Leucochloridium paradoxum

Last updated

Leucochloridium paradoxum
Leucochloridium paradoxum.jpg
Leucochloridium paradoxum, parasite in Succinea putris
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Trematoda
Order: Diplostomida
Family: Leucochloridiidae
Genus: Leucochloridium
Species:
L. paradoxum
Binomial name
Leucochloridium paradoxum
(Carus, 1835) [1]

Leucochloridium paradoxum, the green-banded broodsac, is a parasitic flatworm (or helminth). Its intermediate hosts are land snails, usually of the genus Succinea . The pulsating, green broodsacs fill the eye stalks of the snail, thereby attracting predation by birds, the primary host. These broodsacs visually imitate caterpillars, a prey of birds. [2] The adult parasite lives in the bird's cloaca, releasing its eggs into the faeces.

Contents

Life cycle

The species in Leucochloridium share a similar life cycle. [3] [4] They are parasites of snails and birds. This is a truncated life cycle compared with typical trematodes, because the snail acts as both the first and second intermediate host. [5]

Eggs ingested by the snail hatch into miracidia, which develop in the snail's hepatopancreas into the next stage, a sporocyst. The mature sporocyst consists of a number of branches spreading through the haemocoel and may make up a fifth or more of the snail's weight. [6] Some of the branches develop into long tubes ending in a swollen broodsac, but these are staggered in their states of development, so that normally only 2 or 3 are mature simultaneously. [7] One or both of the snail's tentacles become occupied by a mature broodsac, which transforms the appearance. The tentacle is swollen and the pulsating, colourful, banded broodsac visible inside mimics the appearance of an insect larva like a caterpillar. This encourages their consumption by the next host, insectivorous birds. Observations in captivity indicated that birds tore the broodsac out of the snail before eating it, [8] so the snail may survive this. Birds may also become infected by eating broodsacs that have spontaneously burst from the tentacle, surviving for an hour whilst they continue to pulsate. [7] [9] [10]

At their base, [11] the sporocysts produce asexually many tail-less cercariae, which develop directly into metacercariae within the sporocyst, depositing a thick mucoid coat around themselves. The mature metacercariae are oval in shape, 1.2 × 0.8 mm; typically 100–250 such metacercariae accumulate in a broodsac. [11] If the broodsac is eaten by a bird, the metacercariae pass along its alimentary tract, and lodge in the cloaca. Having lost the mucoid coat, they develop into adult distomes, c.1.5 mm long. This form has two suckers on the ventral side, which anchor it to the cloacal wall, and a smooth dorsal surface. The adults are hermaphroditic and release eggs into the bird's faeces. Some will be eaten by a snail, thus completing the life cycle. [9] [10]

In a study in Russia, snails became infected in spring and summer. The resultant sporocysts were producing infective metacercariae in the following spring but then died in late summer. [7] The lifetime of the adult stage in its bird host is believed to be of the order of weeks or months. [12]

Behaviour of the broodsacs and infected snails

Sporocyst of congener Leucochloridium variae within a snail. (video clip, 1m 30s)

The pulsations of the broodsacs typically vary from 40 to 75 times a minute depending on temperature, but they cease in the dark. [6]

The parasite manipulates the snail host's behaviour in a way likely to make it more conspicuous to birds. In one study of Succinea putris hosts, infected snails stayed in better lit places for longer, sat on higher vegetation, and were more mobile. Whereas 53% of infected snails remained fully exposed for the 45 minutes of the observation period, the figure was only 28% for the controls (nearby snails without Leucochloridium broodsacs). [2] Infected snails may survive for at least a year and continue to be able to use the eyes on the ends of their tentacles. [6] Although snails infected by other Leucochloridium species are reported to continue to reproduce, [3] snails infected by L. paradoxum often show a reduction of the sexual organs. [6]

The appearance and behaviour of the sporocysts is a case of aggressive mimicry, where the parasite vaguely resembles the food of the host, thereby gaining the parasite entry into the host's body by being eaten. This is unlike most other cases of aggressive mimicry, in which the mimic eats the duped animal. [13]

Taxonomy

In older literature, L. paradoxum may be referred to as L. macrostomum, derived from Rudolphi's 1803 description of Fasciola macrostoma, which he later (1809) renamed Distomum macrostomum. Zeller (1874) misidentified specimens of L. paradoxum as D. macrostomum. Rudolphi's species is now in the genus Urogonimus. [14] Leucochloridium heckerti Kagan, 1951 is also considered a synonym of L. paradoxum. [9]

The snail Succinea putris with broodsac inside its left tentacle Succinea mit Leucocholoridium.jpg
The snail Succinea putris with broodsac inside its left tentacle

Identification

The easiest way to differentiate between Leucochloridium species is from the appearance of the broodsacs in the tentacle of the host snail. Leucochloridium paradoxum exhibits broodsacs that have green bands with dark brown and black spots, and with a dark-brown or reddish-brown tip. [9] [6] Nowadays this method of identification may be supported with ribosomal DNA sequences. [12] A snail may be simultaneously infected by more than one species of Leucochloridium. [15]

The adults, found in the cloaca of birds, are less well known, so that distinguishing the species is less straightforward. [12]

Habitat

Leucochlordium paradoxum is found in moist areas, such as marshes, where the usual intermediate host Succinea snails are found.

Distribution

Type locality: island in the Elbe at Pillnitz Pillnitz panorama.jpg
Type locality: island in the Elbe at Pillnitz

Leucochloridium paradoxum was originally described based on its sporocyst stage, collected from an island in the river Elbe at Pillnitz, near Dresden, Germany. [1] Other known locations are Poland, Belarus, the Saint Petersburg area of Russia, Denmark, Sweden, Norway, the Netherlands, the United Kingdom and Japan. [12] [15] [9] [16] It is believed to be the species of Leuchochloridium infecting an endemic species of semi-slug on Robinson Crusoe Island in the Pacific, the only record from the Southern Hemisphere. [17]

Hosts

Intermediate hosts:

Hosts:

Related Research Articles

<span class="mw-page-title-main">Trematoda</span> Class of parasitic flatworms

Trematoda is a class of flatworms known as flukes or trematodes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish.

<span class="mw-page-title-main">Digenea</span> Class of flukes

Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date.

<span class="mw-page-title-main">Trematode life cycle stages</span>

Trematodes are parasitic flatworms of the class Trematoda, specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions.

<i>Echinostoma</i> Genus of flukes

Echinostoma is a genus of trematodes (flukes), which can infect both humans and other animals. These intestinal flukes have a three-host life cycle with snails or other aquatic organisms as intermediate hosts, and a variety of animals, including humans, as their definitive hosts.

<i>Leucochloridium</i> Genus of flukes

Leucochloridium is a genus of parasitic trematode worms in the order Diplostomida. It Is the sole genus in the family Leucochloridiidae. Members of this genus cause pulsating swellings in the eye-stalks of snails, so as to attract the attention of predatory birds required in the parasites' lifecycle.

<i>Brachylaima</i> Genus of flukes

Brachylaima is a genus of trematodes that can infect the gastrointestinal tract of human beings.

Metagonimoides oregonensis is a trematode, or fluke worm, in the family Heterophyidae. This North American parasite is found primarily in the intestines of raccoons, American minks, frogs in the genus Rana, and freshwater snails in the genus Goniobasis. It was first described in 1931 by E. W. Price. The parasite has a large distribution, from Oregon to North Carolina. Adult flukes vary in host range and morphology dependent on the geographical location. This results in different life cycles, as well as intermediate hosts, across the United States. On the west coast, the intermediate host is freshwater snails (Goniobasis), while on the east coast the intermediate host is salamanders (Desmognathus). The parasites on the west coast are generally much larger than on the east coast. For example, the pharynx as well as the body of the parasite are distinctly larger in Oregon than in North Carolina. The reverse pattern is observed on the east coast for uterine eggs, which are larger on the west coast. In snails, there is also a higher rate of infection in female snails than in males. Research on the life history traits of the parasites have been performed with hamsters and frogs as model species.

<i>Leucochloridium variae</i> Species of fluke

Leucochloridium variae, the brown-banded broodsac, is a species of trematode whose life cycle involves the alternate parasitic infection of certain species of snail and bird. While there is no external evidence of the worm's existence within the bird host, the infection of the snail host is visible when its eye stalks become grotesquely engorged with the parasite's brood sacs. These brood sacks pulsate and move to imitate insect larva, attracting the parasite's next host, insectivore birds. The bird rips off the eye stalk and eats it, thus becoming infected. Later on, the parasite's eggs are dropped with the bird's feces. Similar life-histories are found in other species of the genus Leucochloridium, including Leucochloridium paradoxum.

<i>Novisuccinea ovalis</i> Species of gastropod

Novisuccinea ovalis, commonly called the oval ambersnail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Succineidae, the ambersnails.

<i>Fasciolopsis</i> Genus of flukes

Fasciolopsis is a genus of trematodes. They are also known as giant intestinal flukes.

<i>Bucephalus polymorphus</i> Species of fluke

Bucephalus polymorphus is a type of flatworm. This species is within the Bucephalidae family of Digenea, which in turn is a subclass of Trematodes within the phylum Platyhelminthes. It is characterized by having a mouth near the middle of its body, along with a sac-like gut. The mouth opening is located in the centre of the ventral surface. This is a specific body type of cecaria known as a gastrostome.

Halipegus eccentricus is a monoecious, digenea parasitic trematode commonly found in true frogs in North America. It was first described in 1939.

<i>Echinostoma revolutum</i> Species of fluke

Echinostoma revolutum is a trematode parasite of which the adults can infect birds and mammals, including humans. In humans, it causes echinostomiasis.

Echinostoma hortense is an intestinal fluke of the class Trematoda, which has been found to infect humans in East Asian countries such as Korea, China, and Japan. This parasite resides in the intestines of birds, rats and other mammals such as humans. While human infections are very rare in other regions of the world, East Asian countries have reported human infections up to about 24% of the population in some endemic sub-regions. E. hortense infections are zoonotic infections, which occurs from eating raw or undercooked freshwater fish. The primary disease associated with an E. hortense infection is called echinostomiasis, which is a general name given to diseases caused by Trematodes of the genus Echinostoma.

<i>Clinostomum marginatum</i> Species of fluke

Clinostomum marginatum is a species of parasitic fluke. It is commonly called the "Yellow grub". It is found in many freshwater fish in North America, and no fish so far is immune to this parasite. It is also found in frogs. Clinostomum marginatum can also be found in the mouth of aquatic birds such as herons and egrets. They are commonly present in the esophagus of fish-eating birds and reptiles. Eggs of these trematodes are shed in the feces of aquatic birds and released into water. Aquatic birds become hosts of this parasite by ingesting infected freshwater fish. The metacercariae are found right beneath the skin or in the muscles of host fish.

Megalodiscus temperatus is a Digenean in the phylum Platyhelminthes. This parasite belongs to the Cladorchiidae family and is a common parasite located in the urinary bladder and rectum of frogs. The primary host is frogs and the intermediate hosts of Megalodiscus temeperatus are freshwater snails in the genus Helisoma.

<i>Philophthalmus gralli</i> Species of fluke

Philophthalmus gralli, commonly known as the Oriental avian eye fluke, parasitises the conjunctival sac of the eyes of many species of birds, including birds of the orders Galliformes and Anseriformes. In Brazil this parasite was reported in native Anseriformes species. It was first discovered by Mathis and Leger in 1910 in domestic chickens from Hanoi, Vietnam. Birds are definitive hosts and freshwater snail species are intermediate hosts. Human cases of philophthalmosis are rare, but have been previously reported in Europe, Asia, and America.

Microphallus turgidus is a widespread and locally common flatworm parasite in New Zealand lakes and streams. Multilocus allozyme genotype data show that Microphallus turgidus is a single outbred species with high levels of gene flow among South Island populations. Microphallus turgidus is commonly found in the abdominal muscles of grass shrimp.

<i>Metagonimus yokogawai</i> Species of fluke

Metagonimus yokogawai, or the Yokogawa fluke, is a species of a trematode, or fluke worm, in the family Heterophyidae.

<span class="mw-page-title-main">Gastropod-borne parasitic disease</span> Medical condition

Gastropod-borne parasitic diseases (GPDs) are a group of infectious diseases that require a gastropod species to serve as an intermediate host for a parasitic organism that can infect humans upon ingesting the parasite or coming into contact with contaminated water sources. These diseases can cause a range of symptoms, from mild discomfort to severe, life-threatening conditions, with them being prevalent in many parts of the world, particularly in developing regions. Preventive measures such as proper sanitation and hygiene practices, avoiding contact with infected gastropods and cooking or boiling food properly can help to reduce the risk of these diseases.

References

  1. 1 2 Carus, C.G. (1835). "Beobachtung über einen merkwürdigen schöngefärbten Eingeweidewurm, Leucochloridium paradoxum mihi, und dessen parasitische Erzeugung in einer Landschnecke, Succinea amphibia Drap. Helix putris Linn". Nova Acta Physico-Medica. Academiae Caesareae Leopoldino Carolinae Naturae Curiosorum. 17 (2. s., v. 7, pt. 1): 85-100 + Pl. VII.
  2. 1 2 Wesołowska, W.; Wesołowski, T. (March 2014). "Do Leucochloridium sporocysts manipulate the behaviour of their snail hosts?". Journal of Zoology. 292 (3): 151–155. doi:10.1111/jzo.12094.
  3. 1 2 Kagan, I.G. (1951). "Aspects in the life history of Neoleucochloridium problematicum (Magath, 1920) New Comb. and Leucochloridium cyanocittae McIntosh, 1932 (Trematoda:Brachylaemidae)". Transactions of the American Microscopical Society. 70 (4): 281–3184. doi:10.2307/3223567. JSTOR   3223567.
  4. Lewis, P.D. (1974). "Helminths of terrestrial molluscs in Nebraska. II. Life cycle of Leucochloridium variae McIntosh, 1932 (Digenea: Leucochloridiidae)". Journal of Parasitology. 60 (2): 251–255. doi:10.2307/3278459. JSTOR   3278459.
  5. Poulin, R.; Cribb, T. H. (2002). "Trematode life cycles: short is sweet?". Trends in Parasitology. 18 (4): 176–183. doi:10.1016/S1471-4922(02)02262-6. PMID   11998706.
  6. 1 2 3 4 5 Wesenberg-Lund, C. (1931). "Contributions to the development of the Trematoda Digenea. I. The biology of Leucochloridium paradoxum". Det Kongelike Danske Videnskakbernes Selskab, Naturvidenskabelig-mathematisk Afdeling. 4: 90–142.
  7. 1 2 3 Tokmakova, A.S.; Ataev, G.L. (2015). "Сезонные изменения в биологии Leucochloridium paradoxum (Trematoda, Leucochlomorphidae)" [Seasonal changes in the biology of Leucochloridium paradoxum (Trematoda, Leucochlomorphidae)](PDF). Parazitologiya (in Russian). 49 (3): 200–207.
  8. Zeller, E. (1874). "Über Leucochloridium paradoxum Carus und die weitere Entwickung seiner Distomenbrut". Zeitschrift für wissenschaftliche Zoologie. 24: 564–578 + Pl. XLVIII.
  9. 1 2 3 4 5 6 Bakke, T. A. (April 1980). "A revision of the family Leucochloridiidae Poche (Digenea) and studies on the morphology of Leucochloridium paradoxum Carus, 1835". Systematic Parasitology. 1 (3–4): 189–202. doi:10.1007/BF00009845.
  10. 1 2 Heckert, G.A. (1889). "Leucochloridium paradoxam. Monographische darstellung der entwicklungs- und Lebensgeschichte des Distomum macmstomum". Bibliotheca Zoologica. 4: 1-66 + Pls I-IV.
  11. 1 2 Ataev, G.L.; Dobrovolskij, A.A.; Tokmakova, A.S. (2014). "Размножение партенит трематод Leucochloridium paradoxum (Trematoda: Leucochloridiidae)" [Reproduction of trematode Leucochloridium paradoxum sporocysts (Trematoda: Leucochloridiidae)](PDF). Parazitologiya (in Russian). 47 (2): 178–182.
  12. 1 2 3 4 5 Casey, S.P.; Bakke, T.A.; Harris, P.D.; Cable, J. (2003). "Use of ITS rDNA for discrimination of European green- and brown-banded sporocysts within the genus Leucochloridium Carus, 1835 (Digenea: Leucochloriidae)". Systematic Parasitology. 56 (3): 163–168. doi:10.1023/B:SYPA.0000003809.15982.ca. PMID   14707500.
  13. Jackson, R. R.; Cross, F. R. (2013). "A cognitive perspective on aggressive mimicry". Journal of Zoology. 290 (3): 161–171. doi:10.1111/jzo.12036. PMC   3748996 . PMID   23976823.
  14. Kagan, I.G. (1952). "Revision of the subfamily Leucochloridiinae Poche, 1907 (Trematoda: Brachylaemidae)". American Midland Naturalist. 48 (2): 257–301. doi:10.2307/2422256. JSTOR   2422256.
  15. 1 2 Ataev, G. L.; Zhukova, A. A.; Tokmakova, А. S.; Prokhorova, Е. E. (August 2016). "Multiple infection of amber Succinea putris snails with sporocysts of Leucochloridium spp. (Trematoda)". Parasitology Research. 115 (8): 3203–3208. doi:10.1007/s00436-016-5082-6.
  16. 1 2 Nakao, Minoru; Sasaki, Mizuki; Waki, Tsukasa; Iwaki, Takashi; Morii, Yuta; Yanagida, Kazumi; Watanabe, Megumi; Tsuchitani, Yoshikazu; Saito, Takumi; Asakawa, Mitsuhiko (October 2019). "Distribution records of three species of Leucochloridium (Trematoda: Leucochloridiidae) in Japan, with comments on their microtaxonomy and ecology". Parasitology International. 72: 101936. doi:10.1016/j.parint.2019.101936. PMID   31153919.
  17. 1 2 Castillo, V.M.; González, H. (2021). "Evidence of parasitism in the semi-slug Omalonyx gayana d'Orbigny, 1835 with Leucochloridium paradoxum (Carus, 1835) sporocysts on Robinson Crusoe Island" (PDF). Tentacle. 29: 34–35.