Sunday, March 4, 2012

Titillating Tadpoles

Hey ya'll 

If there's something I especially love about insects and invertebrates, it is their ability to change almost completely in terms of form, shape and color as they grow up. Not many other animals that I know of, specifically vertebrate animals, can boast of such a radical change in their entire physical structure as they age. Indeed, insects and arachnids aside, one of the other animals I can think off of the top of my head that does this  are the amphibians, frogs and toads and salamanders as such. Starting their lives as fish-like tadpoles before they emerge as full grown amphibians that can walk on land, I always fantasize that the growing up process of these animals resembles somewhat the transition our own aquatic ancestors must have gone through millennia ago!

Tadpoles of the Common Asian Toad (bufo melanostictus)
And why shouldn't I be reminded of that, when Charles Darwin himself remarked in the study of embryology, that the immature stage of many metamorphosing animals, amphibians and certain insects for example, are often so similar to each other (the larvae of a beetle is really quite similar to the larvae of a butterfly or moth, so too are the tadpoles of almost all species of frogs, toads and newts) is that they in many ways resemble the original form of these creatures before evolution bestowed them with so many diverse and wonderful traits. In that sense, although many of these animals adapted to be able to live in both land and water, they never quite cut their ties with their land of birth and consequently must continue to reproduce there. Indeed, certain species of toads which are almost entirely terrestrial still breed in pretty much the same way and go through several life stages from tadpole to adult. Conversely there are species of salamanders and newts which do not entirely mature at all, suggesting stronger ties between the creature and its embryonic "original" state. Indeed, though they may seem superficially similar to reptiles, Amphibians are really quite a distinct order. While all reptiles are amniotes (which means they lay eggs that have been terrestrially adapted to land) amphibians are not and therefore exhibit closer ties to their aquatic ancestry. It is no coincidence, that the tadpole breathes with gills when the species as a whole evolved from bony fish like creatures that adapted to "walking" short distances on land.

Try to imagine a dinosaur sized, one of these!!!
All the aside, I'm really quite psyched to begin raising these guys (which I obtained from my aunt's place, by the way) as it has been quite awhile since my last amphibian. You will remember, of course, our darling Trevor that was eventually released back into the wild so that he may partake in the breeding rituals of his kind. I wonder what he is doing now... indeed, if he is even still alive. Considering how I released him into a forested area, I am hoping he would not have been accidentally run over by a car, although, I suppose there are always snakes around. Meanwhile, I've housed the current tadpoles on my table tank, together with the rest of my fishes although I am rather concerned what to do with the toadlets when they emerge (they need to find dry land to transform or risk drowning) but I have put in lots of plants for now that they may cling to and eventually climb to the surface. I suppose, however, if I find any sprouting legs I can always fish them up with a net myself. For now they are very useful as the bottom feeders of my tank.


No comments: