ZOO 115 Invertebrate Zoology Phylum Annelida Class Clitellata
ZOO 115 Invertebrate Zoology Phylum Annelida Class Clitellata Subclass Hiruninoidea
Subclass Hiruninoidea- General Characteristics n ~ 350 species n n n Terrestrial, freshwater and Marine Ectoparasites or predators Leeches n Range from 1 cm to 30 cm in size http: //faculty. clintoncc. suny. edu/faculty/Michael. Gregory /files/Bio%20102/Bio% 20102 %20 Laboratory/Protostomes/ protostomes. htm http: //news. nationalgeographic. com/kids/2003/10/imag es/leech-big. jpg
Subclass Hiruninoidea- General Characteristics n n All have a terminal or posterior sucker No Chaetae
Subclass Hirundinomorpha external anatomy n Typically have an anterior sucker as well http: //www. mathematik. uni-bielefeld. de/~alscher/anatomy. html
Subclass Hiruninoidea- locomotion Musculature Circular Diagonal Longitudinal Dorso-ventral http: //bio. classes. ucsc. edu/bio 136/annelids/hirudinea/ hirudinea 1. gif http: //biodidac. bio. uottawa. ca/thumbnails/images/HIR U 001 B. gif
Subclass Hiruninoidea- Nervous system n Similar to Oligochaetes n n Anterior and Posterior Ganglia more concentrated because of suckers Have sensory papilla along body n Small projecting discs containing many sensory cells Chemosensory n Vibration n Heat n
Subclass Hiruninoidea- Feeding and Digestion n Mouth usually Salivary glands in anterior sucker Jaws cut flesh Most have jaws Salivary Muscular Pharynx glands http: //animaldiversity. ummz. umich. ed u/site/resources/Grzimek_inverts/Hiru secrete dinea/v 02_id 297_con_hiranat. jpg/vie w. html Hirudin
Subclass Hiruninoidea- Feeding and Digestion Gastric cecum n n -note that it has been disconnected from the pharynx and moved to show other parts of the anatomy Blood or prey sucked in with pharynx Blood meal up 10 x body weight Passed to simple gastric cecum Bacteria do most of the digestion http: //animaldiversity. ummz. umich. ed u/site/resources/Grzimek_inverts/Hiru dinea/v 02_id 297_con_hiranat. jpg/vie w. html
Subclass Hiruninoidea- Feeding and Digestion n Anus is dorsal and anterior to the posterior sucker
Subclass Hiruninoidea- Circulatory system n Simple system reverting back to sinuses n Coelom is a global circulatory system
Subclass Hiruninoidea- Excretion n Metanephridia n Usually one pair per segment
Subclass Hiruninoidea- Respiration n n Mostly by diffusion through the body wall A few species have gills
Subclass Hiruninoidea. Reproduction Prostate gland n Sexual only n Hermaphrodites n However they are protandric n n Penis in sheath Male then Female Ovary Copulation Annual or 2 yr cycle n Many have a penis n Others use hypodermic penetration n Vagina Testis sacs in posterior of animal - not shown
Subclass Hiruninoidea. Reproduction Prostate gland n n n Clitellum used to develop cocoon for eggs Penis in sheath Eggs laid from a few days to months after copulation Hatch 3 -5 wks Vagina Ovary Testis sacs in posterior of animal - not shown
Problems caused by leeches n Gut bacteria can cause wound infection. n n In the post-operative use of leeches this is closely monitored and dealt with by use of the appropriate antibiotic. There is no evidence to suggest that leeches transmit diseases or parasites. n The presence of trypanosomes, (malarial parasites), in the gut of jawless leeches has been noted, but jawed leeches do not appear to be hosts.
Problems caused by leeches n In 1799, soldiers serving under Napoleon marched from Egypt across the Sinai Peninsula to Syria. n n They drank water from waters contaminated by leeches. Leeches attached to the insides of the soldiers noses, mouths, and throats. Once attached, the leeches gorged on blood and enlarged Many of the soldiers died from suffocation. In addition, other soldiers died from excessive blood loss.
Medicinal uses n Plastic surgeons use them when venous congestion of skin and muscle flaps is a problem. n n n Leeches are treated in the same way as blood products and are reused only on the same patient. Treatment of black eyes Hirudin n n treatment of inflammation of the middle ear being developed for experimental use as a systemic anticoagulant
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