Stingray Dissection *Warning Graphic Images

[Dieselhybrid]

I need to thank D davenmandy for always giving sound advice and support. Also the Jedi master vincentwugwg for putting up with my endless questions at all hours of the night.

I developed the habit back in University, to delay writing conclusions for a few days. It's always seemed to help me have a more thorough comprehension and make sure I'm not overlooking anything. Which I definitely have:

I'm realizing I have neglected to mention a potential factor in the death of the ray. Our lake recently suffered a cyanobacteria blue/green algae bloom. We get our drinking water from the lake, so this posed a serious problem. The state tests the water once a month as a standard. If there is a high test, they then test weekly until the water stabilizes. Tests came back high in anatoxin-a about 7-8 weeks ago. We are banned from using the water and all fishing and boating is shut down. I immediately turned off the drip systems and began trucking in water from town 1000 gallons at a time, 1-2 times a week. No more drips we have been back to regular manual water changes, using trucked municipal water for the last 8 weeks to avoid exposing the fish to the tainted lake water. Anatoxin-a is deadly stuff, it caused the mass die-off in the Indian River in Florida last year. Here's the thing, it's a very fast acting toxin. Causing damage and death within 4-48 hours. So having her die 7-8 weeks after being exposed, seems unlikely. . However it could have damaged her organs, which later led to death through decreased function. It has to be also mentioned that dozens of pups and small juvenile rays have been in the same water conditions without any loss of life or symptoms. The toxin is an unlikely, yet possible factor to be discussed as my knowledge base here isn't the deepest. The lake tested within acceptable standards last week, if it tests again next week (2 consecutive) within acceptable levels it will be open to recreation and for us to consume again. (Thank the heavens don't take clean water for granted!) Thoughts on this as a potential factor?

 

[Dieselhybrid]

I'm happy Grinch mentioned the size of the ovaries and eggs. I had another friend in the hobby mention that as well which I sent him the summary. I did also weigh the total egg/ovary mass at 193 grams. That's just shy of 1/2 pound. I regret that I did not weigh the eggs individually but you can see from the photos that they are quite massive. Perhaps they were fertile, as I'm not sure they get that large without being fertilized? I'm looking back through my logs and I can see that 2 months ago a big spot male was observed biting and courting her although no sperm plug or anything definitive was noticed at the time. This behavior was observed for 2-3 days. More recently we observed a weight gain near the tail region and recent growth spurt which are both sometimes signs of early pregnancy. She was marked "possibly pregnant" which is our lowest pregnancy suspicion level. Two possible theories emerge. Is it possible those eggs were fertile and this was a reproductive issue as first pregnancies can be dangerous? Or the the eggs were old and she became bound? There were 22 total eggs counted in the ovaries. About 8-9 were much larger than the others. Anyone with knowledge here or any ideas please feel free to share.

 

[yargnits]

Very interesting and also very hard to do to a beloved pet. But once its passed .. as with people , we dont like to think about what happens. After reading i would guess breeding attemots or birth attempts were an issue , but just a guess.
Very interesting either way and im sure it was very difficult to do. I speak from experience as i tried something similar years ago and posted on mfk also. I wish i had the organ info you did back then . I was mainly posting in the hope that it would help someone else and help the hobby in some way .
whilst its an incredibly difficult thing to do. The information could help the hobby in the future in unknown ways as there really is very little scientific info about rays.
Its a sad thing but thanks for the info too.
Good luck with the rest of your rays and fish.

 

[Dieselhybrid]

I'm sorry for your loss and the lack of concrete explanation, but thank you for taking the time to share the dissection, it's really interesting.

Kind words from an experienced fish keeping veteran. Thank you Cohazard , I'm glad you found it informative and interesting. Always appreciate your support

thanks for sharing valuable information...

You are welcome and thank you for the support!

Hi DieselHybrid. Are you a doctor or veterinarian? I'm a vet myself and you did it really well. I'm sorry for your loss.

Hi Cichlidae ! Your question is flattering thank you. I am not a veterinarian or medical doctor. I do have a long history in the medical industry and Chriopractic, so that baseline of knowledge was beneficial. We did the best we knew how and are happy that people have found it beneficial. We are handling the loss well. This thread and everyone's input really helps with that! Thank you

Fascinating, awesome job.

Thank you buddy! Always appreciate you

Sorry for the loss my friend but nevertheless, great job on the dissection! Very interesting anatomy.

I feel the same my friend, it's nice to find "a silver lining in the clouds" during the difficult times. I agree they have a very unique and interesting anatomy. There's not a whole lot of information out there on freshwater stingrays, this forum is probably the most comprehensive source along with Dr. Ross. So happy to try and contribute in a some way.

 

[Dieselhybrid]

Sorry for the loss Dieselhybrid ....
Thank you for doing what you did.. ( im sure it was not easy) for the benefit of everyone ..
Much has been learned again.

Sorry if im out of line... i think this would make a good sticky thread.."anatomy of a stingray"?

You are welcome Maria, I'm pleased it has been a learning experience that we could "virtually" share with everyone. I hope we all can better understand the amazing creatures we care for through this. Hopefully this can be a resource or sort of outline should anyone choose to try and perform a necropsy on a lost ray. Hopefully some of the same data can be recorded with future specimens and we can create a better understanding within the community.

Maria I'm not typically one to "vote for myself," but I agree. Having this easily accessible could benefit the Stingray forum in years to come after this thread become buried by other threads. With the potential for injury during the procedure, having a guide that clearly addresses the procedure and safety concerns, while providing illustrations/photographs is necessary.

Sorry again for your loss buddy... She was an absolute stunner! I'm glad I could be of some help. You did a hell of a write up and this should be a pinned post here. Mods can you please make this happen. Anyone could take this thread and do a dissection on their own!
Thank you for taking the time to do such an awesome job!

Hey buddy thanks for the condolences and lending a shoulder for me to cry on. She was a beauty and a truly unique ray. I never really seen anything like her before and probably won't again.

I'm not sure the process for getting a thread "stickied" but from the feedback and messages I've received people feel this way. I'm sure a moderator will read and chime in if they feel the same. Or feel free to send one a direct message. In my experience and from what I've heard they're all really great folks with a lot of information and enthusiasm. If you want it, ask for it

 

[Thekid]

Chicxulub JK47 koltsixx Oddball
What's it take to get a sticky around here?

 

[JK47]

Chicxulub JK47 koltsixx Oddball
What's it take to get a sticky around here?

Complimenting my rugged good looks usually will get a sticky the fastest..

I'll post this up for staff review and get their take. Thanks for the suggestion man.

 

[Grinch]

I'm realizing I have neglected to mention a potential factor in the death of the ray. Our lake recently suffered a cyanobacteria blue/green algae bloom. We get our drinking water from the lake, so this posed a serious problem. The state tests the water once a month as a standard. If there is a high test, they then test weekly until the water stabilizes. Tests came back high in anatoxin-a about 7-8 weeks ago. We are banned from using the water and all fishing and boating is shut down. I immediately turned off the drip systems and began trucking in water from town 1000 gallons at a time, 1-2 times a week. No more drips we have been back to regular manual water changes, using trucked municipal water for the last 8 weeks to avoid exposing the fish to the tainted lake water. Anatoxin-a is deadly stuff, it caused the mass die-off in the Indian River in Florida last year. Here's the thing, it's a very fast acting toxin. Causing damage and death within 4-48 hours. So having her die 7-8 weeks after being exposed, seems unlikely. . However it could have damaged her organs, which later led to death through decreased function. It has to be also mentioned that dozens of pups and small juvenile rays have been in the same water conditions without any loss of life or symptoms. The toxin is an unlikely, yet possible factor to be discussed as my knowledge base here isn't the deepest. The lake tested within acceptable standards last week, if it tests again next week (2 consecutive) within acceptable levels it will be open to recreation and for us to consume again. (Thank the heavens don't take clean water for granted!) Thoughts on this as a potential factor?

ANTX-a (Anatoxin-a) can be removed via ozone filtration and/or reverse osmosis. See citation below. I was not able to easily locate a full text, but I imagine that if you ask the corresponding author very nicely, they'll send you a copy of the paper, and might even give you some practical advice. Keep in mind that if you are having ANTX-a problems in your local waterbody, you're probably having cyano-toxin problems in general; there are likely other cyano-toxin present in your water at relevant concentrations.

Granulated activated carbon may also remove ANTX-a, but how exactly this works (i.e. the most effective porosity and whether biodegradation occurs after adsorption) is an active area of research at this time.

If the water authority is allowing you to drink the water, it's likely safe for your fish. ANTX-a is an acetylcholine mimic; both humans and rays have acetylcholine receptors. Given that the cyanobacterial species associated with environmental contamination with ANTX-a have a world-wide distribution, it's likely that rays have encountered this compound at some point in their evolutionary history, and therefore possess adaptations to deal with background levels of contamination. That is, I wouldn't stress out about it if you have "some" ANTX-a in your tanks. With the amount of money you have locked up in rays and the water authority testing on a weekly basis while you are doing water changes 2x/week, I think it would be prudent to install a RO or ozone pre-filter.

This is unlikely to have caused they death of your ray by itself given that you have not reported ill-effects in your other fish, but this is certainly a source of that amorphous and cumulative thing we call "stress".

++++++++++++

Removal of the cyanotoxin anatoxin-a by drinking water treatment processes: a review
By:Vlad, S (Vlad, Silvia)[ 1 ] ; Anderson, WB (Anderson, William B.)[ 1 ] ; Peldszus, S (Peldszus, Sigrid)[ 1 ] ; Huck, PM (Huck, Peter M.)[ 1 ]

JOURNAL OF WATER AND HEALTH

Volume: 12

Issue: 4

Pages: 601-617

DOI: 10.2166/wh.2014.018

Published: 2014

View Journal Information

Abstract
Anatoxin-a (ANTX-a) is a potent alkaloid neurotoxin, produced by several species of cyanobacteria and detected throughout the world. The presence of cyanotoxins, including ANTX-a, in drinking water sources is a potential risk to public health. This article presents a thorough examination of the cumulative body of research on the use of drinking water treatment technologies for extracellular ANTX-a removal, focusing on providing an analysis of the specific operating parameters required for effective treatment and on compiling a series of best-practice recommendations for owners and operators of systems impacted by this cyanotoxin. Of the oxidants used in drinking water treatment, chlorine-based processes (chlorine, chloramines and chlorine dioxide) have been shown to be ineffective for ANTX-a treatment, while ozone, advanced oxidation processes and permanganate can be successful. High-pressure membrane filtration (nanofiltration and reverse osmosis) is likely effective, while adsorption and biofiltration may be effective but further investigation into the implementation of these processes is necessary. Given the lack of full-scale verification, a multiple-barrier approach is recommended, employing a combination of chemical and non-chemical processes.

Author Information
Reprint Address: Vlad, S (reprint author)

Univ Waterloo, Dept Civil & Environm Engn, 200 Univ Ave W, Waterloo, ON N2L 3G1, Canada.
Addresses:

[ 1 ] Univ Waterloo, Dept Civil & Environm Engn, Waterloo, ON N2L 3G1, Canada
E-mail Addresses:svlad@uwaterloo.ca

 

[Oddball]

Outstanding journal necropsy! I'm sorry that the conditions allowing such an investigation requires such a loss.
I agree with Grinch in that the egg-bound condition may have led to a sepsis condition. Ovoviviparous species tend to absorb eggs that are past their usefulness. A chemical change or calcification of the ovum could have prevented the conditions needed for reabsorption by the female. I once saw a crude test where a suspected calcified egg was freeze dried then subjected to a hydrochloric acid wash. A reaction from the calcifications proved that the egg had been infused with calcium preventing the body from reabsorbing the egg as nutrients back to the body. The massive protein bolus of the egg's nutrients became a battlefield of bacteria leading to sepsis of the reproductive organs and blood poisoning of the specimen.

In preserving the pattern of the specimen, I'd recommend the Japanese art called; Gyutaku or fish-printing.

There are 'how-to' videos on the procedures and many books available on this ancient art form.

In using this art form, transfer defects can be filled in and blended. Also, colors can be matched to what the living specimen displayed. The traditional backings can be readily sealed against fading and olfactory by-products better than a wet, slimy towel can.

To further the investigative possibilities of future necropsies, I highly recommend incorporating a dissection microscope into the study. Simple slide-prep procedures are available on-line from numerous sites. Checking blood and viscera for bacteria/fungi/protozoans/etc. may yield blaring answers for the reason of a sudden-death loss. Dissection microscopes are easily found in places like eBay for much better prices than those at university or medical supply outlets. (pic is just one example. There are many brands and configurations available. Many have digital cameras allowing computer storage of microscope captures for later study and manipulation by software).


Finally, off the top of my head, for expensive specimens as this ray, I recommend consulting your local vet in the procedure to draw and preserve blood samples for sending off to the proper lab for a basic battery of testing. Your vet may be willing to provide the drawing materials, standard and anti-coagulant blood tubes, and anything else he feels may assist in the necropsy. More involved testing may include blood culturing for bacteria and fungi but, those may be cost prohibitive.

 

[Oddball]

The topic of cyanobacteria dredged up a memory from back when I lived in S. D., CA. We had periodic bouts of fish losses, in the county, that turned out to be caused by fire retardant used during wildfire events in SOCAL. The water dept. stated they did not have any procedures in place of warning the municipality that fire retardant may have washed down into the reservoirs. The MSDS (Material Safety Data Sheet) from the chemical's manufacturer states "Hazardous to Aquatic Life". Therefore, I would check your area for these events and refrain from water changes using your municipal supply until the breakdown point listed in the MSDS for whatever chemical was used to combat a local wildfire. Check with your fire dept. to find out the chemicals that may be used to combat fires in your area and, if possible, who the manufacturer(s) is(are).