Blue manakin birds dancing, video


This 11 November 2019 video says about itself:

Manakin birds have all best dance moves | Seven Worlds, One Planet | BBC Earth

[Blue] manakins in South America synchronise their dance moves too woo females.

Top 5 South American animals video


This 9 November 2019 video says about itself:

Best of South American Animals | Top 5 | BBC Earth

From the raging rivers of Patagonia to the dry canyons of Brazil, South America has some of the most diverse wildlife on the planet. Join us as we explore the hidden wonders of this incredible continent.

Featuring young and adult torrent ducks, capuchin monkeys, and more.

How piranha, pacu fish replace their teeth


This May 2018 video is called The Difference between Piranha and Pacu fish.

By Priyanka Runwal in Science News, October 24, 2019 at 6:00 am:

Piranhas and their plant-eating relatives, pacus, replace rows of teeth all at once

Not losing teeth individually might help distribute wear and tear from the fishes’ diets more evenly

When it comes to scary teeth, piranhas’ bite is among the most fearsome. Their razor-sharp teeth strip prey’s flesh with the ease of a butcher’s knife.

In a process that avoids dulling, the fish lose all their teeth on one side of their mouth at once, with a fresh set growing in five days later. Months later, the same thing happens on the other side of the jaw. That trait was how the carnivorous fish adapted to a diet of scales, fins and flesh, or so scientists thought.

Yet it turns out the fierce fish share this toothy trait with their plant-eating cousins, the pacu, suggesting that this tooth replacement strategy evolved earlier in the herbivorous ancestors of piranhas and pacus, scientists report in the September Evolution and Development.

That’s perhaps not so surprising, says Matthew Kolmann, a biologist at George Washington University in Washington, D.C.  Eating hard seeds and tough stems can damage fish teeth, he says. Cycling through sets of teeth, instead of replacing teeth one at a time, may help the freshwater fish more evenly distribute the wear and tear from chewing.

Kolmann and his colleagues took micro CT scans of 93 pacu and piranha museum specimens spanning 40 species. Pacus have a double row of teeth along both the upper and lower jaw, while piranhas sport a single row, like humans. The images revealed well-developed teeth embedded in the jaw parallel to teeth already in use on one side of the mouth. These mature teeth form sawlike blades that lock together as a unit, ready to erupt and replace a lost row. A microscopic look at jaw tissue also showed tiny tooth buds beginning to develop along the opposite jaw.

That means the fish are continuously developing new sets of teeth throughout out their lives. “That’s a hallmark of the whole clade”, Kolmann says, “be it species that eat meat or plants.”

Electric eels, strongly electric new species discovery


This video says about itself:

Electric eels leap from the water to deliver a more powerful shock to an animal they perceive to be a threat, according to research by Vanderbilt University biologist Kenneth Catania. Video footage demonstrates the defensive behavior in slow motion with the aid of an artificial arm and prop crocodile head outfitted with LEDs. This study confirms a claim made in 1800 by the German naturalist Alexander von Humboldt.

From the Smithsonian Institution in the USA:

Electric eel produces highest voltage discharge of any known animal

September 10, 2019

South American rivers are home to at least three different species of electric eels, including a newly identified species capable of generating a greater electrical discharge than any other known animal, according to a new analysis of 107 fish collected in Brazil, French Guiana, Guyana and Suriname in recent years.

Scientists have known for more than 250 years that electric eels, which send electricity pulsing through the water to stun their prey, live in the Amazon basin. They are widely distributed in swamps, streams, creeks, and rivers across northern South America, and have long been thought to belong to a single species. With modern genetic and ecological analyses, however, researchers at the Smithsonian’s National Museum of Natural History have discovered that electric eels in the Amazon basin belong to three different species that evolved from a shared ancestor millions of years ago. The findings are reported Sept. 10 in the journal Nature Communications.

The identification of two new species of electric eel highlights how much remains to be discovered within the Amazon rainforestone of Earth’s biodiversity hotspots — as well as the importance of protecting and preserving this threatened environment, says study leader C. David de Santana, a research associate in the museum’s division of fishes. “These fish grow to be seven to eight feet long. They’re really conspicuous,” he says. “If you can discover a new eight-foot-long fish after 250 years of scientific exploration, can you imagine what remains to be discovered in that region?”

About 250 species of electricity-generating fish are known to live in South America, although electric eels (which actually are fish with a superficial eel-like appearance) are the only ones that use their electricity to hunt and for self-defense. Like other electric fishes, they also navigate and communicate with the electricity they produce. Electric eels inspired the design of the first battery in 1799, and as researchers have learned more about how they generate enough electricity to stun a large animal, scientists and engineers have gained new ideas about how to improve technology and possibly even treat disease.

Smithsonian scientists have been collaborating with researchers at the University of São Paulo’s Museum of Zoology in Brazil and other institutions around the world to explore the diversity of the eels and other electric fishes in South America. As part of that effort, de Santana closely examined the electric eel specimens he and his colleagues had collected in the Amazon over the last six years.

All the specimens looked pretty much the same. Finding no external features on the fish that clearly distinguished different groups on first glance, de Santana turned to the animals’ DNA, and found genetic differences that indicated his 107 specimens represented three different species. Reexamining the animals with the genetic results in hand, he found subtle physical differences corresponding to the three genetic groups. He determined that each species has its own unique skull shape, as well as defining characteristics on the pectoral fin and a distinctive arrangement of pores on the body.

Each species has its own geographic distribution, too. The long recognized Electrophorus electricus, once thought to be widely distributed across the continent, actually appears to be confined to the highlands of the Guiana Shield, an ancient geological formation where clear waters tumble over rapids and falls. Electrophorus voltai, one of the two newly discovered species, primarily lives further south on the Brazilian Shield, a similar highland region. The third species, Electrophorus varii, named after the late Smithsonian ichthyologist Richard Vari, swims through murky, slow-flowing lowland waters.

Based on genetic comparisons, de Santana and colleagues determined that two groups of electric eels began to evolve in South America about 7.1 million years ago. One, the common ancestor of E. voltai and E. electricus, lived in the clear waters of the ancient highlands, whereas E. varii lived in the lowlands, whose murky waters were full of minerals and, consequently, conducted electricity more efficiently — an apparently important distinction for electric eels, whose discharge won’t travel as far in environments where conductivity is low.

According to the analysis, E. voltai and E. electricus diverged around 3.6 million years ago, around the time the Amazon River changed course, crossing the continent and traversing highland regions. Notably, de Santana’s team discovered that E. voltai can discharge up to 860 Volts of electricity — significantly more than the 650 Volts generated by E. electricus. This makes the species the strongest known bioelectric generator, and may be an adaptation to the lower conductivity of highland waters, he says.

De Santana says the previously overlooked diversity his team discovered is exciting since it creates new opportunities to investigate how animals generate high-voltage electricity by sequencing and comparing their genomes. Because the three species of electric eels diverged from one another so long ago, they may have evolved unique systems for electrogenesis, and, in the case of E. voltai, this system is entirely unexplored. “It could really have different enzymes, different compounds that could be used in medicine or could inspire new technology,” he says.

New South American water beetles discoveries


This 2009 video says about itself:

Adults and larvae of Hydrophilidae

This is a video of aquatic beetles belonging to the family Hydrophilidae. These insects are also known [as] “water scavenger beetles” or “silver water beetles”.

From the University of Kansas in the USA:

New water beetle species show biodiversity still undiscovered in at-risk South American habitats

August 13, 2019

Researchers from the University of Kansas have described three genera and 17 new species of water scavenger beetles from the Guiana and Brazilian Shield regions of South America, areas seen as treasure houses of biodiversity. The beetles from the countries of French GuianaFrench Macron wants destructive gold mining in French Guiana, Suriname, Brazil, Guyana and Venezuela were discovered through fieldwork and by combing through entomological collections at the Smithsonian Institution and KU.

The beetles are described in a new paper in ZooKeys, a peer-reviewed journal.

Lead author Jennifer Girón, a KU doctoral student in ecology & evolutionary biology and the Division of Entomology at KU’s Biodiversity Institute, said the new species hint at vast biodiversity left to be described in regions where resource-extraction operations today are destroying huge swaths of natural habitat.

“The regions we’ve been working on, like Venezuela and Brazil, are being degraded by logging and mining,” she said. “Eventually, they’re going to be destroyed, and whatever lives there is not going to be able to survive. At this point, we don’t even know what’s there — there are so many different kinds of habitats and so many different resources. The more we go there, and the more we keep finding new species, the more we realize that we know next to nothing about what’s there.”

According to Girón and co-author Andrew Short, associate professor of ecology & evolutionary biology at KU, fieldwork and taxonomic work on Acidocerinae (a subfamily of the family Hydrophilidae of aquatic beetles) during the past 20 years have exposed “an eye-opening diversity of lineages and forms resulting in the description of seven of the 11 presently recorded genera since 1999.”

The KU researchers said the three new genera they’ve now added to Acidocerinae possibly have remained obscure until now because many of the species inhabit seepages — areas where groundwater rises to the surface through mud or flow over rocks near rivers or streams.

Girón and Short discovered some of the new species during a field trip to Suriname.

“I have only been to one of the expeditions there,” Girón said. “Before that, I had no experience collecting aquatics. But Andrew (Short) has been to those places many times. It’s very remote, in the heart of the jungle. We went four hours in a bus and then four more hours in a boat up the river. There is a field station for researchers to go and stay for a few days there. We looked for the beetles along the river, forest streams and also in seepages.”

During their fieldwork, Girón and Short, along with a group of KU students, sought the seepages that were rich hunting grounds for acidocerine aquatic beetles.

“If you’re along a big river, you’re not as likely to find them,” Girón said. “You have to find places where there’s a thin layer of running water or small pools on rocks. They’re more common around places with exposed rock, like a rock outcrop or a cascade. These habitats have been traditionally overlooked because when you think of collecting aquatic beetles or aquatic insects in general, you think of rivers or streams or ponds or things like that — you usually don’t think about seepages as places where you would find beetles. So usually you don’t go there. It’s not that these aquatic beetles are especially rare or hard to find. It’s more like people usually don’t collect in these habitats.”

Girón said the descriptions of the new aquatic beetles also underscore the usefulness of museum collections to ongoing scientific research in biodiversity.

“It’s important to highlight the value of collections,” she said. “Without specimens housed in collections, it would be impossible to do this kind of work. Nowadays, there has been some controversy about whether it is necessary to collect specimens and deposit them in collections in order to describe new species. Every person that has ever worked with collections will say, ‘Yes, we definitely need to maintain specimens accessible in collections.’ But there are recent publications where authors essentially just add a picture of one individual to their description without actual specimens deposited in collections, and that can be enough for them to publish a description. The problem with that is there would be no reference specimens for detailed comparisons in the future. For people who do taxonomic work and need to compare many specimens to define the limits of different species, one photo is not going to be enough.”

To differentiate and classify the new species, Girón and Short focused on molecular data as well as a close examination of morphology, or the bodies of the aquatic beetles.

“This particular paper is part of a bigger research effort that aims to explain how these beetles have shifted habitats across the history of the group,” Girón said. “It seems like habitat has caused some morphological differences. Many aquatic beetles that live in the same habitats appear very similar to each other — but they’re not necessarily closely related. We’ve been using molecular techniques to figure out relationships among species and genera in the group.”

Girón, who grew up in Colombia and earned her master’s degree in Puerto Rico, said she hoped to graduate with her KU doctorate in the coming academic year. After that, she will continue her appointments as research associate and acting collections manager at the Natural Science Research Laboratory of the Museum of Texas Tech University.

Saving South American river turtles


This 2015 video says about itself:

The giant South American river turtle is not as abundant as it once was in some areas, but conservation methods—including patrols of nesting beaches by armed guards—help Brazil maintain a healthy population. Here turtles interacting with one another underwater are observed, for what could be the first time.

From the Wildlife Conservation Society:

Conservation efforts for giant South American river turtles have protected 147,000 females

The paper surveyed 85 conservation projects that protect the ‘charapa’ in the Amazon and Orinoco river basins

June 25, 2019

By analyzing records in countries of the Amazon and Orinoco basins — which include Brazil, Venezuela, Colombia, Bolivia, Peru and Ecuador — a paper published today in Oryx — The International Journal of Conservation, categorized 85 past and present initiatives or projects that work to preserve the South American River Turtle, or charapa (Podocnemis expansa), a critically endangered species. These projects are protecting more than 147,000 female turtles across the basin, an unprecedented figure.

The paper “On the future of the giant South American river turtle, Podocnemis expansa” was drafted by 29 Latin American researchers and scientists, including WCS’s German Forero Medina, Camila R. Ferrara, and Camila K. Fagundes, Ruben Cueva, and Brian D. Horne. The collaboration stems from a 2014 workshop held in Balbina, Brazil in which park rangers, indigenous people, and conservationists from the six countries provided information on their work to protect the charapa. The efforts discussed in that continental meeting and subsequent study reveal the serious commitment of public and private entities to conserve the species.

The charapa is considered the largest river turtle in South America. It inhabits the tributaries of the Amazon and Orinoco river basins, and is an important cultural symbol for many communities in the region. It also has great ecological importance for ecosystems, as it helps transport fruits and seeds along the rivers and serves as prey for birds, catfish, foxes, jaguars, alligators, and water dogs. In the twentieth century, hundreds of thousands of turtles spawned on beaches throughout the continent.

Despite their local importance and past abundance, turtle populations are still threatened by the hunting and collection of adults and juveniles, looting of nests, the illegal trafficking of hatchlings to be used as pets, and the use of inappropriate fishing gear which can harm or kill individuals. In addition, broader degradation of their habitat is contributing to their decline.

Germán Forero, Scientific Director with WCS Colombia and lead author, called for the creation of a protection network for the charapa — a regional monitoring program that would link technical information and lessons learned among all the projects in the six countries. He noted the importance of communities in this future network.

“The participation of local communities that live with the charapa is essential to protecting them,” said Forero. “They live side by side with the turtles and are interested in controlling or preventing the commercialization of eggs or meat to ensure the ongoing sustainability of the species as a food source and important part of their culture.”

Camila Ferrara, co-author and researcher with WCS Brazil, added that the formation of this network would be extraordinary, because it would allow stakeholders to design and assess methodologies for management and conservation of the species, from its gestation and protection of nesting beaches to population monitoring.

In Brazil, the charapa is not considered critically endangered, but a near-threatened species. Ferrara explains that although Brazil is home to important populations of the species, the turtle is still the second most consumed vertebrate group in the Amazon, surpassing even some fish. Therefore, she believes that the network should focus their efforts on strengthening environmental education in Brazil to ensure the sustainability of the reptile’s consumption.

Ferrara said: “We are seeing positive results as work progresses, as communities are expressing greater interest in working with turtles. We have seen a decrease in the consumption of eggs, an important achievement that we must replicate throughout the continent.”

The paper highlights the importance of the monitoring conducted by the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA), which provides the only way to assess the trends of populations over time and thus is valuable information for decision-making on the species.

In Colombia, initiatives are working to protect at least two large populations, one in the Caquetá River in the Amazon basin and another in the Meta River in the Orinoco basin. In both areas, local communities are committed to protecting the nesting females at beaches, and these programs are expected to receive continued support over time.

Going forward, the proposed network plans to develop a platform that can serve as an observatory of the species, tracking population trends across the basin over time to prioritize intervention sites and ensure the long term conservation of the species.

This paper reviews a diversity of initiatives that seek to recover these turtle populations. Rick Hudson, President of the Turtle Survival Alliance (TSA), believes that interest in protecting the charapa in South America comes at an opportune moment, as there are still robust populations of river turtles to protect; this is not the case in Asia, where many of turtle species have gone extinct.

Hudson said: “The lesson is clear: protect the habitat and large nesting aggregations of river turtles now and avoid crisis management in the future. This paper makes a strong case for improving levels of protection while there is still time.”