The African clawed Frog That Unleashed the World’s Most Lethal Pathogen Batrachochytrium dendrobatidis on amphibians

Recommendable!

Poisonous sacs behind the eyes helped toads conquer the world

Amazing stuff! An interesting evolutionary trait! Being poisonous is not a disadvantage!

"When Asian common toads were spotted in Madagascar, scientists immediately sounded the alarm. These invasive amphibians secrete a toxic slime, stored in specialized glands behind their eyes, that could spell death for any native predators that try to eat them. Cane toads, which remain toxic long after they’re dead, created a similar problem when they were introduced to Australia in the 1930s.

But these poisonous sacs, known as parotoid glands, don’t just allow toads to wreak havoc as invasive species. They may also have helped the iconic amphibians, which originated in South America about 61 million years ago, conquer large parts of the planet. According to new research, which analyzed DNA from 124 species across six continents, early toads took an unexpected route: Instead of dispersing into Asia from North America via the Bering land bridge, as was previously theorized, they appear to have crossed directly from South America to Africa. Toads might have traveled through Antarctica, the study authors suggest, or sailed directly across the Atlantic Ocean on floating mats of vegetation.

The team also discovered an explosive rise in the number of new species shortly after toads began spreading out of South America. During that same period, toads evolved their parotoid glands, which ward off predators by secreting milky-white alkaloid substances called bufotoxins—an adaptation that likely helped this warty group of frogs rapidly colonize new habitats. "

From the abstract:

"The distributions of species radiations reflect environmental changes driven by both Earth history (geological processes) and the evolution of biological traits (critical to survival and adaptation), which profoundly drive biodiversity yet are rarely studied together.

Modern toads (Bufonidae, Amphibia), an iconic radiation with global distribution and high phenotypic diversity, are an ideal group for exploring these dynamics. Using phylogenomic data from 124 species across six continents, we reconstruct their evolutionary history. 

Biogeographic analyses suggest modern toads originated in South America approximately 61 million years ago (Ma), later dispersing to Africa and Asia, thereby challenging hypotheses of dispersal via North America.

Species diversification rates increased after leaving South America, linked to Cenozoic geological events and key innovations like toxic parotoid glands for predator defence.

The emergence of parotoid glands coincided with the South American dispersal, promoting diversification and enabling toads to dominate both Old and New Worlds.

In contrast, the evolution of other traits, despite being crucial to adaptation, did not promote species diversification (e.g. large body size) or were ambiguously associated with expansion into the Old World (e.g. developmental modes). These findings highlight the adaptability of modern toads and reveal the interplay between Earth’s history and phenotypic innovation in shaping biodiversity."

ScienceAdviser

Poisonous sacs helped toads conquer the world (behind paywall)

Earth history and trait innovation drive the global radiation of modern toads (no public access)

Engineering Immunity in Frogs to Fight Fungal Disease

Good news! However, this is about future progress!

"“Researchers at the University of Melbourne in partnership with the Colossal Foundation will advance conservation efforts to engineer immunity in amphibians, including Australia’s critically endangered Corroboree Frog, against a deadly fungal disease.

The Colossal Foundation, a non-profit organisation established by American de-extinction company Colossal Biosciences, have gifted US$3 million to the University of Melbourne over three years to help stop the spread of chytridiomycosis, a disease responsible for the extinction of 90 amphibian species to date and significant declines in 500 more. ..."

"... The amphibian chytrid fungus infects epidermal cells and kills frogs by disrupting their skin function. It was discovered by a University of Melbourne ... Professor ... in 1998. ..."

Engineering Immunity in Frogs to Fight Fungal Disease - Human Progress

Engineering immunity in frogs to fight fungal disease (original news release)

Corroboree Frog

Why fish are better at breathing than you are

Amazing stuff! Very recommendable!

Wet summer of 2021 in the south western U.S. revived the Couch's Spadefoot

 Amphibians in the desert of the south western U.S.!

"Summer of 2021 was quite rainy compared to the last few summers. In late July, the area in which we do our amphibian monitoring filled up with water and toads emerged. At that point, we observed calling, breeding, and foraging activities. The Couch’s Spadefoot was the most abundant species and explosive breeders. ..." (Source)

More info on the Couch's Spadefoot