Land planariums
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Obama burmeisteri , head left. Atlantic rainforest, southern Brazil |
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| Stimpson , 1857 |
The land planarians (Geoplanidae) are a family of the flatworms belonging flatworms that have become predators feed on various small animals. They are mainly found in tropical and subtropical, but also temperate and colder regions of the world. Many of them appear as Neozoa and can cause massive changes in the local or endemic soil ecology . There are more than 800 species described.
features
You are part of the Bilateria . The intestine of the land planarians, which ends blindly - as with all vortex worms - branches into three main branches just behind the mouth, which is why the land planarians are counted among the tricladidae. They are 1 to 20 cm long and are often brightly colored and patterned. The nervous system of the land planarians has an axillary ventral plexus . In addition, the land planarians have a creep sole with cilia and predominantly cyanophilic mucous glands (which can be colored with water blue ). The animals crawl using the cilia, muscle action, or a combination of both.
In contrast to other vortex worms, the land planarians are completely adapted to life in the country. They do not have any water-storing mechanisms and are therefore dependent on moisture in their microhabitat . On the other hand, all land planarians avoid a completely wet environment. They occur in mesophilic to xerophilic habitats from alpine herbaceous vegetation to sandy semi-deserts and tropical rainforests . Land planarians are primarily proterandric hermaphrodites and normally reproduce sexually.
Range of prey and fishing methods
All land planarians eat meat , with most species hunting live prey, but some being scavengers . The prey animals include insects and their larvae, millipedes , woodlice , earthworms , snails and other flatworms.
The prey animals are usually detected by chemical stimuli. The captured prey is pre-digested and killed by enzymes that are expelled through the everted pharynx , and the dissolved tissue is then pumped through the pharynx into the intestine, often leaving nothing of the prey.
There are different fishing methods. Bipalium kewense and other Bipalium species attack earthworms by grasping them and digesting them externally in this position . Arthurdendyus triangulatus and Platydemus manokwari do the same with their prey. For example, Platydemus manokwari and Endeavouria septemlineata attack giant African snails in large groups. Rhynchodemus sylvaticus uses an enlarged hood to catch small insects, while the African Microplana termitophaga uses its sticky slime to catch termite workers who it waits for in the ventilation ducts of the termite burrows.
Different types of land planarians reduce the prey populations considerably, which is particularly noticeable in newly introduced invasive species , such as Arthurdendyus triangulatus on earthworms in Great Britain and Ireland. Platydemus manokwari is even associated with the extinction of entire snail species in the Pacific region.
Enemies
Due to their poisonous slime and repulsive taste, land planarians have few enemies and are classified as top predators . Most predatory vertebrates disdain them. There are reports of ground beetles and rove beetles that triangulatus Arthurdendyus eat. The predatory snail Rectartemon depressus from the Streptaxidae family, which lives in Brazil, Colombia and Uruguay, also eats land planarians, along with other prey. The mosquito Planarivora insignis specializes in planarians , whose larvae act as parasitoids to eat the flatworm from the inside. On the other hand, the land planarie Platydemus manokwari prey on both predatory snails such as Euglandina rosea and Gonaxis quadrilateralis and flatworms such as Bipalium kewense .
Systematics
The land planariums are traditionally compared within the Tricladida as terricola to the maricola (marine planariums), cavernicola (cave planariums) and paludicola (freshwater planariums). Sluys et al. (2009), on the other hand, summarize the freshwater and land planariums as Continenticola and place the land planariums in the rank of the Geoplanidae family as a sister group to the Dugesiidae in the superfamily Geoplanoidea, while the other three freshwater planarium families in the superfamily Planarioidea stand opposite.
| Tricladida |
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The land planariums have thus been downgraded from a subordination - or infraorder - (Terricola) to a family (Geoplanidae). The terricola (land planarians) are traditionally divided into three families based on their morphology:
- Bipaliidae (land planarians with a hammer-like widened head and numerous pinpoint eyes)
- Rhynchodemidae (land planarians without a broadened head and with a pair of eyes), with 2 subfamilies:
- Rhynchodeminae (with longitudinal muscle fibers in large bundles under the epithelium)
- Microplaninae (with weaker longitudinal muscle fibers under the epithelium, not in bundles)
- Geoplanidae (land planariums without a broadened head and with numerous point eyes), with 3 subfamilies:
- Geoplaninae (with dorsal testicles and strong longitudinal muscles under the epithelium)
- Caenoplaninae (with ventral testicles and strong longitudinal muscles under the epithelium)
- Pelmatoplaninae (with ventral testes and weaker longitudinal muscles under the epithelium)
Recent phylogenetic analyzes indicate that the Rhynchodeminae and Microplaninae are not sister groups and that the Caenoplaninae are closer to the Rhynchodeminae than the Geoplaninae. Álvarez-Presas et al. (2008) divide the land planariums (Geoplanidae in the new, expanded sense) as follows: The former subfamilies Caenoplaninae and Pelmatoplaninae are now placed as tribe Caenoplanini and Pelmatoplanini in the subfamily Rhynchodeminae. The genera Spathula and Romankenkius, which were previously part of the freshwater planarium family Dugesiidae, have been placed in the family Geoplanidae by Álvarez-Presas as a sister group of the Microplaninae.
| Geoplanoidea |
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Distribution areas
The animals have a great ability to adapt , so that they can occupy biogeographically similar habitats in different regions where suitable living conditions prevail.
See also
literature
- Leigh Winsor, PM Johns, GM Yeates (1998): Introduction, and ecological and systematic background, to the Terricola (Tricladida) . Pedobiologia 42 (5-6), 389-404. PDF
- Robert E. Ogren: Predation behavior of land planarians. Hydrobiologia 305, (1995) pp 105-111. doi : 10.1007 / BF00036370 .
- R. Sluys, M. Kawakatsu, M. Riutort, J. Baguñà (2009). A new higher classification of planarian flatworms (Platyhelminthes, Tricladida). Journal of Natural History 43 (29-30), pp. 1763-1777. doi : 10.1080 / 00222930902741669 .
Web links
- Geoplanidae from continenticola.org. Retrieved October 21, 2015
- Tyler S, Schilling S, Hooge M, and Bush LF (comp.) (2006-2015) Turbellarian taxonomic database. Version 1.8
Individual evidence
- ^ Ronald Sluys: Invasion of the Flatworms. Spectrum of Science May 2017, p. 32
- ↑ Winsor et al. (1998), p. 1.
- ↑ Sluys et al. (2009), p. 1773.
- ↑ a b c Winsor et al. (1998), p. 9.
- ↑ a b Robert E. Ogren (1995), p. 1.
- ↑ David R. Hopper, Barry D. Smith (1992): Status of tree snails (Gastropoda: Partulidae) on Guam, with a resurvey of sites studied by HE Crampton in 1920 . Pacific Science 46, pp. 77-85. PDF
- ↑ VS Lemos, R. Canello, AM Leal-Zanchet (2012): Carnivore mollusks as natural enemies of invasive land flatworms . Annals of Applied Biology 161 (2), pp. 127-131. doi : 10.1111 / j.1744-7348.2012.00556.x
- ↑ Elisa von Groll: Hunter Snail - Rectartemon depressus . Retrieved October 21, 2015.
- ^ VV Hickman (1965): On Planarivora insignis gen. Et sp. n. (Diptera: Mycetophilidae), whose larval stages are parasitic in land planarians . Papers and Proceedings of the Royal Society of Tasmania 99, pp. 1-9.
- ^ Jean-Lou Justine, Leigh Winsor, Delphine Gey, Pierre Gros, Jessica Thévenot: The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now. . In: PeerJ . 2, 2014, p. E297. doi : 10.7717 / peerj.297 .
- ↑ Sluys et al. (2009), p. 1767.
- ^ Robert E. Ogren, Masaharu Kawakatsu (1988): Index to the species of the family Rhynchodemidae (Turbellaria, Tricladida, Terricola) Part I: Rhynchodeminae . Bulletin of Fuji Women's College 26 (2), pp. 39-91.
- ^ Robert E. Ogren, Masaharu Kawakatsu (1991): Index to the species of the family Geoplanidae (Turbellaria, Tricladida, Terricola) Part II: Caenoplaninae and Pelmatoplaninae . Bulletin of Fuji Women's College 29 (2), pp. 35-58.
- ↑ a b M. Álvarez-Presas, J. Baguñà, M. Riutort: Molecular phylogeny of land and freshwater planarians (Tricladida, Platyhelminthes): From freshwater to land and back . In: Molecular Phylogenetics and Evolution . 47, No. 2, 2008, pp. 555-568. doi : 10.1016 / j.ympev.2008.01.032 . PMID 18359250 .
- ↑ Sluys et al. (2009), p. 1770.