Questions related to Fisheries Biology
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?
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.
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......
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.
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!
Kim T. Halvorsen
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?
I am working on fish bacteriology band presently facing problems in analysis of SEM photographs
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.
Can anyone help to identify the attached otolith, fish scale ( may same species) sorted from oceanic squid stomach ?
Can any one help me in identifying this Rhinoptera sp. and and provide literature on its taxonomy.
Area of collection: Andaman sea, Disc width:49cm, Tail length:38.5cm, Sex: male. spine present.
I want to get a age structur of a population without having informations about growth rates.
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.
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?
What is the most accurate and fastest quantitative method to determine total protein content of fish flesh? Can I have an explanation? Thank you.
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?
If someone has specific experience and has worked with Pb or Po that will be very interesting.
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.
My interest outcomes from a revisor question, appointingthe continuous water flow as a false replicates system when applying probiotic supplemented diet.
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?
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.
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.
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!
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.
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?
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.
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
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.
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.
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
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?
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.
here is an example for the genus Diodon, is it ok if i use the geometric mean values as circled below?
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).
Tutorial at: https://youtu.be/Tpd_v5NY-pE
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.
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.
I have uploaded its black & white picture but I am searching for a colored one as well as a latest one.
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?
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?
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?
Which deep-sea resources are currently exploited in the Caribbean Sea? Which nations are the main actors and what is the environmental impact?
I want to analyze the residual analysis in fish tissues by HPLC method,if anybody know the procedure of sample preparation,please help me.
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.
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?
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?
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
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?
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?
Does any one know how many time the abalone and freshwater angel fish eggs will hatch after incubation?
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.
I want to test the differences on the model when I include and/or exclude body growth density dependence
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.
I need to find the total quantity of fish present in a reservoir for the auction purpose. Please suggest some accurate methods.
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
I am particularly interested in work in the northwest Atlantic where it will be assessed for risk of extinction in the near future.