1. Introduction
Ammonia is the major metabolic end product during the catabolism of proteins, amino acids and other nitrogen containing biomolecules in different animal tissues. Ammonia is very toxic to the fish. Its toxicity leads to reduced growth rate (Atwood et al., 2000; El-Shafai et al., 2004; Hegazi and Hasanein, 2010), disruption of ion-osmo homeostasis (Knoph and Thorud, 1996; Person-Le Ruyet et al., 2003, 1998), gill hyperplasia (Benli et al., 2008), and if present in very high concentration, it causes hyperexcitability, coma, convulsions and finally death (Ip et al., 2001b).
To survive the effect of the ammonia toxicity, fish modifies its metabolism by either decreasing the production of ammonia, increasing its excretion, or converting the ammonia to glutamine and/or urea (Ip et al., 2001b). Most of the freshwater teleosts are ammoniotelic, as they excrete ammonia as primary excretory product to the external environment mainly by diffusion through the gills (Saha and Ratha, 2007). But, several species of fish have adapted to unique environmental circumstances by expressing high levels of OUC-enzymes and thus converting more than 50% of waste nitrogen as urea-N, they are considered as ureotelic (Anderson, 2001; Saha and Ratha, 2007). Though, quite a few recent studies have proposed an alternate to ureotelism (i.e. increased OUC pathway activity) as a mechanism for responding to such environmental circumstances. For example, in marble goby (Oxyeleotris marmoratus) a facultative freshwater air-breather, which can tolerate continuous air exposure for up to a week, glutamine synthetase (GS) appears to function as ammonia trap (Jow et al., 1999). A similar observation was made in the swamp eel (Monopterus albus) (Tay et al.,...
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...) concentrations. Furthermore, water evaporation at the high temperatures of the tropics can concentrate external ammonia (EA) (Rao et al., 1994). The situation is further aggreavated for those fish living in rice fields, where agricultural fertilization can lead to high concentrations of EA (Rao et al., 1994).
In the present study presence of multiple GS mRNA transcripts and their differential expression pattern in tissues air-breathing walking catfish (C. batrachus) during exposure to high environmental ammonia (HEA) (50 mM NH4Cl) were investigated. In addition, attempts were made for characterization of different GS proteins, and for this integrated approaches of computational analysis and expression profiling were used to predict properties and features that may be important for their function and to elucidate its possible association with hyper-ammonia stress.
Nitrogen and nitrates relate to Hypoxia via the process of eutrophication. Since Nitrogen is a limiting nutrient in most waters, the added input of nitrate causes massive growth in algae. The algae rapidly consume all available N, and once the nutrient is limited again, the alga dies en masse. As the alga decomposes, oxygen is depleted in the water. This lowers dangerously lowers the level of dissolved oxygen in the water, which harms living organisms in the area. Small organisms and organisms that are immobile or unable to escape low-oxygen areas are particularly vulnerable. Hypoxia and resulting “dead zones” are harmful to local fishing and shrimping industries and algal blooms hurt the tourism industry. Hypoxia has lead to a decrease of about 25% in the brown shrimp habitat, forcing shrimping operations further offshore. As the hypoxia issue continues to grow, negative human effects will only increase. Since nitrate runoff from ag. has been proven to be the dominant source of hypoxia, policies could be enacted to effectively deal with “point-source” pollution. This makes enacting environmental policy more easily adapted, possibly included in past policy such as the Clean Water Act.
To begin the lab, the variable treatment was prepared as the Loggerlite probe, used to later measure oxygen consumption, warmed up for approximately 10 minutes. To prepare the variable treatment, 200ml of Sodium and Ammo-lock water was measured in a container and a pre-prepared “tea bag” of tobacco was steeped in the room temperature treated water until a light yellow color was visible. After preparing the tobacco solution the preparation for the live goldfish began as two beakers were filled with 100 ml of treated water. Each beaker was weighed before addi...
Acknowledgements: Slides of dead fish courtesy of OKDEQ. We would like to thank our students Trevor Nance Jr, and Matt Ward for their help in the laboratory sample preparations. We would also like to thank OKDEQ (Chris Armstrong) and EPA Region 6 (Rick McMillin) for their patience.
In the early development process of many organisms, it is important to be able to minimize exposure to agents of stunted or arrested development. By decreasing the mortality rate for a generation of a species, that species is given an advantage in later reproduction; by increasing the number of organisms of the same species within a limited environment, more organisms of the same species are able to reproduce, resulting in an augmented overall population ("Reproduction and Development", 2013). However, when toxins are introduced to an environment, an embryo’s viability can decrease. Mortality rates for the generation of the species can increase, and defects that are harmful to the reproductive cycle can emerge. Thus, it is necessary to measure and observe the effects of certain toxins on embryonic development. The North American brine shrimp, or Artemia Franciscana (Artemia Salina), is subject to changes in its environment. Toxins introduced to its hatching environment, such as ethanol (in concentrations of 0.1%, 0.15%, and 0.2%), can have significant impact for the hatching process and embryonic development. The experiment sought to explore the relationship between birth defects and exposure to ethanol at early developmental stages through the use of American brine shrimp. However, to be able to fully comprehend the impact that certain toxins would have on the embryonic development of the North American brine shrimp, it is first important to be versed in its specific hatching process.
Ammonia (NH3) concentration in biogas does not exceed 0.1 mg/m3. The presence of ammonia in higher concentration is attributed to the increased nitrogen content of the substrate used (e.g. poultry manure).
within the soil. In this experiment, the liberation of ammonia is being employed as an indicator. Other components being utilized play a vital role in controlling the conditions of the experiment, as the THAM buffer, and the limitation of microbial activity, through toluene. The control experiment is crucial as it eliminates the addition of ammonia content being released by other sources within the soil into the final reading, providing accurate data.
Fish bioenergetics is really a matter of efficiency. Potential profit for a fish at any given position in a stream is simply the amount of energy coming into its system as prey minus the cost of staying at that position. This simplified model can be desribed by
In 5 petri dishes used pipettes to gather 20 live brine shrimp and place in each dish. Labeled each petri dish accordingly and then observed the live brine shrimp in their controlled environment for 5 minutes. After the 5 minutes I counted the number of live brine shrimp and recorded the information. Hypothesis is that 20% concentration of ammonia will kill off 50% of the brine shrimp.
Le Quesne, Will,J.F., and John K. Pinnegar. "The Potential Impacts of Ocean Acidification: Scaling from Physiology to Fisheries*." Fish and Fisheries 13.3 (2012): 333-44. ProQuest. Web. 21 Apr. 2014.
...et al. (2011). Using fluorescent imaging, the researchers found evidence of abnormal vascularization, neuron branching, and neuromast cell development in zebrafish (Danio rerio) exposed to the known endocrine disruptor during early life stages. Aluru et al. (2010) determined that maternal exposure to BPA can cause multiple adverse effects on developing offspring. Unfertilized rainbow trout eggs were treated with three different concentrations, fertilized, and resulting juveniles were observed throughout development. Aluru et al. (2010) concluded that oocyte exposure to BPA leads to modified stress performance, delayed hatching times, and growth suppression in juvenile rainbow trout. The following image is taken from Aluru et al. (2010), showing both the decrease in body size and production of yolk observed in juvenile rainbow trout hatched from BPA-exposed oocytes.
Osmoregulation is an example of an organism maintaining homeostasis. More specifically, osmoregulation involves an animal regulating osmotic pressure, or its fluid content. Brine shrimp, Artemia, use osmoregulation to regulate the saline levels of fluid within their body. Because brine shrimps live in seawater, an environment with a high saline concentration, they must actively excrete excess salt. Brine Shrimps use metepipodites as the location of the ion pump which secretes sodium. This is an active transport of ions because it is moving against the gradient, a higher salt content outside the body. The two following studies describe the environmental conditions ideal for brine shrimp and the possible genetic explanation for the osmoregulation of brine shrimp, respectively.
Oroian, Viman Oana I. "Damaging Effects of Overall Water Pollution." BioFlux (2010): 113-15. Web. 16 Apr. 2014.
Nitrogen is used by plants in order to synthesize protein peptide bonds and for cell growth. Not only is this nutrient required in the largest quantity by plants, but it is also the most frequently limiting factor when it comes to productivity in crops. Plants cannot use nitrogen in the air and in the soil system it is lost easily. Because of this plants are forced to obtain nitrogen in the form of nitrate and ammonium from the soil. Too much nitrate can cause a negative effect on the plant including nitrate toxicity. High levels of nitrate are not only bad for plants but can also be dangerous to animals or humans in their presence. Here I discuss the scientific evidence of the effects of nitrate accumulation on plants and the environment and argue that too much nitrate accumulation can be harmful to its surroundings.
If there is not enough oxygen in the water, it may lead to the death of many organisms, reduction in their growth or even failure to survive. The pH is a measure of how acidic or alkaline the water. It is defined as the negative log of the hydrogen ion concentration. According to Fondriest Environmental Inc, a well-known Fundamental Environmental organization, the pH scale goes from 0 to 14. As the scale of pH decreases, water becomes more acidic. Many chemical reactions inside aquatic organisms are necessary for survival and growth of organisms. At the extreme ends of the pH scale, (2 or 13) physical damage to gills, exoskeleton, fins, occurs. Changes in pH may alter the concentrations of other substances in water to a more toxic form. Examples: a decrease in pH (below 6) may increase the amount of mercury soluble in water. An increase in pH (above 8.5) enhances the conversion of nontoxic ammonia (ammonium ion) to a toxic form of ammonia (un-ionized ammonia). (Fondriest,
First type of biogeochemical cycle is nitrogen cycle. Nitrogen is abundant and chemically inert gases, constitutes of about 78% of the atmosphere. According to Stevenson and Cole (1999), accumulation in soil happens through microbial fixation of nitrogen in the presence of ammonia, nitrate and nitrite; depletion exists in the process of crop removal, leaching and volatilization. In term of that, the process of releasing compound during decomposition is called mineralization. Mineralization process is carried out by the microorganisms in which it releases carbon, and also ammonium (Sprent, 1987). As a result, many kinds of organic reduce nitrogen present, like urea, organic bases, such as purines and pyrimidines, and amino compounds. Animals have nitrogenous wastes and will eventually produce lots of nitrogen (Sprent, 1987). Several pathways are illustrated throughout the nitrogen cycle, such as nitrogen fixation, ammonification, nitrification and denitrification. Gates (1921) stated that the process of converted gaseous nitrogen into ammonia or ammonium is nitrogen fixation, while ammonium can also be produced through the decaying of nitrogenous organic substance, which is called ammonification. Afte...