Leech

Leech Nama Latin : Hirudo medicinalis Phylum : Annelida Sub Phylum : - Ordo : Gnathobdellida Family : Hirudinidae Genus : - Species : Hirudo medicinalis Kelas : Hirudinea Nama Daerah : Lintah Pacat

Pernapasan: Respiration is carried on at the surface of the body, oxygen being taken into, and carbon dioxide given off by, many blood capillaries in the skin. Waste products are extracted from the blood and coelomic fluid by seventeen pairs of nephridia which resemble those of the earthworm, but frequently lack the internal opening. Habitat: Hirudo, like most of the members of its family, lives in relatively shallow water in temperate or subtropical regions. Pencernaan: The alimentary tract is fitted for the digestion of the blood of vertebrates, which forms the principal food of some leeches. The mouth lies in the anterior sucker and is provided with three jaws armed with chitinous teeth for biting. The blood flow caused by the bite of leech is difficult to stop, since a secretion from glands opening near the jaws prevents coagulation. Blood is sucked up by the dilation of the muscular pharynx. The short esophagus leads from the pharynx into the crop, which has 11 pairs of lateral branches. Here the blood is stored until digested, presumably by the action of symbiotic bacteria. A leech is able to ingest three times its own weight in blood, and since it may take as long as 9 months to digest this amount, meals are few and far between. The intestine leads from the crop and stomach to the rectum which opens through the anus on the dorsal surface of the posterior sucker. The absorbed food passes into the blood vessels and the coelomic cavities, and is carried to all parts of the body. The coelom is usually small bacause of the development of the botryoidal tissue, which is homologous to the chloragogen tissue of the oligochaetes. The spaces in the body which are not filled up by this tissue are called sinuses, and in many species contain a fluid very much like true blood. Reproduksi: Leeches are hermaphroditic, but the eggs of one animal are fertilized by spermatozoa from another leech. the spermatozoa arise in the nine pairs of segmentally arranged testes: the pass into the vas deferens, then into a convuluted tube called the epididymus, where they are fastened into bundles called spermatophores, and are finally deposited within the body of another leech by means of the muscular penis. The eggs arise in the ovaries of which there is a single pair; they pass into the oviduct, then into the uterus, and finally out through the genital pore. Copulation and the formation of a cocoon are similiar to these process in the earthworm. Peranan: The hirudids visit animals to take blood meals infrequently. Some, however, enter the upper respiratory tract of cattle and horses as they drink, causing respiratory difficulties and secondary infections.