Geoplanidae: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
templatize refs, w/ electronic links
Line 9: Line 9:
| subordo = [[Continenticola]]
| subordo = [[Continenticola]]
| familia= '''Geoplanidae'''
| familia= '''Geoplanidae'''
| familia_authority= Stimpson, 1857
| familia_authority= [[William Stimpson|Stimpson]], 1857
| subdivision_ranks = [[Subfamily|Subfamilies]]<ref name="Sluys09">Sluys, R., Kawakatsu, M., Riutort, M. & Baguñà, J. 2009. "A new higher classification of planarian flatworms (Platyhelminthes, Tricladida)". ''Journal of Natural History'', vol. 43, 1763-1777 pp.</ref>
| subdivision_ranks = [[Subfamily|Subfamilies]]<ref name="Sluys09">{{cite doi | 10.1080/00222930902741669}}</ref>
| subdivision =
| subdivision =
*[[Bipaliinae]]
*[[Bipaliinae]]
Line 20: Line 20:
The Family '''Geoplanidae''', [[common name]] '''Land planarians''' (Platyhelminthes, Tricladida, Geoplanidae) is an understudied but important group of [[flatworms]] that belong to the soil ecosystem.<ref>Winsor, L.; Johns, P.M. & Yeates, G.W. 1998. Introduction, and ecological and systematic background, to the Terricola (Tricladida). ''Pedobiologia'' 42: 389-404.</ref>
The Family '''Geoplanidae''', [[common name]] '''Land planarians''' (Platyhelminthes, Tricladida, Geoplanidae) is an understudied but important group of [[flatworms]] that belong to the soil ecosystem.<ref>Winsor, L.; Johns, P.M. & Yeates, G.W. 1998. Introduction, and ecological and systematic background, to the Terricola (Tricladida). ''Pedobiologia'' 42: 389-404.</ref>


These flatworms range between 1 and 20&nbsp;cm in size{{Citation needed|date=October 2009}}, and are predators of other invertebrates such as [[earthworm]]s, [[snail]]s, [[slug]]s, [[insect]]s and [[chelicerate]]s, which they hunt for, attack and capture using physical force and the adhesive and digestive properties of their mucus.<ref name="Ogren, R.E 1995">Ogren, R.E. 1995. Predation behaviour of land planarians. ''Hydrobiologia'' 305: 105-111.</ref> They lack water-retaining mechanisms and are therefore very sensitive to humidity variations of their environment.
These flatworms range between 1 and 20&nbsp;cm in size{{Citation needed|date=October 2009}}, and are predators of other invertebrates such as [[earthworm]]s, [[snail]]s, [[slug]]s, [[insect]]s and [[chelicerate]]s, which they hunt for, attack and capture using physical force and the adhesive and digestive properties of their mucus.<ref name="Ogren, R.E 1995">{{cite doi | 10.1007/BF00036370}}</ref> They lack water-retaining mechanisms and are therefore very sensitive to humidity variations of their environment.


Because of their limited ecological requirements, some species have been proposed as indicators of the conservation state of their habitats.<ref>Sluys, R. 1999. Global diversity of land planarians (Platyhelminthes, Tricladida, Terricola): a new indicator-taxon in biodiversity and conservation studies. ''Biodiversity and Conservation''. 8: 1663-1681.</ref><ref>Carbayo, F.; Leal-Zanchet, A.M & Vieira, E.M. 2002. Terrestrial flatworm (Platyhelminthes: Tricladida: Terricola) diversity vs. man-induced disturbance in a subtropical rainforest from Southern Brazil. ''Biodiversity and Conservation'' 11: 1091-1104</ref> They are generally animals with low [[vagility]] and with very specific habitat requirements, so they can be also used to accurately determine the distribution of biogeographic zones. Today the fauna of these mostly rather fragile animals is being used to select conservation priorities in the Atlantic rainforest in southern [[Brazil]].
Because of their limited ecological requirements, some species have been proposed as indicators of the conservation state of their habitats.<ref name="Sluys99">{{cite doi|10.1023/A:1008994925673}}</ref><ref name="Carbayo02">{{cite doi | 10.1023/A:1015865005604}}</ref> They are generally animals with low [[vagility]] and with very specific habitat requirements, so they can be also used to accurately determine the distribution of biogeographic zones. Today the fauna of these mostly rather fragile animals is being used to select conservation priorities in the Atlantic rainforest in southern [[Brazil]].


At the other extreme, one species in this family, ''[[Platydemus manokwari]]'' has become an [[invasive species]] in both disturbed and wild habitats in the [[Pacific Islands]], and has damaged the endemic land [[snail]] faunas.
At the other extreme, one species in this family, ''[[Platydemus manokwari]]'' has become an [[invasive species]] in both disturbed and wild habitats in the [[Pacific Islands]], and has damaged the endemic land [[snail]] faunas.
Line 55: Line 55:


==Phylogeny==
==Phylogeny==
Phylogenetic supertree after Sluys et al., 2009:<ref name="Sluys09">Sluys, R., Kawakatsu, M., Riutort, M. & Baguñà, J. 2009. "A new higher classification of planarian flatworms (Platyhelminthes, Tricladida)". ''Journal of Natural History'', vol. 43, 1763-1777 pp.</ref>
Phylogenetic supertree after Sluys et al., 2009:<ref name="Sluys09"/>
{{clade| style=font-size:100%;line-height:80%
{{clade| style=font-size:100%;line-height:80%
|label1=[[Tricladida]]
|label1=[[Tricladida]]

Revision as of 15:50, 4 March 2012

Geoplanidae
Geoplana burmeisteri Schultze & Mueller, 1857, a typical Geoplanidae from the Atlantic rainforests of southern Brazil
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Suborder:
Family:
Geoplanidae

Stimpson, 1857
Subfamilies[1]
Polycladus gayi Blanchard, 1845, a large Geoplanidae from the Valdivian rainforests of southern Chile

The Family Geoplanidae, common name Land planarians (Platyhelminthes, Tricladida, Geoplanidae) is an understudied but important group of flatworms that belong to the soil ecosystem.[2]

These flatworms range between 1 and 20 cm in size[citation needed], and are predators of other invertebrates such as earthworms, snails, slugs, insects and chelicerates, which they hunt for, attack and capture using physical force and the adhesive and digestive properties of their mucus.[3] They lack water-retaining mechanisms and are therefore very sensitive to humidity variations of their environment.

Because of their limited ecological requirements, some species have been proposed as indicators of the conservation state of their habitats.[4][5] They are generally animals with low vagility and with very specific habitat requirements, so they can be also used to accurately determine the distribution of biogeographic zones. Today the fauna of these mostly rather fragile animals is being used to select conservation priorities in the Atlantic rainforest in southern Brazil.

At the other extreme, one species in this family, Platydemus manokwari has become an invasive species in both disturbed and wild habitats in the Pacific Islands, and has damaged the endemic land snail faunas.

Diversity

The Family Geoplanidae is composed of four subfamilies:

  • Rhynchodeminae: the oldest family, characterized by having only two eyes in the anterior end of the body
  • Bipaliinae, consisting of Asiatic species that have a half-circle head shape
  • Geoplaninae, the most modern family of terrestrial flatworms; it includes land planarians from south America and Oceania
  • Microplaninae

Although there are over 820 known species of Geoplanidae in the world, the diversity of land planarians is still very poorly known, because there are so few number of researchers investigating this group of animals.

Feeding and predatory behavior

"If contact with food is made, and the planarian is ready to feed, arousal and predatory behaviour will occur" (Neck, 1987)

Despite their delicate aspect these terrestrial flatworms are voracious predators. All planarians feed through a muscular and reversible pharynx located in ventral side of the body. The pharynx is an extensible tube-like mouth, it bears complex muscular coat that specialized as a penetration organ for those planarians that feed on arthropods; or as a grasping for those planarians that feed on other soft bodied invertebrates such as earthworms. All pharynxes are equipped with glandular secretions that externally digest and dissolve their prey.[3]

As part of the soil ecosystem land planarians feed mainly on other invertebrates such as earthworms, slugs and snails, termites, isopods, and other land planarians. Two facts prove the effectiveness of land planarians as predators:

  • Some species of land planarians have become invasive pest species. The New Zealand flatworm, Artioposthia triangulata, and the Australian flatworm, Caenoplana alba, have been introduced in the British Isles and are considered to be pest species since they prey upon earthworms and thus may negatively affect soil structure and fertility.

Some land planarians show hunting behaviour, using chemical signals to detect their prey. Most land planarians have chemical sensory organs in the anterior part of the body, such as sensory pits and epidermal folds which serve as chemical radars for detecting their food. The mucus trails from the slime of slugs, snails and other planarians orient planarians towards their prey.

Different species of land planarians use different techniques for capturing and immobilizing their prey, such as entrapment with sticky mucus and immobilization by physical force.

Cannibalism has been observed in land planarians.

Phylogeny

Phylogenetic supertree after Sluys et al., 2009:[1]

Tricladida

Image gallery

References

  1. ^ a b Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1080/00222930902741669, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi= 10.1080/00222930902741669 instead.
  2. ^ Winsor, L.; Johns, P.M. & Yeates, G.W. 1998. Introduction, and ecological and systematic background, to the Terricola (Tricladida). Pedobiologia 42: 389-404.
  3. ^ a b Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1007/BF00036370, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi= 10.1007/BF00036370 instead.
  4. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1023/A:1008994925673, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1023/A:1008994925673 instead.
  5. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1023/A:1015865005604, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi= 10.1023/A:1015865005604 instead.

External links