For the love of all things slimy

Amphibians.

For a while now, I've been working/studying with a lab that researched a certain type chytrid fungus.  It's a herpetology lab (herpetology: the study of reptiles and amphibians, no one knows why they were lumped together, but they were), and the lab focuses on Bd.  That is going to change soon, as I am going to begin studying birds, but I'd like to share a little bit of information I've picked up at my current place of work.

In the vernacular, chytrid fungus is a very old type of fungus, and the species were thought to either be saprobes (they eat dead/decaying stuff) or parasites that live on plants and invertebrate animals.  Recently, however, and when I say recent I mean 1999, which in the world of science is very recent, a species was discovered that infected the skin of amphibians.  Batrachochytrium dendrobatidis (shortened to Bd) was unusual because it was the only chytrid known that affected vertebrates, amphibians specifically.

This is important because Bd appears to be capable of infecting almost all of the worlds amphibian species. An infection with a large amount of Bd is called chytridiomycosis.  This disease causes the skin to become very thick, usually deadly in amphibians because they drink and absorb salts(electrolytes) through their skin, not their mouth.  Abnormal levels of electrolytes can cause heart failure.  In the lungless salamander, which uses its skin to breathe, chytridiomycosis can cause suffocation.

Since it was discovered, Bd has been found on every continent inhabited by amphibians in both wild and captive species.  So far, there is still debate over whether this has been historically present and infecting populations all along and recent environmental changes caused a spike in the disease, or because it was only recently introduced to populations which have no defense.    


This is a serious disease and has contributed to the recent global decline of amphibian populations.  Other factors include environmental change and pollution, and habitat destruction (always a huge and horrible factor, so we need to work on saving the rain forest!). 

Japanese Giant Salamander


Amphibians are critically important to our knowledge of the world around us.  They are the best indicator species.  An indicator species is a species whose presence/absence/health gives an indication of the health of the ecosystem as a whole.  Amphibians are excellent indicators because not only to they live on land and in the water, they also absorb the environment right into their skin: water, salts, toxins, everything in the ecosystem.  


Right now, their decline is telling us something very important.  Habitats and ecosystems are critically changing.  In the United States alone since just 1980, the number of native species suffering in severe population decline has doubled.  The current extinction rate of amphibians is calculated to be at least 200 times the normal rate of background extinction.


Amphibians require a plentiful supply of fresh water free from chemicals and microbes to survive.  So do humans.  Human population growth and climate change are combining to create a situation in which a large and increasing proportion of the human population is denied access to sufficient, clean water. The rapid decline of the world's amphibians is a warning that this most precious of natural resources is under serious threat.  Frogs aren't the ones contaminating said resources with chemicals.  We are.  


We need to wake up and get our shit together. 


Sources: 
Gagliardo, R., P.Crump , E. Griffith,et al. 2008. The principles of rapid response for amphibian conservation using the programmes in Panama as an example, International Zoo Yearbook 42: 125-135.


Hyatt, A.D., DG Boyle, Olsen V et al. 2007. Diagnostic assays and sampling protocols for the detection of Batrachochytrium dendrobatidis, Diseases of Aquatic Organisms 73: 175–192.


Murray, K.A., L.F. Skerratt, R. Speare, and H. McCallum. 2009. Impact and dynamics of disease in species threatened by the amphibian chytrid fungus, Batrachochytrium dendrobatidis. Conservation Biology:23:1242-52.


Rachowicz, L.J., J. Hero, R.A. Alford, J.W. Taylor, J.A.T. Morgan, V.T. Vrendenberg, J.P. Collins, & C.J. Briggs. 2005. The novel and endemic pathogen hypotheses: Competing explanations for the origin of emerging infectious diseases of wildlife. Conservation Biology 19: 1441-1448.


Skerratt, L.F., L. Berger, R. Speare, S. Cashins, K.R. Mcdonald, A. Phillott, H.Hines, and N. Kenyon. 2007. Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs. EcoHealth 4:125-134.

Costa Rica

Is where I'll be this summer!  Researching avian ecology and the Chestnut-backed Antbird.  Specifically nest predation.

I have never been to Costa Rica, so today I am sharing what I'm teaching myself, and you're welcome to correct me if you know more.

But first, the Chestnut-backed Antbird:

photo credit to: Jorge Chincilla

Puffy little thing.  Common in the understory of wet forests.  Like most antbirds, it doesn't actually survive solely by preying on army ant swarms, it just forages on them opportunistically.

This is a male, probably.  Like I said, I'm not completely familiar with the species, but the females are said to have brown coloration on their breast and belly, and males have black.

Other things I should look out for when I'm down there are venomous snakes (like bushmasters) and jaguars (I really want to see one, but if I couldn't live to talk about it, it wouldn't be worth seeing), all manner of really awesome bugs (check out the list here), and bird heaven.  I will be in tropical wet forest.

From what I've seen of species maps, Costa Rica is apparently home to two species of bushmaster, the Black-headed bushmaster and the Central American bushmaster.

Black-headed bushmaster (Lachesis melanocephala)

Central American bushmaster (Lachesis stenophrys)

Not a super great shot of the body, but the difference in head coloration is mainly what you need to see.  Genus Lachesis consist of three species of venomous pit vipers (not shown here is the South American bushmaster).  Bushmasters are the longest venomous snakes in the western hemisphere, and longest viper.  The venom can be fatal, but usually only causes sever pain, vomiting, nausea and the chills.  Thankfully the snake is most efficient as a nocturnal predator and it's contact with humans is limited because of this.  With regards to the myth that they hunt in pairs and are attracted to fire, I've found millions of statements denying both.

Another snake to fear would be the Fer-de-lance, or terciopelo (Bothrops asper).  Another viper.  You can research that one on your own.

As far as snakes in Costa Rica go, unless you know your stuff, leave them alone.  This is directed at myself.  Though hopefully I will meet an expert down there and benefit from their knowledge and wisdom.

As far as bugs go, I really want to see a Hercules Beetle (Spanish name: Cornizuelo, Dynastes hercules), and here is why:

That thing is awesome.  I want to hold it right by my face and take a very cliche photograph with it.

As far as mammals go, I haven't got anything specific in mind, but I will be on the lookout for pretty much everything.  I'm hoping to procure a couple field guides.  Not sure which are the greatest yet, but don't worry, I will do my research.

Also, on a related note, I'd like to make sure everybody knows how to differentiate between a venomous snake and non venomous snake.  The guideline I'm including is a rough guide, there are exceptions.  The part to pay most attention to is the head shape, because that's usually what you can see from a ways away.

Also, it says U.S. snakes, but it's pretty universal, and this chart also doesn't include sea snakes, simply because the one with sea snakes wasn't as well drawn.

Use wisely.

Age of Arthropods

Arthropods.

Segmented, jointed invertebrates with an exoskeleton.  They make up over 90% of all known living animal species.  Humans like to eat them, raise them, and kill them.  We like to love them and fear them.  We think some are tasty, and we think some are the most creepy things we've ever seen in our lives.

What we need to keep in mind, however, is that we need to respect them.  When it comes to humans and bugs, one might naturally think that because humans are bigger, they are better and more superior.

This would be a mistake.  Bugs are crazy awesome.  They are well adapted to almost every environment, and can survive a lot more than humans can.  We throw all our waste at them and they simply keep on trucking.  If any person on this earth is foolish enough to think that this is the age of man, and that humans are ruling the earth, they merely have to look at the facts.  Some studies estimate that there are over 200 million insects for every human.  That's not even including crustaceans, which are also in this category.  We're outnumbered.  Badly.

And we're amazingly lucky that their size is limited by their exoskeleton so that movies like this

will never actually happen.  (The weight of the exoskeleton would crush them if they were that large)

Thank God.  But please don't think that you shouldn't be afraid of bugs.  They're disease carriers, they're poisonous, venomous (yes there's a difference between poisonous and venomous, look it up) and all very well adapted to survive.  If you don't believe me, check out this link.  It's a hilarious but pretty accurate description of some truly terrifying arthropods.

It's not my intention to freak you out with that article, but I do wish to impress upon readers that arthropods are all extraordinarily impressive creatures, and we would do well to learn more about them before they take over the world.