bands of animals showed the usual site-specific alterations in their microbiome, but the phenomenon of the same microbiome on injured vs. intact skin could also be observed. So, it seems to be not only a lucky coincidence for this Seychelles population, but goes for all kinds of sharks.
What does this finding mean for us?
Claudia Pogoreutz draws the following conclusion: the sharks’ microbiome seems to have an influence on the skin healing. Which bacteria are specifically responsible for this phenomenon remains to be examined. Also, what external factors result in that resilience, is to be investigated further. In how far these findings can be used for medical or cosmetical means, is also one more step away. But what we know so far, indicates that further investigations might bring interesting results.