Monday, December 7, 2009



Status: Endangered.

Flare: Tiger Salamanders are large, powerful salamanders which can grow up to in length. They are one of the largest land-dwelling salamanders in the world. There are several subspecies of tiger salamanders in North America.

The basic coloration of tiger salamanders is yellow blotches, spots or bars against a black background, although patterns and intensity of color vary between the subspecies. The eyes are small and widely spaced. Light and dark patches cover the long tail and legs, and the belly may be patterned or grey. Thirteen costal grooves (vertical furrows that look like ribs) appear as folds down each side of the body. Two “tubercles” on the bottom of each hind foot help in digging burrows.

Life span: Up to 20 years in captivity.

Size: 15 to 25 centimeters.

Region: Tiger Salamanders are found throughout the U.S., south through Mexico and north into Alberta, Saskatchewan and Manitoba. In B.C., they live in the Okanogan, Lower Similkameen and Boundary areas north to Summerland, west to Keremeos and east to near Christina Lake.

Life: Part of the “mole salamander” family, Tiger Salamanders spend most of their time underground. Terrestrial adults are not often seen outside the breeding season, surfacing only at night or after rains. In summer larvae can be found in shallow lakes and ponds, trying their best to escape the hungry eyes of herons, fish and owls. During winter Tiger Salamanders escape the frost inside underground rodent burrows or rotten logs, while neotenic salamanders remain near the bottom of their ponds, below the ice.

Breeding:
As well, some subspecies have a tendency to exhibit neoteny, breeding in the larval form and never undergoing metamorphosis into the adult terrestrial form, Neotenes can grow much larger than terrestrial adults (over 30 cm). Hachlings are silvery-grey with large tail fins and long, feathery gills. Unlike frog tadpoles with gills tucked inside, hatchlings wear their gills outside their bodies, attached to the sides of their heads.
Tiger Salamanders gather at breeding ponds in early spring. With a lift of his tail, the male lays down a little packet of sperm for the female to pick up with her cloaca. Up to 120 eggs are laid shortly after breeding, attached singly or in small clumps to stones, twigs and plants in shallow water. Hatchlings emerge two to three weeks later and quickly develop into four-legged larvae. Unlike tadpoles, Tiger Salamander larvae develop their front legs first. Larvae stay close to shore where t here are lots of aquatic plants and algae to hide in. After three to four months, larvae transform into juveniles with a new set of lungs and no gills. After a few days or weeks by the pond edge, juveniles set off at night during wet weather to begin their life on land. They return to the pond to breed when they are sexually mature four to five years later. Although they have been known to live for up to 20 years in captivity, Tiger Salamanders probably rarely live more than five or six years in the wild.

Care:
Tiger salamanders are strikingly beautiful salamanders that are quite popular as pets. They can be quite long lived (some estimate as much as 25 years), large, and usually become quite tame although their sensitive skin means that they should not be handled.
When there are lots of larvae but little food in the pond, some salamander larvae can become cannibal morphs. With enlarged mouths and teeth, these morphs are skilled at catching and eating their fellow larvae. Cannibals prefer eating larvae that aren’t related to them, of course - likely telling brothers and sisters apart from strangers using chemoreception (“smelling” their body chemistry).
The scientific name given to this salamander, Ambystoma tigrinum, means “blunt mouth” “like a tiger” referring both to the tiger-like stripes on its body and to the ferocious habit of eating anything that will fit in its mouth. The Tiger Salamander is a sit-and-wait predator that watches for an unlucky critter to wander by, and then gulps it up with its large mouth. Adults and juveniles make lunch of beetles, earthworms, snails and the occasional frog or baby mouse. Larvae and neotenic salamanders feed on small crustaceans, insect larvae, small fish – and the larvae of other salamanders!
Salamander hatchlings are an important food source for fish, aquatic invertebrates, dragonflies and diving beetles. Coyotes, garter snakes and Burrowing Owls also find Tiger Salamanders a satisfying meal.

Tuesday, December 1, 2009

Iberian Ribbed Newt






Iberian Ribbed Newt, or the Spanish/Sharp Ribbed Newt (Pleurodeles Waltl), primarily resides in the Iberian Peninsula (in Southwest Europe) and Morocco. These rather well-known newts are commonly kept as pets, regarded very highly for their bold appearance - a cream or yellow belly starkly contrasted against a darker greenish-brown back - and a rather unusual defense mechanism.

Their common names refer to the ability to rotate their ribs within their own bodies and drive them out, creating a series of petrusions that, when combined with the naturally toxic secretions of the newt, establish a very effective (and often lethal) defense against predators. Although it was previously believed the newt had specific spores to aid this process, it has been established that the newt actually pushes the ribs through its flesh when it engages this mechanism in times of distress. However, the newt has a natural immunity to the toxic it creates (as this process would almost certainly prove fatal to the newt otherwise), and a remarkable ability to regenerate tissue - as a result, this response does not appear to be particularly detrimental to the newt. The Ribbed Newt would make a rather unpleasant meal, but has consistently proven to make an excellent pet.

Care:

Mature newts can grow to be quite sizable (noticeably larger than most other types of newt), and one should make sure to give them the appropriate amount of space. Also, in their natural habitat, this variety of newt spends a great deal of time around ponds, ditches, and other slow-moving bodies of water - it is important to factor this into establishing its home. These newts are quite comfortable with a largely aquatic environment, provided they have something to rest upon when they wish. A few reasonably-sized pieces of cork wood should serve this purpose, offering them a pleasant respite from the water. As with many other varieties of newt, water straight from the tap is potentially harmful, so it is recommended to use de-chlorinated water or spring water. It is suggested your newt have some form of filtration for its aquatic environment - an undergravel or power filter should do nicely.

The Ribbed Newt is a carnivore, and will require different varieties of live food as it matures. Their tastes are not particularly exotic, and they share many preferences with other species of newt. Younger ones will prefer smaller prey such as whiteworm and tubiflex, while older (and therefore larger) pets will quite happily dine on slugs and earthworms. They are rather shy, and will occasionally abstain from eating while observed - particularly early on. As the newt becomes more comfortable with its environment, it will generally become bolder. As in many other regards, patience is tremendously valuable in working towards putting your new newt at ease.

If you're considering a newt as a pet, the Ribbed Newt would be an excellent choice. They are interesting, beautiful and remarkably low-maintained creatures. With the proper care and attention, they are quite content in captivity. This having been said, it may be wise to properly secure their environment - the Ribbed Newt has a reputation for escape attempts.