Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca, Notostraca, the Devonian Lepidocaris and possibly the Cambrian Rehbachiella. They are mostly small, freshwater animals that feed on plankton and detritus.
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water or from debris accumulating around it. The plants on which epiphytes grow are called phorophytes. Epiphytes take part in nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism. They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively. An organism that grows on another organism that is not a plant may be called an epibiont. Epiphytes are usually found in the temperate zone or in the tropics. Epiphyte species make good houseplants due to their minimal water and soil requirements. Epiphytes provide a rich and diverse habitat for other organisms including animals, fungi, bacteria, and myxomycetes.
A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Ecologists can broadly define all life forms as either autotrophs or heterotrophs, based on their trophic levels, the position that they occupy in the food web. To maintain their bodies, grow, develop, and to reproduce, autotrophs produce organic matter from inorganic substances, including both minerals and gases such as carbon dioxide. These chemical reactions require energy, which mainly comes from the Sun and largely by photosynthesis, although a very small amount comes from bioelectrogenesis in wetlands, and mineral electron donors in hydrothermal vents and hot springs. These trophic levels are not binary, but form a gradient that includes complete autotrophs, which obtain their sole source of carbon from the atmosphere, mixotrophs, which are autotrophic organisms that partially obtain organic matter from sources other than the atmosphere, and complete heterotrophs that must feed to obtain organic matter.
An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in water for all or most of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic animals may breathe air or extract oxygen from water through specialised organs called gills, or directly through the skin. Natural environments and the animals that live in them can be categorized as aquatic (water) or terrestrial (land). This designation is polyphyletic.
Freshwater ecosystems are a subset of Earth's aquatic ecosystems. They include lakes, ponds, rivers, streams, springs, bogs, and wetlands. They can be contrasted with marine ecosystems, which have a larger salt content. Freshwater habitats can be classified by different factors, including temperature, light penetration, nutrients, and vegetation. There are three basic types of freshwater ecosystems: Lentic, lotic and wetlands. Freshwater ecosystems contain 41% of the world's known fish species.
Onychopoda are a specialised order of branchiopod crustaceans, belonging to the superorder Cladocera.
Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (N2O) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of N2O emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the history of anthropogenic N inputs, and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems.
Bythotrephes longimanus, or the spiny water flea, is a planktonic crustacean less than 15 millimetres (0.6 in) long. It is native to fresh waters of Northern Europe and Asia, but has been accidentally introduced and widely distributed in the Great Lakes area of North America since the 1980s. Bythotrephes is typified by a long abdominal spine with several barbs which protect it from predators.
Fishing bait is any luring substance used specifically to attract and catch fish, typically when angling with a hook and line. There are generally two types of baits used in angling: hookbaits, which are directly mounted onto fish hooks and are what the term "fishing bait" typically refers to; and groundbaits, which are scattered separately into the water as an "appetizer" to attract the fish nearer to the hook. Despite the bait's sole importance is to provoke a feeding response out of the target fish, the way how fish react to different baits is quite poorly understood.
The Diplostraca or Cladocera, commonly known as water fleas, is a superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory.
Moina is a genus of crustaceans within the family Moinidae. The genus was first described by W. Baird in 1850. They are referred to as water fleas, but are related to the much larger Daphnia magna and the larger Daphnia pulex. This genus demonstrates the ability to survive in waters containing low oxygen levels, high salinity, and other impurities, including salt pans, and commonly eutrophication. An example of such an extreme habitat is the highly saline Makgadikgadi Pans of Botswana, which supports prolific numbers of Moina belli.
Ballast water discharges by ships can have a negative impact on the marine environment. The discharge of ballast water and sediments by ships is governed globally under the Ballast Water Management Convention, since its entry into force in September 2017. It is also controlled through national regulations, which may be separate from the Convention, such as in the United States.
In ecology, the term productivity refers to the rate of generation of biomass in an ecosystem, usually expressed in units of mass per volume per unit of time, such as grams per square metre per day. The unit of mass can relate to dry matter or to the mass of generated carbon. The productivity of autotrophs, such as plants, is called primary productivity, while the productivity of heterotrophs, such as animals, is called secondary productivity.
Biological pollution is the impact of humanity's actions on the quality of aquatic and terrestrial environment. Specifically, biological pollution is the introduction of non-indigenous and invasive species, otherwise known as Invasive Alien Species (IAS). When the biological pollution is introduced to an aquatic environment, it contributes to water pollution.
Canadian aquatic invasive species are all forms of life that traditionally has not been native to Canada's waterways. In Eastern Canada, non-native plant and animal species are a concern to biologists. Bringing non-native species such as invasive fishes into Canada can damage the environment and ecosystem by repressing native species due to food competition or preying. Invasive fishes enter the fresh waters of Canada in several ways including drifting, deliberate introduction, accidental release, experimental purposes and, most commonly, through the attachment on international boat hulls. Invasive species are the second biggest threat to fish and other marine life in Canada behind loss of habitat and degradation. The threat to native species is primarily caused by impacts on the food web; however, invasive species also bring dangerous pathogens and physically interfere with existing aquatic life. Invasive species include sea lampreys, zebra mussels, smallmouth bass, European green crab, vase tunicate, and sea squirts.
Cape Lowland Freshwater Wetland is a critically endangered vegetation type of the Western Cape, South Africa.
Ephippia are winter or dry-season eggs of the various species of small crustacean in the order Cladocera ; they are provided with an extra shell layer, which preserves and protects the resting stages inside from harsh environmental conditions until the more favorable times, such as spring, when the reproductive cycle is able to take place once again. Ephippia are part of the back of a mother carrying them until they are fully developed. After molting, the ephippium stays in the water, or in the soil of dried puddles, small ponds, and vernal pools. The resting stages are often called eggs, but are in fact embryos with arrested development. Ephippia can rest for many years before the embryo resumes development upon an appropriate hatching stimulus.
Sididae is a family of ctenopods in the order Diplostraca. There are about 6 genera and at least 20 described species in Sididae. Some Sididae are non-native species.
Chydoridae is a family of water fleas in the order Anomopoda. There are more than 50 genera and 520 described species in Chydoridae. A lot of Chydoridae species are non-native species, many of which pose a great threat to aquatic ecosystems.
Harp Lake is an oligotrophic, single-basin lake in Ontario, Canada. The lake covers over 710,000 m2 and has a depth of 37.5 m. Harp Lake does have dimitic stratification and is a temperate lake. Additionally, Harp Lake does not have anaerobic conditions in the water column because it is a relatively deep lake. The water in Harp Lake has a pH of 6.3. This pH is caused by the presence of acids and the lack of alkaline bases.[3] Slightly acidic lakes normally have a granite or siliceous bedrock and they are poorly buffered. Also, these lakes commonly have calcium-poor soils or thin soils.
