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Marine Worm
Any worm that lives in a ocean, marine environment (biophysical), environment is considered a sea or marine worm. Marine worms are found in several different phylum (biology), phyla, including the Platyhelminthes, Nematoda, Annelida (segmented worms), Chaetognatha, Hemichordata, and Phoronida. Reproduction Marine worms exhibit numerous types of reproduction, both sexually and asexually. Asexually many are able to reproduce via budding or regeneration. This regeneration is most notably studied in Plathelminths or Triclad, known for being one of the earliest animals to be studied for its regenerative capabilities. Marine worms will also sexually reproduce, internally and externally, with some releasing spawn into the ocean currents. This is in opposition to the much more internal and invasive method displayed by flat-worms called Penis fencing where hermaphroditic organisms will flight to try and impregnate their opponent while avoiding becoming impregnated. This method is driven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parborlasia Corrugatus
''Parborlasia corrugatus'' is a proboscis worm in the family Lineidae. It was formerly placed in family Cerebratulidae. This species of proboscis or ribbon worm can grow to in length, and lives in marine environments down to . This scavenger and predator is widely distributed in the cold Southern Ocean. Description ''Parborlasia corrugatus'' is smooth and flat. Adults measure , with a diameter of approximately . Specimens can weigh up to . Their colouration is variable, ranging from cream through various tones of black.Peter Brueggeman''Nemertina, proboscis worms – Underwater Field Guide to Ross Island & McMurdo Sound, Antarctica''/ref> This worm has a wedge-shaped head containing a cavity filled with fluid. It uses this to fire an adhesive, barbed proboscis as a means of defense, and to capture prey. This organ has adhesive secretion to aid in securing its meal. Although this creature does not have a dedicated respiratory system, ''Parborlasia corrugata'' is able to obta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoronida
Phoronids ( taxonomic name Phoronida, sometimes called horseshoe worms) are a small phylum of marine animals that filter-feed with a lophophore (a "crown" of tentacles), and build upright tubes of chitin to support and protect their soft bodies. They live in most of the oceans and seas, including the Arctic Ocean but excluding the Antarctic Ocean, and between the intertidal zone and about 400 meters down. Most adult phoronids are 2 cm long and about 1.5 mm wide, although the largest are 50 cm long. The name of the group comes from its type genus: '' Phoronis''. Overview The bottom end of the body is an ampulla (a flask-like swelling), which anchors the animal in the tube and enables it to retract its body very quickly when threatened. When the lophophore is extended at the top of the body, cilia (little hairs) on the sides of the tentacles draw food particles to the mouth, which is inside and slightly to one side of the base of the lophophore. Unwanted ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keystone Species
A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf and lion, are also apex predators. The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Islands
The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of slightly over 33,000 (2020). The province is divided into the Cantons of Ecuador, cantons of San Cristóbal Island, San Cristóbal, Santa Cruz Island (Galápagos), Santa Cruz, and Isabela Island (Galápagos), Isabela, the three most populated islands in the chain. The Galápagos are famous for their large number of Endemism, endemic species, which were studied by Charles Darwin in the 1830s and inception of Darwin's theory, inspired his theory of evolution by means of natural selection. All of these islands are protected as part of Ecuador's Galápagos National Park and Galápagos Marine Reserve, Marine Reserve. Thus far, there is no firm evidence that Polynesian expansion, Polynesians or the indigenous peoples of South America, Indigenous pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Trench
Oceanic trenches are prominent, long, narrow topography, topographic depression (geology), depressions of the seabed, ocean floor. They are typically wide and below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about of oceanic trenches worldwide, mostly around the Pacific Ocean, but also in the eastern Indian Ocean and a few other locations. The greatest ocean depth measured is in the Challenger Deep of the Mariana Trench, at a depth of below sea level. Oceanic trenches are a feature of the Earth's distinctive plate tectonics. They mark the locations of convergent boundary, convergent plate boundaries, along which lithosphere, lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year. Oceanic lithosphere moves into trenches at a global rate of about per year. A trench marks the position at which the flexed, subduction, subducting slab (geology), slab begins to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macdonald%20Mid-Ocean%20Ridge%20Tectonics.pdf Volcanoes can also form where there is stretching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Tube Worm
''Riftia pachyptila'', commonly known as the giant tube worm and less commonly known as the giant beardworm, is a marine invertebrate in the phylum Annelida (formerly grouped in phylum Pogonophora and Vestimentifera) related to tube worms commonly found in the intertidal and pelagic zones. ''R. pachyptila'' lives on the floor of the Pacific Ocean near hydrothermal vents. The vents provide a natural ambient temperature in their environment ranging from 2 to 30 °C, and this organism can tolerate extremely high hydrogen sulfide levels. These worms can reach a length of , and their tubular bodies have a diameter of . Its common name "giant tube worm" is, however, also applied to the largest living species of shipworm, '' Kuphus polythalamius'', which despite the name "worm", is a bivalve mollusc rather than an annelid. Discovery ''R. pachyptila'' was discovered in 1977 on an expedition of the American bathyscaphe DSV ''Alvin'' to the Galápagos Rift led by geologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube Worm (body Plan)
A tubeworm is any worm-like sessile invertebrate that anchors its tail to an underwater surface and secretes around its body a mineral tube, into which it can withdraw its entire body. Tubeworms are found among the following taxa: * Annelida, the phylum containing segmented worms ** Polychaetea, the class containing bristle worms *** Canalipalpata, the order containing bristle-footed annelids or fan-head worms **** Siboglinidae, the family of beard worms ***** '' Riftia pachyptila'', a species known as giant tube worms ***** Lamellibrachia, a genus **** Serpulidae, a family **** Sabellidae, the family containing feather duster worms * Phoronid Phoronids (Taxonomy (biology), taxonomic name Phoronida, sometimes called horseshoe worms) are a small phylum of marine animals that Filter feeder, filter-feed with a lophophore (a "crown" of tentacles), and build upright tubes of chitin to suppo ...a, the phylum containing horseshoe worms * Microconchida, an order of extinct tubeworms * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trophosome
A trophosome is a highly vascularised organ found in some animals that houses symbiotic bacteria that provide food for their host. Trophosomes are contained by the coelom of tube worms (family Siboglinidae, e.g. the giant tube worm ''Riftia pachyptila'') and in the body of symbiotic flatworms of the genus ''Paracatenula''. Organization Initially, the trophosome in Frenulata, frenulates and vestimentiferans, which are now classified as members of the Siboglinidae, had been identified as a mesodermal tissue. The discovery of bacteria inside the trophosomal tissue only occurred in 1981 when the ultrastructure of trophosome of several frenulate species and of ''Sclerolinum brattstromi'' was studied. The bacteriocytes and Symbiosis, symbionts composed of 70.5% and 24.1% of the trophosome's volume respectively. Generally, trophosome extends over the entire trunk region between the two longitudinal blood vessels from immediately posterior to the ventral ciliary band of the forepart to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siboglinidae
Siboglinidae is a family (biology), family of polychaete Annelida, annelid worms whose members made up the former phylum, phyla Pogonophora and Vestimentifera (the giant tube worms). The family is composed of around 100 species of vermiform creatures which live in thin tubes buried in sediment (Pogonophora) or in tubes attached to hard substratum (Vestimentifera) at ocean depths ranging from . They can also be found in association with hydrothermal vents, methane seeps, sunken plant material, and Whale fall, whale carcasses. The first specimen was dredged from the waters of Indonesia in 1900. These specimens were given to French zoologist Maurice Caullery, who studied them for nearly 50 years. Anatomy Most siboglinids are less than in diameter, but in length. They inhabit tubular structures composed of chitin which are fixed to rocks or substrates. The tubes are often clustered together in large colonies. Their bodies are divided into four regions. The anterior end is called th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penis Fencing
__NOTOC__ Penis fencing is a mating behavior engaged in by many species of flatworm, such as '' Pseudobiceros hancockanus''. Species which engage in the practice are hermaphroditic; each individual has both egg-producing ovaries and sperm-producing testes. The flatworms "fence" using extendable two-headed dagger-like stylets. These stylets are pointed (and in some species hooked) in order to pierce their mate's epidermis and inject sperm into the haemocoel in an act known as intradermal hypodermic insemination, or traumatic insemination. Pairs can either compete, with only one individual transferring sperm to the other, or the pair can transfer sperm bilaterally. Both forms of sperm transfer can occur in the same species, depending on various factors. Unilateral sperm transfer One organism will inseminate the other, with the inseminating individual being the father. The sperm is absorbed through pores or sometimes wounds in the skin from the partner's stylet, causing fertili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triclad
Planarians (triclads) are free-living flatworms of the class Turbellaria, order Tricladida, which includes hundreds of species, found in freshwater, marine, and terrestrial habitats.pp 3., "Planarians (the popular name for the group as a whole), or triclad flatworms (the more scientific designation of the same group), are acoelomate bilaterians". Planarians are characterized by a three-branched intestine, including a single anterior and two posterior branches. Their body is populated by adult stem cells called neoblasts, which planarians use for regenerating missing body parts. Many species are able to Regeneration (biology), regenerate any missing organ, which has made planarians a popular model in research of regeneration and stem cell biology. The genome sequences of several species are available, as are tools for molecular biology analysis. The order Tricladida is split into three suborders, according to their phylogenetic relationships: Maricola, Dimarcusidae, Cavernicola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
