The Axolotl

The Axolotl is a species of salamander that is closely related to the tiger salamander. It is also known as the Mexican salamander (Ambystoma mexicanum) or Mexican walking fish, although instead of a fish it is actually an amphibian.

Physical Description: 

Sexually mature males (at about 18-24 months) range in length from 6-18 inches (15-45 cm) with sizes closer to 9 in inches (23 cm) being the most common and any individual over 12 inches (30 cm) is pretty rare. axolotls possess features that are usually typical of salamander larvae, including external gills and a caudal fin extending from behind the head to the vent.

They have wide heads and they have no eyelids. They possess underdeveloped looking limbs that have long, thin digits. Males can be distinguished by their swollen cloacae (that's their boy parts for anyone that doesn't know) lined with papillae while the females are distinguished by their wide bodies that are full of eggs. Three pairs of gill stalks called rami originate behind their heads and help move oxygenated water. The external gill rami are lined with filaments to increase surface area for gas exchange. There are four gill slits lined with what's called gill rakers that are hidden underneath the external gills.



Axolotls have barely visible vestigial teeth which would have developed if they were a normal salamander that had gone through normal salamander metamorphosis. That's the thing about Axolotls, they don't go through the same process that other salamanders do, because instead of going through development and setting foot on land,Axolotls remain in the water once they reach adulthood. Their primary method of feeding is through suction, which is done by their rakers interlocking to close the gill slits. External gills are used for breathing, although buccal pumping (gulping up air from the surface) may also be something they use to gather much needed oxygen.


Axolotls come in very few colors. The two normal colors are "wildtype" (various shades of brown with spots) and melanoid (black). The two mutant colors are leucistic (pale pink with black eyes), and albino (golden, tan, or pale pink with pink eyes).

Fast Tracking to Adulthood

Axolotls exhibit something called neoteny, meaning that they reach adulthood without going through the typical metamorphosis that all other salamanders normally go through. Many species in the same genus are either entirely neotenic, or have neotenic properties. It is something that has been observed in all salamander families and seems to be a survival mechanism that only occurs in aquatic environments in the mountains and hills where this little food and a lack of iodine. Unlike some neotenic salamanders, metamorphosis can be induced in Axolotls through an injection of iodine or by shots of thyroxine hormone. An adult can look like a species of terrestrial plateau tiger salamander, but it has several differences which include longer toes which supports its status as a separate species.

Basically, if there is a generous amount of iodine in their environment, the salamander larvae can ingest it either directly or indirectly through cannibalism, and then they quickly go through metamorphosis and become mature adults with higher dietary requirements, but because Axolotls don't live in these types of environments, they don't which allows them to live and thrive on less.

If you want to find out more about Axolotls and how they were used as a model organisms before anyone learned about their neotony you can look right here.

Habitat

Axolotls are only native to two lakes in Central Mexico: Lake Xochimilco and Lake Chalco. Lake Chaico no longer exists as it was artificially drained to avoid periodic flooding and Lake Xochimilco is a remnant of its former self, only existing as a series of canals. The water temperature in Lake Xochimilco rarely rises above 20 degrees Celsius (which is 68 degrees Fahrenheit), though it may fall even lower in the winter months.

Axolotls are members of the Ambystoma tigrinum (Tiger salamander) complex, along with all other Mexican species of Ambystoma. Their habitat is like that of most neotenic species, a high altitude body of water surrounded by a risky terrestrial environment. These conditions are thought to favor neoteny, but there is a population of tiger salamanders that also inhabit the Axolotls' habitat.

Diet

Axolotls are carnivorous, consuming small creatures such as worms, insects, and small fish in the wild. They locate their food by smell, and will "snap" at any potential meal, sucking the food into their stomachs by vacuum forces.

Conservation Status: 

The Axolotl is listed as critically endangered on the IUCN's red list of endangered species. Current population numbers are unknown, but it is known that the numbers have declined significantly according to surveys that have been done since 2002.

Main Threats: 

 The species is suffering due lake drainage and the growing population of Mexico City. They are also under threat from harvesting for consumption by local people as well as pollution, and degradation of the canal system of Lake Xochimilco. Introduced predatory fish into their environment is also a grave threat to the species. 

What's Being done? 

Conservation action focusing on conserving the species is focused on raising the profile of Lake Xochimilco through conservation education and a nature tourism initiative, along with work on habitat restoration. An action plan for conserving the species is currently underway. This species is protected under the category Pr (Special Protection) by the government of Mexico and is in the process of being amended to a higher category. The Axolotl is currently at Appendix II on CITES, restricting international trade to protect the species from over-harvesting in the wild, where it has been listed since 1975. However the species is currently undergoing the process of "Review of Species included in CITES Appendices."

The Irawaddy Dolphin

I am sure pretty much everyone out there has heard of Flipper, and I am sure that there are several of us out there that may have even caught a dolphin show or two at one of Sea World's many parks (yes, I know about Blackfish. No, I will not discuss it). THOSE dolphins are a species known as Atlantic Bottlenose Dolphins, but did you know that there are other species of dolphin as well? Orcas, for instance, or Killer Whales, are not actually whales at all but they are actually a very large species in the dolphin family.

But I'm not here to talk about any of those. I am here to talk about ANOTHER species of dolphin.....

The Irrawaddy Dolphin. 

The Irrawaddy dolphin (or Orcaella brevirostris) is a species of dolphin that is primarily found in estuaries and mangrove areas of South East Asia with freshwater populations occurring in river systems.

• Social Structure: There are usually no more than ten individuals to a group, and solitary individuals are rarely seen.
• Diet: This animal likes to munch on fish and crustaceans.

Physical Characteristics

The Irrawaddy dolphin can be identified by its bulging forehead, short beak, 12-19 teeth on each side of its jaw, with a broadly triangular pectoral fin, and a small dorsal fin on the rear end of the back. Its identifying colors range from a slaty blue to a slaty grey with the underbelly usually being much paler.


When it's diving, this breathes in 70-150 second intervals. The head usually appears first, and then the back, but the tail is rarely ever seen. It's body size is 180 - 275 cm (about 71 in. - about 108 in.)


Population Distribution: 

This species has small populations that are spread out over a large area. Freshwater populations occur in the river Mahakam in Kalimantan (Indonesian Borneo), the Ayeyarwady (formerly Irrawaddy) of Myanmar (formerly Burma), and the Mekong Delta of Laos, Cambodia, and Vietnam. Populations have also been reported in isolated brackish (both saltwater and freshwater) bodies of water such as Chilka Lake in India and and Songkhla Lake in Thailand.


Conservation Status: 

Severe declines in population numbers have been occurring in parts of Thailand, and in the Mahakam freshwater sub-populations. The latter was classified by the IUCN Red List as Critically Endangered in 2000 because only a few tens of dolphins were found in an approximately 300 km segment of river (that's about 186 miles give or take).

The population of Irrawaddy dolphins residing in the Philippines in the Malampaya Sound (Palawan) seem to be geographically isolated from other populations and a survey that was done in 2001 put their population numbers at about 77 individuals which gave them the listing of "critically endangered" because that was how many individuals that were found in a 133km(2) area (Google Conversion puts that at about 82.6 miles).


Main Threats:

The Irrawaddy dolphins are not an overly exploited animal, but they are being threatened with extinction due to fishing (being accidentally caught in fishermen's nets), habitat degradation thanks to the building of dams, deforestation, and mining (but mostly fishing).

The small population living in the Makaham and possibly that of the Ayeyarwady River (formerly Myanmar, now Burma) are also captured live for display purposes.


What's Being Done?


The World Wildife Fund is working hard to help protect these unique dolphins by working with the Cambodian goverment's department of fisheries to help implement the Cambodian Mekong Dolphin Conservation Strategy. WWF also implemented the Malampaya Sound Research and Conservation Project in 2001 to help sustainably manage the fisheries in Malampaya Sound to help manage and protect the dolphin population in that area. In 2004 they helped support a ban on the trading of Irawaddy dolphins for oceanaria by the Convention on International Trade of Wild Fauna and Flora (a.k.a CITES).

How Can I Help?

You can help protect these rare dolphins by supporting efforts to improve fishing gear by only buying seafood that is MSC certified. This can help reduce the incidence of marine by catch (animals getting caught in nets that were not intended to be caught), which kills whales, dolphins, turtles, seabirds, and other marine animals. You can also help by spreading the word! Use the hashtag #ObscureNature to help spread the word so that other people can come and read this blog post. Also, you can find helpful links to other projects concerning the Irawaddy dolphin by heading over to the How Can I Help? section of this blog.

The Mimic Octopus

The Mimic Octopus (Thaumoctopus mimicus) is an amazing creature that was discovered really only a few years ago (1998 to be exact). It gets its name due to it's awesome ability to pretty much LITERALLY shape shift and impersonate a variety of different creatures other than itself as a form of camouflage. Believe it or not, I actually first learned about this animal on a kids show known as Octonauts (for more information here OR if you want to know about the books that the television series is based on, click here. Trust me, it's awesome and you and your potential children will love i.t)

Habitat Range

This creature is found almost exclusively found in the waters of Indonesia and Malaysia.

                (Photo Source: http://www.divernet.com)

Characteristics  

The mimic octopus uses a jet of water through its funnel to help it to glide over the sand while searching for its prey (namely crab, small fish, and worms). Like its fellow octopuses, the mimic octopus's body is made of muscle, without spine or armor. It is not obviously poisonous which makes it ideal prey for much larger, deep water carnivores like barracuda or small sharks.

Oscar Winning Performance? 

If there were ever an Oscar for Best Actor in an Underwater Shape Shifting Performance, this animal would win. Period.

Remember those big bad predators I mentioned earlier? Well, sometimes they are a little hard to get away from, and that is where the mimic octopus's awesome impersonation skills come in handy as it cannot squirt ink like other octopuses can. I have a distinct feeling that just having text here is not going to do this animal any sort of justice so here is some video that I managed to find of the mimic octopus in action. The video depicts the octopus's amazing shape shifting abilities along with some of the animals that it shifts into. Prepare to be amazed:

https://www.youtube.com/watch?v=os6HD-sCRn8 (There is also some narration with the video as well)

And just because I want to show everyone how awesome Octonauts really is: https://www.youtube.com/watch?v=RuDA8KSQDI8. This from the original version that airs over in England, but the show also airs on Disney Jr. here in the United States.

(Photo Source: http://www.palscience.com)

Conservation Status: 

The mimic octopus is not currently listed as endangered, but some biologists do worry that because of the attention this creature has been getting thanks to forms of media such as the Internet it may eventually become just that. There is apparently a pretty steep bounty placed on the mimic octopus by private collectors and some worry that this could cause a decrease in the creature's numbers.

Recently, there was an article on The Cephalopod Page by Dr. Roy Caldwell that describes the problem:


"There is no question that the mimic octopus and its relatives such as wunderpus are remarkable animals ... However, as the animals become better known, they are also becoming more desirable for public aquarists, scientists and hobbyists alike. The pressures to acquire and attempt to keep and display them are rapidly increasing. It is not uncommon to see requests for such animals and often the amount of money offered for them is staggering - $100 and up. At this point, I think we should all take a deep breath and think seriously about the biology of this species, what such bounties are likely to mean for its survival, and what motivates us to want a mimic for our very own."

The link to the full article can be found here.

Want to learn more? 

As mentioned before, it seems that mimics are growing quite popular, which may actually prove detrimental to their numbers in the wild so I felt like it was important to try and find a link that would help educate those that were even remotely curious about what the risks were exactly when it came to the exotic pet trade:

Facts about the Exotic Pet Trade (You can thank Animal Planet for the article)