HOME DISPATCHES

 

PORQUE?

         Little is still known about the biodiversity of bloodfeeding terrestrial leeches of the world. The number of described species is most likely an underestimation of what exists in nature. As part of a large-scale project funded by NSF-PEET (Partnership for Enhancing Expertise in Taxonomy), our goal is to obtain a better assessment of the diversity of leeches and shed a bright light on their evolutionary relationships and current distribution. As mentioned (on the Blood Lust 1 site), bloodfeeding terrestrial leeches have a unique distribution, compared to other leech groups, in that they are found in damp terrestrial environments, many being restricted to high elevation montane regions, in tropical and subtropical forests throughout the Indo-Pacific.

         Land leeches are intolerant of salt water and few species are parasitic on birds (a possible mode of dispersal across oceanic barriers). Therefore one explanation for their current distribution is that it mirrors the breakup of the supercontinental landmass Gondwana. The endemicity of species found throughout their range provides another line of evidence to suggest this. In other words, leeches found in each of Australia, Madagascar and New Zealand, for example, are found nowhere else in the world. Therefore, having a better understanding of the evolutionary relationships of land leeches and accompanied with what we know about the timing of the breakup of each of the gondwanan landmasses, this group may have origins that date as far back as the mid to late Jurassic (>130, 000, 000 years ago).

         After finding a rare species in Chile, we began our search for land leeches in earnest in 2002 traveling to Madagascar and the Seychelles. We have continued this work in Malaysia and Thailand (Blood Lust II; 2005). Now we are engaging in an expedition to Australia to attempt to better characterize the diversity of leeches there. Here we are not interested in only looking for bloodfeeding land leeches, but also freshwater bloodsucking (a.k.a. "medicinal") leeches and leeches parasitic on fish and turtles. There have been few, and now mostly out of date, published works on the diversity of the leeches of Australia (e.g. Richardson, 1975, Sawyer, 1986). The most recent treatment of this group (Govedich, 2001, CRC for Freshwater Ecology, identification guide no. 35.) provides an overview of leech systematics and the currently recognized taxonomy of leeches from Australia, including Oceana, New Guinea and New Zealand. However, the evolution of the leeches of Australia is still poorly understood and their relationships have yet to be treated under a phylogenetic framework.

         In a nutshell, our journey will begin by our departure from Sydney and make our way up to Brisbane. The drive up will take about a week, collecting all the way. While in Brisbane and Sydney, we will visit the Queensland Museum and photodocument the museum's leech collections. We will then move on to Darwin, then Cairns and back to Sydney. All of this is in two and half weeks. More importantly, along the way we will be collecting from type localities (a locality which was identified by an author or authors as the primary site of collection of a newly described species), and other suitable leech "habitats" in order to obtain representatives of known species, and possibly of those species not yet known to science.

 

TIMELINE


~ 150,000,000 yrs ago


~ 120,000,000 yrs ago


~ 80,000,000 yrs ago


~ 45,000,000 yrs ago


~ 20,000,000 yrs ago