Megascolecidae | |
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Megascolecidae found in Sai Kung West Country Park, Hong Kong belonging to genus Amynthas | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Annelida |
Clade: | Pleistoannelida |
Clade: | Sedentaria |
Class: | Clitellata |
Order: | Opisthopora |
Suborder: | Crassiclitellata |
Family: | Megascolecidae Rosa, 1891 [1] |
Genera | |
Over 65, see text |
Megascolecidae is a family of earthworms native to Madagascar, Australia, New Zealand, Asia, and North America. [2] At up to 2 meters in length, [3] their large size distinguishes the Megascolecidae from other earthworm families. They are an essential part of maintaining soil structure, minor carbon sequestration, and maintaining terrestrial ecosystems.
Different species of the Megascolecidae have different physiological features, but some similarities of physiological features can be found between species. [4] The family contains relatively large individuals. The length of earthworms can vary from 1.0 cm (0.39 in) to 2 m (6 ft 7 in). [3] The number of spermathecal pores is normally paired, but multiples can be present in some species. The location of spermathecal pores and how they are positioned in different segmental locations is used in the identification of different megascolecidids. [5]
Earthworms ingest a variety of organic materials in the soil since they live in terrestrial environments. [6] Earthworms in this family have the ability to decompose lignocellulose, which requires assistance from microorganisms in their digestive system. [7] Aside from microorganisms, digestive enzymes such as amylase and cellulase, and proteins can be found in different regions of the gut. Chemical digestion mainly occurs in the intestinal caeca of earthworms, which have higher protease activity than other parts of the gut. [6]
Genital markings in the Megascolecidae family can be used to distinguish species. [8]
The Megascolecidae are oviparous, laying eggs to reproduce. They are biparental. [9] The ideal condition of reproduction for the megascolecidids is 25 °C, where the eggs hatch the quickest and have the highest cocoon production. [10]
The male reproductive organ of the Megascolecidae includes testes, seminal vesicles, spermathecae, prostate glands, [11] and spermathecal pores. [12] The sperm can be found in testes and seminal vesicles, but cannot be found in spermathecae. [9] The female reproductive organ consists of female pores, which normally occur in pairs. [8] Both male and female reproductive organs are present in earthworms because they are monoecious. To breed, two earthworms exchange sperm. Long after they are separated, the egg case is secreted. It forms a ring around the worm, then the worm removes the ring from its body and injects its own eggs and the other worm's sperm into it. Afterwards, the egg case is sealed and ready to hatch, grow, and become a cocoon. [13]
The Megascolecidae lifecycle takes around 50–57 days, depending on the external environments and habitat. The rate of growth during the first 14 days is very low, however; after 21 – 28 days, the rate of growth increases and then cycles up and down throughout the worm's life with no pattern. [14] The growth rate of these worms is correlated to the temperature of their environment. As temperatures increase from 30 °C, a significant growth rate and decreasing the time to sexual maturity are seen. The ideal living temperature of megascolecidids is around 15 to 30 °C. [15] Overall mean growth is 1.79 mg/day, 1.57 mg/day, and 1.34 mg/day depending on the abundance of worms and environment condition and size. [14] The cocoon production of Megascolecidae species also is correlated with the temperature of the environment. [16]
Megascolecidae species can be in Australia, New Zealand, Asia, North America, South America, and Europe. [17] The intercontinental presence of Megascolecidae species can be explained by the Permanence of Continent Theory, which provides the explanation of most Cenozoic distributions; this theory,though, does not explain the presence of European Megascolecidae in North America. The intercontinental distribution of Megascolecidae has two different theories that explains its phenomenon -land bridges and continental drift. [18]
The Megascolecidae family originated in Australia. [19] Australia has number of species that are native to different parts of the country; Anisochaeta sebastiani is an example. This species can be found from Queensland to Tasmania. [20] Fifty-three known species of these earthworms can be found in Western Australia; Graliophilus georgei and G. secundus are some examples. [21] G. zeilensis can be found in the Northern Territory, specifically in Mount Zeil, West MacDonnell Ranges. G. zeilensis also can be found on the highest point of the mountain where average rainfall of the region is 250 mm annually. This distinguishes them from other species from Graliophilus. [22]
Metaphire and Amynthas are two common genera belonging to the Megascolecidae family. They can be found in different countries in Asia. [23]
Eight different species of Metaphire can be found in Malaysia: M. sedimensis, M. hijaunensis, M..e songkhlaensis, M. pulauensis, M. pulauensis, M. fovella, M. balingensis, and M. strellana. These species are commonly found in soil containing medium to high organic material. such as loamy soil. [24]
In Indonesia, 9 different genera can be found; Amynthas , Archipheretima, Metaphire, Metapheretima, Pheretima , Pithemera , Planapheretima, Pleinogaster, and Polypheretima.Pheretimoid is the biggest group of species, which consists of 65 species. Some intrageneric groups are restricted to mainland Asia, but others are native to Indo-Australian Archipelago. [25]
The ideal habitat for Megascolecidae is a terrestrial environment with soil with a high content of organic material, such as loamy soil, [14] cattlebor pig manure, and aerobically digested sewage sludge. [10] Megascolecidae species grow and produce more cocoons during the summer than the winter, because their lifecycle is highly correlated to the temperature and humidity of the environment. [14] Some Megascolecidae species have adapted to colder temperatures and drier areas, though, which enables them to live in higher-altitude regions of the land. [22]
Megascolecidae form an important part of the soil ecosystem, in that they indicate soil health and maintain soil productivity. The abundance of earthworms is highly correlated to soil pH, texture, water content, and temperature. [26] Earthworms have the ability to biomonitor soil pollutants. [27] This is because of earthworms' burrowing habit serves to facilitate water flow and agrochemicals through the soil profile, so are able to perform carbon sequestration and reduce soil pollutants]. [26] Invasive earthworms can have a significant impact causing changes in soil profiles, nutrient and organic matter content and other soil organisms or plant communities. In most cases the disturbed areas includes agricultural systems or previously areas that are lacking of earthworms would see the biggest impact of the invasive earthworms. [28] The impact of earthworms on soil structure is due to the rate of net nitrogen mineralization. [29]
Lumbricus terrestris is a large, reddish worm species thought to be native to Western Europe, now widely distributed around the world. In some areas where it is an introduced species, some people consider it to be a significant pest for out-competing native worms.
The Lumbricidae are a family of earthworms. About 33 lumbricid species have become naturalized around the world, but the bulk of the species are in the Holarctic region: from Canada and the United States and throughout Eurasia to Japan. An enigmatic species in Tasmania is Eophila eti. Currently, 670 valid species and subspecies in about 42 genera are recognized. This family includes the majority of earthworm species well known in Europe and Asia.
Oligochaeta is a subclass of soft-bodied animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms, and freshwater or semiterrestrial microdrile forms, including the tubificids, pot worms and ice worms (Enchytraeidae), blackworms (Lumbriculidae) and several interstitial marine worms.
Eisenia fetida, known under various common names such as manure worm, redworm, brandling worm, panfish worm, trout worm, tiger worm, red wiggler worm, etc., is a species of earthworm adapted to decaying organic material. These worms thrive in rotting vegetation, compost, and manure. They are epigean, rarely found in soil. In this trait, they resemble Lumbricus rubellus.
The Clitellata are a class of annelid worms, characterized by having a clitellum – the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed.
Spenceriella is a genus of worms in the family Megascolecidae that is now included in the prior genus Anisochaeta although some other species are transferred to Celeriella.
The Acanthodrilidae are an ancient and widely distributed family of earthworms which has native representatives in Australia, New Zealand, South Africa, South America, and North America. No native species are known from India nor Asia. The family possibly shows a pre-Pangaean distribution.
An earthworm is a soil-dwelling terrestrial invertebrate that belongs to the phylum Annelida. The term is the common name for the largest members of the class Oligochaeta. In classical systems, they were in the order of Opisthopora since the male pores opened posterior to the female pores, although the internal male segments are anterior to the female. Theoretical cladistic studies have placed them in the suborder Lumbricina of the order Haplotaxida, but this may change. Other slang names for earthworms include "dew-worm", "rainworm", "nightcrawler", and "angleworm". Larger terrestrial earthworms are also called megadriles as opposed to the microdriles in the semiaquatic families Tubificidae, Lumbricidae and Enchytraeidae. The megadriles are characterized by a distinct clitellum and a vascular system with true capillaries.
Rhinodrilus fafner is a presumed extinct giant earthworm of the family Glossoscolecidae. It is only known by the badly preserved holotype discovered in 1912 near Belo Horizonte in the Brazilian state of Minas Gerais and described in 1918 by German zoologist Wilhelm Michaelsen (1860–1937) from the National History Museum in Hamburg. The collected individual has is 210 cm, 24 mm in diameter and consists of 600 segments. Along with Amynthas mekongianus and Megascolides australis, Rhinodrilus fafner is among the largest known giant earthworms. Rhinodrilus fafner was confined to a small habitat and vanished possibly due to habitat destruction. It was officially declared extinct by the Brazilian Ministry of Environment (MMA) in 2003. However, the rediscoveries of the Giant Palouse earthworm in 2005 and the Brazilian earthworm Fimoscolex sporadochaetus in 2007 created hope that Rhinodrilus fafner may be found again.
Amynthas is a genus of earthworms in the family Megascolecidae. They are known as jumping worms, snake worms, or crazy worms because of their erratic thrashing behaviour when disturbed. The genus is native to East Asia, but they are invasive in many areas of the United States. They are a matter of concern in many states, as they disrupt the native forest ecology by affecting soil structure and chemistry.
Earthworms are invasive species throughout the world. Of a total of about 6,000 species of earthworm, about 120 species are widely distributed around the globe. These are the peregrine or cosmopolitan earthworms. Some of these are invasive species in many regions.
Samuel James is an American scientist, a researcher specializing in evolutionary biology, focusing on earthworm taxonomy. James, with fellow researchers, has discovered numerous species of annelids, including Diplocardia californiana, Diplocardia woodi, Diplocardia montana, and a new species related to the Giant Palouse earthworm.
Octochaetus multiporus, commonly known as the New Zealand earthworm, is a megascolecid worm endemic to New Zealand. It is mainly found in the south of Manawatu but may also be found along the east coast of the South Island. A bioluminescent worm, Octochaetus multiporus secretes a luminescent fluid from its mouth when disturbed or punctured.
Amynthas mekongianus, the Mekong worm or Mekong giant earthworm, previously known as Megascolex mekongianus, is a species of earthworm in the family Megascolecidae. It is native to the vicinity of the River Mekong in southeastern Asia and may have more than 500 segments and grow to a length of 2.9 m (10 ft).
Megascolecidae earthworm Amynthas japonicus is an extinct Japanese native probably collected from Nagasaki in the 1820s. It was one of three native earthworms featured in Dr P.F.B. von Siebold's extensive collection and recorded as one of Japan's earliest pheretimoid species. It is now deemed extinct given that a 2018 Nagasaki expedition and earlier 1930s reports failed to locate it. It is featured on The Recently Extinct Plants and Animals Database.
Amynthas agrestis, the Asian jumping worm, is a species of worm in the family Megascolecidae. It has a smooth, glossy, grey or brown body with a milky-white clitellum, and can range from 1.5 to 8 in in length. Amynthas agrestis is native to Japan and the Korean Peninsula, and was introduced to North America due to increased human activity during the 19th century; it is considered to be an invasive species in the United States. Worms within the genus Amynthas reproduce and develop quicker than their European counterparts.
Amynthas tokioensis, the Asian jumping worm, is a species of earthworm in the family Megascolecidae. It is native to Japan and the Korean Peninsula. It is an invasive species in North America.
Aridulodrilus molesworthae is a large Australian earthworm occurring, unusually, in a semiarid region of New South Wales. It was recognised as a species of Megascolecidae, a family with extreme diversity in the wetter coastal regions of the continent, but distinguished as a new monotypic genus Aridulodrilus, a name derived from Latin meaning a semi-desert worm. This animal was first recorded by a Broken Hill property's manager, Rosalind Molesworth, after substantial rain had brought them to the surface; the specific epithet molesworthae honours its discoverer.
Polypheretima is a genus of annelid earthworms belonging to the family Megascolecidae, erected by Wilhelm Michaelsen in 1934. Species have been recorded mostly from Africa and Asia, with several apparently very locally endemic.
Metapheretima is a genus of annelid earthworms belonging to the family Megascolecidae, erected by Wilhelm Michaelsen in 1928. Species have been recorded mostly from Asia, Australia and Pacific Islands.
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: CS1 maint: DOI inactive as of December 2024 (link)