Dracunculus medinensis-The Guinea Worm  BIO 203

D. medinensis larvae



            Scientific Name: Dracunculus medinensis
            Common Name: Guinea Worm
            Named by Linnaeus in 1758

Domain: Eukarya

Kingdom: Animalia

Phylum: Nematoda

Class: Secernentea

Order: Camallanida

Family: Dracunculidae

Genus: Dracunculus

Species: medinensis

   Male and Female D. medinensis            D. medinensis larvae           Guinea Worm Disease

Domain: Eukarya:: Dracunculus medinensis is an organism in which each cell contains a nucleus and membrane-bound organelles.
Kingdom: Animalia:: D. medinensis is a multicelluar organism that is heterotrophic, meaning that its energy is derived from the consumption of other organisms.  Due to D. medinensis being a parasite, it receives nutrition from its host. To learn more about parasitic animals please visit Taenia saginata.
Phylum: Nematoda:: Nematodes, including the Guinea Worm, contain a cuticle around their body for protection. This is their synapamorphy, or derived characteristic, shared by all organisms within the phylum. In addition, these organisms move with the use of a hydrostaticskeleton. These skeletons use the force and pressure of water to move in aquatic, soil, and other environments. The Guinea Worm is a parasite, and therefore uses its hydrostaticskeleton to move throughout mammalian and reptilian hosts. Nematodes can also be classified by their bodies containing: radial symmetry and true tissues composed of specialized cells working together for different functions. These tissues can be associated with three different body sections of a triploblast: endoderm, mesoderm, and exoderm. The differentiation of these body sections begins with the formation of the mouth and leads to the formation of the anus. This is referred to as a protostome.  Nematodes are also ecdysozoa meaning that at some point within their life cycle, they will molt. D. medinensis molt twice within their lifetime (Yusuf 2011). More information on the life cycle of D. medinensis can be found on the reproduction page. For more information on Nematoda please read through the classification of the Dog Whipworm and Heartworm.
Class: Secernentea:: The guinea worm is from class Secernentea (Yusuf 2011). Secernentea are terrestrial parasites that contain a speared head to puncture hosts (animals.jrank.org 2014). In the case of D. medinensis, their hosts range from mammals to reptiles as discussed in further detail in habitat and geography. For more information on parasitic Secernentea please read about the classification page of Wuchereria bancrofti.
Order: Camallanida:: Dracunulus medinensis is from the order Camallanida (Yusuf 2011). Camallanida are parasites of copepods, or cylops (plpmenweb.ucdavis.edu 2001). D. medinensis infects cyclops in pond water where it is then drank by the host and travels through the digestive system (Cairncross, Tayeh, and Korkor 2012).
Family: Dracunculidae:: D. medinensis is classified into the family Dracunculidae (Yusuf 2011).
Genus: Dracunculus:: The genus of the guinea worm is Dracunculus (Yusuf 2011). This genus
contains mammalian and reptilian parasites. The Guinea Worm has been found in both mammals and reptiles (Wijová, Moravec, Horák, Modrý and Lukeš 2005). Although, recent genetic analysis suggests that the Guinea Worm infects only humans (Yusuf 2011).
Species: medinensis:: The specific epithet of the guinea worm is medinensis. This species infects humans in the African region, but are not fatal (Yusuf 2011).

Phylogenetic tree of D. medinensis

This phylogenetic tree shows Dracunculus medinensis as an outgroup in the comparison of the evolutionary relatedness of the family Thelaziidae. This tree was created using mitochondrial genetic material. All of the listed species are from the phylum Nematoda (Liu G-H, Gasser RB, Otranto D, Xu M-J, et al. 2013). The fact that D. medinensis is an outgroup refers to the idea that it is not immediatley related to Thelazia callipaeda, but was used to help establish the evolutionary relatedness of the species to be placed within a phylogeny. For more information on the use of D. medinensis aiding in the classification of Thelazia callipeada please read this article: "Mitochondrial Genome of the Eyeworm, Thelazia callipaeda (Nematoda: Spirurida), as the First Representative fromt the Family Thelaziidae."


Phylogenetic Tree based on Phyllum Classification

 This phylogenetic tree is based off of the classification of Phyla within the family Animalia. Dracunculus medinensis is in the phyllum Nematoda. As mentioned above, nematodes are round worms. Within this phylogeny, Nemaotoda is most closesly related to Arthropoda which are known for their jointed limbs. An example of an Arthropoda can be found here Gastrophilus intestinalis.

For more information on the classification of Dracunculus medinensis please read: "End of the horror worm: Dracunculus medinensis."

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