''Rhabdias bufonis'' is a species of

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Rhabdiasidae. It was first described from the lungs of the European

common toad The common toad, European toad, or in Anglophone parts of Europe, simply the toad (''Bufo bufo'', from Latin ''bufo'' "toad"), is a frog found throughout most of Europe (with the exception of Ireland, Iceland, and some Mediterranean islands), in ...

(''Bufo bufo'') but has also been found in a number of other species of frog.

Life cycle

''Rhabdias bufonis'' has a heterogonic lifestyle in which a generation of parasitic individuals is succeeded by a free-living generation. This is advantageous to the parasite as it allows reproduction for one or more generations in the absence of the host. The free-living male and female worms mate and produce eggs which hatch inside the mother. They feed on her internal organs and moult twice before they leave her body. They are now infective larvae and can penetrate the skin of a frog. Once inside, they can migrate to the lungs and further develop there, feeding on the lung tissue. The adult parasitic worm is a

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

and grows to be about ten times the length of the free-living form. The eggs it produces are coughed into the frog's mouth, are swallowed and develop in its intestine. They are passed in the feces and develop into free-living forms. In the soil, the worms feed on bacteria and other organic matter. The female may produce a pheromone to attract a male.

Parasitism

''Rhabdias bufonis'' is found in the parts of Europe and Asia in which its host frogs are found. Besides the common toad from which this roundworm was first described, it has been found in the common spadefoot toad ('' Pelobates fuscus''), the common frog ('' Rana temporaria''), the moor frog ('' Rana arvalis''), the agile frog ('' Rana dalmatina''), the European fire-bellied toad ('' Bombina bombina''), the yellow-bellied toad ('' Bombina variegata''), water frogs (''

Pelophylax ''Pelophylax'' is a genus of true frogs widespread in Eurasia, with a few species ranging into northern Africa. This genus was erected by Leopold Fitzinger in 1843 to accommodate the green frogs of the Old World, which he considered distinct fro ...

spp.'') and the European green toad ('' Bufo viridis''). Juvenile frogs are often infected and a heavy worm burden can seriously restrict their growth. In a study, some of the infected juveniles were only half as heavy as controls with no worms. The parasite-induced

anorexia Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...

caused a decrease in food intake and some of the young host frogs died.

References

{{Taxonbar, from=Q7319958 Rhabditida Nematodes described in 1788 Parasitic nematodes of vertebrates Parasites of amphibians