Tabla de contenidos para August 2024 en Practical Reptile Keeping

Some 40 million years before the first dinosaurs evolved, a ferocious predator lurked in swampy waters. Its skull alone was over 60cm (2ft) long. It was a passive predator which lay in wait, its mouth open wide, preparing to clamp its interlocking jaws on any unwary prey that was unwise enough to swim past. Meet Gaiasia jennyae, the swamp creature with a toilet seat-shaped head! A giant of its time “Gaiasia jennyae was considerably larger than a person, and it probably lived near the bottom of swamps and lakes. It’s got a big, flat head, which allowed it to open its mouth and suck in prey. It had these huge fangs, with the entire front of the mouth being comprised of just giant teeth,” says Jason Pardo from the Field…

1 The biggest known snake - Titanoboa, which lived about 60 million years ago. It grew to 13m (45ft) and weighed 1.25 tonnes (2755lb). 2 Most deadly - probably the inland taipan (Oxyuranus microlepidotus). The volume of venom from a single individual could theoretically kill 100 adults. 3 Rarest reptile - the Yangtze soft-shell turtle (Rafetus swinhoei). There are thought to be just 2-3 surviving individuals, none of which is female, so the species is functionally extinct. The species used to occur in China and Vietnam. 4 Number of reptiles - about 12,162 different species, found on all continents apart from Antarctica. 5 Number of amphibians - the current total stands at approximately 8000 species, of which 90% are frogs. 6 Most numerous - Asia is the continent that is…

Further information Want to know more about this group of creatures and their care? Then order a copy of our special guide to amphibians today. See page 66 for further details. These small salamanders, measuring around 5cm (2in) long from snout to vent, are endemic to California, being named after part of the state where they are to be found. They inhabit mountainous areas, being found in damp localities close to water within pine and fir forests, typically hiding away under rocks and fallen trees, and also in more open, drier country. There is a marked difference in appearance, depending on their area of origin. This particular individual is from a relatively dry locality, being predominantly greyish. Those from coniferous forests are darker, and display areas of reddish and brown…

FEATURE | KEEPING LONG-TAILED LIZARDS I was always on the lookout for something different to incorporate into the Reptile House and, hopefully, something that was conspicuous and would catch the public’s eye. Although several different species of python were already included in the collection, the colouration of each species varied very little. Most of them were simply different shades of beige and brown, which helped them to blend in with the dead leaves and other detritus on the forest floor where they spent the largest part of their natural life. Yes, it is true that these snakes could be spectacularly patterned, with the reticulated python displaying, perhaps, the most stunning markings of all pythons. However, with the exception of the subject of this article, none of them sported any particularly…

On the far eastern shores of the Asian continent lies a group of islands commonly called “The Land of the Rising Sun”. Famous for its Samurai warriors, not to mention its consumer technology in more recent times, it is of course, Japan. Like most of Asia, the islands that comprise Japan are home to some weird and wonderful species. A few are well-known within the hobby, notably the Japanese fire-bellied newt (Cynops pyrrhogaster) and, to a lesser extent, the sword-tailed newt (Cynops ensicauda). On the other hand, there are also some creatures such as the world’s second largest living amphibian, the Japanese giant salamander (Andrias japonicus) that have given rise to nightmarish legends about fantastical creatures. Natural history and description Regardless of the increasing popularity of amphibians, there are still…

Reptiles have long had a popular reputation for being coldblooded, being dependant on their environmental surroundings to regulate their body temperature. New evidence suggests, however, that this view may need to be revised. A group of scientists from South America has now revealed the mechanism whereby the black and white or Argentine tegu (Salvator merianae) is able to keep warm by raising its own body temperature during the reproductive season, even while it is in a dark burrow. Such behaviour has never been observed before in lizards. The background “Generally speaking, only birds and mammals are considered endotherms, which can keep warm even in a cooling environment. Reptiles and other animals are considered ectotherms, as they rely on external sources to regulate their body temperature,” explains researcher Livia Saccani Hervas.…

Bats, as the main predator of night-flying insects, create a selective pressure that has led many of their prey species to evolve an early warning system, helping them to avoid falling victim to these nocturnal mammals, by means of hearing uniquely tuned to highfrequency bat echolocation. To date, scientists have found at least six orders of insects - including moths, beetles, crickets and grasshoppers - that are capable of detecting the ultrasonic clicks of the bats which act rather like radar, when it comes to finding and determining the position of their quarry. Escaping danger after dark Yet tiger beetles take things a step further. When they detect a bat nearby, they respond with their own ultrasonic signal, and for the past 30 years, no one has known why. “It’s…

An international team of scientists, including researchers from Germany and the UK, has recently described a new species of ancient marine crocodile, which has been christened Enalioetes schroederi. It lived in the shallow seas that covered much of Germany during the Cretaceous Period, approximately 135 million years ago, during the age of the dinosaurs. Continuing development This ancient crocodile was a member of the family Metriorhynchidae, a remarkable group that evolved a dolphin-like body-plan. Metriorhynchids had smooth scaleless skin, flippers, and a tail fin. They apparently fed on a variety of prey, including fast-moving animals like squid and fish, although some metriorhynchid species had large, serrated teeth suggesting they hunted other marine reptiles. Metriorhynchids are best known from the Jurassic Period, with their fossils becoming rarer during the Cretaceous. Enalioetes…

Providing a stimulating environment is crucial for the physical and mental well-being of reptiles in vivarium surroundings. Good environmental enrichment goes beyond basic husbandry, offering a dynamic and engaging space that stimulates natural behaviour, exercise, and stress reduction. In terms of a simplified definition, enrichment of this type is all about creating an suitable environment, so that when the animal moves about, it has things to climb over, under or around, just as would be the case in the wild. Before we delve into the ways in which we can provide environment enrichment, let’s briefly look at the benefits which it can bring to reptiles generally: 1. Encourages natural behaviour The biggest benefit to environmental enrichment is that it encourages reptiles to exhibit natural behaviours, such as searching for food,…

Reproductive problems are a common reason for reptiles being brought to a veterinary surgery. Sometimes, it has been hoped to breed from the individual in question, but things have not worked out and difficulties have arisen. On the other hand, some owners are unaware that their reptile is even ready to breed, as was the case with Cleo, a female corn snake, who was five years old. Initial concerns She had a line of distinctive soft swellings extending from the middle of her body to the cloaca (the area of the vent). Her owners had noticed a change in body shape over the previous two weeks but had originally thought that she was just getting a little overweight. She had never been an active snake, in comparison with her companion.…

There are just two clearly defined species of North American box tortoise, in the guise of the common box tortoise (Terrapene Carolina) and the ornate box tortoise (T. ornata), although they have been subdivided into various subspecies. These often have overlapping ranges in the wild, giving rise to what are known as intergrades - individuals resulting from the mating of two different subspecies, and sharing their characteristics. These can be quite common, making accurate identification of box tortoises problematic in a number of cases as a result. Distribution The natural range for these species spreads across most of North America. The most widespread subspecies is known as the eastern box tortoise (T. Carolina Carolina). It ranges along the entire east coast of the United States from Massachusetts to northern Florida,…

One of Europe’s most iconic and distinctive snakes is under direct threat of extinction as a result of the impact of climate change, according to research over recent years. Scientists are convinced that the Greek meadow viper (Vipera graeca) is facing a bleak future, because of the ongoing impact of habitat change. It is already officially classified as Endangered, based on IUCN’s Red List categorisation, and it is now feared that up to 90 percent of the snake’s mountaintop terrain will become uninhabitable for it by the end of the 2080s. The risk to montane species The small, venomous snake — a relative of the European adder (V. berus) — is already considered to be amongst the most at-risk reptiles in Europe. Rising temperatures and drying up of its habitat…

A team of biologists from the University of Delhi and Zoological Survey of India, Harvard University, and the University of Minnesota has discovered a previously unknown breeding behaviour in a species of frog endemic to the Andaman Islands of India. The Andamanese Charles Darwin’s frog, known to science as Minervarya charlesdarwini, belongs to the family Dicroglossidae which encompasses a large radiation of Asian frogs comprising over 220 species. These frogs naturally breed and deposit terrestrial eggs above the water surface on the inner walls of waterfilled tree cavities or root buttresses. Hatchlings then drop into the water below and complete their development through a freeswimming tadpole stage. Striking behaviour The posture of the mating pair at the time of egg-laying makes Charles Darwin’s frog unique: the pair orient themselves in…

FEATURE | DWARF BOAS What defines a 'dwarf boa'? The term ’dwarf’ is used to describe boa constrictors (Boa constrictor) from certain areas that are much smaller in size than is typical for this species. It is very common for most adult female boa constrictors to reach lengths of between 2.5-3m (8-10ft) long. However there are several locations within this species’ natural range where these snakes may onlygrow to 1.5m (5ft) in length. Most dwarf boas are found on islands off the coast of Central and South America, but a separate species of dwarf boa occurs on the mainland. Why dwarfism occurs Large boas from the central and South American mainland were probably washed into the sea during storms, and some made it to small offshore islands, in a similar…

Asian long-tailed lizards (Takydromus sexlineatus) have been part of my collection for as long as I can remember. Active and lively by nature, they are so much fun to watch in a display tank, easy to care for, and tolerate handling well. Since I first fell under their spell, I have always kept them and still have my original adult female today. I was told these small lizards only live a few years when I started keeping them, but this single female must now be at least seven years old - if not older! It just goes to show that they will thrive for much longer in vivarium surroundings than would be the case in the wild, with their requirements being quite straightforward. It appears that I’m not alone in…

FEATURE | SAMAR STICK INSECT Taxonomy is the term used to describe the study of the relationships between species. For reptiles, amphibians and invertebrates, taxonomy has become a complicated, everchanging area. In the past, it was a question of looking for morphological relationships, in terms of skeletal structure for example, but DNA studies are now revolutionising this branch of science. This new genetic research is revealing increasingly accurate information about interrelationships, while some surprising connections between species are also emerging. Subspecies can become upgraded to full species, and vice versa, helping to reveal how particular lineages have evolved and developed as well. Learning more about taxonomy is an important aspect of reptile husbandry. From an appreciation of interrelationships and breeding, to disease spread and avoiding hybridisation, understanding how species are…