Fish Biology - Science topic

As per I know, Acrylic (PMMA) and thermoplastic polymer (PC-7) materials would be a good choice and economically beneficial solution to build a UV permeable enclosure system specially for a shallow waterbody. oh, they are long lasting, recyclable and easy to operate.

Andreas K. I think the issue might be with the plant nutrition as the rock wool is a blank medium for the nutrients, and for the soil, the source might be an important factor to consider. In our lab, we plant the normal plants in the autoclaved compost and sometimes provide nutrition by NPK spray. Please check the roots of the plants for any fungus as it could also be an important factor. In that case, you should try using a broad-range fungicide. Please share your results; it would be very interesting.

Implementing a smart water quality prediction system for biofloc aquaculture can create several potential business opportunities, including:

To leverage these opportunities and create a competitive advantage in the aquaculture industry, biofloc aquaculture farmers can:

Hi Carl:

There is a method of counting caudal-fin rays (Fricke 1983); see the attached paper.

With best wishes,

Ron

Just try with "Journal of Ichthyology" and "Acta Ichthyologica et Piscatoria".

Does it work

I suggest some article, hope they are useful

Regards

Pierre Cresson , great paper, I downloaded it early today and then came looking for more info on the conversion subject, and found the author himself :D Thank you!

From scientific references it is found, the reproductive season of Lagocephalus sceleratus was found to extend from late spring to middle summer (reproductive peak recorded in June), this is indicated by Rousou, et al. 2014 (doi: 10.3354/sedao00005).

schejch, Luciobarbus Heckel [J. J.] 1843:1055 [65] [Ichthyologie [von Syrien]. In Russegger v. 1 (pt 2); ref. 2066] Syria. Syntypes: NMW 50399 (1), 54520 (2). Spelled schech on p. 1019 [29] and 1098 [108], discrepancy not noted in corrigenda. •Questionably a synonym of Barbus pectoralisHeckel 1843 -- (Coad 1991:14 [ref. 15702], Coad 1995:13 [ref. 23608]). •Synonym of Luciobarbus pectoralis (Heckel 1843) based on generic placement of pectoralis. Current status: Synonym of Luciobarbus pectoralis (Heckel 1843).Cyprinidae: Cyprininae. Habitat: freshwater.

Christina, you can use xylene. Best

how make anti alga for ornamental fish tank

yes, it is, because it is very good for health.

Nice

The world of micronutrients still has many gaps, and the specific case of vitamin b12 is particularly complex given the clinical importance of its levels, which are low, but also high. In this sense, in complement to the debate question, I want to share with you the following manuscript detailing the aspects associated with high levels of vitamin b12.

Kindly go through the following RG link and PDF attachments.

There are reports that storing DNA in 50% glycerol helps to significantly reduce degradation with a frequent freeze-thaw cycle. However, I do not know exactly why this technique is not very popular.

Probably, in my opinion, there is a difficulty in what concentration of DNA is best stored with glycerol. It is not very advisable to store low-concentrated working solutions, for example, 20 ng / μl, due to the possible inhibition or change in the physicochemical properties of the PCR reaction or other reaction (for example, when measured by Qubit). In addition, in the case of storage of stock DNA solutions, it becomes difficult to measure using spectrophotometers, in particular, Nanodrop analogs, since glycerin can lead to difficulties in cleaning it from mirrors and sensors.

In addition, it is possible if stock DNA is stored, the preparation of working DNA solutions will be difficult to obtain accurate dilutions.

In fact, I am also looking for a Tg hsp70-egfp ZF line source. Strangely enough, EZRC in Karlsruhe suggests only 2 Tg lines for "hsp" query. Tg(hsp70l:mCherry,Cre-ERT2) and Tg(hsp70l:mCherry,Cre-ERT2)tud105(AB/TL). Not the one, Vlad mentions - Tg(Hsp70:EGFP-HRAS). Is there something wrong with their search engine or with my query, I wonder?

Hello guys,

Do you know what package in R I can use to calculate the Vanderploeg and Scavia's Electivity Index?

Marine Pollution Bulletin. Vol. 91, Issue 2, 28 February 2015, Pages 518-523

For identification we would need more detailed photographs of the fins, especially pelvic fins, dorsal and caudal fins. Might be a gobiid or microdesmid; probably not a clupeiform, and certainly no engraulid.

Respected Sir,

I think it comes under antennaridae,mostly the genus may be antennarus spp

Thank you both for your contribution. I look for quantities already set by others and not conduct my own lab work, as currently don't have access to any. I looked in the suggested papers and couldn't find what I am looking. To be more precise, I look for the Arctic char quantities of N and P inside their body. For instance, for Rainbow trout: In 26%dry matter, there is 6.8%N and 1.2%P.

Sorry to say but the formula is not correct; it has to be: SGR = (ln(final weight in grams) - ln(initial weight in grams)) x100 / t (in days).

Hi Mahnaz,

No, I'm sorry, it interests me too!

This link of chapter is may be useful

Hi.

Do you have some publication about this eggs?

The added paper by A.E. Ellis on lysozyme assays in fish could be helpful. Best wishes, Willem Van Muiswinkel

You can have a photo of Potamon gedrosianum in this paper of mine

Records of non marine brachyuran crab species of Pakistan including note on their ecology & description of juveniles of Sartoriana blanfordi

Yes it is true combined action of toxicants may reduce the toxic effect of induvidual chemical effect on organans/tissues.

If you are asking how to construct a phylogenetic tree using fish morphology and meristic characters, then you are not talking about "classical taxonomy".

You have already received several comprehensive and helpful suggestions and advise from four colleagues. You have then been informed about different methods that you may use. However, all of those programs work with a matrix that you will have to build by yourself and this is a most difficult part because, and depending on the list of characters that you have and of their coding, the selected outgroup(s) to polarize characters, and also the composition of the selected ingroup, the results may be different.  

It varies within species. It is partly heritable, and partly dependent on a range of environmental factors during development affecting developmental rates, e.g. temperature. Meristic differences between populations of the same species can depend on different temperatures in the water when they grow up. If you search for "meristic variation" on Google Scholar you will find many papers on this.

HI, you might look into literature on the startle response in fishes. I seem to recall several studies that used cameras and a background grid system to document the behavior in larval fishes. I don't think the goal was to measure speed, more about behavior and reaction time, but the methods might give you some ideas.

This reference has been published on the composition of the eggs of three species in captivity (including copper) . Regards

Devauchelle, N., Brichon, G., Lamour, F., & Stephan, G. (1982, January). Biochemical composition of ovules and fecund eggs of sea-bass (Dicentrarchus labrax), sole,(Solea vulgaris) and turbot (Scophthalmus). In International Symposium on Reproductive Physiology of Fish Wageningen, the Netherlands 2-6 August 1982. (online)

I've find DNA calibrator in Beckman coulter. It's OK for ploidy study

Take the length in cm and weight in gm. Find the log values of both.Draw a scatter diagram and add the trend line . Find the extreme outliers and remove it. Then insert the trend line and get the regression equation. Simple excel you can do this

Dear Imen,

I think you should first determine what your H0 hypothesis is. As a reminder, the H0 hypothesis is the hypothesis where you consider that two or more statistical datasets are not different from each other. These datasets should be built so as to check whether a scientific assumption is most probably true or not. It is important to precisely define this scientific assumption and be able able to write it down, so that it is a yes/no assumption. Then, you can choose the appropriate statistical test to check if it is probably true or not. There is no statistical test which will emits the scientific assumption and conclusion by itself.

In your case, it is unclear what the scientific assumption is and what these datasets are. From what you explained, I could propose many scientific assumptions to look for. But I think you already have your own idea. So, as Andreas said,  I think it looks like you're trying something over-sophisticated because you did not provide the scientific assumption and what the corresponding datasets exactly are.

If you're looking for discussions  about ideas of scientific assumptions to be tested, this is another story and I would be glad to discuss it, although I'm no expert at all in fish behaviour. So, you may not learn much from me and I would probably learn much from you.

Best regards,

Neil

Condition factor and indices of energetics such as hepatosomatic index are good estimates of fish health in wild. But they work only if compared to a control group 

Hello Ernesto, please follow the link above. You may also follow the instruction from the providers (sigma) of the SHK-1 cells ( http://www.sigmaaldrich.com/catalog/product/sigma/97111106?lang=en&region=NO )

https://www.researchgate.net/.../How_much_affects_on_the_circadian..

this link will help you

We are working on the agonist SCH for reproduction. When we asked if dopamine and SCH are stables in time, the manufacturer told us that it is not stable beyond 24 hours.

So you need to prepare fresh solution daily.

To my knowledge the most common method is still to analyze maturity ogives i..e. plot the proportion of mature individuals (or separate females and males) by length class and analyze the resulting curve, which should be logistic. Many people then detemrine the point  at which 50% of the observed individuals within a length class are mature (LM50), but you can also use any other threshold depending on what you would like to do with your results.

Anyhow you need length and maturity data (i.e. in stages) for this.

 good answer Gloria Arratia

Thankyou All for supportive responses.

The image does not show all the characters necessary for identification, but judging from the striped colour pattern and the shape of the esca this is probably Antennarius hispidus (Bloch & Schneider 1801) (family ANTENNARIIDAE). This species is known from India, but it is also widespread in the Indo-West Pacific (Red Sea and East Africa east to Tonga).

when u setup fish breeding the male fish dont movie in large place so you will block small area. 

Interesting question. Reminds me of (Huber and Rylander 1992) paper (citation below) where brain morphology (e.g., ofactory and optic lobe size) and turbidity preference was measured for some minnows. Hope this helps!

Huber, Robert, and Michael K. Rylander. "Brain morphology and turbidity preference in Notropis and related genera (Cyprinidae, Teleostei)." Environmental biology of European cyprinids. Springer Netherlands, 1992. 153-166.

Lots of checks! I was going to go with 11 years old with your first image-- great to have Beth weigh in.  

Sorry Dear jawed ...so maybe usful to other researchers 

Regards 

Ok thanks again Fahmi

You can find 61 species' TL-gape relationships in my publication, as well as general ones based on species' functional trophic groups:

KARACHLE PK & STERGIOU KI. 2011. Mouth allometry and feeding habits in fishes. – Acta Ichthyologica et Piscatoria, 41 (4): 255-275. (attached)

To my knowledge there is no such general relationship .

Regards

Voula

Dear Siri,

I suggest that you try first with one brain and test the results. I am suggesting this because I have not had the best results when doing preparations for nervous system  and depending on the results I had to do several modifications to the process that in one specimen gave nice results, but not in others. I am not able to explain this because some of our colleagues have very nice slides. Thus, try first with one brain and evaluate the results.

With my best wishes.

You've already hit the fundamental distinction.  Anadromous O. mykiss are steelhead, and non-anadromous O. mykiss are rainbow trout.  In our research (Hodge et al. 2016), we found that steelhead mothers could give rise to rainbow trout progeny, and rainbow trout mothers could give rise to steelhead progeny (might also see Zimmerman and Reeves 2000 and Zimmerman and Reeves 2002).  That said, progeny of anadromous mothers were more likely to become steelhead than trout.  We also found some patterns with respect to freshwater growth rates and anadromy/nonanadromy.  In general, rainbow trout grew faster in freshwater than juvenile steelhead (but there was a notable exception).

Overall, the "fate" of O. mykiss offspring probably reflects an interaction of genetic and environmental factors.  That said, I wouldn't call an individual a steelhead until it entered the ocean, regardless of its maternal/genetic origin.

Please say more about sampling ground.

Hi Juergen, I can't comment on the ID of this ray but it appears to be a melanistic or pseudomelanistic individual. It's pretty common in elasmobranchs. I've seen it in several Squalus and Mustelus lenticulatus. The magpie banjo ray (name eludes me right now) described from South Australia was recently shown to be a melanistic morph of the southern banjo ray.

Hi everyone, thanks for your answers! The linked article was very informative. I think my plan will be to use a modified Bradford assay, but stain with both coomassie blue for total proteins and alcian blue for sialoglycans, and use a standard like purified fetuin to quantify the strained sialoglycans. I might have trouble reading the alcian blue-stained samples via spectrophotometry because the stain molecules aggregate, so I've been told to use a solvent like DMSO or ethanol. Will also need to troubleshoot the range of protein standard to capture the concentrations found in my samples, but also be sensitive enough for sample variation.

hi, here some publications you may interest.

There is a vast literature on this subject, including several textbooks. Try searching on BKD, bacterial kidney disease, or just use appropriate search terms in google scholar. 

https://www.cabdirect.org/cabdirect/abstract/19892296976 

Gracias Luís, si que me interesa

That depends on a couple of questions:

Are you interested in extracellular or intracellular proteins. For extracellular use Na⁺; for intracellular use K⁺. The physiological pH inside cells is somewhat lower (6.8) than that of the extracellular fluid (7.4).

If you want to use ion exchange chromatography, make sure that your buffer ion doesn't bind to the resin. I.e., for cation exchange use an anionic buffer (like HEPES), for anion exchange a cationic (e.g., Tris).

Osmolytes (glycerol, sugar, mannitol) may be useful to adjust the osmotic pressure, but not all proteins require them.

You may need some ions (Ca, Mg) or small molecules (substrates) to stabilise your protein. Don't forget protease inhibitors!

Dear Anu, We also changed our fish collection from formalin to alcohol some years ago. If the fish were fixed in formalin first, there no problem with conservation in alcohol. Use glass jar only as plastic one deteriorate after years. Just make sure to use very good lid on top of your jar to prevent as much as possible evaporation. It will occur anyway so you need to have a well ventilated  room for health and safety. A special care should also be given to fire risk analysis and prevention. In case you do not want to put your specimens anymore in formalin and you want to fix them directly in alcohol make sure you have enough volume because alcohol is not very for fixing tissues. You will need a large amount of alcohol compare to the volume needed with formalin. I hope this can help you. 

Ramon:

May kindly have a look for confirmed northern limit of Pristis pristis in western Atlantic:

Best

Syed

Dear Aasma Noureen

you can assess the tail movement, head length and tail length of comet assay by micrometer (µm) using  the comet score -image analysis Software (TriTek Corp., Sumerduck, VA)  

Hi Milad,

you do not have to calculate GSI to estimate age at maturity. You need just to know the age of every fish you sampled (in months or in years, depending on life expectancy) and physiological status (adult, mature vs immature). Then you need to calculate a sigmoid curve describing changes in percentage of adults in the sample with age (beginning from zero in juveniles, eventually it will be 100% when all fish become adults). The age when this curve crosses 50% is age at maturity.

Best regards,

Vlad

I agree with Istigobius diadema. Great to have a goby specialist around!

Dear Lola

As far as I know, there is (neither theoretical or practical ) no PCR enzyme which can carry out all the amplification you desire. You have to try a few enzymes to get the required results.

This link might be of help

Hello,

I would say as Antonio: Diplodus puntazzo. On of the helpfull details is the shape of the dark mark on the caudal peduncle: in D. sargus, it does not touch the bottom edge of the peduncle, while for D. puntazzo it does (see attached file).

All the best,

Adrien

Dear Ifra,

Please refer to the following links.

Regards

SM Najim

Dear Kalidah

I attach the search. I wish to be helpful to you

Beast Wishes

Amjed K. Resen

Dear Paraskevi,

Please check the following resources.

Regards

SM Najim

Fish from the family Callionymidae, probably Callionymus filamentosus

Dear friends thanks to you all.

If you assume that:

No it isn't perfect... But it does provide a hypothesis when species ID is not known a priori...