Fish - Science topic

Honoured

Alberts Auzins!

In addition to fish meal and fish fat, it is possible to obtain pearl pate from fish scales, which is an initial component for the production of pharmaceutical substances such as acyclovir and others. The issue of the yield of finished products is improving with each new stage of production technology.

Maybe DEI could help us find someone with the eggs. I wrote this for DEI: https://www.researchgate.net/publication/380427514_Kalergi_and_Hart-Cellerand_Memetics_White_Antifragility

I recommend the H2O2 and low temperatures or perhaps

dry the tissue and mill it if you want just the concentration of MPs in the tissue

but you need to consider the thermal and chemical effects on polymers. .........................

Hi

depends on skills and money you got and what you're searching for...FISH is OK, array CGH is better, and WGS is far resulting

all the best

fred

Thank you Aldo for your suggestion. I can see the general framework.

Cheers!

Hi Daniel,

Standardization of monthly fish catch without any data on fishing effort (vessels, days, fishermen) is tricky, but there are a few approaches that you can consider:

· Monthly average: Since months have different lengths, dividing the total catch by the number of days in the month provides a basic standardization. However, this doesn't explain the seasonal variations in fish abundance or the effort put into fishing activity.

· Comparison to the historical data: If you have historical catch data for the Amazon fishery of the location of interest, you can calculate the average catch for each month over a defined period (e.g., past 5 years). Then, visualize the trend of the current month's catch as a percentage of the historical monthly average. This approach accounts for seasonal variations but may not be ideal if fishing pressure has significantly changed with time.

· Environmental data: Fish abundance can be influenced by environmental factors like water temperature, salinity, or land runoffs. With such data, you might be able to establish correlations between these factors and historical catch data. This allows you to estimate a "baseline" catch expected for certain environmental conditions and compare the current month's catch to that expectation.

· Indigenous knowledge: Consulting with indigenous and local fishers can provide valuable insights. With their experience, they might be able to explain seasonal patterns in fish abundance or fishing activity that can be used to adjust the catch data for better comparability between months qualitatively.

The results might not be as statistically robust as those obtained with standardized Catch Per Unit Effort (CPUE), but it might give you some insight into the trend.

Hi, small opening remark, fish are not 'other marine mammals'. Fish and other gill breathing animals are strongly affected by water temperature, irrespective of the origin. First of all, fish, except big tuna, have environment temperature, not a fixed one around 36°C like mammals. The proteins of fish adapted to high latitudes function best in cold or cool waters, where disolved oxygen tends to be much higher than in warm, tropical waters.

As gas exchange in water breathing animals is much more energy intensive than air breathing, fish must expend a large part of their energy budget on breathing. Moreover, gills are surfaces, while the body of fish will grow in volume. At some point, the surface limitation of gas exchange through the gills will not allow fish to transform food into own body cells because of lack of oxygen supply. This is why fish species in the warmer part of their distribution range attain a lower maximum size than in the cooler part of their distribution range. It has also been observed, that e.g. salmon can grow a bit more after spawning (spawning reduces body weight requiring oxygen supply). This gill-oxygen limitation theory (GOLT) proposed by Pauly also explains why we observe polewards migrations of fish species as the ocean surface waters warm. They want to remain within their preferred temperature range - if they can. It means also that tropical regions loose species without replacement because it's becoming too warm (oxygen too low, even without overfishing), while temperate and polar regions gain, at least temporarily. But cold adapted animals may be at risk, e.g. mass mortality of snow crabs in the rapidly warming Arctic. Air breathing marine mammals are not affected by this phenomenon, except indirectly in that they prey species may move as a result of a warming ocean.

A priori selection based on a mechanistic explanation of a species niche "preferences" is advised. Selection procedures via p-values (backward and/or forward selection), dropping "insignificant" variables, AIC (or BIC) are not proper statistical approaches for selection and are all somehow "related" so result in problematic conclusions see the sources (https://royalsocietypublishing.org/doi/10.1098/rspb.2023.1261, https://www.tandfonline.com/doi/full/10.1080/09332480.2018.1549817 or see F. Harrell's book

https://link.springer.com/book/10.1007/978-3-319-19425-7).

A niche could be defined as some abstract multivariate space constructed by univariate vectors under which a taxon was observed. I see no need to select a variable perse, because a niche does not imply "causality", unless defined otherwise ofcourse. If you have too many variable you could start by addressing why a particular variable would be of interest for a species occupation of this space. Ofcourse in ecology we often deal with indirect relations so one could "explain away" every relation and by some model selection it tends to become tricky and we likely end up with a spurious relation (e.g., https://www.sciencedirect.com/science/article/pii/S0022316622012196).

I would keep it straightforward and focus on those of "direct" relations. I never read something about reef fish, but I assume reef structure, algae biomass and specific food source or oxygen, might be of interest. Iam much more interested in your knowledge and ideas of how such variables shape the niche given a qualitative good introduction en mechanistic explanation then why a "mindless" model wold select it.

Best,

Hello,

By any chance, have you found a solution to the background signal issue with your FISH probe? It would be great to know if you've had any success with resolving this issue.

Yes Amy, you have to put your ages into categories.

Mr. Adhan, Iodine mixed with salt can be harmful to freshwater fish fingerlings in aquaculture due to its potential toxicity. Elevated iodine levels can disrupt fish osmoregulation, causing stress and negatively impacting their growth and survival. Maintaining proper water quality and avoiding excessive iodine concentrations is crucial for the well-being your fish. so be cautious while handling fingerlings.

One possibility is that the amount of protein added is too high. Try diluting the sample with water and doing the assay again.

Another possibility is that the amount of other substances besides protein is the problem. This could be nucleic acids and fats, for example. Some additional preparation of the sample may be needed.

Hi Alana Barton It would be good to have more information here to be able to help more, but have you tried a GLM with both years and temperatures included in the model? Perhaps you'd also need to add an interaction effect between temperature and year (as from what you said there's seems to be an interaction). Further explanatory variables could be added to the model if you have measured them.

Several studies have reported an increase in antioxidant enzymes due to oxidative stress, but a decrease in these has been noted in cases of severe oxidative stress, an indication that the organism has been overwhelmed by the radical attack.

Thank you, Erinke. This was helpful.

This variation can be influenced by the available nutrients, and also by the environmental conditions that allow the absorption of one or another nutrient.

Hey there!

I have done zebrafish xenotransplantation before and I never had much mortality after injection. Some die off is expected and inevitable. What age are the larvae? In my experience, 48 hpf larvae seemed to survive ok when injected in tricane (maybe check your concentration, too high of a conc. can kill them), then washed in embryo water. I would then put them in fresh embryo water and put in the incubator at 33C. I used this temp because I was injecting human cancer cells and had to keep a happy medium between larvae temp and human temp. They never had any issue surviving at 33C.

Hola Julián, no tengo el libro pero me dedico al tema. Quizás pueda ayudarte.

Dear Dilan Serdar

As membrane I used nitrocellulose and I denatured the nick-translated DNA probes at 95°C for 5 minutes before spotting them on the nitrocellulose, then I baked it for about 1 hr at 80°C in a drying oven. Hope this helps.

The stress value represents how close the reduced space in NMDS is to the multidimensional space (no reduction). Thus, the higher the number of dimensions included in the solution, the lower the stress value. Technically, if you include all possible dimensions (as many as the number of variables in the ordination; 'species'), the stress value will be zero. Are you including all dimensions in your analysis?

Note that NMDS is an unconstrained ordination; thus, the 7 environmental variables you mention have nothing to do with the solution and patterns in species composition in your solution.

This fish can eat local fish eggs that stick to the bottom or water plants. Apart from that, fish have more adaptive eating characteristics so they develop more quickly and become competitors for other fish both in terms of space and food.

Fish can survive anywhere , with best environment condition.

The metabolism of fish, as in other species, is directly related to its temperature. They are poikilothermic organisms (they do not regulate the internal temperature of the body), they depend on the ambient temperature, if it is low their metabolism and growth are also low.

No problem, I ask about amb gene. Thank you for your help and attention.

I was previously worked on amh (anti-Müllerian hormone) gene.

Please note that the application should be sent through the application portal.

Environmental flows for low-head dams aim to mimic natural river flow patterns to facilitate fish passage. Techniques include pulsed flow releases, fish passage structures like ladders or ramps, and monitoring for adaptive management. These strategies help restore fish migration routes and improve river health by addressing barriers created by dams. Collaboration among stakeholders is crucial for effective implementation.

Did you try to load your sample on a shredder column before the extraction?

it helps with saliva.

Sure! You may as well abuse mice to extrapolate to earthworms. Both are animals, isn't it?

Depends on the species you are trying to culture. When it comes to hydrogels you can use agar, starch, pectin or gelatin but some species are able to digest the matrix resulting in a loss of stiffness/liquefaction. As gelatin is made of protein it is highly likely that it will be digested by many species.

Hey there Chouaib Siouda! Making fish food float is a piece of cake. All you Chouaib Siouda need is a bit of kitchen ingenuity. Try mixing gelatin with your usual fish food concoction. The gelatin will give it that buoyant kick. It's like the jelly of the fish world – they'll be swimming up for more in no time. Experiment with the ratios until you Chouaib Siouda achieve the perfect floating feast for your aquatic buddies. And remember, it's all about keeping those fish fins flapping!

Hello Maruf Adnan

Catfish possesses a pair of suprabranchial chambers located in the dorsal-posterior part of the branchial cavity having extensions from the upper parts of the second and fourth gill arches, forming the arborescent organs. This structure is an air-breathing organ (ABO) and allows aerial breathing.

In stale waters which is not properly aerated or small water bodies or even in mud without water, the catfish will breathe air using the air-breathing organ for their survival. The oxygen is extracted as a gas from the atmosphere by the catfish.

So, catfish can use their gills when they in water that is aerated as well as use their air-breathing organ or air bladders when water is scanty or not well aerated.

Best.

Hi Maruf,

Fish usually swim against the current for various reasons. One of the reasons is to locate food, as struggling against the water's flow can take them to areas with more food sources. Additionally, some fish swim against the current to reach their spawning grounds, where they can reproduce. Some fish make long journeys, and swimming upstream helps them reach their destination. By swimming against the flow, they can go upstream to where they lay eggs or return to their starting point. Fish create territories for breeding or finding food, essential for protecting their home.

Dear Kylian Manon Eggink ,

Let me first express that to me the protocol looks hopelessly complicated and confusing, and I definitely would use another method as well.

Anyway, I noticed in your calculation sheet concentrations expressed in mM while I read in the protocol (when it comes to the standard curve): “A typical standard series should consist of five samples, ranging from 1 × 10⁻⁶ to 1 × 10⁻⁵ M malonaldehyde.”

I notice in the (last) calculation step always a high number like 2.88x10¹⁰ in 2.88 × 10¹⁰/(slope × % recovery). Meaning that the slope should be high or the 1/slope very small in order to ‘normalize’ the TBA value. Could it be the concentration of MA that should be in the range of 10^-5 or 10^-6 instead of mM?

Kind regards.

Hi William Furtado

I was wondering how you went with this in the end and if you made any other adjustments? I'm working with a species that's giving me the same issues that you were experiencing... I was going to try warming the sample + lysis buffer and EB tomorrow but was wondering if you'd optimised any further and had any tips.

Thanks :D

Dear, thank you.

Dear Doctor

"Icefish blood is colorless because it lacks hemoglobin, the oxygen-binding protein in blood. Channichthyidae are the only known vertebrates to lack hemoglobin as adults. Although they do not manufacture hemoglobin, remnants of hemoglobin genes can be found in their genome. The hemoglobin protein is made of two subunits (alpha and beta). In 15 of the 16 icefish species, the beta subunit gene has been completely deleted and the alpha subunit gene has been partially deleted. One icefish species, Neopagetopsis ionah, has a more complete, but still nonfunctional, hemoglobin gene.

Red blood cells (RBCs) are usually absent, and if present, are rare and defunct. Oxygen is dissolved in the plasma and transported throughout the body without the hemoglobin protein. The fish can live without hemoglobin via low metabolic rates and the high solubility of oxygen in water at the low temperatures of their environment (the solubility of a gas tends to increase as temperature decreases). However, the oxygen-carrying capacity of icefish blood is less than 10% that of their relatives with hemoglobin.

Myoglobin, the oxygen-binding protein used in muscles, is absent from all icefish skeletal muscles. In 10 species, myoglobin is found in the heart muscle, specifically ventricles. Loss of myoglobin gene expression in icefish heart ventricles has occurred at least four separate times.

To compensate for the absence of hemoglobin, icefish have larger blood vessels (including capillaries), greater blood volumes (four-fold those of other fish), larger hearts, and greater cardiac outputs (five-fold greater) compared to other fish. Their hearts lack coronary arteries, and the ventricle muscles are very spongy, enabling them to absorb oxygen directly from the blood they pump. Their hearts, large blood vessels and low-viscosity (RBC-free) blood are specialized to carry out very high flow rates at low pressures. This helps to reduce the problems caused by the lack of hemoglobin. In the past, their scaleless skin had been widely thought to help absorb oxygen. However, current analysis has shown that the amount of oxygen absorbed by the skin is much less than that absorbed through the gills. The little extra oxygen absorbed by the skin may play a part in supplementing the oxygen supply to the heart, which receives venous blood from the skin and body before pumping it to the gills. Additionally, icefish have larger cardiac mitochondria and increased mitochondrial biogenesis in comparison to red-blooded notothenioids. This adaptation facilitates enhanced oxygen delivery by increasing mitochondrial surface area, and reducing distance between the extracellular area and the mitochondria."

You have to check Universities web sites for post doc position.

Good luck

@all The concentration of acridine orange for staining DNA in a comet assay can vary depending on the specific protocol and the sensitivity required for your experiment. However, a common concentration range for acridine orange staining in comet assays is typically between 1 and 10 μg/mL. Here are some considerations:

Remember to document the concentrations and conditions you use during optimization, and keep track of any changes made. If you are still facing issues with staining, it may be helpful to consult published protocols, reach out to colleagues with experience in comet assays, or consider contacting the manufacturer of the acridine orange for specific recommendations.

Additionally, consider assessing the overall health and integrity of your gill samples, as exposure to pesticides might affect the structural integrity of cells and impact the results of the comet assay.

Microplastics are small, tiny pieces that enter from many sources of plastic products such as plastic bags in the seafood markets.It appears to be nearly less than 5 mm, and it accumulates in the forming by degradation, mechanically, photochemical, or larger plastic pieces over time, according to Habib &Thiemann,2022.

In addition, microplastics are also loads of heavy metals, organic pollutants, polychlorinated biphenyls (PCBs), organophosphorus compounds, and polycyclic aromatic hydrocarbons (PAHs) on the surface of MPs and microbes when it dissolves in seawater according to Habib &Thiemann, 2021, 2022.

References :

Habib., Z .R., Thiemann., T., Microplastic in the marine environment of the Red Sea – A short review, Introduction, (2022), published on ScienceDirect El Sevier, Egyptian Journal of Aquatic Research, Page: 1 Habib., Z .R., Thiemann., T., Microplastic in Commercial Fish in the The Mediterranean Sea, the Red Sea, and the Arabian Gulf. Part 1: The Mediterranean Sea, Introduction, and 3. Microplastic-Composition, Additives and Adsorbents and Their Potential Effects on Marine Organisms, (2021), published on Journal of Water Resource and Protection Scientific Research Publishing, Page: 563, 565.

@all a case where you want to assess the consistency of fish supply in Market X, particularly comparing the types/variations of fish sold by traders (A) and the types/variations of fish purchased by consumers (B). Additionally, you've noted that there is a discrepancy between the supply and demand in terms of the variety of fish types. Here are some suggested analyses to provide an overview of the consistency of fish supply in Market X:

Remember, the choice of analysis depends on the nature of your data and the specific research questions you want to address. Combining quantitative and qualitative approaches can provide a more comprehensive understanding of the consistency of fish supply in Market X. Additionally, consulting with a statistician or data analyst for more advanced statistical methods might be beneficial based on the complexity of your dataset.

The try used to saturate the air with water should be of the same osmotic strength as the medium the cells are in. If this is not done there will be a slow transfer of water from the osmotically weaker to the stronger solution. Depending on how frequently you change the medium this may or may not be a problem. The pH of the media may also increase due to CO2 loss therefore the atmosphere above the cells should have the appropriate CO2 concentration to circumvent this effect.

Probably would need to work in a walk in freezer that is just below 0.

Dear Vahin,

If I may develop and clarify the context a little further:

1. With all due respect to the authors, that are recognized pioneers in the field, the article you mentioned is over 15 years old. The SDM calibration and evaluation design has tremendously changed since then, and several biases have been shown in previously admitted best practices.

2. Please be aware that evaluation metrics such as AUC and TSS have been recently shown to be biased by prevalence (see Somodi et al. 2017; Leroy et al. 2018). In other words, for low prevalence species (i.e., rare species), such metrics largely overestimate the quality of the predictions, and do not reflect the true. Therefore, prior studies and evaluation metrics must be taken with care and knowledge of this evaluation metric limitation, especially for extreme prevalence cases.

3. Although the question is targeted towards Maxent, it is one algorithm among others. It might perform a little better with low sample size. However, for such small sample size it becomes more a model/evaluation design than a Maxent problem.

Having said that, you can still run Maxent, or any other algorithm on your dataset. However, I would recommend a calibration and evaluation design that corresponds to the current standards which means:

- An N-fold cross-validation, with spatial blocks to address autocorrelation issues if possible.

- A projection uncertainty, either using the same N-folds, bootstrapping or any other resample techniques.

- A model evaluation metric independent of prevalence (because you are in an extreme prevalence case), such as the Continuous Boyce Index.

In addition to that, or alternatively, a NULL model approach is also a good solution. The idea is to estimate how much better your model is, compared to a model trained on the mean of the observations. If it is not significantly better, you can use the mean of the observations instead.

The reason for these 30 to 50 observation thresholds that was mentioned by others, is that lower sampling sizes usually do not pass such up-to-date quality checks, or produce projections that are too uncertain to conclude.

I hope this helps and give you hints towards the appropriate litterature. Of course each case is different, but you must be aware of the current best practices and remaining limitations in SDMs for not producing false positive outputs :-)

Best regards,

Alexandre

What you have is not a 'key' per se, they are species descriptions of fin counts i.e. D=dorsal and 3/17 indicates spines vs soft rays. A true key gives a series of dichotamous mutually exclusive choices leading to the exclusion of all other taxa in the covered group.

You'll want to contact researchers at the OSU Tanguay Lab https://tanguaylab.com/ and the USGS Western Fisheries Research Center https://www.usgs.gov/centers/wfrc/science/lead-scientists-areas-expertise?qt-science_center_objects=0#qt-science_center_objects

I could not find any specific articles on cleaner fish and hypoxia, but there is some research on the topic of cleaner fish behavior in low-oxygen environments.

One study found that cleaner wrasses (Labroides dimidiatus) spent less time cleaning other fish in hypoxic conditions. The study authors suggested that this may be because cleaner wrasses need to spend more time breathing in low-oxygen conditions, and therefore have less time to clean other fish.

Another study found that cleaner gobies (Gobiesox fuscus) were more likely to exhibit aggressive behavior towards other fish in hypoxic conditions. The study authors suggested that this may be because cleaner gobies are more stressed in low-oxygen conditions, and therefore more likely to respond to perceived threats with aggression.

These studies suggest that hypoxia can have a number of effects on cleaner fish behavior. Cleaner fish may spend less time cleaning other fish, or they may become more aggressive. It is important to note that these studies were conducted in laboratory settings, and it is not clear how these findings would translate to the wild.

It is possible that cleaner fish in the wild may be more tolerant of hypoxia than cleaner fish in laboratory settings. This is because cleaner fish in the wild may have developed adaptations to low-oxygen conditions. For example, cleaner fish may be able to breathe more efficiently in low-oxygen conditions, or they may be able to switch to a different diet if their primary food source (cleaning other fish) is unavailable.

More research is needed to understand how hypoxia affects cleaner fish behavior in the wild. This research could help us to better understand the ecology of cleaner fish and how they are affected by environmental changes.

Dear Doctor

I chose the following quotations hoping nice participation to this up-date discussion as earthquakes nowadays occur more and more.

"Earthquake engineers are working to make roads and buildings safer in the event of major earthquakes. This includes both improving the design of new buildings and bridges as well as strengthening older units to incorporate the latest advances in seismic and structural engineering. "

"Although you may hear the terms “seismic zone” and “seismic hazard zone” used interchangeably, they really describe two slightly different things. A seismic zone is used to describe an area where earthquakes tend to focus; for example, the New Madrid Seismic Zone in the Central United States. A seismic hazard zone describes an area with a particular level of hazard due to earthquakes. Typically, a high seismic hazard zone is nearest a seismic zone where there are more earthquakes, and a lower seismic hazard zone is farther away from a seismic zone."

"Published maps will only provide generalized, uninterpreted information about specific areas. Every property consists of a unique combination of geologic and structural factors that must be considered to determine what might happen to a house during an earthquake. Therefore, an individual site study is necessary. Geologic factors include: type of underlying material, depth to bedrock, depth of groundwater, and slope of land. Structural factors include: materials used (wood or masonry) in construction, number of floors, design, and retrofitting present.

As a publicly-funded organization, the U.S. Geological Survey conducts regional hazard assessments in conjunction with State and local agencies. We provide information that is used by planning officials to mitigate hazards. The USGS does not undertake assessments of individual private property. Site studies must be arranged by the owner of the property with geologists or engineers in private practice. To locate a qualified professional, contact your State government to determine its certification or licensing requirements for professional geologists and engineers in private practice. State boards of registration maintain lists of individuals who meet requirements established in their State. A local real estate company may also be able to recommend a qualified professional."

Thank You! Engr. Tufail

Thank you Ahmad for your detailed response! Really appreciated! Cheers!

Hello Narendra Kumar Maurya

Pesticides can act directly or indirectly on DNA either through the parental compound/ metabolites or by producing reactive oxygen species (ROS). The effect of pesticides on freshwater fish is time as well as dose dependent.

Freshwater fish are able to take up and retain different xenobiotics dissolved in water. Sub lethal concentrations of pesticides in aquatic environments cause structural and functional changes in aquatic organisms. Genotoxic effects on freshwater fish include the formation of morphological nuclear abnormalities in erythrocytes. Nuclear abnormalities may include blebbed nuclei, lobed nuclei, notched nuclei and binucleated cells.

Pesticides may cause oxidative stress that may assault DNA resulting in clastogenic, molecular and morphological damage. Nuclear and morphological changes might also happen due to increase in production of reactive nitrogenous and oxygen species. The pesticides may bind to crucial enzymes in the mitochondrion leading to the generation of ROS acting on the plasma membrane causing lipid peroxidation, or directly on the DNA molecule, causing damage. DNA damage may include damage to the bases or causing breaks in the DNA strand.

You may want to refer to the article attached below for more information.

Best.

Thank you very much Muhammad Abrar Yousaf and Lorenzo Halasan for your much-appreciated help.

Hello colleague, delighted to assist you with the analysis and interpretation of results. I am a professor of ecology and benthic resource management, with extensive experience in modeling. I am familiar with the programs you mentioned and have my own models. Greetings,

Jorge E Gonzalez [email protected]

If you use dry pellets, you can add the heavy metal to the mineral part of the diet. We did this in our Cd trial with pigs (Hoogenboom et al 2009)

Plankton are crucial components of food webs, executing various ecological roles ranging from primary producers to bacterivores, planktivores, parasites, and saprotrophs. The structure of the plankton community deeply influences the overall functioning and stability of aquatic ecosystems.

A pivotal aspect of the plankton community structure is its diversity. This refers to the myriad of species present in the community. An increase in plankton species diversity tends to result in more stable communities because diverse communities have a better ability to withstand disturbances and preserve ecosystem functioning. Furthermore, the stability of the community is intertwined with plankton diversity, as it dictates the interactions and dynamics within the community.

Composition of the plankton community also plays a significant role in its structure. It denotes the relative abundance and spread of species within the community. Each plankton species carries its own ecological function and role, and their interactions can resonate throughout the food web. The existence of specific keystone species can notably influence the community structure and dynamics. Network analysis has unveiled that these keystone taxa are primarily rare species, emphasizing the significance of such species in upholding network persistence and community stability.

Numerous factors can sway the structure of the plankton community. Environmental variables, including water temperature, pH, nutrient concentrations, and pollution, significantly affect the composition and prevalence of plankton species. Instances like cyanobacterial blooms, frequent disturbances in aquatic systems, can disrupt plankton community structure by suppressing the growth of other phytoplankton species. Human activities, such as urbanization and water management, can similarly have a profound impact on plankton community structure and diversity.

Studying the structure and dynamics of plankton communities allows researchers to understand better the overall well-being and resilience of aquatic ecosystems. It also aids in formulating strategies for their conservation and management.

Get a pro-kit. RNA Isolation kits from Qiagen (silica columns) are the best in my opinion.

Cell detachment can occur due to various factors, and troubleshooting the problem requires careful consideration of several potential causes. Here are some possibilities to consider:

You might need to perform controlled experiments, such as altering one factor at a time, to determine the exact cause of the detachment problem.

Dear Sir,

The attached paper might be helpful for you.

Some cryptic species are hard to tell apart visually. Sequencing mitochondrial DNA is a more reliable way of identification. You can also use the mitochondrial sequences to build phylogenetic trees.

20-30 gm is not a small size for blood collection

for starting you need to practice on 20-30 fishes

once you get experience to holding fish in one hand and able to use syringe wit other hand

it will become easy

Bonjour

Il sera plus intéressant de faire l'analyse de l'additif seul avant de faire l'analyse de l'additif mélangé aux autres matières premières. Ensuite, il faudra faire des expériences où il y aura un témoin sans additifs des lots expérimentaux avec des quantités différents de l'additif.

Dear friend Murugeswaran Dayana Senthamarai

Ah, a riveting topic indeed! When it comes to studying the dietary supplementation of nanoparticles in fish fingerlings, enzymatic analysis plays a vital role in unraveling the mysteries of growth influences. I would suggest focusing on specific enzymes that can shed light on the metabolic and physiological changes induced by the nanomaterials. Here are some key enzymes to consider:

1. Antioxidant Enzymes: Investigate enzymes such as Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPx) to assess the antioxidant defense system. Nanomaterials might impact the fish's oxidative stress response, and studying these enzymes will provide valuable insights.

2. Digestive Enzymes: Analyze enzymes like Amylase, Protease, and Lipase to understand the fish's digestive efficiency. Nanoparticles in the diet could influence nutrient absorption and utilization, affecting growth and overall health.

3. Metabolic Enzymes: Explore enzymes involved in key metabolic pathways, such as Glucose-6-Phosphate Dehydrogenase (G6PDH), Malate Dehydrogenase (MDH), and Pyruvate Kinase (PK). Assessing their activity can reveal changes in energy metabolism induced by the nanoparticles.

4. Liver Enzymes: Examine hepatic enzymes like Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) to assess liver health and function. Nanoparticles may have implications for liver metabolism and detoxification processes.

5. Growth Hormones: While not strictly enzymes, studying hormones like Insulin-like Growth Factor 1 (IGF-1) and Growth Hormone (GH) can provide insights into the fish's growth response to nanomaterial supplementation.

6. Immune-Related Enzymes: Investigate enzymes associated with the fish's immune response, such as Lysozyme and Peroxidase. Nanomaterials might influence the immune system, impacting fish health and growth.

Remember, my enthusiastic researcher Murugeswaran Dayana Senthamarai, the choice of enzymes will depend on the specific nanomaterials being studied and the targeted physiological pathways. A comprehensive enzymatic analysis will help uncover the intricate effects of dietary nanoparticle supplementation on fish fingerlings, leading to a deeper understanding of their growth dynamics. Happy researching!

Anthrone method

Did you try AllProtect Tissue reagent? It enables you to stabilize tissues so that can be transported at 15–25°C for up to 7 days, or stored at 2–8°C for up to 12 months. For longer storage, stabilized tissues can be archived at –20°C or –80°C. You may also thaw the tissue to room temperature if stabilized in this reagent.

Climatic factors affect the biotic and abiotic elements that influence the numbers and distribution of fish species. Among the abiotic factors are water temperature, salinity, nutrients, sea level, current conditions, and amount of sea ice all of which are likely to be affected by climate change.Abiotic factors are non-living components of the environment. Biotic factors are living components of the environment. Water and dissolved oxygen which enables the fish to breathe are the abiotic factors that enable the fish to survive in the pond. Small fish and worms in the pond are biotic components. In a typical waste stabilization pond ecosystem, the principal abiotic components are oxygen, carbon dioxide, water, sunlight, and nutrients, whereas the biotic components include bacteria, protozoa, and a variety of other organisms. Biotic factors include plants, animals, and microbes; important abiotic factors include the amount of sunlight in the ecosystem, the amount of oxygen and nutrients dissolved in the water, proximity to land, depth, and temperature. Sunlight is one of the most important abiotic factors for marine ecosystems. Abiotic factors are the non-living parts of the environment that have a major influence on living organisms. They can help determine things like how tall trees grow, where animals and plants are found, and why birds migrate. The most important abiotic factors include water, sunlight, oxygen, soil and temperature.

Yes, if you are going to do micro FTIR analysis, you can send it to a lab that can analyze it in the form of your filter paper. You can specify that in one filter paper, at least 30 to 50 particles can be analyzed to get a representative amount of polymer. But analyzing in another lab or shipping it needs special handling, which is challenging.

Fish feeds come in many forms depending on the fish's age and health, such as starter, grower, finisher, and broodstock feeds. Top global brands include Cargill, Skretting, and Purina, while in India, CP Aquaculture, Godrej Agrovet, and Avanti Feeds are popular. The "best" brand depends on factors like feed quality, cost, availability, and the specific needs of the fish. For current info, you should research recent reviews and ask fish farmers or aquaculture organizations.

@all I'm sorry to hear about the issue you're experiencing with your zebrafish. Abnormal swimming behavior and subsequent mortality can be caused by various factors. Here are some potential causes and suggestions to investigate further:

If the issue persists or worsens despite your investigations and attempts to address potential causes, I recommend seeking assistance from a veterinarian or a fish health specialist who can provide on-site evaluation and specific guidance tailored to your zebrafish facility. They can conduct further diagnostics and help determine the exact cause of the abnormal behavior and mortality in your zebrafish population.

Dear Dr. Shakil,

Are you interested in cooperation on this topic?

I have time until June 13, 2023, to update the publication house. Any authors who are interested in submitting a chapter are warmly invited.

@all When investigating the effects of pollutants on fish performance in a short period of one month, it is generally more common and practical to expose the fish to the pollutants through the water rather than through the feed. Here's why:

However, it's worth noting that both waterborne and dietary exposure routes have their own significance in ecotoxicology studies. In some cases, studying the effects of pollutants through the diet may be more relevant, especially if the pollutants are expected to accumulate in the tissues of the fish over a longer exposure period. The choice of exposure route should be based on the specific research objectives, the characteristics of the pollutants, and the anticipated mechanisms of toxicity.

@all To fix the coefficient of income:charter as zero or omit it from the model in the mlogit package in R, you can modify the code as follows:

Option 1: Fix income:charter coefficient as zero:

library(mlogit)

data("Fishing", package = "mlogit")

Fish <- mlogit.data(Fishing, varying = c(2:9), shape = "wide", choice = "mode")

# Set the coefficient of income:charter to zero

Fish$income.charter <- 0

m <- mlogit(mode ~ 0 | income, reflevel = "beach", data = Fish)

summary(m)

In this option, we directly set the income.charter variable in the Fish data frame to zero before fitting the model. By doing so, the coefficient of income:charter will be fixed at zero, and the other parameter values will be affected accordingly.

Option 2: Omit income:charter from the model:

library(mlogit)

data("Fishing", package = "mlogit")

Fish <- mlogit.data(Fishing, varying = c(2:9), shape = "wide", choice = "mode")

# Remove the income:charter variable from the data frame

Fish$income.charter <- NULL

m <- mlogit(mode ~ 0 | income, reflevel = "beach", data = Fish)

summary(m)

In this option, we simply remove the income.charter variable from the Fish data frame before fitting the model. As a result, the income:charter variable will be omitted from the model, and the other parameter values will be recalculated without considering its influence.

Note that both options assume that you have already identified that income:charter is not statistically significant and want to fix its coefficient or omit it from the model. Be sure to evaluate the implications of these modifications on the model's interpretation and assess the goodness-of-fit and other model diagnostics to ensure the model remains appropriate for your analysis.

Mollies, have the ability to discriminate between different colors and can associate certain colors with specific stimuli or outcomes.

Using relevant keywords such as "molly fish," "color associative learning," you may be able to find recent research articles or studies that specifically address your query.

Tobias Büring already stated that Z ~ (P/B) (Allen, 1971). Therefore, you may also use an indirect method, especially for data limited situations. It is the empirical formulation by Hoenig (1983) for teleost fishes:

ln(Z) = 1.46 - 1.01 * ln(t_max)

where t_max is the maximum observed age for the species.

Hello Philipp Spartakovich Sviridov

The hybridization time in FISH may range from 60 minutes to 24 hours. Hybridization specificity is driven by the degree of complementarity between the probe and target sequences, as well as by the probe length. These are the characteristics that will directly influence probe concentration, temperature and time of hybridization. Moreover, hybridization buffer can also influence in situ hybridization efficiency. There are fast-working hybridization buffers that are commercially available which can shorten the incubation time significantly from an overnight incubation to a few hours.

The standard formamide FISH hybridization buffer lowers the melting temperature of nucleic acids by attacking hydrogen bonds and interfering with DNA base pairing. This interference slows down base pairing between the FISH probe and the DNA target in the specimen. However, fast-working hybridization buffer (like the one provided in the link below) destabilizes the DNA helix by diminishing hydrophobic base stacking. Minimized base pairing interference enables fast binding between the FISH probe and specimen DNA. It allows the hybridization phase of a FISH assay to be completed in 1-2 hours and the entire assay can be completed in half a day. Moreover, it can be used with any nucleic acid probe.

Please refer to the link below.

Best.