Leech on a Tadpole

A new article on BioMed Central has discovered something new about the taxonomy of these little “suckers”.  (I couldn’t help it.)

Here’s their results:

This study is the first to evaluate molecular evidence from hirudinid and haemopid leeches in a manner that encompasses the global scope of their taxonomic distributions. We evaluated the presumed monophyly of the Hirudinidae and assessed previous well-accepted classification schemes. The Hirudinidae were found not to be monophyletic, falling instead into two distinct and unrelated clades. Members of the non-bloodfeeding family Haemopidae were scattered throughout the tree and among traditional hirudinid genera. A combination of nuclear 18S rDNA and 28S rDNA with mitochondrial 12S rDNA and cytochrome c oxidase I were analyzed with Parsimony and with Bayesian methods.

Mmm .. Bayesian methods.

These types of leeches were instrumental in fascilitating the 19th century blood letting craze.  (I’m glad we’re past that, by the way.)  They conclude that “The family Hirudinidae must be refined to include only the clade containing Hirudo medicinalis (European medicinal leech) and related leeches irrespective of bloodfeeding behavior.”

I know that taxonomy is notorious for boring the living hell out of students.  But, I actually find it cool.  It’s a very human thing to try and categorize  all the elements, creatures, etc of the world.  We even do it with abstract notions like numbers and sets, and sets of sets, and sets of sets of sets.

Oh, and I spoke to soon about us being past the blood letting phase our history.  Check this site out.