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

Male Great Crested Newts undergo an amazing change in appearance during the breeding season.  In Part I of this article I introduced the natural history of this most beautiful newt, and discussed how to bring it into breeding condition.  I’ll cover breeding details and raising the larvae here.

Courtship and Egg Deposition

Breeding male newts tend to fight and, although severe damage is rarely inflicted, less dominant animals may become stressed and cease feeding. Courting males position themselves near females and appear to direct pheromones towards them with their tails. Females thus stimulated follow the males, push against their tails, and eventually pick up the spermatophore that the male has dropped.

Several hundred eggs are laid, each being individually attached to an aquatic plant. Females use their rear legs to bend a plant leaf around each egg – quite an ordeal, and well-worth watching!

Adults may consume eggs and so should be removed from the aquarium after egg-laying has been completed.  If prevented from returning to land after breeding, adult crested newts usually become quite stressed, thrashing about wildly.  Some subspecies, however, can be habituated to a more-or-less permanent aquatic existence.

Raising the Larvae

Crested Newt larvae generally hatch within a month and transform into the terrestrial phase within 3 months, at which point they average 2.4 inches in length.

The larvae can be raised on chopped live blackworms, brine shrimp, daphnia and similar foods; new metamorphs can be offered 10 day old crickets, blackworms, termites and tiny sow bugs.  Sexual maturity occurs in approximately two years, at which time they will re-enter water to breed.

An Even More Flamboyant Relative

A close relative, Triturus vittatus ophryticus develops an incredibly high crest that starts at the nose area and ends at the tail. This species is now showing up in the pet trade, and can be bred in a similar manner to the Crested Newt.

Further Reading

Please see a book I’ve written, Newts and Salamanders, for more on the care and natural history of Crested Newts and their relatives.

You can learn more about the natural history of each newt in the genus Triturus here.

Larval Crested Newt image referenced from wikipedia and originally posted by Piet Spaans

Few amphibians exhibit a more dramatic change in appearance than male Crested Newts in breeding condition.  It really is something to see and, fortunately, breeding this species is actually quite feasible.  Breeding the crested newt in captivity also has great conservation value, as this species is in decline throughout Europe.  Furthermore, any information garnered is applicable to other species of concern, including the Alpine Newt, Triturus alpestris and the Swiss Newt, T. helveticus.

Natural History

The Crested Newt, which may reach 6.4 inches in length, is grayish to black above and orange with round black spots below.   

Living a largely terrestrial existence for most of the year, both sexes enter breeding ponds in late winter or early spring.  At this point, the males’ colors intensify and a large, comb-like dorsal crest develops. In both sexes the tail also becomes more paddle-like to facilitate swimming. Males also usually develop a white line along the sides of the tail, while reproductively active females sport a white line down the back.

Bringing Newts into Breeding Condition

While breeding may occur spontaneously in captivity, the most consistent results will be obtained if the newts are over-wintered at 36-42 F.  An increase in water depth may stimulate breeding outside of the normal cycle, but fewer viable eggs will be produced).

Upon emergence from hibernation, the newts should be housed in aquarium, or their terrestrial terrarium should be modified to provide a large water area. Resting sites such as cork bark slabs or basking platforms should be provided.

Due to their unique egg-laying behavior (females fold a plant leaf around each egg), crested newts slated for breeding are best housed in well-lit aquariums stocked with live plants.  The water should, if possible, be maintained at 54-65 F (a cool basement or garage often proves ideal).

We’ll take a look at raising the larvae next week. 

One of the world’s rarest amphibians is being bred by dedicated hobbyists and is now available in the US pet trade. Anderson’s salamander, Ambystoma andersoni, which was only formally described in 1984, is limited in range to a single high altitude (6,000+ feet above sea level) lake and stream in south-central Mexico (Laguna de Zacupa, Michoacan, Mexico).  The IUCN lists it as “Critically Endangered”.

Rare Aquatic Salamanders of Mexico’s Highlands

Anderson’s salamander is part of a complex of similar aquatic, neotenic salamanders which includes the Mexican axolotl (A. mexicanum).  Neotenic species retain larval characteristics such as external gills and an aquatic lifestyle upon maturity.

A dozen or more species of these unique, poorly-studied amphibians inhabit mountain lakes in Mexico.  Most are found only in a single lake or, in the case of the axolotl, may exist only in canals and other habitat remnants. Some, including the Dumeril’s salamander (A. dumrelii), seem to have adapted to waters that are somewhat saline in nature.

Hope for the Species’ Survival

The sole population of Anderson’s salamanders is threatened by pollution, habitat loss and collection for the (human) food trade.  Its relative, the Mexican axolotl, was saved from extinction by captive breeding efforts, and is now in the unique position of being one of the most common captive and rarest wild salamanders.

Originally surfacing in Europe, captive-bred Anderson’s salamanders are now available in the USA as well.  This represents a unique opportunity for serious hobbyists to help learn about and conserve an endangered species. As a bonus, Anderson’s salamander is large, beautifully patterned and relatively hardy as well.

Keeping Anderson’s Salamander

The captive husbandry of Anderson’s salamander is similar to that of the Mexican axolotl (please see article referenced below)…please write in if you are interested in becoming involved what may become a most worthwhile amphibian breeding effort.  At this point, noted salamander specialist Michael Shrom is likely the only person breeding Anderson’s salamanders in the USA. You can contact Michael at shrommj at ptd.net.

Further Reading

You can read more about the natural history of Anderson’s salamander and its relatives at http://www.mexico-herps.com/caudata/ambystoma/ambystoma-andersoni.

For information on the Mexican axolotl, please see my article The Natural History and Care of the Mexican Axolotl http://blogs.thatpetplace.com/thatreptileblog/2008/12/19/the-natural-history-and-captive-care-of-the-mexican-axolotl-ambystoma-mexicanum-natural-history-part-1/.

Photos courtesy of Michael Shrom.

As mentioned in Part I of this article, tiger salamander larvae (Ambystoma tigrinum), run through with a hook while alive, are still used as fishing bait in some parts of the USA.  Last time we learned about the bait trade’s role in spreading a Chitrid fungus that is decimating amphibian populations worldwide, and in hastening the extinction of endangered tiger salamanders through hybridization.

Endangered but Legally Exploited

Despite the aforementioned environmental nightmares, the bait trade in tiger salamanders remains largely unregulated, resulting in infected animals being shipped from state to state.  This practice hastens the spread of already fast-moving pathogens and of non-native salamanders, as surveys have revealed that most people and bait shops release unused larvae into local waterways.

The situation is rendered all the more bizarre by the fact that these largest of all terrestrial salamanders are critically endangered in many areas.  In fact, several subspecies, including the Eastern tiger salamander (Ambystoma tigrinum tigrinum), are protected by individual states as endangered species!

Other Threats

Tiger salamanders also face serious threats from habitat loss, pollution and the introduction of game fish to breeding ponds.  Their use of two distinct habitats – aquatic and terrestrial – renders them especially vulnerable.

Protection, when offered, is often ineffective.  In New York State, for example, 75 feet of land around breeding ponds is closed to development – but research has shown that few if any adults live within that radius!

Tiger Salamanders in Captivity

Tiger salamanders make interesting and unusually responsive captives. Longevities exceed 30 years, but captive reproduction is still somewhat problematical.  They certainly deserve more attention from hobbyists …please write in for further information.

American Bullfrogs

American bullfrogs (Rana/Lithobates catesbeianus) have also recently been implicated in spreading amphibian diseases (New Scientist: May, 2009).  Researchers monitoring food markets in NYC and California discovered that 8% of the frogs being offered for sale carried ranavirus and nearly 70% were infected with Chytrid!

Further Reading

You can learn about the natural history of the eastern tiger salamander, and the steps being taken by the NYS DEC to prevent its extinction, at

http://www.dec.ny.gov/animals/7143.html.

The Organization Amphibian Ark has taken a leading role in Chytrid research.  Read about how this fungus has caused amphibian extinctions, and predictions for the future of the epidemic, at http://www.amphibianark.org/chytrid.htm.

Image referenced from Wikipedia and originally posted by Tigershrike.

Please see Part I of this article for general information on some of earth’s most toxic amphibians (if not creatures in general) and for additional newt-keeping observations.

Tiny Newt vs. Giant Toad

The familiar red-spotted or Eastern newt (Notopthalmus viridescens) is at its most toxic in the immature eft (land) stage, but the aquatic adults are none-the-less well protected.

Decades ago, the mascot of an animal importer for whom I worked was a huge marine toad (Bufo marinus).  In those days, animals imported from then French Guyana were particularly massive, and this friendly, 4 pound+ specimen was no exception.  Imported animals which did not thrive following their long journey to the USA, ranging from giant Vietnamese centipedes to small rats and finches, all went to filling this amphibian behemoth’s huge appetite.

As a naïve 13 year old animal caretaker, I once tossed a nearly dead, 3-inch- long Eastern newt to the toad.  The newt was swallowed immediately and, right before my eyes, the toad flipped over…dead (along with my budding career!).  Years later, a co-worker reported a similar incident involving a Western painted turtle (Chrysemys picta bellii).

Interesting Means of Toxin Introduction

Several salamanders have quite unique ways of distributing their protective secretions – fire salamanders (Salamandra salamandra), for example, can squirt theirs for some distance.  Perhaps strangest of all, the Spanish ribbed newt (Pleurodeles waltl) actually drives toxin-tipped ribs through the skin of its back when confronted by a predator!

Cautions regarding Pet Newts and Salamanders

Highly toxic newts and salamanders, including all mentioned in this article, are widely available in the pet trade.  Many make interesting and long-lived pets.  However, please treat all newts and salamanders with caution…always wash well after handling them (most need not be handled, and none appreciate it) and, of course, do not trust them around children, mentally challenged persons, or pets.

Further Reading

Please check out my book Newts and Salamanders  for more information on the natural history and captive care of red-spotted newt, ribbed newts, fire salamanders and their relatives.

Image referenced from Wikipedia and originally posted by Peter Galaxy.