Reptile & Amphibian Forums

Hi there,
I have the opportunity to regularly procure some crayfish from a guy who has them in a private reservoir here in Oregon, and I was hoping to get a few on and off to feed to a Nile. This means they're 'wild caught' even if the reservoir doesn't get strange run-off into it, and that brings up a few questions.

He said they test for water quality once per week- should I get any sort of tests run on the food animals themselves if I'm going to buy them regularly?
Should they be frozen and thawed before use to kill any bacteria/parasites, or should they be okay to feed fresh? I worry about environmental contaminants, but the area he is in has extremely good air/water quality, and no obvious sources of industrial pollution.

Basically, just wondering if this is a good idea or not, or just about equal with feeding store-bought shrimp or fish, or something like that.

I was also wondering about the pollution like the level of mercury in the animals. I'm sure it's OK every now and then just like any other fish, but wouldn't include it as larger part of its diet.

I think these things would be the first to get affected by the pollution if I'm not mistaken and accumulate much pollutant in it's body particularly in the head. [shrug]

Of course, many people I know would recommend mainly rodents diet.

Rodents are what I am calling a high energy food.

Which means, the monitor being fed rodents must be progressing, growing or reproducing. It must have

For monitors kept in lesser conditions, a lower energy diet would be better.

So in reality, the best diet is one that serves the needs of that particular individual monitor.

To me, no offense Ben, but this crayfish vs. mice, debate is very silly, its all about performance. Its also about confidence, availability and reliability.

Again no offense but, you could raise dums or any one of many monitors on earthworm sausages. Varanids consume just about anything. Even wrenches and coke cans. Cheers

I really should stop posting on these forums, nobody seems to be able to think anymore, just argue.
I'm not now nor have I ever been anti-rodent, you guys just don't get it. You call me names because you can't have a dynamic conversation. I feed crawfish to my dums because it works, has for years,can any of you show me ANYONE ANYWHERE who has bred dums to over 3 generations on a rodent diet? I've bred them to 5, seriously put up or shut up.
I have no problems with rodents, feed all you like, but stop putting words in my mouth. I said I prefer shellfish to rodents for ONE of the species I work with, and listed my reasons. The O.P asked if it was possible to use them so I shared my personal view based on years of experience, obviously not good enough for those with prejudiced mindsets. I bet you'd blow a gasket if you found out what I feed my olivaceous!
Shellfish are readily available, cheap, easy to use and PROVEN to be a viable staple food for monitors, if you have evidence to the contrary show it.
I've never once said my point or position is shrimp VS rodents, never, that's a simplified, dumbed down smoke screen you made up to keep from having to think.
Best.

Don't let Frank ruffle your feathers.....

He prides himself on doing so.
-----
Regards,
Wayne A. Harvey
Thamnophis US
Savannah Monitors
Snakes and Lizards, It don't get any better....

Ben, there is something the matter with you, I did not call you names, nor did I say crayfish were bad.

I offerred my experience and you offered yours, that is exactly what these forums are for.

I also stated if that posted wanted to discuss it further, I would love to.

There are many reasons what folks do what they do, and that includes you. Its up to the individual person to choose what they want to do. Again that includes you.

If you want to so something the hard way, go for it, I will not stop you. In fact, I love to see folks do something the hard way. I can learn from that.

So stop with your sensitive BS and express your experience, all of it, and then we can have a decent conversation.

The FACT that there are many ways to allow and support success is a great thing. But they do not have to be equal. And there are many reasons for choosing a base diet.

For instance, where i live, getting fresh crayfish is difficult and inconsistant. Which makes them a poor choice for me, no matter what the other reasons are. Cheers

If you want to have a decent conversation then answer my questions instead of condescending me. I'm going to start calling you frank the academic from now on, as you seem to only be able to stick to your preconceived conclusions based on no data and math.
Feeding shellfish is the hard way eh Fr? So answer my question, can you show me anyone, anywhere who has bred dumeril's to generations on a rodent based diet, seriously?
Can you show me the poor results of a properly housed long term captive fed on shellfish?
Have you ever tried a whole bodied diet long term that wasn't rodents?
You are not being honest when you say you can't get shellfish where you live, I lived right down the street from you for 4 years and never once had a problem finding cheap shellfish. I bought from local stores in your area and also had them shipped, so these food items are available to you, cheap and easy, you just came to your conclusion based on no info, and you want me to respect your opinion?
Silly indeed.
Ben

A couple of things, first, this thread is about NILES, not Dums.

Its also about choices, we as keepers do have choices, each of us can decide whats BEST FOR US. Which includes what is handy for us.

If you really wanted to have a discussion, you would stop with all your personal BS, if you look at your post, it really has nothing to do with the thread, just crap from your past. Niles, not Dums Ben. Don't let your emotions throw you off your game.

If its about diet in general, then I suggest you testing mice vs. crayfish. You know, to a comparative study with several groups of monitors of several species.

Also, about crayfish and Dums, I really do question what our local crayfish have to do with wild dums and their natural diet. I also question the thought that any species consumes one prey item over their entire range. Also, I suspect that what makes a dietary item in captivity valuable is what its made out of and how well that works on monitors in captivity.

Send me some baby dums and I will test my part, then you can keep some and test them with crayfish, lets see how that works out. hahahahahahahahahahahaha

But back to the subject, NILES, crayfish and water quality. Cheers

There's nothing personal, just being my usual irascible self
Yes, niles. I know, I shared my experience with dums and shellfish as an example of a species that shellfish has worked well with.
You stated that my opinion was wrong and that rodents were a superior food source and implied that shellfish are less than adequate and unproven, I called you on that B.S.
I actually have done the research Fr, years of it, back and forth with rodents and shellfish over generations, that's how I came to my conclusions, you know actual hands on experience. You want to tell me that your theory trumps my experience, again I call B.S
I don't need to test it anymore, I have the results.
My thoughts are that a shellfish staple would work great for Niles, waters and several other medium to large species and would like to see others results. We have the results of niles and waters kept on a rodent diet, both with adequate and inadequate husbandry, lets see what the results are for shellfish.My guess is that shellfish could be proven out to be a far better choice.
Your comment on dums, crawfish and prey item value shows you have no ability to absorb or comprehend information Frank.
Local crawfish have nothing to do with this conversation, the value of the prey does, again you are unable to grasp this concept or answer a question. Do you have any evidence of anyone anywhere breeding this species (or niles) to generations on rodents? What do you think shellfish lack as a staple? What evidence do you have that rodents are superior to shellfish for these species?
You want some dums, fine, come over and get them, I've thrown hundreds of eggs in the trash for the last few years and will never again sell monitors to the public, but I have a gravid female now, I'll incubate the clutch and you can have as many as you'd like. I have no problem putting my money where my mouth is do you?
Ben

Don't let him get to you, dude. It's not worth the headache.

Learn to read sir, Ben, I said, rodents have shown superior results and they have, whatever experience you have, I have many times that. Sorry but true. And you know it.

I did not say crayfish were bad, I did say rodents have shown superior results, and I can and will proof that with pics, of many many many species and their progress. You really do not want to go there.

I would love to do a test.

It appears your have some manner of complex, because, it someone says something you do not do is good, it means to you that what you do is BAD, which I never said what you did was bad.

So yes, your whole envolvement in this thread is awfully wierd. As I said, if that person wanted to talk about, I would. But you don't want to talk, because if i did show superior results, you would think what you did was bad, which was never my intention.

Back to niles, how many crayfish would fill up an average sized nile, now how about rats? or rabbits, sir you really need to use some common sense. Cheers

HAhahaha, you dish but can't take.
You called me out on this thread, you picked the fight with me, that's why I'm here.
Whatever.
I'll put my reading comprehension skill up against yours any day.
I have no clue what you mean about me thinking what I do is bad??? You should really spend a lot less time trying to figure out what I think, so far you've never gotten it right, what's this 10 years in? If you must put words in my mouth at least make them funny.
Yes Frank let's talk about how many pounds of food it would take to fill a nile...hmm how would a pound of rodent differ from a pound of shellfish and how would that animal use that pound in captivity, what would the short and long term results of those pounds of food be??????? Tell me, seeing as you feel you have a moratorium on common sense, if a pound of shellfish cost $2.99 and a pound of rodent costs $9.99 which makes more sense to buy and why. Would a pound of shellfish have the same nutritional value as rodents? How would it differ? How would the long term effects of this affect reproduction? longevity? keeper interest? Growth rates?
I'm dead serious about the dums Frank, I still have your #, I'll call you when they hatch, you just gotta pick them up here.
B

I know a lot people here talk to you like you're not even there. It's frustrating sometime, especially whey you are bipolar like me. But he's not right about everything, you know. I think it pisses him off more if you are not angry about it. lol I know that from experience. If you go to Thailand, there are signs that say you can't get angry. [chuck] His time will come.

What, you cannot ship, I will pay the shipping. No problem You really need to understand, if I was in your neigborhood, I would stop and pick them up. But to travel from there to there, proving anything to you or anybody is not that important. But it would be fun to raise up some Dums, raising up reptiles is my favorite part.

One of the dietary needs that is puzzling to me is fat. rodents and captive bred rodents in particular, carry a fairly high amount of fat.

While many people, being anthropormorphic, think fat is a bad thing. In nature, fat(energy) sources are valued.

With most fast growing and reproducing animals, the need for a high fat content is known. Yet, when it comes to reptiles, not much is known.

I really never had the need to have a lab analize prey items, but there is something in mice that allows young monitors to grow guickly and strong and females to reproduce well and do so over and over.

what is missing in most diets is FAT. So I am guessing that may be important. ITs very important in the production of mice. With mice, the conditions perdict what fat levels are needed. In hot conditions, lower levels are required, In cold conditions, like most labs use, higher levels are required.

On the otherhand, animals kept static(non growing or reproducing) I would recomend a low fat diet, such as crayfish. That includes older individuals, particularly old males.

It may also be Type of fat, that is important. I don't know. Nor do I care.

Again, what I find so odd about this is, the ability for you guys to have a grown up conversation. That is, comparing success to success. You see, I am past the old, can this be done, I would think we all should be past that. We should be.

This my way/your way, BS, is so silly, which is why I mentioned it above.

Again, you are so very knowing, you state costs, yet you have no idea what your talking about. There is no question on earth, mice are far less expensive then crayfish, for me!. What others do or how they purchase, is theirs to do. So your arguement on price is off and baseless. Also, you should know this, for many people its not about the cost. It may be, or not, thats for the individual to decide.

You seem to have found a way to obtain crayfish inexpensively, well sir, there are indeed ways to obtain rodents inexpensively as well. But that does not bode well for your arguement.

So Ben, if you do really want to talk about what may be different and what "may" be why one item performs better then the other, how about starting a new thread. I would love that.

You also talk about my gut feeling, I do not go by my gut feeling, or by what I read, I go by expressed results, which is think is really the important part.

About testing, sir if you knew me at all, and you don't. You would know, all I do is test, test and more testing. In fact, I wish I was not wired that way.

For instance, that cage above, while it is also a test, its also just because I like it. So what do you think of that cage Ben, I noticed you did not say a thing about the cage. Cheers

So this is the Jekyll/Hyde thread? Fair enough.
I'm going to address each of your points but I'm not going through the trouble of quoting you again.

No Frank I won't ship, come and get them or no deal.
I lived in your neighborhood, don't remember ever seeing you.
It has nothing to do with proving anything. I've always said you will find me to be polite and courteous, just not agreeable.
If you saw what I do here at least you would stop making stuff up about me, no way I would carry on a long term conversation with you having to constantly defend myself against your pretend version of me and what I do.

Fat. yes, many people do anthropomorphize animals and what they need and certainly they need and use fat differently in captivity vs. nature. Ever seen a captive specimen and a wild ones fat stores compared? Ever seen a captive female's fat stores right after oviposition?

I've never needed a lab to analyze my prey items either BUT there is something in shellfish that allows young monitors to grow quickly and strong and females to reproduce well and do so over and over.

Yes I'd agree that older males could do well on a shellfish diet.

Yes Frank, let's be past the past and grow up.
Let's compare oranges to oranges.
I'll share my experience with dumerils and you share yours.
We can compare results.
I'd like that, and I'd love to have an actual conversation with you about diet, husbandry of all species so you don't feel I'm just trying to talk about one species, that would be fine Frank.

Oh, reading on, your post you just fire up the insults and lies right after calling a truce, smooth move dude! check your meds!

Guess what Frank? I did live where you do and did buy shellfish, you ignore this fact every time and spew your talking points, you keep saying they aren't available, and they are expensive, more so than mice, and you know so by not ever looking for them. Again, you have no data, but you have a strong opinion, good for you tuff guy, say what's that restaurant down the street..

hello my room mate and I have recently gotten two dumeril's monitors in hopes to breed them in captivity... you are the only person I have seen thus far that has. I was wondering if you would be willing to help us? which leads me to ask why you said you would never again sell monitors to the public.

Crawfish are an excellent staple food source for varanids, I've been feeding almost exclusively shellfish to my dumerilii for over 16 years and have never had a problem ever. I've bred dumerilii to 5 generations on crawfish.
Ben Aller

Hi,

I do not think they would be a problem, but mice/rodents would be a far better choice.

First off they are totally proven to allow a wide varity of larger species to prosper to a superior level in growth and reproduction.

They are easy to obtain, both live or frozen.

I would love to discuss why rodents are superior, if you wish. Best of luck

I agree with Franks on this subject. Rodents have a lot more nutrients than insects and other arthropods which they need being large lizards. They are not tiny geckos that can live the rest of their lives feeding on insects.

Crayfish would have to be fed by the bucket load to make a Nile happy.

Maybe a nice treat, but hardly a satisfying meal.
-----
Regards,
Wayne A. Harvey
Thamnophis US
Savannah Monitors
Snakes and Lizards, It don't get any better....

Darn, missed this thread until now; rarely come on this forum anymore.

I will plainly state that my experience is very limited as to what success may be accomplished from either food source exclusively. I am also NOT saying people shouldnt feed rodents. However, since we are talking about scientific nutritional values I can add some to that discussion.

As regards the nutritional content, crayfish are higher in usable calcium. They also have higher amounts of other minerals, though not in any crucial way. Vitamin contents vary, of course, but crayfish are higher in Vit E, which is a shortcoming of rodents. However, rodents are higher in Vit A, so Id say its easy to call them equal but different for the sake of vitamin content alone.

Fats are a big difference. Rodents are very high in saturated fats, whereas crayfish are pretty much all unsaturated and polyunsaturated fats. Let me be clear, the actual ramification of this difference has not been studied in varanids specifically. However, it is important to note two things. First, Niles in the wild, like many varanids, are not exposed to high levels of saturated fats in their diet. Second, we are finding that in numerous species and genus of animals generally, a change to diets high in saturated fats results in health issues. (It should be noted that these are usually issues in old age)

It doesnt matter that these are captives, since we are talking genetic predisposition towards lipid metabolism. However, this does depend on species, of course. There are a number of varanids that do eat a large amount of red meat in the wild, and are adapted to that diet.

As for the OP's question about problems with wild caught specimens, there is that possibility. Crayfish build up in heavy metals. The easiest and best way to find out is to look at water surveys in your area. Fish/Wildlife and County governments will have those figures. If the heavy metals are within acceptable ranges, then you should be fine.

I think Fank is on to something here.

Once upon a time I was part of the (silly) Anti-rodent campaign...

Not any more.

If you buy frozen rodents from a reputable place like rodent pro, You are assured a CLEAN (chemical / parasite free) food that provides both nutrition and high moisture content.

Support your lizard correctly and it will not get fat on mice.

In regards to those crayfish, I wouldn't worry too much if the water is clean, chances are it has to be cleaner than some of those swill holes in third world countries.
-----
Regards,
Wayne A. Harvey
Thamnophis US
Savannah Monitors
Snakes and Lizards, It don't get any better....

I wouldn't worry about testing for contaminants.
Feeding live or frozen is fine, one thing I've learned over the years when freezing crawfish is to put them in a large zip-lock bag and lay flat in the freezer, that way they don't freeze in a big clump making thawing easier. I've found shellfish to be much cheaper than rodents, easier(quicker) to thaw, readily available and a most excellent staple for raising generations of varanids. Plus, it's fun to watch them eat shellfish, they really know what to do with them.
Best.
Ben Aller

Monitors eat some really nasty stuff in the wild...I won't even go into what they eat...but mice, roaches, crickets, crayfish are no problem. I've even fed freshwater snails.

Dear AnnaCB, sometimes these threads get carried away, and this lively debate may or may not have addressed your Q about crayfish/water quality etc.

Regarding crayfish, some keepers think a varied diet is OK, and maybe your Nile monitor would enjoy eating crayfish whether or not they compare nutritionally/conditionally/economically to rodents? I tend to offer my animals (none of which are monitors at this point) a variety of prey items, simply to try and provide trace elements, buffer against excesses/deficiencies, and try to add stimulation to the captive environment. Not sure why you could not offer both, rather than exclude one in favor of another? I am addressing crayfish, which I have a lot of experience with, not monitors.

Crayfish are so easy to trap, and you have them in abundance in Oregon ponds and streams. Many crayfish populations are nonative and you will be encouraged in some areas to harvest them. Internet trap sources exist, for very reasonable, and limits in many states do not exist or are very liberal. I think trapping them is sort of fun, and when I fill the traps, I sometimes invite friends over for a crayfish feed, and still have plenty for animals. In the right spot, you could probably harvest hundreds of pounds in just a weekend.

Your water quality is quite likely way better than the water from many commercially available sources. Crayfish are often harvested in California, Texas and Louisiana rice fields (they are a pest to germinating rice)and inland waterways, often from water you would not want to drink without heavy treatment. I think it would be wise to freeze them first, on the theory you might eliminate parasite transmission, but of course the same could be said for rodents or mollusks. I am not suggesting crayfish are a likley source of parasites, I do not know. I can assure you monitors living near the banks of the upper Nile river are exposed to some poor water quality...I would imagine Nile monitors are pretty tough and can do well on a wide variety of prey items. Let us know if you try them and if they are well received.

Does anyone know if crayfish shells are digestible? Are they chitonous or do they have available Calcium? I would be concered about meeting a breeding monitors needs for Calcium with any prey source...and I wonder if crayfish are an adequate source? Thus, I would offer a variety of prey items and cover that base or prevent that potential deficiency. Good luck, Vic

Yes, the shells and the whole crawfish are totally digestible. Go on youtube and type in "monitor lizard eats crawfish" and I have a young male Argus trying to figure out how to tackle a live big crawdaddy for the first time. After a couple weeks (yes, I fed and still do sometimes feed craws), they get really good at how to dismantle and swallow them properly so they don't get their mouths poked. It all becomes poop in a day and seafood has it's own "flavor" when it comes out compared to feeding all mice (worse smell with seafoods for some reason).

The exoskeletons (shells) of crabs and craws and lobsters, insects and all arthropods is a composite mix of chitin (sort of a leathery, elastic polymer) and Calcium Carbonate. Pure chitin is actually soft like a caterpillars skin. Harder shells have more Ca++ in them. It's a fine food source and can be cheap. Mice work well too. I think you could succeed a lot of ways and it's about what's most economical and convenient for the keeper and as long as it's whole prey, it tends to work - fishes, rodents, dusted insects, crabs, whatever.

Thanks for that referral, that is a fun film and an impressive beast. I also noticed some related films to trapping crayfish down in the cypress swamps. My traps usually yield far more per trap, but I am not competing with commercial ventures and probably the Oregon resident who started this thread won't either. For those unfamiliar, many crayfish populations are nonnative invasives, and trapping them is desirable. They are an issue in California and Arizona for sure.

I often find huge crayfish in the bellies of bullfrogs, which I can only assume digest the shells. I am thinking the reddish colors in the shells may be a source of carotenel, and I wonder if it may influence colors in monitors? Certainly it does in salmon and trout.

I think the Australians have crayfish too, they call them "yabbies" or similar...? Do wild populations of monitors commonly consume them in Australia? Crocdoc or FR, do you know? Yes, I know captive is a different situation, I am just trying to learn more about monitors and the range of diet that is commonly consumed. Thanks, Vic

Varanus mertensi certainly do feed on crayfish (aka "yabbies" ) in the NT. They root around on the bottom and feel for the movement of the crawdads and snatch them with perfect aim underwater. There's been some awesome NatGeo type underwater camera work I saw somewhere capturing this on TV.

Your missing the point about diet. The approach of a varied diet is addressed in two basic ways.Hmmm at least two basic ways.

One is the insecurity of the keeper, like you mentioned. You do not understand what a good diet is, so you try everything. While you rationalize it well, your so off base. There is always the question of theory vs. repeated results. In this case, there IS repeated reliable results.

My recomendations are based of extensive experience, That is what is KNOWN AND PROVEN, rodents(mice) are PROVEN to be a superior diet. That is, generations upon generations of many many species of monitors. My own personal experience, not what I read or heard from some other yahooo.

To pacify some others, surperior means, amoungst the best dietary item. We can debate which is "the" best, at another time, if at all.

But that does not mean, thats all you should feed, its odd to me that folks tend to think in that old sorry, A or Z, that is, one way of the other. Rodents as superior as a BASE of any diet and even as a stand alone. All that means is, you can rely on it. Thats a freedom that should be understood and utilized. Of course, you can do things the hard way if you like. Or any other way.

The next area, that stimulaiton you mention, is a bit odd. If you kept monitors, any and all prey items stimilate them. WHats stimulating to them is a full stomach. kinda like my dog! What actually stimlates them is capturing and KILLING live prey items. And thats the truth!!!!!!!

The problem is, when dealing with a newbie, your making something simple, DIFFICULT. If I were a newbie, I would want to know what is PROVEN to work, so I could concentrate on what is actually questionable. Like conditions and substrate and dehydration, nesting and such, you know REAL problems. Just the subject of substrate or deep substrate needs lots of attention.

In this case, Diet items is NOT the problem, caging and conditions, normally are the problem. Newbies need to work on what the ACTUAL problem is, not what blows your shorts up. You say you think this and that about diet, great, your thinking which is what I do like to see in a keeper. But in this case, you do not have to think. Not about base diet. Of course, once your captive is thriving, you can play to your hearts content. Or think(theorize) until your ears turn blue.

Newbies really need to address the damage other keepers or importers have levied on their monitor. Its rare to recieve a non compromised individual monitor. In otherwords, most individuals you recieve are screwed up in some way. That needs your attention. Your full attention

About mertens, I have spent time watching them in nature. Crayfish, I am not sure they occur there, prawns is what they call them, yabbies, mudbugs, etc are local common names. But mostly crabs and fish, are taken. (personal observations)

They will take frogs by the millions. In the dry season, the above and in particular frogs congregate in ponds(billibongs, sp) and are harvested in mass.

Also, if a bird falls near or in the water, its taken, and if a kangaroo is hit on the road, they will consume it too. Again, monitors do not turn up their nose to a decent meal. It seems to me, what they do is, seek a steady reliable source of food and utilize it. COMPLETELY

Rubbish piles, chicken ranches, behind restarants, hotels, all attract monitors. Even fast food places. Of course the old picinic table monitors(Park monitors) are common in Australia. They consume garbage and do well. Its conditions that determine their overall health, dietary items, not so much.

They all seem to florish fine, if not better then their natural brothers. ITs not about the type, more about how much and how often. They then stay with that prey item until its gone. ITs what they do. Its why they stay at rubbish tips and picinic tables. A reliable food source.

But sadly, that is not the problem with captives. The problem is caging and misguided ideas about what a varanid is. They are a ectotherm raccoon.

Again, for newbies, it SHOULD be handy to know what WORKS, so you can work on what really needs work. Cheers

ps. All those neonates and more are a product of MICE.