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Hi,
This type of leech was found recently in our farm but we couldn't recognize it.
Can anyone help us?
Sincerely,
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it looks a bit like a horse leech, I know that one, Haemopis sanguisuga, but it's ventral side is greenish in color
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I performed a multiple regression test with the area of otoliths (growth variable) and the effectives principal componentes of the PCA (PCR method). I found a significant correlation. How can i correct the effects of allometry in the original data? and How can i reconstruct the countours (with the SHAPE program) considering the allometric corrections?
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I have data of catch and catch per unit effort of cuttlefish for 2 years. The data came from artisanal hook and line fishery. Can we simply use the equation which relate CPUE and abundance to estimate fish biomass? How to estimate the catchability coefficient in such case? There are many factors affecting this relationship and sometimes it is difficult to take account of them.
The data I have include catch, effort in time spent fishing (from handheld gps loggers) and the estimated CPUE.
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Nice
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What is its impact on aquatic animals?
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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.
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Dear colelagues, can you recommend the method description to analyse diet of jellyfish? Especially - is it possible and if so how to fix the stomachs of jellyfish and what paremeters of jellyfish (size, weight, sex) are needed?
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Hello, What do you think about freeze the jellyfish in plastic bags ?
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Using fish as an example, if you have total length and age and compute a growth rate by dividing total length by age would this "age-specific" growth rate, "absolute" growth rate, etc.?
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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).
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classical taxonomy...
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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.  
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Hi all, 
    For estimating Lm, different researchers uses different methodologies. Some uses the lowest recorded mature fish as Lm. Some researchers estimated it by eye observation of visible egg. Some estimates from the first peak og GSI. Some uses cumulative percentage of all samples of fully matured egg (Stage v and above) to estimate Lm. But is there any method to calculate Lm based on histological  stages (i-vii) and maturity stages i.e., cumulative percentage of samples over certain maturity stages  (stages i-vii/viii) ?
waiting for your innovative ideas...... 
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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.
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 I am attempting to key out hatchery reared larval fish ranging from 10 days old to 65 days old. I find Auer's larval key to be not as helpful as I would like.
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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.
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I am trying to get an overview of commercial and recreational fisheries where large individuals are protected and have to be released upon capture. Any additional information such as on scientific rational for the size limits and effects on the population is also highly appreciated!
Cheers,
Kim T. Halvorsen
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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
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Normally the stripped eggs have to be fertilized and put into hatching condition. However, if the fertilization could not do at that moment, what should we do? can we store for a couple hours or days?  
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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
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I am working on fish bacteriology band presently facing problems in analysis of SEM photographs
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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. 
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comet assay
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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)  
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Are there any confirmed relationship between HSI and liver composition with fish reproductive status or activity ?
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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
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Hello everyone. It is my first time working with otolith’s microchemistry and I have some doubts about storing process. I’ve already collected the fishes and stored them frozen (up to two months now), but I would like to unfreeze them to get some morphological aspects before extracting the otoliths. Basically, I want unfreeze the samples, and then freeze again to later extract the otoliths.
I was wondering if, during that process, is there any chance to affect the results? I would also like to know if the storing period can affect the elements composition.
Grateful, Júlio
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Thanks Jason, i will have a look..
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Can anyone help to identify the attached otolith, fish scale ( may same species) sorted from oceanic squid stomach ?
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Dear Saji,
which oceanic squid are we talking about? Onychoteuthis, Symplectoteuthis etc..?? from west coat??
best 
Deepak
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nil
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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
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Found this unidentified species ovipositing on a fig fruit.
Location: Kashmir Himalayas (India)
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Well, correcting my previous comment, this actually is a Ficobracon sp. as confirmed by van Achterberg.
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Can any one help me in identifying this Rhinoptera sp. and and provide literature on its taxonomy. 
Details:
Area of collection: Andaman sea, Disc width:49cm, Tail length:38.5cm, Sex: male. spine present.
regards,
pradeep 
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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
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This is probably a species of Atherinomorus, possibly Atherinomorus lacunosus, family Atherinidae.
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I want to get a age structur of a population without having informations about growth rates.
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I use the software FISAT with "Laa" programme. it give a good results on crustacean species
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Looking for information on the relationship of fish eviscerated weight to whole fish weight?
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Okay... I will make some graphs and send them to you :)...
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I have observed in a fishery for White-spotted rabbitfish (Siganus canaliculatus) that when these fishes are subjected to artificial light sources used by fishermen they appear stunned and collapse to one side, making it easier for them to be caught. Has this type of reaction been studied already? If yes, I'd appreciate some references I can look up. 
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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).
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I am conducting fecundity works for Macrobrachium rosenbergii. However, some of the eggs samples have irregularities in shape and size. Thus, this has made me a bit confuse while conducting the experiment. Refers to the picture given:
Picture 1: Represent a good sample with same shape and size.
Picture 2: Represent not a good sample with different shape and size.
There are three different conditions of eggs that I had recognized and need to be justified to include it in counting or not (Refer to Picture 2 Box A, B & C). The question is, do I need to include eggs in Box A,B or C in counting ? If yes (or not), what is the clear justification would be made in these situation?
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I'm agree with Gideon Khoo.
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Effects it might have on industrial fishing.
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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
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What is the most accurate and fastest quantitative method to determine total protein content of fish flesh? Can I have an explanation? Thank you.
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the best way is method Kjeldahl method
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I want to Hybridized four FISH molecular probes on a single point. which probe will I use first, second, third and fourth and how will I wash them?
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What is FA concentration of the probes?
Probes with different FA concentration must be applied in different hybridizations starting with the highest FA concentration.
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If someone has specific experience and has worked with Pb or Po that will be very interesting.
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trace metals in the aquatic system enters inside the aquatic organisms through the process of bio-accumulation, 
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I have computed the population parameter of a certain fish species but I don't know how to get the F50 which is important parameter for setting a limit reference point or the target reference point. I'm using FISAT II.
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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.
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Heavy metals contaminate the marine environment.
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It depends on the region from where the sample is obtained
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My interest outcomes from a revisor question, appointingthe continuous water flow as a false replicates system when applying probiotic supplemented diet.
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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.     
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We are going to establish the oyster depuration plant in small scale. What are the protocol for the oyster depuration plant. Can you suggest me the what are the main steps we need to follows from received place to dispatch place?
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National Shellfish Sanitation Program guidance:  See Chapter XV. Depuration beginning on page 127 and Guidance Document beginning on page 275
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Management of a renewable natural resource such as stock of fish is key to sustainability of the resource. While simulating the population of a renewable resource such as fish stock, we expect the system (Stock & harvest) to converge to a steady state equilibrium (i.e. initial stock is in the basin of attraction). However, this is often not the case since there is a likelihood of experiencing a complex dynamic behavior  including deterministic chaos where steady state equilibrium is never reached. Consequently, managing a fishery becomes a nightmare. What are some of the key determinants of such complex dynamic behaviors & how should a resource economist deal with such problems as far as managing a renewable natural resource is concerned?
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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! 
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One of the main types of fungal diseases in farmed salmonid fish is saprolegniasis, caused by species in the genus Saprolegnia. It causes considerable economic problems in the fish farming industry  infecting both fish and fish eggs.
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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? 
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i have conducted an experiment aimed at investigating the effect of aloe on sex ratio in tilapia. I found out that aloe at low inclusion level presented a significant difference compared to the control, the following inclusion levels did not present any significant difference when compared to aloe unsupplemented fish, however, significant different was again present at the highest dosage. How do i explain this pattern of data in this field. literatures are also welcome.
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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)
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I m looking for the effects of boat motors in a fisheries without this, since there is a possibility of introduce this kind of boats in this place. Thanks!
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Gracias Luiz!
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Is there any method to determine the digestibility of feed on fish without using chromic oxide? Most literature I've found used chromic oxide as an indicator. However, I didn't incorporated the chromic oxide in the feed that I tested on the fish. The fish I'm using is red hybrid tilapia.
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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
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We know eels are a very active fish. This year we studied eel growth in Sulawesi and we tried to tag the fish, but because we tagged them without anesthetizing, it took about 5-10 minutes to measure the length, weight and then tag them. Does anyone know of a tagging study from their research?
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thanks all for your suggestion...
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Hello,
I'm in literature search with the increase in the protein content in fish (mackerel and sardines), over the last decade.
In recent years, the results of our analyzes showed a clear evolution of the protein content:
We passed from 11.4g / 100g (2008) to 18g / 100g (2014) => this is much more a variation due to a change of diet, or a laying period.
WHY?
Because of an evolution of the species?
What assumptions can we emit?
What are the causes of variability in the protein content in both species?
thanks for your help
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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.
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Why condition factor of a fish drop suddenly in a month from a smooth pattern (figure added)?
It is in the case of tapper tail anchovy Coilia ramcarati along the coast of Chittagong, Bangladesh.
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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).
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I have treated my fish with dietary prebiotics and probiotics for 16 weeks. This was my first phase.
The second phase was started with the treated fish fed with control diet without any feed supplementation. I want to see how long the feeding trial of dietary prebiotics and probiotics on growth and other performance? I got a good result. But my question is:
Has anybody done the same experiment with other or same diet supplements for fish? If so, let me give the reference and provide the full paper, please.
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Thank you all. You will see my paper very soon.
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I am reading a lot of literature related to, but I am very interested in testing some open tools as proxies in order to improve my discussion
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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
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I am conducting research involving boat electrofishing. I would like to quantify the effects of the electrofishing on the occurrence of mortalities and injuries to the sampled fish, without sacrificing the fish themselves. Is this possible to do? 
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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.
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The breeding technology is successful but the survival of hatchling to fry is very low in the case of Pangasius hypophthalmus. It needs to solve by proper research. The science behind the low survival is clear but the technique to increase the survival is lacking.
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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. 
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here is an example for the genus Diodon, is it ok if i use the geometric mean values as circled below?
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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.
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My colleagues and I have designed a survey to compile data about fish gonad or eggs rRNA profiles. Recently a series of transcripts related to the process of have been described as useful markers for the molecular identification of sex and of xenoestrogenic effects in teleost fish. An electrophoresis of total RNA extracted from gonads allows identifying the presence of oocytes due to the high 5SrRNA expression levels (Diaz de Cerio et al, 2012). This technique has been probed also in some commercially relevant fish (Rojo Bartolome et al, 2012a,b).
So now… Researcher, we need your help!
Basically, we want to create collaborative network to extend developed 5S/18S rRNA index as a robust method to identify fish sex and female reproductive stage in fish with different reproductive strategies and in different environmental scenarios. And to build a database for fish gonad/egg rRNA profiles.
For this purpose, we need Bioanalyzer 2100 XDA format files of fish gonad/egg samples (and related histology pictures if it is possible).
Your benefit:
All data generated from your samples will be made available to you. And if sufficient information were gathered we propose to write a revision paper in which a member from each contributing laboratory will be invited to sign.
Interesting Reading
Diaz de Cerio O., Rojo-Bartolomé I, Bizarro C, Ortiz-Zarragoitia M , and Cancio I. 2012. 5S rRNA and Accompanying Proteins in Gonads: Powerful Markers to Identify Sex and Reproductive Endocrine Disruption in Fish. Environ. Sci. Technol., 2012, 46 (14), pp 7763–7771.
Rojo-Bartolomé I, Diaz de Cerio O, Cancio I. 2012. 5S rRNA in gonads, a powerful marker for the identification of sex in fish. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 163. S55.
Rojo-Bartolomé I, O. Diaz de Cerio, J. Martos-Bernal, E. Bilbao, M. Ortiz-Zarragoitia, I. Cancio. 2012. 5S to 18S rRNA ratio in gonads as an easy and inexpensive index for the identification of sex in a pollution sentinel fish species (Chelon labrosus). Comparative Biochemistry and Physiology, Part A 163 (2012) S55–S60.
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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
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I have uploaded its black & white picture but I am searching for a colored one as well as a latest one. 
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Maybe I can help you with this article.
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Freshwater fish total protein estimation sample preparation method?
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Depend on methods. Classical Kjeldal method is common.
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Does anyone have information about effect of level of protein in diet and lysozyme in rainbow trout serum? if protein level of diet decrease, what happen to lysozyme?
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It is changes according to the protein resources, and ratio of feed, feed additives, feed production methods,  feed storage media etc...
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I am studying a bat that forages over the ocean. To understand it's foraging behavior, it is important to know the distribution of it's prey, which are small fish and shrimp that vertically migrate to the surface each night. I have tried using sonar, but this does not appear to be very effective for such small fish and when focusing on the surface waters. One method I will try next year is trawling, however, I am hoping for a less labor intensive method. Can anyone recommend established methods for sampling the density and distribution of fish near the surface of the ocean?
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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!
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Kindly help me to identify this Siphonostomatid found in sea fish.
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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).   
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I am looking at cortisol levels in rainbow trout (as an indicator of stress) after being exposed to different anesthetics for immediate release in the field. However, the size of the rainbow trout we received were much smaller than we had anticipated. The fish are about 7.62 centimeters (three inches), when we needed about 12.7 minimum (five inches). Therefore, what I am wondering is that since they are so small, will they release enough cortisol in the water for me to detect it?
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Thank you!
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I want to analyze the residual analysis in fish tissues by HPLC method,if anybody know the procedure of sample preparation,please help me.
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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.
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the images is from gill and liver tissue in fish that expose to benzo(a)pyrene(oil contaminant).
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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
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I want to set up an experiment (in lab) in order to study European Chub growth using different feed structures. In this purpose in need some papers related to growth densities, water physico-chemical composition and types of feed used.
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b value in LWR may vary due to combination of one or more factors such as area / season effect, habitat, age, gonadal maturity, fish condition and fish health while K value in Condition Factor are depending on habitat, food source availability, age and sex of different species. They are somehow inter-related but how can we differentiate them?
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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.
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How to determine day age of sturgeon ? pls provide me some sugesstion or papers
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Morphology for the first month of development is very well described by Dettlaff (1993) 
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I have observed significant difference (1.5 fold difference in magnitude) in relative gut length between wild and cultured climbing perch populations. I was wondering if fish could evolve very fast (fewer than 10 generations) to adapt to aquaculture conditions where fish are fed a large amount of commercial feed. Do you know any evidence in other species?
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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.
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i'm doing my lab report on sexual maturity examination related with fecundity GSI and HSI. i'm not really understand what is the correlation between the three of measurement. tq
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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
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In case of carp culture.
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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.
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In gut content analysis originally index of preponderance uses volume and frequency of occurance. But often measuring weight is easier than measuring volume of items in the guts. I thnk weight and volume represent almost the same property, quantity of substance. So can we use weight to replace volume for the index of preponderance?
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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?
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I want to dechorion sea bass eggs to stablish a embrionic cell line. I have thought that the best thing is to obtain embryonic cells eliminating the chorion.  Maybe another alternative is possible 
Is somebody able to help me?
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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 
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Food and feeding in fish
Filling index
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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.
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tilapia fish, catfish
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Please refer to follow book.
Methods for the estimation of production of aquatic animals.  by G.G. Winberg
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For commercial culture of the species.
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Thanks, will take a look.
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I want to know the significance of moisture content in Nile tilapia carcass.
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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.
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I am looking to find the latest techniques in breeding trout
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Hi Javad. Here it is a FAO publication that might help you.
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Does any one know how many time the abalone and freshwater angel fish eggs will hatch after incubation?
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Thank you all valuable answer
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I am conducting a study using Artemia salina as a model organism for algal toxicity.  Previously I had only raised artemia to the point of hatching (24-48 hrs) and used them for feeding larval fish.  I now want to raise them to older ages, meta-nauplii stage (in which digestive track has formed) and adult.  To keep consistent with the conditions preferred by the algae I am studying, the artemia will be hatched and raised in 25 ppt artificial seawater in an incubator set to 25* C 12:12 light, dark cycle.  Any advice on distinguishing between the many molts phases this species progresses through before reaching adulthood would also be helpful.  
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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
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I want to test the differences on the model when I include and/or exclude body growth density dependence
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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.
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Hi there,
   I'm looking to obtain as many artisanal fisheries catch data-sets from throughout the Caribbean region as I can to examine species level life histories.
If anyone has one available that I can use for my research, or know of people in possession of one I'd be pleased to hear from you.
Kind regards
Richard
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Thanks dave. Didn't realise opwall had been collecting fisheries data overexploitation there.  I'll contact dan.
Cheers
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I need to find the total quantity of fish present in a reservoir for the auction purpose. Please suggest some accurate methods.
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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.
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Last week a new web-based service has been launched that aims at helping marine ecologists - or more precisely ecologists that need to measure fish otoliths (e.g. ornithologists, fisheries scientists, etc.) for allometrics size determination. Might be a helpful resource to some of you. Check it out at
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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.
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I am particularly interested in work in the northwest Atlantic where it will be assessed for risk of extinction in the near future.
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Here is one that I think you dont have already
Please take contact if you have any further questions
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What is the best method to catch large bodied catfish in lake and river ecosystems?
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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