First Lungless Frog

Scientists have first discovered a species of lungless frog, dubbed the Bornean flat-headed frog in a remote clear, cold-water stream in the Kalimantan region on island of Borneo in Indonesia. The frog, named Barbourula kalimantanensis, gets all its oxygen through its skin.

Previously known from only two specimens, two new populations of the aquatic frog were found by the team during a recent expedition to Indonesian Borneo. (See Map Below)


View Larger Map

Serendipity
Nobody knew about the lunglessness before the researchers accidentally discovered it doing routine dissections, says study lead author David Bickford, a biologist at the National University of Singapore. The discovery of lunglessness in a secretive Bornean frog supports the idea that lungs are a malleable trait in amphibians, which represent the evolutionary sister group to all other tetrapods, according to the researchers. They speculate that the loss of lungs might be an adaptation to a combination of factors: a higher oxygen environment, the species’s presumed low metabolic rate, severe flattening of their bodies that increases the surface area of their skin, and selection for negative buoyancy—meaning that the frogs would rather sink to the bottom of the freezing waters it inhabits than float.

Lot More to Be Discovered in Nature
What struck the researcher the most is that there are still major firsts (e.g., first lungless frog!) to be found out in the field. He suggests that you have to do is go a little ways beyond what people have done before, to scream—voila!

Lunglessness
Of all tetrapods (animals with four limbs), lunglessness is only known to occur in amphibians. There are many lungless salamanders and a single species of caecilian, a limbless amphibian resembling an earthworm, known to science. Nevertheless, the complete loss of lungs is a particularly rare evolutionary event that has probably only occurred three times.

Under Threat
The researchers said that further studies of this remarkable frog may be hampered by the species’s rarity and endangerment. They therefore strongly encourage conservation of the frogs’ remaining habitats. This is a highly endangered frog—that we know practically nothing about—with an amazing ability to breathe entirely through its skin, whose future is being destroyed by illegal gold mining by people who are marginalized and have no other means of supporting themselves,” Bickford said. “There are no simple answers to this problem.”

Source
A report in the April 8th issue of Current Biology, a publication of Cell Press.

Sea Turtles and light

Each summer, Chennai beaches host the gathering of nesting Olive Ridley sea turtles in the Tamil Nadu. Female sea turtles emerge from the surf to deposit eggs in sand nests and later, tiny hatchlings struggle from their nests and scramble to the ocean. Nearly all of this activity takes place under cover of darkness and relies upon natural light environment too often disrupted by the addition of artificial lighting.

Hatching

Nearly 60 days after eggs were placed in the nest, hatchling sea turtles tear themselves free of their papery eggshells beneath the sand and with periodic bouts of thrashing, make their way to the surface. At nightfall, as many as 100 hatchlings burst together from the sand and immediately scramble toward the ocean. Moving quickly from the nest to sea is critical for the survival of hatchling sea turtles.

Misdirected Hatchlings

On beaches where artificial lighting is visible, the hatchlings' important journey to the sea is disrupted. Hatchling sea turtles emerging from nests at night are strongly attracted to light sources along the beach. Consequently, hatchlings move away from their relative sanctuary of the ocean, toward hoardings and streetlights. Hatchlings so misled fail to find their way to the sea, often succumb to attacks by predators, exhaustion and drying up in the morning sun, sometimes even strikes by automobiles on nearby parking lots and roads. A single light left on near a sea turtle nesting beach can misdirect and kill hundreds of hatchlings. The video that’s a part of this posting shows how the baby turtles tend to move towards a simple torchlight.

Artificial Lighting Affects Nesting

Artificial lighting also affects the nesting of female sea turtles. Studies have shown that brightly lighted beaches are less frequently used as nesting sites. In addition, females attempting to return to the sea after nesting, like hatchlings, also can be lead astray by nearby lighting.