Overview

Distribution

Geographic Range

The range of Leucochloridium paradoxum follows that of its host, snails of the genus Succinea that live in Europe and North America.

Biogeographic Regions: nearctic (Native ); palearctic (Native )

  • Dawes, B. 1946. The Trematoda. Cambridge, UK: University Press.
  • Rennie, J. 1992. Trends In Parasitology: Living Together. Scientific American, January: 123-33.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Physical Description

The worm has different sizes and shapes throughout its development. The eggs are brown and oval shaped. After hatching, the miracidia or first stage larvae are clear and elongate. After transformation, the miracidia become sack-like objects called sporocysts. The sporocysts cause the eyestalks of their snail hosts to pulsate yellow, green, and red. Some sporocysts then give rise to cercaria, or juveniles, which have tails and a more complex digestive tract. The cercaria have a lined excretory bladder which extends into their tails a bit and the tails also have finfolds on the top and bottom as well as setae on the sides. The cercaria also have two eyespots. Cercaria quickly become an encysted metacercaria from which emerge the adults. The adults are spined, long, dorsally flattened, and have suckers for attachment within their definitive hosts.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

  • Fried, B., T. Graczyk. 1997. Advances in Trematode Biology. Boca Raton, FL: CRC Press.
  • Roberts, L., J. Janovy Jr.. 2000. Foundations of Parasitology 6th ed.. Boston: McGraw-Hill.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

The worm is both an endoparasite of Succinea snails and of various birds such as crows, jays, sparrows and finches. It encounters these animals in temperate forests of North America and Europe. The egg is the only stage of development that exists outside of a host but it must remain moist to survive.

Habitat Regions: terrestrial

Terrestrial Biomes: forest

Other Habitat Features: agricultural

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Trophic Strategy

Food Habits

Leucochloridium paradoxum is an endoparasite of the rectum of birds as an adult. There it feeds on passing digested matter. It shows little definitive host specificity as it is known to parasitize more than fifteen bird species including crows, jays, sparrows and finches. As a sporocyst, the worm absorbs nutrients through its tegument from its intermediate hosts, Succinea snails.

Animal Foods: body fluids

Other Foods: dung

Primary Diet: carnivore (Eats body fluids)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Associations

Ecosystem Roles

The worm is both an endoparasite of Succinea snails and of various birds such as crows, jays, sparrows and finches. It encounters these animals in temperate forests of North America and Europe. The egg is the only stage of development that exists outside of a host but it must remain moist to survive.

Ecosystem Impact: parasite

Species Used as Host:

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Predation

These animals are probably not preyed on directly but are ingested. Egg and larval mortality are high since the parasites often do not reach appropriate hosts.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Behavior

Communication and Perception

Bristles and small spines probably act as tactile receptors, and these animals may have reduced chemoreceptors.

Communication Channels: chemical

Perception Channels: tactile ; chemical

  • Brusca, R., G. Brusca. 2003. Invertebrates. Sunderland, Massachusetts: Sinauer Associates, Inc..
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Cycle

Development

After a succinid snail ingests the worm's eggs, the sporocysts that arise from the miracidia have one of two destinies. Some sporocysts give rise to cercaria and others asexually produce more daughter sporocysts. When a bird ingests the snail, the remaining sporocysts become cercaria, which eventually develop into adults. The adults are monoecious, or hermaphroditic, although they can cross fertilize when in close proximity. The resulting eggs are released by the worms in the rectum and excreted by the bird host along with its feces.

  • Erasmus, D. 1972. The Biology of Trematodes. New York: Crane, Russack, & Company.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Reproduction

Leucochloridium paradoxum reproduces asexually. The adults are monoecious, or hermaphroditic, although they can cross fertilize when in close proximity. The resulting eggs are released by the worms in the rectum and excreted by the bird host along with its feces.

Key Reproductive Features: simultaneous hermaphrodite; sexual ; asexual ; fertilization (Internal ); oviparous

There is no parental investment beyond the time eggs are released.

Parental Investment: pre-fertilization (Provisioning)

  • Erasmus, D. 1972. The Biology of Trematodes. New York: Crane, Russack, & Company.
  • Fried, B., T. Graczyk. 1997. Advances in Trematode Biology. Boca Raton, FL: CRC Press.
  • Roberts, L., J. Janovy Jr.. 2000. Foundations of Parasitology 6th ed.. Boston: McGraw-Hill.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Economic Importance for Humans: Negative

The parasitism of Leucochloridium paradoxum on succinid snails has no effect on humans. In their definitive bird hosts, they inhabit the rectum where they essentially feed on waste that is about to be excreted so their pathogenic effects on their hosts and ultimately on humans are negligible.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Economic Importance for Humans: Positive

Leucochloridium paradoxum presents no known benefits to humans.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Leucochloridium paradoxum

Leucochloridium paradoxum, common name green-banded broodsac, is a parasitic flatworm (or "helminth") that uses gastropods as an intermediate host. It is typically found in Succinea that live in Europe and North America where it infects the host’s eyes making them appear as caterpillars that other birds prey on. Various birds consume these infected gastropods, becoming the definitive host for L. paradoxum to mature and release eggs in the rectum that are later found in the feces of the bird host.

Morphology[edit]

It is hard to distinguish Leucochloridium species from one another due to their similarities in appearances as adults. Many of them lack a hard structure and have a variety of ranges in sizes. The most common way to differentiate between Leucochloridium species is by looking at the broodsacs and banding patterns. L. paradoxum typically exhibits broodsacs that have green bands with dark brown and black spots.[1] During development, the parasite has different sizes and shapes. L. paradoxum eggs are known to be brown colored and exhibit an oval shape.[2] The miracidia during the first stage of development is clear and elongated. Once the miracidia transform into sporocysts, they appear as broodsacs that infect the snail hosts in their eyes and begin to pulsate green, yellow, and red. The sporocysts turn into cercaria (juveniles) that have a tail along with a digestive tract that is lined with an excretory bladder that extends into the tail. The tail of a cercaria has finfolds on the top and bottom and setae on the sides. Cercaria also has two eyespots. At the end of the cycle, the adults appear as worms that have spines and are dorsally flattened with suckers in order to attach to the definitive host.[3]

Life cycle[edit]

The worm in its larval, miracidia stage, travels into the digestive system of a snail to develop into the next stage, sporocyst. The sporocyst grows into long tubes to form swollen "broodsacs" filled with tens to hundreds of cercariae. These broodsacs invade the snail's tentacles (preferring the left, when available), causing a brilliant transformation of the tentacles into a swollen, pulsating, colorful display that mimics the appearance of a caterpillar or grub. The broodsacs seem to pulsate in response to light intensity, and in total darkness do not pulse at all.[4] The infection of the tentacles of the eyes seems to inhibit the perception of light intensity. Whereas uninfected snails seek dark areas to prevent predation, infected snails have a deficit in light detection, and are more likely to become exposed to predators, such as birds. In a study done in Poland, 53% of infected snails stayed in more open places longer, sat on higher vegetation, and stayed in better lit places than uninfected snails. Only 28% of the uninfected snails remained fully exposed for the duration of the observation period. [5] Birds are the definitive hosts where the cercariae develop into adult distomes in the digestive system of the bird. These adult forms sexually reproduce and lay eggs that are released from the host via the bird's excretory system. These droppings are then consumed by snails to complete the life cycle of this parasitic worm.

Sporocyst (leucochloridium sp.) in a snail. (video clip, 1m 30s)

The resulting behavior of the flatworm is a case of aggressive mimicry, where the parasite vaguely resembles the food of the host. This gains the parasite entry into the host's body; this is unlike most other cases of aggressive mimicry, in which only a part of the host resembles the target's prey and the mimic itself then eats the duped animal.

This life cycle is similar to other species of genus Leucochloridium.

Habitat[edit]

L. paradoxum are found in moist areas such as the forests of North America and Europe where their definitive and intermediate hosts such as Succinea snails and various birds (crows, jays, sparrows and finches) are found.

Distribution[edit]

Leucochloridium paradoxum was originally reported from Germany.[6] Other locations include: Norway [1] and Poland. [7]

Land snail Succinea putris with Leucochloridium paradoxum inside its left eye stalk.

Hosts[edit]

intermediate hosts:

hosts:

References[edit]

  1. ^ a b c T. A. Bakke (April) 1980. A revision of the family Leucochloridiidae Poche (Digenea) and studies on the morphology of Leucochloridium paradoxum Carus, 1835. Systematic Parasitology, Volume 1, Numbers 3-4. 189-202.
  2. ^ Schmidt, G.D. (2000). Foundations in Parasitology, 6th ed. McGraw-Hill Comp. 
  3. ^ Fried, B. (1997). Advances in Termatode Biology. Boca Raton: CRC Press. 
  4. ^ Edwin J. Robinson, Jr. (December 1947). "Notes on the Life History of Leucochloridium fuscostriatum n. sp. provis. (Trematoda: Brachylaemidae)". The Journal of Parasitology 34 (6): 467–475. doi:10.2307/3273326. JSTOR 3273326. PMID 18903602. 
  5. ^ W. Wesoowska, T. Wesoowiski,Journal of Zoology (October) 2013. Do Leucochloridum sporocysts manipulate the behaviour of their snail hosts? August 2013. Journal of Zoology. Issue 292, 2014: 151-5.
  6. ^ S.P. Casey, T.A. Bakke, P.D. Harris & J. Cable (November) 2004. Use of ITS rDNA for discrimination of European green- and brown-banded sporocysts within the genus Leucochloridium Carus, 1835 (Digenea: Leucochloriidae). Systematic Parasitology. Volume 56, Number 3: 163-168.
  7. ^ W. Wesoowska, T. Wesoowiski,Journal of Zoology (October) 2013. Do Leucochloridum sporocysts manipulate the behaviour of their snail hosts? August 2013. Journal of Zoology. Issue 292, 2014: 151-5.
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!