Dracunculus medinensis: The Guinea Worm Distribution Dracunculus medinensis, commonly known as guinea-worm is a parasite of the dog, horse, cow, wolf, leopard, monkey, and baboon that also commonly infects man. The majority of humaninfections occur in parts of West Africa, East Africa, and India. The larvae, which measure between 500 and 700 micrometers, can live for 6 days in clean water and 2 to 3 weeks in muddy water(see picture below taken from Peters andGilles 1991). The larvae are then ingested by Cyclops which actively chase them. Once ingested, the larvae mature into their infective stage in approximately 14 days and can thenreinfect humans. Pathology The female guinea-worm lives in the connective tissues of the limbs and truck where she usually does not cause any noticable pathological conditions (see X-ray below taken from Peters and Gilles 1991). After the ingested Cyclops is destroyed by stomach acids the free larvae penetrate the gut lining and migrate to subcutaneous tissues via the lymphatics. This process takes approximately 43 days and once in subcutaneous tissue the worms mature slowly, reaching fulldevelopment in one year. They then mate and the small male (1.2-2.9 cm long) dies and is absorbed into the larger female (60cm in length). When the embryos in the female's uterus reach maturity she migrates to areas of the body in contact with water (90% move to the feet and legs). Once in these areas the worm penetrates the skin, extrudes its uterus through its mouth, and discharges larvae into the water and dies(see picture below taken from Peters and Gilles 1991). Life Cycle The guinea-worm like all filarial nematodes goes through six developmental stages. The however unlike any other filarial parasite that can be transmitted to humans the infective larvae enter the body through the ingestion of various species of freshwater crustacea Cyclops (see picture below taken from Peters and Gilles 1991). Although heavy infestations in the joint can cause arthritic conditions and require the removal of the worms (see picture below taken from Peters and Gilles 1991), most pathology is associated with infection occuring when the female dies after discharging her larvae. The death of the worm causes the formation of a sterile abscess, which when secondarily infected results in cellulitis and local blistering of the skin (see picture belowtaken from Peters and Gilles 1991). However, chills fever and local painful swellings commonly precede the emergence of the worm. D.medinensis has also been found coiled in the hernial sac and retroplacentally causing bleeding inpregnancy. ****************************************** Diaptomus Diaptomus is a native freshwater Calanoid Copepod which has been largely displaced by introduced Copepods. Neomysis and Zooplankton The monitoring of neomysis and zooplankton is preformed by the Neomysis and Zooplankton Survey. The following is a list of zooplankton species for which enough information is gathered to develop abundance indices. This list is not an all inclusive list of the species encountered in SanFrancisco Bay and Estuary. Neomysis mercedes Acartia Diptomus Euytemora Sinocalanus List of introduced copepods and mysid shrimp. COPEPOD SPECIES ORIGIN YEAR INTRODUCED For more information contact: Jim Orsi at [log in to unmask] *************************************** http://www.delta.dfg.ca.gov/baydelta/monitoring/diaptom.html NONINDIGENOUS AQUATIC SPECIES IN A UNITED STATES ESTUARY: A CASE STUDY OF THE BIOLOGICAL INVASIONS OF THE SAN FRANCISCO BAY AND DELTA The San Francisco Estuary can now be recognized as the most invaded aquatic ecosystem in North America. Now recognized in the Estuary are 212 introduced species : 69 percent of these are invertebrates, 15 percent are fish and other vertebrates, 12 percent are vascular plants and 4 percent are protists. ***************************************** http://www.glerl.noaa.gov/pubs/abs81.html VANDERPLOEG, H.A. Seasonal particle-size selection by Diaptomus sicilis in offshore Lake Michigan. Canadian Journal of Fisheries and Aquatic Sciences 38(5):504-517(1981). Diaptomus sicilis feeding on offshore Lake Michigan seston exhibited a relatively invariant pattern of particle-size selection in 23 separate feeding experiments conducted from spring through fall over a 2-yr period. ****************************************** http://epaserver.ciesin.org:7777/glreis/glnpo/data/phytop/EPA-905-3-90-003/E PA-905-3-90-003.html 20. The presence of the oligotrophic rotifer association, the presence of the oligotrophic crustacean indicator species Diaptomus sicilis and Limnocalanus macrurus, the predominance of mesotrophic diatom species, the similarity of the plankton ratio on the north-south axis and a phytoplankton and zooplankton abundance and biomass between those of the eutrophic Lake Erieand oligotrophic Lake Huron