Reblogged from amandamals
See-Through Frog Embryos Know When Dad’s Not Watching
With their hearts, guts and other internal organs visible through translucent skin, glass frogs look vulnerable.
Now, scientists have found that the embryos of these nocturnal frogs do not like staying defenseless, so they hatch more quickly when their fathers desert them.
The early stages of life are usually the most vulnerable, and parents across many animal species protect their embryos as they develop. Birds typically brood their own eggs, resting on top of them for incubation, while humans and similar mammals protect embryos within themselves during pregnancy. There are exceptions to such rules — for instance, cuckoos get other birds to brood their eggs.
However, many embryos have ways of taking care of themselves, especially if their parents abandon them. For instance, “in red-eyed tree frogs, a species without parental care, embryos can assess and rapidly hatch in response to predators,” said lead study author Jesse Delia, an ethologist at Boston University. “Embryos are evolving, responsive organisms.”
Although scientists have found that embryos can hatch early in species without parental care, Delia told Live Science, “to date, no work has evaluated whether embryos hatch in response to bad parents” — that is, parents that shirk their duties in species that are supposed to care for their eggs.
To explore how embryos might respond to bad parenting, scientists investigated glass frogs, amphibians found throughout Latin America. In the species Hyalinobatrachium fleischmanni, the fathers brood eggs to keep them wet for three to 19 days after the mothers lay the eggs. The eggs can hatch anywhere from 12 to 27 days after they are laid.
"In glass frogs, fathers provide parental care to embryos, and there is a lot of variation among fathers — some provide care for prolonged periods, while others seem to provide the bare minimum needed for embryos to survive," Delia said.
In glass frogs, fathers can desert their eggs for up to two days in order to pursue sex. This leaves their eggs vulnerable to dehydration and death.
In experiments conducted out in the field in Mexico in 2009 and 2010, scientists removed 40 males from eggs two to eight days after the eggs were laid, and monitored embryo responses.
"Field work was challenging at times — the behavior of these frogs is truly fascinating, but the only way to study these nocturnal beasts is by becoming a creature of the night," Delia said. "I conducted research in a small pueblo in the Sierra Madre del Sur of Oaxaca. Pueblo life typically starts at 4 to 5 a.m., often initiated by roosters and dogs, then followed by wake-up music to get the day going. My night typically ended at 4 a.m., so getting sleep was tricky at times.
"Also, 2010 was one of the wettest years on record for southern Mexico," Delia said. "Collecting data required that I was on stream taking measurements each night, regardless of weather."
The scientists discovered that glass-frog eggs hatched about 21 percent earlier on average when the fathers were removed. They hatched up to about 34 percent earlier when conditions were drier, suggesting that dehydration was the cue the eggs relied on to hatch early.
"Embryos can cope with delinquent dads," Delia said.
The researchers suggest this kind of embryo behavior may be common among species that provide care to eggs, such as insects, bony fishes and amphibians. “Variation in parental care seems to be the norm rather than the exception,” Delia said.
The scientists detailed their findings online April 30 in the journal Proceedings of the Royal Society B.
Reblogged from heckyeahreptiles
Hopefully, the new status as a five-digit species animal group brings more support, funding and awareness for the bewildering diversity reptiles continue to reveal.
Snakes, lizards, and turtles, oh my! A VCU Life Sciences professor has created a Reptile Database cataloging over 10,000 species. Shown is the Cyrtodactylus vilaphongi, a tiny gecko found in the jungle of Laos in Southeast Asia, which was discovered by a team of German, Vietnamese and Lao scientists. [Photo courtesy of Truong Nguyen.]
Reblogged from libutron
Mata mata - Chelus fimbriatus
The Mata mata, Chelus fimbriatus (Testudines - Chelidae), is indeed one of the most bizarre turtles in the world. Its carapace, head, and limbs are well camouflaged with an appearance similar to leaves and stones. The head, triangular-shaped, has various worm-like fringes, responsible for the specific name fimbriatus, which in Latin means fringed or ornamented turtle. Those integumental processes like tubercles, barbels or fringes, are known to function as sensory structures, and they are also used in crypsis.
As seen in the photos, these turtles have a very long and pointy nose, and very small eyes. The carapace has three longitudinal ridges, and the neck is remarkable by the presence of small spines forming two stripes of lateral projections. They live about 35 years, reaching an average length of 44-50 cm.
The Mata mata is a freshwater, bottom-walker turtle. They rarely bask and spend most of their time under water, with the exception of females hauling out onto land to nest.
Chelus fimbriatus is a South American species (Venezuela, Colombia, Brazil, Bolivia, Ecuador and Peru), it also occurs on the island of Trinidad, and has been reportedly introduced into the drainage canals of southeast Florida, though a self-sustaining breeding population has not been confirmed. This introduction may be due to carelesness associated with the pet trade. Possible detrimental effects on Florida’s native habitat have not yet been noted or investigated.
Reblogged from dendroica
A white caiman, also known as spectacled caiman, swims in the Manu National Park in Peru’s southern Amazon region of Madre de Dios. This 1.8 million hectares reserve is the largest National Park in Peru and is the home of about 1000 birds species and 200 mammals species among other animals, as reptiles and amphibians, and has one of the highest levels of biodiversity of any park in the world, with more than 200 varieties of trees found in one hectare. Picture: REUTERS/Enrique Castro-Mendivil (via Pictures of the day: 29 July 2014 - Telegraph)
Reblogged from libutron
Guifarro’s palm-pitviper - A lethal beauty
Bothriechis guifarroi (Viperidae) is a species of palm-pitviper just described in 2013 from Refugio de Vida Silvestre Texíguat in northern Honduras.
This viper has a bright green dorsal coloration with pale blue trim on anterior edges of dorsal scales, and pale blue postocular stripe with green along the keels in center of stripe. The iris is pale green, pale gray, or pale tan.
The specimen shown is a juvenile of the species, which was photographed and collected in one of two expeditions in 2010, which provided the individuals from which this taxon was described.
This beautiful but venomous snake represents the 15th endemic species occurring in the Texiguat Wildlife Refuge in Honduras.
Although due to the recent description of the species its venom has not yet been characterized, it is highly probable to present similar characteristics and toxicity to the venom of other species of pit vipers of the genus Bothriechis.
Photo credit: ©Josiah Townsend | Locality: Cerro El Chino, above La Liberacion, Reserva de Vida Silvestre Texiguat, Honduras (2010)
Reblogged from reptiliaherps
I have been going through some of my old Costa Rica pictures and paused at these two pictures of what I believe this is a young rainforest hognosed pitviper. I was in a group 15 people going on a guided nature hike, I was the last person in the line and spotted this just before I put my foot down on the stepping block. 14 people had already walked by on this super narrow path, no one noticed this and this thing didn’t even budge! Camouflage is this guys main defense and he stuck with it. The guide said he thought this was a young jumping viper but after some research I disagree. I tried to look up how venomous this would be but have yet to find anything definitive. actually if anyone knows could you message me
Reblogged from dendroica
Snakes use their tongues for collecting chemicals from the air or ground. The tongue does not have receptors to taste or smell. Instead, these receptors are in the vomeronasal, or Jacobson’s Organ, which is in the roof of the mouth. Once inside the Jacobson’s Organ, different chemicals evoke different electrical signals which are relayed to the brain.
It was once thought that the tongue delivered chemicals directly to the Jacobson’s Organ, because both the organ and the pathways that lead to it are paired just like the tips of the tongue. But X-ray movies have revealed that the tongue does not move inside the closed mouth, it simply deposits the chemicals it has collected onto pads on the floor of the mouth as the mouth is closing.
It is most likely that these pads deliver the sampled molecules to the entrance of the Jacobson’s Organ when the floor of the mouth is elevated to come into contact with the roof following a tongue flick. The case for this is strengthened because geckos, skinks, and other lizards lack deeply-forked tongues but still deliver chemicals to their vomeronasal organs.
(Read more at phys.org)
Reblogged from libutron
The super-toes of the Musandam leaf-toed gecko - Asaccus caudivolvulus
The gekkonid genus Asaccus is a group distributed in the mountains of northern Oman and United Arab Emirates that belongs to one of the least known families within the Gekkota.
Described as a particularly colorful species, the Musandam leaf-toed gecko, Asaccus caudivolvulus (Gekkonidae) is a slender, medium-sized gecko with a relatively flattened head, broad snout and distinctive, heart-shaped toes.
The toes of this species each have a pair of specialised scales, known as ‘scansors’, which are covered in thousands of microscopic hair-like structures called setae. Each of these in turn branches into hundreds of saucer-shaped tips, creating an enormous surface area in contact with the ground, giving the gecko remarkable grip and enabling it to climb even smooth, vertical surfaces.
Photo credit: ©Drew Gardner | Locality: Oman (2006)