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Any worm that lives in a marine environment is considered a water worm. Marine worms are found in several different phyla, including the Platyhelminthes, Nematoda, Annelida (segmented worms), Chaetognatha, Hemichordata, and Phoronida. For a list of marine animals that have been called "sea worms", see sea worm.
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. [1] 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. [2] This method is driven by the biological disadvantages (such as resource need and energy expenditure) behind carrying offspring instead of the more prolific gene passage through multiple impregnations.[ citation needed ]
Polynoid scale worms are estimated to have arrived in deep sea ecosystems around sixty million years ago. Through the comparison of 120 genes, researchers came to the conclusion that genes related to DNA repair, recombination, and integration were only present in the deep sea polynoidae, which correlates with the idea that they have to adapt to deal with potential hypoxia in deep sea environments. [3]
Marine worms can be herbivores, carnivores, parasites, detritivores, or filter feeders, but many strange examples of feeding are seen in this diverse type of animal. The group of Siboglinidae have developed a relationship with symbiotic bacteria within their gut that often perform chemosynthesis from which the worm benefits. These bacteria reside in a specialized organ called the Trophosome. [4] Some worms have an extendable pharynx or a proboscis for consuming prey, while others have developed jaws.[ citation needed ]
Marine worms have a variety of circulation and respiration processes. For example, in platyhelminths this is achieved through diffusion of oxygen (as well as other nutrients) across a moist epithelial layer, whereas annelids have a closed circulatory system with blood vessels lining the body. [5] [6]
Many of these worms have specialized tentacles used for exchanging oxygen and carbon dioxide which also may be used for reproduction. These specialized tentacles allow for gas exchange, further decreasing oxygen content in dead zones and in shallow water, which encourages plant and algae growth.[ citation needed ]
This quality is also observed in deeper oceans, where tube worms that use respiratory plumes with tentacles perform gas exchange of hydrogen sulfide and methane around hydrothermal vents. These types of circulatory systems differ from marine worms previously mentioned that can perform gas exchange through their entire bodies. This synapomorphy of gas exchange causes even related terrestrial annelids to be restricted to moist environments.[ citation needed ]
Marine worms are known to inhabit many different environments, having been found in both fresh and saltwater habitats globally.[ citation needed ]
Some marine worms are tube worms, of which the giant tube worm lives in waters near underwater volcanoes and can withstand temperatures up to 90 °C (194 °F). They share this space with fellow polychaetas known as “pompeii worms” that can resist 105 °C waters coming out of vents for short periods of time, making them one of the most heat resistant animals ever recorded (Islam and Schulze-Makuch,2007). [7]
Some worms can live in extremely deep oceanic trenches, such as in the Pacific Ocean off the Galápagos Islands. [8]
Marine deep sea polychaetes under the genus Osedax will colonize at whale falls in many different oceans, using a symbiont that can digest the bones within the carcasses (Jones et al,2007) This earned them the common name of “boneworms,” and they are speculated to be a keystone species of these types of environments due to lack of organisms in whale falls without observed Osedax worms. These whale falls remain undigested for many more years than those observed with marine worm cultivations. [9]
In recent years, marine worms (especially those found in the ocean) have been observed ingesting microplastic particles found in the oceans. This trend is concerning many scientists, as marine worms act as an important food source for many fish and wading birds. Marine worms are often keystone species in an ecosystem, and the introduction of plastic in the oceans not only diminishes the growth rates of the marine worms, but also affects the food chain of that ecosystem. [10]
The Sipuncula or Sipunculida is a class containing about 162 species of unsegmented marine annelid worms. Sipuncula was once considered a phylum, but was demoted to a class of Annelida, based on recent molecular work.
Siboglinidae is a family of polychaete annelid worms whose members made up the former phyla Pogonophora and Vestimentifera. 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 100 to 10,000 m. They can also be found in association with hydrothermal vents, methane seeps, sunken plant material, and whale carcasses.
Polychaeta is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm and the sandworm or clam worm Alitta.
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 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 3 m, and their tubular bodies have a diameter of 4 cm (1.6 in).
Osedax is a genus of deep-sea siboglinid polychaetes, commonly called boneworms, zombie worms, or bone-eating worms. Osedax is Latin for "bone-eater". The name alludes to how the worms bore into the bones of whale carcasses to reach enclosed lipids, on which they rely for sustenance. They utilize specialized root tissues for bone-boring. It is possible that multiple species of Osedax reside in the same bone. Osedax worms are also known to feed on the collagen itself by making holes in the whale's skeletal structure. These holes can also serve as a form of protection from nearby predators.
A whale fall occurs when the carcass of a whale has fallen onto the ocean floor, typically at a depth greater than 1,000 m (3,300 ft), putting them in the bathyal or abyssal zones. On the sea floor, these carcasses can create complex localized ecosystems that supply sustenance to deep-sea organisms for decades. In some circumstances, particularly in cases with lower water temperatures, they can be found at much shallower depths, with at least one natural instance recorded at 150 m and multiple experimental instances in the range of 30-382 m. Whale falls were first observed in the late 1970s with the development of deep-sea robotic exploration. Since then, several natural and experimental whale falls have been monitored through the use of observations from submersibles and remotely operated underwater vehicles (ROVs) in order to understand patterns of ecological succession on the deep seafloor.
Marine life, sea life, or ocean life is the plants, animals, and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms, mostly microorganisms, produce oxygen and sequester carbon. Marine life, in part, shape and protect shorelines, and some marine organisms even help create new land.
The Monterey Bay Aquarium Research Institute (MBARI) is a private, non-profit oceanographic research center in Moss Landing, California. MBARI was founded in 1987 by David Packard, and is primarily funded by the David and Lucile Packard Foundation. Christopher Scholin serves as the institute's president and chief executive officer, managing a work force of approximately 220 scientists, engineers, and operations and administrative staff.
Polynoidae is a family of marine Polychaete worms known as "scale worms" due to the scale-like elytra on the dorsal surface. Almost 900 species are currently recognised belonging to 9 subfamilies and 167 genera. They are active hunters, but generally dwell in protected environments such as under stones. The group is widely distributed from shallow intertidal waters to hadal trenches. They are the most diverse group of polychaetes in terms of genus number and second most diverse in terms of species number which is almost 8% of all segmented worm species.
Marine invertebrates are the invertebrates that live in marine habitats. Invertebrate is a blanket term that includes all animals apart from the vertebrate members of the chordate phylum. Invertebrates lack a vertebral column, and some have evolved a shell or a hard exoskeleton. As on land and in the air, marine invertebrates have a large variety of body plans, and have been categorised into over 30 phyla. They make up most of the macroscopic life in the oceans.
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 and in the body of symbiotic flatworms of the genus Paracatenula.
Osedax roseus is a species of bathypelagic polychaete worm that lives at abyssal depths and is able to sustain itself on the bones of dead whales. The species is found in the North East Pacific.
Osedax frankpressi is a species of bathypelagic polychaete worm that lives on the seabed and sustains itself on the bones of dead whales. It can be found in the East North Pacific Ocean. The specific epithet is named in honor of Frank Press "for his distinguished service to science".
Osedax japonicus is a species of bathypelagic polychaete tube worm that lives at great depths on the seabed and is able to sustain itself on the bones of a dead whale. It was first described in 2006 from a sunken sperm whale carcase near Kyushu, Japan.
Paracatenula is a genus of millimeter sized free-living marine gutless catenulid flatworms.
Microbial symbiosis in marine animals was not discovered until 1981. In the time following, symbiotic relationships between marine invertebrates and chemoautotrophic bacteria have been found in a variety of ecosystems, ranging from shallow coastal waters to deep-sea hydrothermal vents. Symbiosis is a way for marine organisms to find creative ways to survive in a very dynamic environment. They are different in relation to how dependent the organisms are on each other or how they are associated. It is also considered a selective force behind evolution in some scientific aspects. The symbiotic relationships of organisms has the ability to change behavior, morphology and metabolic pathways. With increased recognition and research, new terminology also arises, such as holobiont, which the relationship between a host and its symbionts as one grouping. Many scientists will look at the hologenome, which is the combined genetic information of the host and its symbionts. These terms are more commonly used to describe microbial symbionts.
Eulagisca gigantea is a species of scale worm. This species is specifically found in the deep-sea in cold waters like the Antarctic Ocean. The scale worms are named for the elytra on their surface that look like scales.
Peinaleopolynoe is a genus belonging to the family Polynoidae. Members of this genus generally live in nutrient-rich environments in the deep sea, such as whale fall, which is the reason for their name.
Oligobrachia is a genus in the family Siboglinidae, commonly known as beard worms. These beard worms are typically found at spreading centers, hydrothermal vents, and undersea volcanoes. The siboglinidae are annelids which can be found buried in sediments. Beard worms do not necessarily exist at one specific part of the world's oceans, however, they are spread out all over the ocean floors as long as the surrounding environment is similar; these are known as metapopulations. Most commonly, these organisms are found at the bottom of the ocean floor, whether it be at a depth of roughly 25 meters or hundreds of meters. Oligobrachia can typically be found near hydrothermal vents and methane seeps. An important characteristic of this genus is that it lacks a mouth and gut. Therefore, it relies on symbiotic bacteria to provide the host organism with energy to survive. The majority of oligobrachia that have been observed have been found in the Arctic and other high-latitude areas of the world's oceans.
Frenulata, "beard worms", is a clade of Siboglinidae, "tube worms". They are one of four lineages with numerous species. They may be the most basal clade in the family. Despite being the first tube worms to be encountered and described, they remain the least studied group. This is because of their slender shape, they often get destroyed as a result of being caught as bycatch or poor preservation. They are found primarily in deep, muddy sediments, cold seeps, and anoxic firth sediments.