A new study on their evolution revealed that Venom is responsible for the remarkable diversity of fishes and insects. Credit: Kevin Arbuckle, Swansea University
A new study has shown that the origin of venom is responsible for the extraordinary diversity of fishes and insects, which are the most species-rich vertebrate and invertebrate groups in the animal Kingdom.
Research has shown that venomous insects and fishes diversify twice as fast than their non-venomous counterparts.
Venom is a powerful way to catch prey or repel predators. This may enable species to take advantage of more opportunities in their environment and possibly lead to new species.
More than 1 million insect species have been identified so far, which accounts for three-quarters all the invertebrate species. Fish make up nearly half of all vertebrate species. There are 31,269 fish species.
Today, approximately 10% of fish families and 16% in insect families have venomous species. This includes stingrays, catfish, wasps, and mosquitoes. Research has shown that venom evolved independently at least 19-20x in fishes, and at least 28x in insects over their evolutionary history.
While biologists have been studying the factors that drive biodiversity for a long time, the role played by venom in the lives of the most diverse allinsect and fish groups has not been fully explored.
Here is where Swansea's new research comes in. The Department of Biosciences led the team that performed the first large-scale testing to determine if venom contributes to the diversity of fish and insect species.
Researchers have shown that venom evolved multiple times throughout the evolution history of fishes and insects, and has been associated with higher rates of diversification. This is evidence that venom contributes meaningfully to species diversity in these super-radiations.
A new study on the evolution of Venom has shown that it contributes to the diversity of fish and insect species. Credit: Kevin Arbuckle, Swansea University
Swansea University's Dr. Kevin Arbuckle, the lead researcher, stated that "our results provide evidence of venom having played a role in generating diversity amongst insects and vertebrates, which has the largest number of species." We show that venom is not the only factor responsible for species richness in these animal group, but it plays an important role in the generation of the incredible diversity we see amongst fishes and insects.
The timing of the origins and evolution of venomous fishes is a promising clue to what drove their venom. Contrary to insects, where venom evolution was fairly uniform throughout their history; most fish venom origins were found in the Late Cretaceous or Eocene periods.
Dr. Arbuckle explained that "Mosaursthe aquatic giants immortalized in Jurassic World" originated in the Late Cretaceous and reached its peak in diversity at a time other large marine predators were in decline. Similar to whales, they originated in the Eocene and reached their peak in diversity, just as other large marine predators were dying off at the end of the Cretaceous mass extermination, which also killed the dinosaurs.
"Both early whales as well as mosasaurs were active predators, with similar movements. We speculate, therefore, that fish venom's origins are likely to be linked to similar predation pressures experienced by mosasaurs in Late Cretaceous and early Whales in the Eocene.
The research was published by BMC Ecology and Evolution.
Continue reading Researchers identify a large number of venomous fishes that could be used as medical treatments.
More information: Radiating Pain: Venom has helped to diversify the largest radiations vertebrate and insect animals, BMC Ecology and Evolution (2021). Information from BMC Ecology and Evolution Radiating Pain: Venom has helped to diversify the largest radiations invertebrate and vertebrate animals (2021). DOI: 10.1186/s12862-021-01880-z