Crustacea - Science topic

Dear Prof. Ferre

What are the chances for this speciemen to be fragments of a blastoid. In Boardman, Cheetham Fossil Invertebrates, page 582, Figure 18.37, Hydrospire in a blastoid is depicted, which shows some resemblance to upper part of this speciemen, I would be thankful to have your response.

Thanksfull dear

Electrical stunning is a method that is used to humanely kill crustaceans, such as shrimp and lobsters, prior to processing or cooking. There are two main types of electrical stunning: dry electrical stunning and wet electrical stunning. Both methods have pros and cons, and the most appropriate method to use will depend on the specific circumstances and the goals of the processor.

Dry electrical stunning involves passing an electric current through the crustacean's body while it is dry, typically using electrodes that are placed on the body or in water. This method has the advantage of being relatively simple and inexpensive, and it can be effective at rendering the crustacean unconscious. However, dry electrical stunning can be less reliable than wet electrical stunning, and there is a risk of overstunning or understunning the crustacean, which can result in animal suffering or reduced meat quality.

Wet electrical stunning involves immersing the crustacean in a conductive solution, such as seawater, and passing an electric current through the solution. This method has the advantage of being more reliable and consistent than dry electrical stunning, as the conductive solution helps to evenly distribute the electric current throughout the body of the crustacean. Wet electrical stunning is also less likely to cause damage to the meat, as it does not involve the use of electrodes. However, wet electrical stunning requires specialized equipment and is more expensive and labor-intensive than dry electrical stunning.

Both dry and wet electrical stunning methods have the potential to cause animal suffering if not properly implemented, and it is important to follow proper guidelines and protocols to ensure the humane treatment of crustaceans. It is also important to consider the economic and practical considerations when choosing between dry and wet electrical stunning methods.

Thank you for your help John. I'm going to write to him and take more photos as well

Have the https://ucedna.com/ cal-e-dna run the DNA test, for less than $200

Gnathiidae is probably correct -- can a brief account of its habitat be provided?

Not my subject, but I think the shadow can be a distinction between species in a population.

In other words, an aid to sorting the individuals in a population. Absolute identification may require other criteria. Unfortunately, keys are often difficult to use. Once the species is known, one can often recognize it on the habitus.

Hello ! If you're working on inland aquatic Ostracods I invite you to check this document :

P.S.: Please bear in mind that it isn't for species level identification but it's a really good starting point.

Have a great day !

Could you read the data into a very simple program, possibly multiplying the numbers to see if you get the error because the file is corrupted a bit. You could also move the lines around before running the program to see where it has the problem. As Liang Chen suggests, it seems like a simple problem with the file.

Check..

Markus Grams

Maxillipeds are appendages that have been adapted to serve as mouthparts. These can be quite similar to pereiopods, especially in less mature decapods. Pereiopods have walking legs that are also employed for food collection.

Maxillipeds. The first three pairs of legs are transformed to maxillipeds, which help in food manipulation by passing food forward to the mandibles for chewing or to the maxillae for cutting into smaller pieces.

Maxillipeds are appendages that have been adapted to serve as mouthparts. These can be quite similar to pereiopods, especially in less mature decapods. Pereiopods have walking legs that are also employed for food collection.

Maxilla is one of the two bones that make up the upper jaw, whereas maxilliped is one of the feeding appendages on the heads of certain crustaceans.

Yes, it is an amphipod. My guess would be family Colomastigidae. Best is to contact Sarah Lecroy, she might know the critter:

All the best, Oliver

Algae

Hello. All soecies of crustaceans growth after of ecdycis and no there arent structures with rings of growth, however, is possible with the measurement of length body use some method as battacharya.

Thanks so much to you too, Prof. Otar Shainidze.

Hi Maizah, I concur with James: each species has a different set of characters, so you will have to study them in advance. I prefer to start taking photo's of living specimens, because they show some behaviour I want to register (see https://nieuwewendingproducties.blogspot.com/2018/03/in-vitro-in-natura.html - http://micksmarinebiology.blogspot.com/2017/10/spookkreeften-determinatietabel.html)

Dear Sergei Turanov

In general, everything can be found on

I did this for different types of beetles. The point is that you need patience, because if there are many records in the database, they must be sorted. On the site you can find sections of genes that have not yet been identified.

Regards, Sergey

Our knowledge of mites is poor in that aspect. There are soft tissue areas on the surface of the mites that we do not know if they do have such function, areas that look like possible ocular function, or perhaps vibration sensor. The correct answer is we do not know, but we should look at it as we were able to capture drop and stop behaviors of plant-feeding mites before the predator mite was over them. Many of these strange areas over the surface have been noticed by the use of the cryo-SEM. See also Functional morphology of tarsal adhesive pads and attachment ability in ticks Ixodes ricinus(Arachnida, Acari, Ixodidae)Dagmar Voigt*,‡and Stanislav Gorb 2017.

Trace fossils followed the same approach as the Code of Zoologic Nomenclature for body fossils, using the Linnaean binomial nomenclature (genus species). To establish a new genus or species requires a type specimen that represents the new trace fossil. This system is imperfect at best and not all that useful, but it has the momentum of history. Photos would not be an accepted basis for naming a new trace fossil. If it is difficult to collect you have no objective evidence for others to compare it with, but if you know what animal made the trace you are farther along than most ichnologists will ever be.

Hi Courtney Bennett ,

This is, without a doubt, a Shellback crab. Genius : Hypoconcha.

It seems like a Hypoconcha arcuata.

There is two more species in Florida (Hypoconcha parasitica and Hypoconcha spinosinima).

Whichever species it is, it's a beautiful speciment!

Cheers,

Greg

Adinda Kurnia Putri

Halichoeres argus is a marine wrasse; reef-associated (https://www.fishbase.se/summary/Halichoeres-argus.html);. By the way, wrasses, which are found in the Indo-Pacific, frequent all coral reefs, so to speak. It is among them that Wrasses which perform cleaning services are encountred. Your observations lead to ask the following question: is the wrasse Halichoeres argus a cleaner fish? To answer this question, an exhaustive bibliographical research is necessary as well as a study of the stomach contents of this species statistically valid in time and in space.

I am looking for a funded PhD position in Aquaculture/Fisheries. Preferred locations are Germany and Canada. I have an MSc. Fisheries Science from Universiti Putra Malaysia and a B. Fisheries and Aquaculture from University of Agriculture Makurdi Nigeria.

My research interests are in the areas of RAS, Aquaponics, Biofloc and wastewater aquaculture.

Kindly find my CV attached for your reference.

This is the calanoid copepod Anomalocera patersoni, which is a regular inhabitant of the North Sea plankton:

Jiri, you might have luck with this outdated guide:

Belk, D. 1975. Key to the Anostraca (fairy shrimps) of North America. The

Southwestern Naturalist 20 (1): 91-103

It is an Anthuroidea species for sure. The estuarine character of your sampling location indicated the possibiloty of Cyathura carinata, but it can also be another species.

Please check Wägele (1981) Study of the Anthuridae (Crustacea: Isopoda: Anthuridae) from the Mediterranean and the Red Sea. Israel Journal of Zoology 30: 113-159

Cheers

Michael

I don't have any experience with Cyromazine but diflubenzuron (trade name Dimilin) is commonly used in public aquaria, as is trichlorfon (Trade name Dylox) - though dylox is an organophosphate and really nasty stuff to work with, also rays and skates tend not to tolerate it as well as dimilin. Milbemycin oxime, commonly used with dogs and cats under the trade name Interceptor will also target crustaceans, and is so benign it is even commonly used in aquaria with corals and jellyfishes.

Javier Morales la idea era poder distinguir tras un tratamiento para la eliminación de larvas, si era o no era eficaz. Por ello tras el tratamiento se tomaban muestra y se evaluaba el % de larvas muertas y de larvas vivas.

Los moluscos muertos si estaban fragmentados si que se teñian, pero no si no estaban dañados.

Un saludo

It is depend on what time of animal digestibility or other living activity but around neutral pH.

Thanks everyone for the very useful tips! I will have them into consideration when I encouter problems again.

I believe the main problem to be the universitality of the primers that were making everything difficult.

Paul Rutland Increasing the Ta inhibited the amplification, I got no bands at all.

Sibnarayan Datta The primers' stocks and diluted aliquots were new and working perfectly with gastropod taxa.

Heather E Doherty the long gel run is a great tip, thanks, I will dot it if the problem persists!

Angel del Marco i did not know SnapGene, I have been using Primer Blast tool to do a first evaluation of the primers vs taxa in study. I am using a commercial kit for total DNA as most of the samples are completely destroyed in the process and we are also using them to obtain nuclear sequences and SSR.

I eventually ordered COI primers specific for bryozoans, designed and published by colleagues, and the gels now seem more promising, I'm waiting for the sequencing results now.

Thanks everyone!

Except that the radiation dose may be excessive in the study of the biological object (presumably alive) that you are studying especially at higher resolutions. And, that there is potentially poor differentiation of soft tissues using CT. Other small animal imaging modalities, ultrasound, MRI, etc. may offer similar useful and complementary information.

I think you mean 'interested' lol

Hello Khaled; The exoskeleton of arthropods is inelastic - the animals' container is rigid. Thus the animals can't grow unless they periodically produce a new, larger exoskeleton. Best regards, Jim Des Lauriers

First of all in your in your question you failed to specify whose juveniles you are working with. Still,based on the five photos, without considering the others attached -

The calanoid copepods are either partially digested and the cyclopoid (may be Eucyclops)copepod is in its copepodite stage and also there exists a nematode worm.

If we consider the "general defence mechanism" of crustaceans, it primarily involves beta-glucan-binding protein, lipopolysaccharide- and glucan-binding protein (LGBP) and lectins produced by various haemocytes. These pattern recognition proteins activate prophenoloxidase (proPO) system to initiate immune response. LGBP is the main molecule in response to infection with fungi and oomycetes.

As to your observation, it can be a tricky business because it is not clear whether the chitinases and LPMOs are from the crayfish or oomycete. This is because these chitin-binding molecules are actually the primary products of the pathogens. And particularly, LPMOs can be the pathogenic factors against the haemocytes of crayfish.

Bitte mal den Kollegen kontaktieren und ihm diese Frage stellen

MfG

Hello ;

Dear Alex

With all respect to my colleagues Reza Hadavi and Alireza Mordadi The DNeasy Quiagen Kit is not the best for this application. The DNeasy kit relies on PBS and proteinase K to lyse cells and this is not efficient for bacteria nor is it sufficiently harsh to recover DNA from bacterial cells that are adherent to the pleopod surface. The Kit I mentioned above uses a strong denaturing solution to lyse the sample and will be superior for extraction of DNA from bacterial cells and hard tissues such as crustacean exoskeleton. In fact, the paper cited by Reza Hadavi shows that a genomic DNA isolation kit similar to the one I mentioned above performed as well as the Qiagen kit. While the Qiagen kit is an excellent product and I have used it myself, as someone who has experience in extracting DNA from arthropod samples specifically I can tell you that it will not be as effective in this application. The paper cited is extracting DNA from bovine soft tissue, and that is a much different matrix than crustacean pleopods. April Stabbins original question was what method is best for extraction of DNA from crustacean pleopod tissue. Simply stating that a variety of techniques exist or recommending a kit or method that hasn't been validated for the application in question is not helpful. Please kindly answer questions about which you have genuine expertise and in a manner that addresses the issue of the original poster.

Typically seawater buffered Davidson's or 95% ethanol. Shields (2017) provides extensive discussion on differential fixation: Jeffrey D Shields, Collection techniques for the analyses of pathogens in crustaceans, Journal of Crustacean Biology, Volume 37, Issue 6, November 2017, Pages 753–763, https://doi.org/10.1093/jcbiol/rux077

link: https://academic.oup.com/jcb/article/37/6/753/4161633

Instantaneously?! For growth, the new exoskeleton is soft and pleated under the old exoskeleton. When it molts, the animal inflates (with water or air), gets out of its old shell and unfolds its new exoskeleton to grow. But this shell is incomplete and have to be completed by complementary secretions. More, the natural sclerotisation time of the new exoskeleton is not instantaneous because it involves various chemical processes: Calcification using external product (crustacean), or tanning (insect).

Alternatively, for instantaneousness in biology, you could contact Harry Potter ;-)

@ Jyl C Marfil : You are welcome

We just published some observations of this phenomenon across arthropods:

Thank you all for the very helpful responses!!

An algal specimen possibly from Dinoplagellates. Planktonic algae normally act as preferred food of Crustacea. The specimen however, needs thorough examination under microscope to achieve taxonomic precision in its identification.

I don't know.

In Invertebrates, the hemolymph, that is to say the liquid that plays the role of blood, does not contain hemoglobin (as in Vertebrates) but hemocyanin. This oxygen carrier pigment contains copper atoms instead of iron atoms (as in hemoglobin), which gives it a blue-green color.

It is for this reason that the blood of insects or crustaceans is not red, but blue-green. The best-known example of a blue-blooded animal is that of an arthropod sometimes called "blue-blood crab": the horseshoe crab (Limulus sp.).

Abhijeet Singh 100bp

Hi Francisco

It is normal to find ciliates or another protozoans organisms living with some larval stages of larger invertebrates. These tiny organisms could be flagellates.

Agus,

The following link should give you a good introduction to the essential elements that are needed for normal function in shrimps.

I have also attached some papers that you may find interesting.

Tomas

Hi, you can have a look at the R library "TropFishR" in R-cran (https://cran.r-project.org/web/packages/TropFishR) or in github (https://github.com/tokami/TropFishR). The Bhattacharya’s method can suit your problem.

Hi Cemal,

To synthesis chitosan from crustaceans, follow these steps

1. Cleaning: Remove the shells from the shrimp or lobster, clean well, dry and blend it.

2. Decalcification: using aqueous HCl (3 to 5% w/v) at room temperature overnight.

3. Deproteinization: using aqueous dil. NaOH(3 to 5% w/v) at room temperature overnight or 80 to 200 ^oC for few hours. You will get the product CHITIN

4. Decolorization: using 0.5 % KMnO₄ and Oxalic acid. (You can avoid this step if you use colourless endoskeleton such as squid gladius)

5. Deacetylation: using hot con. NaOH (40 to 50% w/v) at room temperature. Now you will get an end product CHITOSAN.

Check this links for more information:

Thank you.

Check this link of article.

Greeting

note the middorsal spine in N. couchi

Thank you!!

As long as your shrimps are not moulting you can use superglue mixed with a some inert substance to give it colour and placed as a dot on their backs. I used this method to do a mark recapture experiment on Crangon crangon. Superglue dots will harden underwater.

If you are considering artificial salts, you are also using recycled aquaculture systems (RAS) so my response includes that assumption.

For maturation, spawning and larval rearing high-quality synthetic salt mixes are required that include all trace element and very high-performance RAS. Any water change to prevent the buildup of organics and Nitrate can be added to the growout stage waters.

After PL 10 or so, they become more water quality tolerant and that allows cheaper synthetics that just pay attention to Na/K, Ca/Mg, borates, and TDS, alkalinity etc. while depending upon feed for the input of a lot of the trace elements like Cu, Zn, Fe, Mn, F etc. Denitrification is required to minimize the salt cost.

Not sure how to measure cuticle thickness per se, but you could use an indirect measure: how hard you have to press to puncture the carapace. John Christy and collaborators have done a similar thing a few years back for fiddler crabs (reference below), and they showed that it is harder to puncture the claw than it is to puncture the carapace. Also, the force you needed to puncture the claw was correlated to the pinching force of the claw. These suggest that Nahuel's idea is on the right track.

I would go a bit further and say that not only diet, but how much a given species fight should also correlate to cuticle thickness.

At the individual level I would assume that there should be a good amoung of variation as well. The minerals that make up the cuticle are not easy to come by in water, thus I would guess that some individuals can capture more minerals than others.

It would also be interesting to test if crabs that consistently win fights also have thicker cuticles - that may decrease the force the opponent is able to apply on the individual. That sort of study is missing in the fighting literature...

I hope some of my rambling is helpful.

Cheers,

Alexandre

The paper I commented is this:

Thakns dear Mariel

Hiram:

As per Article 51.3 of ICZN, you may cite your new combination as follows:

Palaeomon pugio (Holthius, 1949) De Grave & Ashley, 2013.

Best

Syed

Dear Danilo,

Thanks a lot. It's closely related topic. I also found some publications on regressions. If it's of interest, there are some more recent examples:

Nakamura et al. 2017 "Length-weight Relationships and Chemical Composition of the Dominant Mesozooplankton Taxa/species in the Subarctic Pacific, with Special Reference to the Effect of Lipid Accumulation in Copepoda"

Robinson et al. 2010 "Length–weight relationships of 216 North Sea benthic invertebrates and fish"

That looks very robust for a phyllocarid, to me. Could it be part of one of the early decapods?

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

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

Dear Md Faisal,

I thought you might like to know that we just added another supplier to our Directory that also offers a Crustacean Tropomyosin ELISA. Here is their page:

I think this is highly unlikely. The main reason is that most trilobite species moulted several times after reaching what is regarded as maturity: their final morphology, with adult number of thoracic ribs. There are also quite a few cases of suspected nesting behaviour, where pairs of the same species (at similar growth stage) are encountered within a shelter such as a nautiloid shell; I've seen this is Wales, and it is common at some levels in Bohemia.

The individuals involved in this are normally not the largest examples known, or even close to it. Therefore, if these were reproductive pairs, then they could survive to moult several more times. Unless reproduction was unlikely at an early adult stage, semelparous trilobites should never have got to their full size.  

This might not apply to all trilobites, of course, and my wife's just reminded me about agnostids... which seem like a good candidate for semelparity, if there is one!

Yes, there is debate about nurseries for the Rhizophoraceae, especially Rhizophora because the 'propagule' (viviparous seedling) is so easy to direct plant. The VN experience in reforesting after the US defoliation in Rung Sat (Can Gio now) and Ca Mau and continuing now in farmers planting in aquaculture areas was/is direct sowing. So easy.

Generally nursery culture is a waste BUT perhaps not in this case if the advanced seedlings are more resistant if grown on in a nursery. An avenue to try, although substitution of the first planted species in affected areas to Avicennia or Sonneratia might be better!? 

Gazi Bay is more saline I think, both being pretty open to the ocean and not having the same intensity of wet season, where everything turns fresh as here, even out to sea at the mouths of the rivers!