Fisheries Biology - Science topic

it looks a bit like a horse leech, I know that one, Haemopis sanguisuga, but it's ventral side is greenish in color

I recommend that you read the newt work:

Nice

Linking two freshwater rivers is likely to to place the downstream channel in a state of disequilibrium, causing channel adjustments, erosion, sediment delivery to estuarine and marine systems. Some anadromous species have strict limits on their native waters, combining streams can alter their migration pattern, introduce species to areas not natural, alter habitats so no longer useful to some native species. But it is hard to predict or give exact effects.

Hello, What do you think about freeze the jellyfish in plastic bags ?

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).

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.  

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.

Gary; Here is a reference that should help you: Hasselman & Bradford. 2012. Discrimination of the endangered Atlantic whitefish (Coregonus huntsmani Scott 1987) larvae and juveniles. Canadian Technical Report Fisheries and Aquatic Science #2993. They distinguish Lake whitefish from ciscos, nice illuystrations. This is available online. Good luck.

Fisheries on White Sturgeon in the Columbia River are managed on a slot size restriction to allow juveniles to reach a desirable size and to protect older fish once they become capable of reproduction. Examples from Washington State fishing regulations below (http://wdfw.wa.gov/publications/01818/wdfw01818.pdf). Also have seasonal closures for retention that are set to avoid spawning timing in some cases.

Below Bonneville Dam - no size restriction

STURGEON May 1-Aug. 31: CLOSED to fishing for STURGEON from Bonneville Dam downstream 9 miles to a line crossing the Columbia from Navigation Marker 82 on the Oregon shore westerly to the boundary marker on the Washington shore upstream of Fir Point. STURGEON fishing is CLOSED on the Washington mainland shore from Bonneville Dam downstream to a boundary marker about 4,000' downstream from the fish ladder at the new Bonneville Dam Powerhouse south to the downstream end of Cascade Island and across to the Oregon angling boundary on Bradford Island (about 850' downstream from fish ladder). From Bonneville Dam to a line from the Hamilton Island boat ramp to an Oregon boundary marker on Robins Island: 1) it is unlawful to fish for STURGEON except with hand-casted lines from shore; 2) it is also unlawful to use a floating device to set lines for STURGEON.

From Bonneville Dam to The Dalles Dam

STURGEON Jan. 1 opens to retention, and closes when the winter quota is met (refer to the WDFW website wdfw.wa.gov). Min. size 38" fork length. Max. size 54" fork length. Daily limit 1.

Catch-and-release allowed when closed to retention. Check the WDFW website

wdfw.wa.gov for 2016 and 2017 summer STURGEON retention seasons.

From The Dalles Dam to McNary Dam

STURGEON May 1-July 31: CLOSED to fishing for STURGEON from John Day Dam downstream 2.4 miles to the west end of the grain silo at Rufus, Oregon. May 1-July 31: CLOSED to fishing for STURGEON from McNary Dam downstream 1.5 miles to Hwy. 82 (Hwy. 395) Bridge.

STURGEON Jan. 1 opens to retention, and closes when annual quotas are met (refer to the WDFW website wdfw.wa.gov). Min. size 43" fork length. Max. size 54" fork length. Daily limit 1. Catch-and-release allowed when closed to retention.

from McNary Dam to Priest Rapids Dam

STURGEON Feb. 1-July 31 Min. size 43" fork length. Max. size 54" fork length. Daily limit 1.

STURGEON Aug. 1-Jan. 31 Catch-and-release. to use a floating device to set lines for STURGEON. STURGEON Year-round Catch-and-release.

Above Priest Rapids Dam

Catch and release only

The storage time for unfertilized ova seems to vary among species and according to storage temperature.  For salmonids, ripe ova can be stored for a considerable amount of time in a fridge at 4 degrees C and still fertilize successfully.  But, for other species the fertilization rate drops more rapidly over time.  I have attached the results of a delayed fertilization experiment that I conducted using walleye

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 

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)  

Dear Rajaa, We are conducting similar studies on rough sharks from the Adriatic sea, what species do you study ? Im interested in comparing results. God bless

Dear Paraskevi,

Please check the following resources.

Regards

SM Najim

Thanks Jason, i will have a look..

Dear Saji,

which oceanic squid are we talking about? Onychoteuthis, Symplectoteuthis etc..?? from west coat??

best 

Deepak

Would suggest you try at Central Marine Fisheries Res.Inst, Cochin/India. True they are focusing on marine fisheries but can give you some lead on identification of freshwater fishes!

Best

Well, correcting my previous comment, this actually is a Ficobracon sp. as confirmed by van Achterberg.

Pradeep:

At one stage R. jayakari was considered as a Synonym of R. javanica. Since you have access to the actual specimen, you need to carefully assess the taxonomic features, as also suggested by Ronald and make your own judgement, as it's occurrence in Andaman-Nicobar sea would be extremely important. Do have a look at this asked for link:

Best

Syed

This is probably a species of Atherinomorus, possibly Atherinomorus lacunosus, family Atherinidae.

I use the software FISAT with "Laa" programme. it give a good results on crustacean species

Okay... I will make some graphs and send them to you :)...

The answer to your question depends on quite many factors. You'd find the info need in the  FAO Fishing Manual:  Fishing with Light, (FAO, Rome).

I'm agree with Gideon Khoo.

Yes, there many marine fish species eat anchovy, as sardinella aurita , scomber japonicus, Etrumeus teres. this in egypt, you can read the paper food and feeding habits of roundherring etrumeus teres in the egyptian mediterranean sea,  by Alaa Osman and Mahmoud Farrag, els

the best way is method Kjeldahl method

What is FA concentration of the probes?

Probes with different FA concentration must be applied in different hybridizations starting with the highest FA concentration.

trace metals in the aquatic system enters inside the aquatic organisms through the process of bio-accumulation, 

You can have at Derek Ogle website.

I think you can find what you need but you also need to be able to work in R.

It depends on the region from where the sample is obtained

I would agree that a trial such as this would require independent systems where the water would not mix. when the diet is added to the system some of the probiotic  would mix in the water. therefore if your systems were not independent, there could be a mixing of your treatments. As for continuous flow, i do not how this would invalidate the replicates. This would only me the case if your continuous water flow was within a closed recirculating system. if it was continuous flow in a flow through system where the water was used only once and discarded don't see how it effects your replicates.     

National Shellfish Sanitation Program guidance:  See Chapter XV. Depuration beginning on page 127 and Guidance Document beginning on page 275

One key determinant of the equilibrium state is a reliable stock-recruit relationship; simply put, when the population of adults is high, the number of fish born that live to be big enough to catch is also high. But this relationship is not often well-understood despite being the basis for most management. And this is but one source of variability.

Fisheries are typically managed in our region by assessing the population size with stock modeling and/or fishery independent indices in relation to thresholds established through historical stock performance or biological limitations. When thresholds are exceeded or approached, the only tactic we use is to reduce fishing effort, including reallocation among user groups. Fortunately, we have an adequate command and control regime so that reductions in effort lead to population growth, although not always does the response happen quickly enough. And we are still vulnerable to the mysteries of recruitment variability! 

We use a product called "Phyzese", but I have to look into the working agents and proper product name... In pond farming they use  "kaliumpergmanat", but I dont know if it would be allowed to use? 

Yes, additives can have different effects at  different inclusion levels. I think it might be related to receptor saturation (when talking  about organ response) and effects on intestinal microbiota (when used as a feed additive for improving growth)

Gracias Luiz!

You can use endogenous or internal markers which are naturally available in the feed such as: ash, crude fiber, cellulose and hydrolysis resistant organic matter. You only need to determine one of these internal indicators in the feed and fecal, then use the formula according to Cho and Slinger (1979) for calculating ADC. For more information please find attached file.

ADC (%) = 100 – [100 × (marker in diet / marker in faeces)] × [(% nutrient in faeces / % nutrient in diet)]. 

Cho, C.Y., Slinger, S.J., 1979. Apparent digestibility measurements in feed stuffs for rainbow       trout. In: Halver, J.E., Tiews, K. (Eds.), Finfish Nutrition and Fish feed Technology, Vol.     2. Heinemann, Berlin, Germany, pp. 239–247.

Best regards

Mansour

thanks all for your suggestion...

Hi Marvin, was increase in protein content correlated with decrease in fat content? If yes, it might be related to differences in water temperature due to oceanographic (climate) changes or sample bias. In warmer waters expenses on metabolism are higher so less of fat to deposit.

No drastic variation was observed between the K values of January (<0.91) and August (>0.90). However, a little variation may be due to the smaller sample size, or feeding factors (amount and quality).

Thank you all. You will see my paper very soon.

Dear Alba

Here in Cuba we have the same problem, because we have a multispecies and multigear fishery for finfishes. Acutally we are working with a group of experts from EDF. First of all, we use first the PSA methodology to determne yhe vulnerbility of the different species, after that we are using catch only methods, and try to obtain length compositions for the most vulnerble species to use stock assessment using lengths. In some cases we used the ORCs methods to obtain a preliminary assessment of some species. I have a lot of information about data poor fisheries and, if you send your e-mail , I can den them to you. Also in Fisheries Research 0f 2015, there are a lot of paper about stock assessment in data poor fisheries. My e-mail is servando@cip.alinet.cu. I expect to hear from you in a near future.

With my best regards

Servando Valle

Mortality and injuries related to electrofishing depend on the species, the body size of the specimens, the conduction current applied to the water, and the conductivity of the water.

To quantify the effects of electrofishing, I am afraid that you need a few goes with high conduction current at different water conductivities first, and examine mortality/injuries to fishes at different size classes. When you have established reference values for mortality/injury, you can use non-lethal, low dose electrofishing, identify species, size classes and specimen numbers, and estimate mortality/injuries caused by higher conduction currents using your reference values.

Generally, it is advisable to use low-dose electrofishing, so that especially the young fishes are neither injured nor killed.

Dear Nagaraj G. Chatakondi and Mohammad A. Momin Siddique ·sir

The number of fertilized eggs are  are sufficient but we found that low survival of hatchlings to fry and fry to fingerlings is due to cannibalism among them. 

The simple answer to your question, as written, is "No". FishBase is an excellent source for quick information and a good starting point for exploring the literature but it is _not_ an appropriate source for particular parameter values for use in analyses. It is not that the values presented in FishBase mis-quote the sources from which they were taken but rather that the sources used are unlikely to be the ones most relevant to your particular analysis.

In your attached example, however, you seem to have selected those estimates of a and b that you have deemed relevant, so I assume you have already examined the available sources. Are you now really asking whether it is appropriate to average your four selected sets of estimates using geometric means? Are you asking whether the implementation of the geometric mean on FishBase is correct? Those are very different questions.

I would not recommend averaging the values of a and those of b in separate calculations. The two parameters are inter-related and, if you had the original data, I would not expect that fitting the W=a(L)^b model to the pooled data would give the same result as averaging the a and b from separate model fits. But what FishBase calls a "geometric mean" may be a result from some more complex calculation.

At the least, I would suggest that you find out what calculation the website actually performs before using the results.

Hi Leonardo,

Thanks for your interest. Your idea about using monoclonal antibodies could be good one depending on your purpose. But, now we are more focused on collecting data from different fish species. One of our aims is to study how widespread is the rRNA profile mentioned above among the different gonad development strategies in fish.

Cheers,

Oihane

Maybe I can help you with this article.

Depend on methods. Classical Kjeldal method is common.

It is changes according to the protein resources, and ratio of feed, feed additives, feed production methods,  feed storage media etc...

A pretty good and proven method is using manta trawls (see Brown & Chang MEPS Vol 5: 225-227).  Deploying these trawls is not that labor intensive. You could easily do the trawls from a small boat like a boston whaler or rhib. The hardest part will me making or purchasing a trawl.  Best of luck!

Without being able to see details of the parasite and based only on the main body shapes, I would suggest you start to look at descriptions of Alebion and Gloiopotes (both Caligidae) specifically, possibly also Euryphorus (less likely). What species of fish did you find this on? That would also help with trying to identify your parasite (especially if its been seen before on the same species).   

Thank you!

These references may be of help. I did some work in this area many years ago.

Greig, R.A., S. Schurman, J. Pereira, and P. Naples. 1983. Metals and PCB concentrations in windowpane flounder from Long Island Sound. Bulletin of Environmental Contamination and Toxicology 31: 257-262.

Greig, R.A., and G. Sennefelder. 1987. PCB concentrations in winter flounder from Long Island Sound, 1984-1986. Bulletin of Environmental Contamination and Toxicology 39: 863-868.

Mercaldo-Allen, R., C.A. Kuropat, R.A. Greig, and G. Sennefelder. 1994. PCB and metal concentrations in American lobsters from the Acushnet River estuary and Long Island Sound. Bulletin of Environmental Contamination and Toxicology 53: 820-827.

Steimle, F., D. Gadbois, S. Chang, G. Sennefelder, and R. Greig. 1996. Organic and metallic contaminants in tissues of tilefish Lopholatilus chamaeleonticeps Goode and Bean and sewage sludge disposal at the 106-Mile Dumpsite.

Dear Milad,

Thanks for your nice Histopathology Images. It seems informative and usefull for all pathologist. As you know benzo(a)pyrene could be a hazard carcinogen and could be occur a kind of Spontaneous liver tumors in mice in experimental trial.

Globing and Clubbing in second Gill lamellae, Atelectasis and some inflammation effects that lead to spread necrosis in liver could be more important lesions in your Images,

Also, defects in the basement membrane, enlarged nuclei with cytoplasmic invaginations, and pleomorphic nucleoli were restricted to squamous metaplasia induced by benzo[a]pyrene-ferric oxide. 

Finally if you are interesting for more share information about above subjects please correspond with me through my email as follows:

I can prepare more information for your article in this regard.

Yours truly

Jalil

See:

Cheers

Josef

The b factor in the standard allometric equation W=aL^b is really determined empirically by collecting a number of fish either under various conditions you describe or alternatively from pooled data to give an overall average.  Fulton's K on the other hand simply assumes that the weight of the fish is simply proportional to the cube of the length K=100(W/L^3), so in Fulton's equation the b exponent is a constant.   Fulton's CF is often useful if you want to get a "quick and dirty" comparison between fish populations when the empirical study to determine b is not done.  The allometric equation becomes a better measure in flatfish such as flounders and soles in which the b exponent can deviate substantially from the approximate estimate of 3.

Morphology for the first month of development is very well described by Dettlaff (1993) 

Some fish (silver carp is a published example) can increase their gut length in a week or two, by up to 50%, and then shrink it again rapidly when conditions change.  It is really remarkable, this ability.  Silver carp guts increase in length when feeding on phytoplankton, and shrink when feeding on zooplankton or other high quality foods.

In reproductive biology study of fish we divide the sexual stages as virgin, developing, developed, mature, spawning and spent. We can plot a line considering first 3 stages are immature and the latter 3 are mature according to previous studies.The cited paper by you, the ripe and non-ripe means mature and immature. The following two paper may be useful to you to carry out your work.

De Silva, S.S. & Chandrasoma, J. 1980. Reproductive biology of Sarotherodon mossambicus, and introduced species in an ancient man-made lake in Sri Lanka.

De Silva, S.S. & Chandrasoma, J. 1980. Reproductive Biology of Puntius sarana, an indigenous species, and Tilapia rendalli (melanopleura), an exotic, in an Ancient Man-Made Lake in Sri Lanka

El efecto de la densidad depende de si el pez es gregario o no , depende de la estructura de dominancia en el grupo, en muchos Piaractus la tendencia de animales grandes es defender un determinado espacio cuando están en bajas densidades (menos de dos animales metro) pero a mayor densidad no manifiestan dicha territorialidad.

Sorry I cannot catch it clear. You mean you use weight for the index of preponderance method (not simply gravimetric method)? Because Natarajan & Jhingran (maybe the first developing index of preponderance) used volume. Are there examples in which writers used weight for the index of preponderance?

Dear Dr.Carlos,

You can try some other catfishes and salmons for isolation of Chorionase enzymes, i think mouse or other lower vertebrates may have this enzyme for establishing embrionic cell lines. We have seabass eggs in our hatchery, you can tell us at what stages of embryonic cells can be taken ...

Regards

Dr.Sethi 

A rapid volumetric method can be adopted for food analysis. Also you can go through other methods as suggested by Hyslop, E. J. (1980) , Journal of Fish Biology 17: 411-429.

Please refer to follow book.

Methods for the estimation of production of aquatic animals.  by G.G. Winberg

Thanks, will take a look.

In healthy fish, there is a very strong relationship between mass of protein and mass of water (and also a very strong relationship between mass of ash and mass of water).  This relationship changes slowly with fish body size; smaller fish have more grams of water per gram of protein than larger fish (for example, 4-5 g water per g protein in small fish; about 3 g water per g protein in large fish).  In starved (freshwater) fish, or (freshwater) fish in osmoregulatory stress, there tends to be more water per gram of protein than in healthy fish.  In fresh water, a dead fish will take up water.  So a fish could have a high water content because it is healthy but has a very small body size (say, less than 2 grams body mass), or because it has been starving, or because it is greatly stressed, or because it died in the tank and was not removed for several hours.

Hi Javad. Here it is a FAO publication that might help you.

Thank you all valuable answer

But do you mean Artemia salina? American brine shrimp, A. franciscana, is the species used in most studies. A. salina is a species restricted to the Mediterranean region and Africa, and is actually threatened by the spread of A. franciscana through aquaculture. See e.g. the following papers

Bertalanffy growth equation is related  to individual growth of body length . It is supposed that growth rate and asymptotical length are constant. You can try to do any parameter as function on density of population. In order to estimate that function , you are to have rich information  about growth measures with different values of population density.   It is not simple task.

Thanks dave. Didn't realise opwall had been collecting fisheries data overexploitation there.  I'll contact dan.

Cheers

I would use mark-and-recapture, the Lincoln-Petersen method (see Pollock et al. 1990 or Krebs 1999). The logic is simple: If the system is closed enough, when you capture, mark and release a first (large) sample, the proportion of marked fish to total fish caught in a second sample (giving time for fish to "mix") is roughly the same proportion between the number of fish caught in the first sample to the total population.

Forresearchers interested in otoliths morphometries is interesting to know AFORO website (http://aforo.cmima.csic.es), an interactive open system to deal with shape analysis of fish otoliths and a classification system based on the mathematical properties of the one-dimensional curves describing the Teleostean otolith contours. The system was created in 2003 and connected a website with a database of complete morphometric (measures and morphological indexes) information, including Elliptic Fourier analysis and wavelets (WT) based in otolith contours of the otolith images of well identified samples. Since 2006, AFORO incorporates an expert system that will allow carrying automatic taxon identification based. In 2009 AFORO was included in GBIF (Global Biodiversity Information facility) databases system, with geographical information of the otolith samples. The AFORO database and public web site (the otolith guide, with its corresponding shape analysis and classification system) keep continuously implemented. At present AFORO includes 4555 images of different specimen from 1381 species, from 216 families, and 36 orders worldwide represented. Nevertheless, Mediterranean Sea is the best represented area (90% of common species, 64% of species sometimes cited in this area, including 50% of Lessepsian species -Red Sea invaders- are showed). The main advance in the last years was the inclusion of videos of 3D otolith objects in 2012, obtained with LED white light-based scanner, which eliminates the speckle noise effect of laser scanners. and the inclusion of automatic morphometric software and numerical information of Fourier and wavelet analysis, which will be used as morphometric bank for researchers that requires precise species identification as paleontologist, archeologist and trophic ecologist.

Here is one that I think you dont have already

Please take contact if you have any further questions

Here is a description of my hoop nets that I run on the South Branch River in WV to collect Channel Catfish.  Dual-chambered nets are 11’ long, 1” mesh throughout, and a front hoop diameter of 2.5’.  1/8” square mesh net bags are used to hold 1/3 of a extruded block of soy and cheese bait.  Rough dimensions of cheese log bait chunk are ~4 x 4”.  The mean CFS for this stream is ~1000.  Catches are certainly enhanced with high flow events due to their propensity to move through riverine systems.  It is possible to collect >70 fish per net in some locations. More realistically, I'm accustomed to about 8 fish pe