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A fish's hypoxia tolerance can be represented in different ways. A commonly used representation is the critical O 2 tension (P crit), which is the lowest water O 2 tension (P O 2) at which a fish can maintain a stable O 2 consumption rate (M O 2). [2]
Breathing air is primarily of use to fish that inhabit shallow, seasonally variable waters where the water's oxygen concentration may seasonally decline. Fish dependent solely on dissolved oxygen, such as perch and cichlids, quickly suffocate, while air-breathers survive for much longer, in some cases in water that is little more than wet mud.
Ectothermic – animals that control body temperature through external means, using the sun, or flowing air or water. Ekman transport – resultant flow at right angles to and to the right of the wind direction in the northern hemisphere, to the left in the southern hemisphere. Elasmobranch – cartilaginous fish that includes sharks, skates ...
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta blockers, beta-2 (β 2) antagonists and alpha-2 (α 2) agonists, which are used to treat high ...
In modern times it is frequently used as a tool to remove alien fish species, [10] as it has a relatively short half-life (days) and is gone from rivers in the course of days and from lakes within a few months, depending on (seasonal) stirring, organic content, availability of sunlight and temperature. [11] Rotenone has been used by government ...
Normal body temperature is around 37°C (98.6°F), and hypothermia sets in when the core body temperature gets lower than 35 °C (95 °F). [2] Usually caused by prolonged exposure to cold temperatures, hypothermia is usually treated by methods that attempt to raise the body temperature back to a normal range.
Recirculating aquaculture systems (RAS) are used in home aquaria and for fish production where water exchange is limited and the use of biofiltration is required to reduce ammonia toxicity. [1] Other types of filtration and environmental control are often also necessary to maintain clean water and provide a suitable habitat for fish. [2]
Examples of sympathomimetic effects include increases in heart rate, force of cardiac contraction, and blood pressure. [1] The primary endogenous agonists of the sympathetic nervous system are the catecholamines (i.e., epinephrine [adrenaline], norepinephrine [noradrenaline], and dopamine ), which function as both neurotransmitters and hormones .