Meryl SigatonCity of Silay, Philippines Leeches (Hirudo medicinalis) are invertebrates of the phylum Annelida whose main diet is blood. They are hermaphrodites and carnivorous, having 700 species that thrive in a variety of environments. Most of them are small, weighing less than 1–1.5 g before feeding, but some may reach a length of twelve centimeters.…