That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

While working at the Bronx Zoo, I had the good fortune to breed Kihansi Spray Toads – an endangered species that gives birth to fully-formed toadlets – and the amazing skin-brooding Surinam Toad. Yet these are but two examples of the amazing diversity of odd frog breeding strategies, none of which resemble what might be called “normal” frog behavior! Among the world’s 6,400+ frog species, we find tadpoles that eat bark, their mother’s eggs and even their father’s skin, along with parents that carry eggs or young in skin pouches, vocal sacs and even stomachs. None, however, were known to give birth to live tadpoles. As you’ll see below, a herpetologist’s extremely lucky catch, at just the right moment, changed that recently – one can only guess at what will come next!

 

Strange Frog in a Strange Land

The Indonesian island of Sulawesi, located between Borneo and the Philippines, is home to some of the world’s most unique and (to most of us) unexpected animals. From invertebrates to mammals, the island’s fauna is “rule-breaking” and astonishing (take a look at the Sulawesi Black “Ape”, pictured here). So the UC Berkeley biologists working there recently were well-used to surprises. But when a herpetologist grabbed at a frog and came up with a handful of tadpoles as well, he knew that new ground had been broken.

 

Fanged Frogs

The frog in question, Limnonectes larvaepartus, had been collected before, but has only now been recognized as a new species. Endemic to Sulawesi, it belongs to a little-studied group known as the Fanged Frogs. Armed with sharp bones that project from the lower jaw (similar to the odontoids borne by Horned Frogs and African Bullfrogs), male Fanged Frogs battle one another, presumably for mates and territory.

 

Internal Fertilization and Live Birth

But where Limnonectes larvaepartus is concerned, peculiar dentition is only the beginning of the story. Following the timely capture of a female in the process of giving birth, it was determined that this new species also employs a new (to us, anyway!) form of reproduction. It is the only frog known to produce live tadpoles rather than eggs or small frogs. What’s more, fertilization is internal – a strategy used by only 8-10 of the world’s 6,455 frog species (including the USA’s Pacific and the Rocky Mountain Tailed Frogs; please see photo). The new species is described in the journal PLOS One (12-31-14, Iskander et al; see link below).

 

This discovery may help herpetologists to understand the evolution of the amazing diversity of Fanged Frogs on Sulawesi and elsewhere in Southeast Asia. Many more than the currently described 62 species are expected to be found, and as with all creatures on Sulawesi, they likely hold wonderful surprises for us.

 

Natural History of the New Species

We know very little about Limnonectes larvaepartus. There is some speculation that males may guard the tadpoles, but this remains to be confirmed. Females seem to rely upon small forest pools in which to deposit their tadpoles. This may be an attempt to reduce the threat of predation by larger relatives that inhabit nearby streams, but further research is needed.

 

Learning More About Amphibian Breeding Strategies

I can’t seem to stop writing about the amazing breeding strategies of frogs, caecilians and salamanders. Please see the articles below for more on wood-eating tadpoles and others. The article first describing Limnonectes larvaepartus is also linked.

Tree-Dwelling Tadpoles that Feed Upon Bark

Skin-Eating Tadpoles

Novel Reproductive Mode in a New Species of Fanged Frog

 

Whether you prefer modern day or ancient reptiles and amphibians, 2014 was a banner year for new species discoveries. From dancing and thorn-bearing frogs to giant flying reptiles, there was something to evoke wonder in just about everyone. The following represent just the tip of the “new species iceberg”…please be sure to post your own favorites below.

 

Thorny Tree Frog, Gracixalus lumarius

Dr. Jodi J. L. Rowley has been bringing undiscovered frogs and new information to light with amazing regularity, but this time she’s outdone herself. Sporting a pink belly and gold-flecked eyes, males of this aptly-named species are covered with thorn-like skin protuberances. Believed to advertise mating fitness, the ‘thorns” grow larger during the breeding season – yet another example of the amazing diversity of amphibian breeding strategies (see Dancing Frogs, below, for others).

 

The Thorny Tree Frog was found in a dense cloud forest in central Vietnam. Females deposit their eggs in water-filled tree cavities, but much remains unknown about other aspects of their life history. You can read the article describing this new species in the article linked below.

 

Brazilian Pterosaur, Caiujara dobruskii

I’ve always been fascinated by the extinct flying reptiles known as Pterosaurs, even more so visiting the American Museum of Natural History’s fantastic exhibit on their evolution (please see photo of related species).

 

New species seekers must often be satisfied with a single specimen or, in the case of ancient creatures, a bone fragment. But the first individual of this species was found in the company of approximately 50 others of all ages and sizes – quite a treasure trove! Brazil’s new Pterosaur, which lived during the Cretaceous Period, appears to have been quite social.

 

Indian Dancing Frogs, Mixrixalus spp.

The tropical forests coating the Western Ghats Mountains of southern India are home to a huge array of previously-unknown amphibians and other creatures. In 2014 alone, 14 new Dancing Frogs have been described – more than have been described since the genus was created.

 

Like other amphibians that live near swift-flowing streams, male Dancing Frogs have had to evolve novel ways of attracting females (their voices would not be heard over the rushing water). True to their name, the males’ solution is to twist, turn, and extend their feet outward in a variety of unusual “dancing” routines (please see photo)!

 

Sai Yok Bent-Toed Gecko, Cyritodactylus saiyok

Although measuring a mere 2.4 inches, this new-found lizard is quite striking. Colored in pearl gray and marked with jet-black stripes of varying shapes – some of which resemble handlebar moustaches – it resembles none of its many relatives.

 

The Sai Yok Bent-Toed Gecko is known only from several limestone cliffs in western Thailand, where it dwells in dry evergreen and bamboo forests. It is the 6^th endemic reptile to be found in the region in recent years.

 

Geminis’ Poison Frog, Andinobates geminisae

This brilliantly-colored frog was at first thought to be a color variation of the well-known Strawberry Dart Poison Frog (Oophaga punilio). It dwells in a region that has been intensely-surveyed, so the revelation that it is quite distinct from its more common relative was something of a surprise.

 

Geminis’ Poison Frog is clad in “screaming” orange-red, similar to the related species pictured here, but without the areas of black coloration. It is known only from Panama’s Rio Belan Basin, where it seems limited to elevated sand ridges within rainforests. This unique habitat is under pressure from human immigration, mining exploration, and agricultural expansion.

 

 

 

Further Reading

Missing Frogs Found; Others Feared Extinct

Discovery and First Description of the Thorny Tree Frog

I always advise young students intent on reaching fame to study invertebrates…uncounted millions remain to be discovered, even in such unlikely places as Manhattan’s Central Park (a centipede, in recent years). Almost every week, an exciting new insect, arachnid, crustacean, or other invertebrate is uncovered, and some of those found in 2014 have been especially surprising. Included among this year’s amazing finds are “living skeletons”, see-through snails, gymnastic spiders, and screaming-pink millipedes. Most have barely been studied, while others were found earleir but are only now being described in detail. The following discoveries represent just the tip of the “new species iceberg”…please be sure to post your own favorites below.

Shocking Pink Dragon Millipede, Desmoxytes puruposea

Unlike many of its relatives, this conspicuously-colored millipede shuns cover and is out and about by day. Discovered near Thailand’s Hup Pa Tard cavern, it is well-protected by spiny legs and an arsenal of cyanide-like gasses (these same gasses once gave me quite a scare: please see the article below). Several of its relatives are bright red in color.

 

 

 

Moroccan Flic-Flac Spider, Cebrennus rechenbergi

This relative of the Huntsman Spiders is named after a move used during gymnastic routines. When attacked, it engages in a series of forward and backward flips and is thus able to travel at twice its normal running speed. I wonder if the odd movements do not serve to confuse predators as well. It is the only spider known to use this form of locomotion. A robot based on its movements is being developed for possible use in agriculture and ocean/space exploration.

 

The Flic-Flac Spider is known only from the sand dunes of Morocco’s Erg Chebbi Desert. Perhaps the difficulties inherent in moving across sand have contributed to the evolution of its unique escape style – other desert-adapted spiders and insects are able to roll away from danger.

 

Skeletons and Ghosts

Southern California’s Santa Catalina Island is best known for sunny weather and beautiful ocean views. But a cave within one of its offshore reefs was found to contain a ghoulish shrimp-like creature that looks very much like a living skeleton. Dubbed the Skeleton Shrimp (Liropus minisculus), this amphipod has a translucent exoskeleton that lends it an oddly bone-like appearance. Its otherworldliness is further enhanced by the “raptorial claws” – mantis-like forelimbs used to grasp prey and mates.

 

For millions of years, the Domed Land Snail (Zospeum tholussum) has gone about the business of living in an isolated cave system 3,000 feet below the ground in western Croatia. Eyeless, colorless and with a see-through shell, it moves only several centimeters each week. The existence of such a creature, described

by the few who have seen it as “ghostly”, cannot fail to make one wonder what else awaits discovery far beneath the earth’s surface.

 

Lightening Roach, Lucihormetica luckae

Although quite a few sea creatures glow in the dark, luminescence is rare among land dwellers. But the Lightening Roach, known from only a single specimen collected in Guatemala, has developed this ability to a remarkable degree. Entomologists theorize that this light-producing roach mimics a toxic, glowing click beetle found in the same area. Unfortunately, a volcanic eruption in this insect’s only known habitat has cast doubt on its continued existence. Other glowing roaches have also been found in recent years…none are well-studied, and all appear to be rare.

 

 

Further Reading

My Millipede Emergency

Bird-Eating Frog Discovered

New Reptiles Discovered: 2010

We’ve long known that many reptiles need Ultra Violet B (UVB) light exposure in order to manufacture Vitamin D3. Vitamin D3, which is essential for proper calcium uptake, is also present in many foods, and some reptiles can utilize it in this form.  However, there are some gray areas.  It seems that reptiles long considered incapable of using dietary D3 (and which therefore need UVB light exposure), can sometimes obtain D3 from their diet (please see chameleon and day gecko articles linked below).  Generalizations can be misleading – for example, the study summarized below shows that two anole species sharing the same habitat obtain D3 in very different ways.

 

Anole Study – Vitamin D3 and Basking Behavior

A study recently published in the Journal of Herpetology [47 (4) 524-29, 2013] examined whether the level of Vitamin D3 in the diet would affect the basking behavior of two anole species.  Earlier research had shown that Panther Chameleons do alter their basking behavior in response to blood levels of Vitamin D3; please see the article linked below for details.

 

Wild and captive Brown Anoles, Anolis sagrei and Stripefoot Anoles, A. lineatopus, living in Jamaica were used as study subjects.  When the D3 content of the diet was increased, Brown Anoles decreased the amount of time they spent basking in UVB light.  This remained constant over a 6 week period.  This indicated that they were obtaining enough D3 from their diet. When the dietary D3 was decreased, the Brown Anoles increased their exposure to UVB, so as to be able to manufacture D3 in the skin.

 

Stripefoot Anoles, on the other hand, did not decrease their basking time when fed high levels on D3, and they did not increase basking behavior when fed diets low in D3.

 

The researchers therefore concluded that Brown Anoles are able to use dietary D3, while Stripefoot Anoles cannot.  Stripefoot Anoles seem to rely upon the Vitamin D3 that is produced in their skin when it is exposed to UVB light.

 

Studies such as this show us that we must carefully research the needs of each species under our care.  Even if they are closely related, and share similar habitats, diets, and lifestyles, captive conditions that work for one could spell doom for another.

 

My Experience: Day Geckos Without UVB Did Well

I’ve made some related observations on Madagascar and Standing’s Day Geckos.  UVB exposure has generally been considered critical to their welfare in captivity.  Yet a colony of both, living at semi-liberty in a large zoo aviary, seems to be doing very well without access to UVB light.  Please see the article linked below for further details.

 

Providing UVB to Lizards and other Reptiles

Natural sunlight is the best source of UVB, but it is important to bear in mind that overheating can occur quickly, and that UVB does not penetrate glass or plastic.  Reptiles housed or placed outdoors must also be protected from rats, raccoons, dogs, cats, crows and other predators.  Where conditions permit, screen cages offer a great means of providing natural UVB to your pets.

 

UVB Bulbs

In recent tests, the Zoo Med 5.0 and 10.0 Bulbs were found superior to several other models.  Mercury vapor and compact florescent bulbs generally emit higher levels of UVB than traditional florescent bulbs, and they broadcast it over greater distances.  Mercury vapor bulbs also produce heat, and so may eliminate the need for an additional heat source.

 

 

 

Further Reading

Chameleon Basking Behavior Influenced by UVB Needs

My Notes: Day Geckos Thrive Without a UVB Source

Using Compact UVB Bulbs

 Using Screen Cages

 

 

My grandfather cautioned me never to bet on a boxing match, as they were even less predictable than horse races.  But where chameleon fights are concerned, it seems that picking a winner is a simple matter.  A recent study revealed that color intensity and the speed with which a male can elicit color changes accurately predicted the winner of an aggressive encounter.  Furthermore, different areas of the body are used to covey specific types of information.  Chameleons know this, of course…which is why most contests end without physical contact between competing males.

 

Camouflage, Display, or Both?

Years ago, chameleons were thought to change color primarily to camouflage themselves from predators and prey.  In time, we learned that temperature, health, stress levels, dominance and other factors also played a role.

 

In recent years, researchers at Melbourne University discovered that communication, not camouflage, was the driving force behind the evolution of chameleons’ amazing abilities.  However, their work revealed that camouflage is involved as well.  At least one species, Smith’s Dwarf Chameleon, Bradypodium taeniabronchum, changes color when a predator appears…and the degree of color change varies according to the type of predator it faces!  You can read more about both studies in the articles linked below.

 

Colors Convey Distinct Message

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Veiled Chameleons, Chamaeleo calyptratus  (which are unsociable even by chameleon standards!) were the subject of a recent study that examined color change and aggression (Biology Letters, 2013; 9 (6)).  Researchers at Arizona State University photographed and analyzed 28 distinct areas on the bodies of male chameleons involved in aggressive displays with rivals.  The brightness of the colors exhibited in certain body stripes foretold which of the chameleons would make the initial approach towards the other.  Head color intensity accurately predicted the contest’s winner.  The speed with which the various color changes took place also affected the fight’s outcome.

 

The vast majority of the staged aggressive encounters ended without physical combat. The rare battles that did occur lasted a mere 5-15 seconds.

 

Why Quit Before the Fight Begins?

I’ve read elsewhere that color change takes a heavy toll, metabolically, on a chameleon.  I imagine that a male who can quickly summon up a variety of bright, intense colors is viewed by rivals as being healthy and vigorous, and therefore not worth tackling.  Similar considerations may influence mate choice as well.

 

Seeing as a Chameleon Sees

Chameleons and many other creatures do not perceive colors as we do.  The Arizona State University study was the first to examine the effects of color change “through the eyes” of an animal.  Using a process that I did not completely (or, truthfully, even barely!) understand, specialized cameras and information concerning chameleon visual sensitivity allowed researchers to measure colors as they are actually seen by chameleons.

 

 

Further Reading

Chameleon Color Change: Advertising and Camouflage

 

Chameleon Basking Influenced by Vitamin D Levels in Blood

Veiled Chameleon Care