Head and lateral line erosion, (HLLE) or hole-in-the-head (HITH) is a disease in fish. Chronic ulcerative dermatopathy or chronic erosive dermatopathy are symptoms of similar conditions with different etiology.
Head and lateral line erosion, (HLLE) or hole-in-the-head (HITH) is a disease in fish. Chronic ulcerative dermatopathy or chronic erosive dermatopathy are symptoms of similar conditions with different etiology.
HLLE begins as small pits of receding epithelium (skin) around the fish's head and/or lateral line, and sometimes onto the unpaired fins. Rarely fatal, it does cause disfigurement, making the fish less suitable for public aquarium display. At least 20 families of fish have been identified as having developed HLLE in captivity.[ clarification needed ] Not all species of fish show the same symptoms, and do not always develop lesions to the same degree. [1]
HLLE has not been sufficiently studied to identify all causes. In marine fish, two studies point to the use of activated carbon in closed aquarium ecosystems as contributors. [2] [3]
Hole in the head can be reversed by removing all activated carbon and conducting large percentage water changes. Greater than 90% water changes may need to be done to reduce the effects of activated carbon. More commonly, cures are made by moving the fish to a new aquarium that has never had fish develop HLLE in it. [4] [5]
The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. Shores are influenced by the topography of the surrounding landscape, as well as by water induced erosion, such as waves. The geological composition of rock and soil dictates the type of shore which is created. The Earth has around 620,000 kilometres (390,000 mi) of coastline. Coasts are important zones in natural ecosystems, often home to a wide range of biodiversity. On land, they harbor important ecosystems such as freshwater or estuarine wetlands, which are important for bird populations and other terrestrial animals. In wave-protected areas they harbor saltmarshes, mangroves or seagrasses, all of which can provide nursery habitat for finfish, shellfish, and other aquatic species. Rocky shores are usually found along exposed coasts and provide habitat for a wide range of sessile animals and various kinds of seaweeds. In physical oceanography, a shore is the wider fringe that is geologically modified by the action of the body of water past and present, while the beach is at the edge of the shore, representing the intertidal zone where there is one. Along tropical coasts with clear, nutrient-poor water, coral reefs can often be found between depths of 1–50 meters.
A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the hands. In some people, a tremor is a symptom of another neurological disorder.
Dieulafoy's lesion is a medical condition characterized by a large tortuous artery most commonly in the stomach wall (submucosal) that erodes and bleeds. It can present in any part of the gastrointestinal tract. It can cause gastric hemorrhage but is relatively uncommon. It is thought to cause less than 5% of all gastrointestinal bleeds in adults. It was named after French surgeon Paul Georges Dieulafoy, who described this condition in his paper "Exulceratio simplex: Leçons 1-3" in 1898. It is also called "caliber-persistent artery" or "aneurysm" of gastric vessels. However, unlike most other aneurysms, these are thought to be developmental malformations rather than degenerative changes.
Land development is the alteration of landscape in any number of ways such as:
Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although marine transportation significantly contributes as well. It is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide.Since most inputs come from land, either via the rivers, sewage or the atmosphere, it means that continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor by carrying off iron, carbonic acid, nitrogen, silicon, sulfur, pesticides or dust particles into the ocean. The pollution often comes from nonpoint sources such as agricultural runoff, wind-blown debris, and dust. These nonpoint sources are largely due to runoff that enters the ocean through rivers, but wind-blown debris and dust can also play a role, as these pollutants can settle into waterways and oceans. Pathways of pollution include direct discharge, land runoff, ship pollution, bilge pollution, atmospheric pollution and, potentially, deep sea mining.
Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture.
Toxic encephalopathy is a neurologic disorder caused by exposure to neurotoxic organic solvents such as toluene, following exposure to heavy metals such as manganese, as a side effect of melarsoprol treatment for African trypanosomiasis, adverse effects to prescription drugs, or exposure to extreme concentrations of any natural toxin such as cyanotoxins found in shellfish or freshwater cyanobacteria crusts. Toxic encephalopathy can occur following acute or chronic exposure to neurotoxicants, which includes all natural toxins. Exposure to toxic substances can lead to a variety of symptoms, characterized by an altered mental status, memory loss, and visual problems. Toxic encephalopathy can be caused by various chemicals, some of which are commonly used in everyday life, or cyanotoxins which are bio-accumulated from harmful algal blooms (HABs) which have settled on the benthic layer of a waterbody. Toxic encephalopathy can permanently damage the brain and currently treatment is mainly just for the symptoms.
Ulcerative dermal necrosis (UDN) is a chronic dermatological disease of cold water salmonid fish that had a severe impact on north Atlantic Salmon and sea trout stocks in the late 1960s and 1970s–1980. Despite much investigation, the cause of UDN has not been determined.
Surface runoff is the unconfined flow of water over the ground surface, in contrast to channel runoff. It occurs when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when the soil is saturated by water to its full capacity, and the rain arrives more quickly than the soil can absorb it. Surface runoff often occurs because impervious areas do not allow water to soak into the ground. Furthermore, runoff can occur either through natural or human-made processes.
Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.
Ornamental fish kept in aquariums are susceptible to numerous diseases. Due to their generally small size and the low cost of replacing diseased or dead fish, the cost of testing and treating diseases is often seen as more trouble than the value of the fish.
Actinic cheilitis is cheilitis caused by long term sunlight exposure. Essentially it is a burn, and a variant of actinic keratosis which occurs on the lip. It is a premalignant condition, as it can develop into squamous cell carcinoma.
Coastal engineering is a branch of civil engineering concerned with the specific demands posed by constructing at or near the coast, as well as the development of the coast itself.
An aquarium is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles, such as turtles, and aquatic plants. The term aquarium, coined by English naturalist Philip Henry Gosse, combines the Latin root aqua, meaning 'water', with the suffix -arium, meaning 'a place for relating to'.
Spironucleus is a diplomonad genus that is bilaterally symmetrical and can be found in various animal hosts. This genus is a binucleate flagellate, which is able to live in the anaerobic conditions of animal intestinal tracts. A characteristic of Spironucleus that is common to all metamonads is that it does not have aerobic mitochondria, but instead rely on hydrogenosomes to produce energy. Spironucleus has six anterior and two posterior flagella. The life cycle of Spironucleus involves one active trophozoite stage and one inactive cyst stage. Spironucleus undergoes asexual reproduction via longitudinal binary fission. Spironucleusvortens can cause lateral line erosion in freshwater anglefish. Spironucleuscolumbae is found to cause hexamitiasis in pigeons. Finally, Spironucleusmuris is found to cause illnesses of the digestive system in mice, rats, and hamsters. The genome of Spironucleus has been studied to exhibit the role of lateral gene transfer from prokaryotes in allowing for anaerobic metabolic processes in diplomonads.
Aquarium granuloma is a rare skin condition caused by a non-tubercular mycobacterium known as Mycobacterium marinum. Skin infections with M. marinum in humans are relatively uncommon, and are usually acquired from contact with contaminated swimming pools, aquariums or infected fish.
Fisheries are affected by climate change in many ways: marine aquatic ecosystems are being affected by rising ocean temperatures, ocean acidification and ocean deoxygenation, while freshwater ecosystems are being impacted by changes in water temperature, water flow, and fish habitat loss. These effects vary in the context of each fishery. Climate change is modifying fish distributions and the productivity of marine and freshwater species. Climate change is expected to lead to significant changes in the availability and trade of fish products. The geopolitical and economic consequences will be significant, especially for the countries most dependent on the sector. The biggest decreases in maximum catch potential can be expected in the tropics, mostly in the South Pacific regions.
Human activities have substantial impact on coral reefs, contributing to their worldwide decline.[1] Damaging activities encompass coral mining, pollution, overfishing, blast fishing, as well as the excavation of canals and access points to islands and bays. Additional threats comprise disease, destructive fishing practices, and the warming of oceans.[2] Furthermore, the ocean's function as a carbon dioxide sink, alterations in the atmosphere, ultraviolet light, ocean acidification, viral infections, the repercussions of dust storms transporting agents to distant reefs, pollutants, and algal blooms represent some of the factors exerting influence on coral reefs. Importantly, the jeopardy faced by coral reefs extends far beyond coastal regions. The ramifications of climate change, notably global warming, induce an elevation in ocean temperatures that triggers coral bleaching—a potentially lethal phenomenon for coral ecosystems.
Edwardsiella ictaluri is a member of the family Hafniaceae. The bacterium is a short, gram negative, pleomorphic rod with flagella. It causes the disease enteric septicaemia of catfish (ESC), which infects a variety of fish species. The bacteria can cause either acute septicaemia or chronic encephalitis in infected fish. Outbreaks normally occur in spring and autumn.
