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The Natural History and Care of the Greater Siren

Greater SirenSalamanders are by no means defenseless – indeed, the skin toxins produced by the California Newt and its relatives are among the most virulent natural chemicals known.  But most herpers tend to regard them as small, slow-moving, inoffensive beasts.  Not so the mighty Greater Siren, Siren lacertina.  This caudate “rule-breaker” can bite viciously in self defense, and is a major predator in its environment…but it is also among the most interesting amphibians that one can keep, and very hardy to boot.


The long, eel-like body is grey or olive to near-black in color.  Measuring up to 38.5 inches in length, Greater Sirens are among the world’s longest salamanders.  They are exceeded in length only by the Two-toed Amphiuma (also native to the USA) and the Japanese and Chinese Giant Salamanders. 

Greater Sirens lack rear legs and are equipped only with tiny forelegs. However, the tail, laterally compressed and equipped with a fin, renders them as powerful, agile swimmers.

Along with Axolotls, Hellbenders and certain others, Greater Sirens do not transform into a land dwelling adult form and retain larval characteristics such as external gills (they have lungs as well) and an aquatic lifestyle.

Salamanders exhibiting these characteristics are termed neotenic.


Greater Sirens are found along the US coastal plain, from Washington, D.C. south to southern Alabama and throughout Florida. There are isolated populations in southern Texas and Tamaulipas, Mexico.


Muddy, weed-choked swamps, ponds, ditches and the vegetated shores of large lakes and streams.  Greater Sirens are nocturnal and completely aquatic but can cross land if necessary.


Greater SirenSiren status is difficult to monitor due to their aquatic habitat and secretive ways.  They are considered, in general, to be common, but are rare and protected in Maryland.  Surveys are needed, especially where wetlands have been drained.


Up to 500 eggs are deposited (February-March), singly or in small clusters, on the pond bottom in densely vegetated sites.  There is some evidence that females may guard eggs, but we do not as yet know whether fertilization is internal or external (great project for an aspiring keeper!)

The eggs hatch in April and May; very little is known of larval period.


Voracious hunters, Greater Sirens take a wide variety of prey, including fish, frogs, other salamanders, tadpoles, insects, crayfishes, shrimps, snails and carrion. Some suggest that ducklings and small rodents are not beyond their grasp, and that algae may be consumed by juveniles.


Greater Sirens aestivate (become dormant) during droughts.  At these times, they dig into the mud and surround themselves with a cocoon made of dead skin cells.  The gills atrophy during this period.

In laboratory situations, these hardy beasts have survived for over 5 years in dormancy, losing more than 85% of their body weight in the process! Typical dormancy in the wild lasts for 1-3 months.

Greater Sirens are major predators within their habitat, and are in turn consumed by water snakes, turtles, alligators, otters and wading birds.

Unlike most salamanders, they are quite vocal – producing loud “yelps” and other sounds when disturbed.

Due to the variety of unique characteristics they possess, Greater Sirens, along with Lesser and Dwarf Sirens, are considered by some taxonomists to belong to a different order than do the true salamanders.

Captive Care

Greater SirenGeneral

The Siren’s innate hardiness (captives have topped 25 years of age) should not be taken as an excuse to ignore water quality.  Effective filtration and frequent water changes are critical to their health.  Please see my article on Mudpuppy Care below for further details on keeping large aquatic salamanders.

Move Sirens by coaxing into net; they can administer a painful bite!  Siren skin damages easily in nylon nets, so handle only when necessary.


The aquarium’s lid should be well-secured, as they will attempt to escape at night (line the lid with foam or enclose in a pillow case so that new arrivals do not damage their snouts by rubbing on screening).  Keep plenty of cover such as plastic plants in aquarium, and provide a cave or PVC pipe where the Siren can get completely out of sight.

Dim lighting by day followed by brighter lights at night may encourage daytime activity, but do this only if animal is feeding and otherwise adjusted to captivity.  Night-viewing bulbs may help to observe Sirens after dark.

Greater Sirens fare best at water temperatures of 70-76 F, but tolerate wider range.

I have kept Sirens on gravel, but a softer substrate, such as sand, is preferable. Avoid any substrate that will raise pH.


Minnows, shiners and other freshwater fish and earthworms should form the bulk of the diet.  Small crayfishes are a great favorite (I remove the claws for safety’s sake); crickets and other insects are also readily accepted.  An occasional pink mouse is fine, but do not rely heavily upon rodents.

Some individuals will take Reptomin and freeze-dried shrimp.

Further Reading

Mudpuppy Care

Video: Captive Greater Siren

The Greater Siren in North Carolina



Greater Siren Headshot image referenced from wikipedia and originally posted by Mokele


  1. avatar

    I Really enjoy your articles .. very good information and well written Frank

  2. avatar

    I have a great siren and I was wondering what kind of substrate to use. I’m currently using sand and I see him/or her trying to dig. Should I make the sand deeper or is there something better for me to use. Any other Siren care information would be great! Thanks!

    • avatar

      Hello Jill, Frank Indiviglio here.

      Thanks for your interest. Great to hear that you are keeping a siren; for some reason they are not popular but they are extremely interesting and we have much to learn, esp. as regards breeding.

      In the wild they like in mud-bottomed ponds, ditches, etc., but mud doesn’t work well in tanks. They do need a secure shelter (watch for nose rubbing on the screen top – if stressed by lack of hiding spot or a small tank, they will try to escape). I’m concerned that sand may be too abrasive – even a tiny cut can lead to an infection, which is difficult to treat. Sand may also be ingested with food, and can cause impactions. Smooth gravel is safer, but you’ll need to use rocks of a size that cannot be swallowed…black stones sold in aquarium stores as “river rocks” are ideal (let me know if you need a link to a supplier).

      Rocks will not allow for burrowing, but sirens will readily accept sections of PVC pipe as a shelter (PVC is safe, other plastics may not be); you can have a piece cut to a suitable length at most hardware stores. You can also use aquarium safe rocks (shale) of driftwood to make a cave, but you’ll need to silicone pieces together as the siren will move the pieces about otherwise. Plastic plants weighed down with fish-safe plant ties (avail at pet stores) can be used to line the bottom and create a sense of security as well (they like weed-choked habitats).

      Water quality and diet are the main concerns in captivity…check ammonia levels regularly, a provided a varied diet, esp. whole fishes and earthworms…please let me know if you have questions on this.

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

  3. avatar

    My husband and I received one of these beasties as a rescue animal. The original owner did not want her and wasn’t taking care of her. (We call her a ‘she’ randomly.) Her new home is a 70 gallon tank with two 55 gallon filters. We plan on setting up a sump for her soon. Just wanted to let you know we find her to be sweet natured. She allows us to touch her sides, which is great for moving her during water changes. We had to slowly nurse her back to health because the old owner wasn’t feeding her. She loves nightcrawlers, and will not eat red wigglers, Silversides, or pink mice. So far, she seems fine with other fish in her tank, unless they are boisterous and worm shaped (weather loaches). We have her on a sand substrate with silk plants, a pvc tube, and other large hideouts. She is 30″ long and a pleasure to own. Her name is Freckles because she has dark spots sprinkled along her body. Thanks and sorry for the long post. I just wanted to tell you that they aren’t all vicious.

    • avatar

      Hello Sandra

      Thanks for the most interesting post. I’ve known some that adjusted well, but have not run across any “picky eaters”. Sirens are not commonly kept or bred in captivity, so anything we learn is very useful…I’m very interested to hear how all goes; please keep me posted if you can.

      Nightcrawlers are fine as a staple, but I suggest trying some other fishes (minnows, shiners) and fresh water shrimp or prawn; calcium needs may not be met by worms alone. Try keeping the animal hungry for a time. If it’s not possible to induce the salamander to take a more varied diet, it would be best to set the nightcrawlers up so that they can feed before being used as a food source. Please see this article for details.

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

  4. avatar

    Hello, Sandra and Freckles again 🙂 we supplement her nightcrawlers with algae tabs and half-melted cubes of frozen foods like bloodworms. She now has 2 fishy companions that seem to make her happy. She was alone for a while and seemed to get bored. She is currently on barebottom because the sand we had got too dirty because she wouldn’t dig. She still has plenty of hides though. I’ve noticed that every once in a while something will startle her and she ends up on the floor. We’ve been using a clean pillow case for these occasions, as she is too big for anything else. She’s looking nice and healthy now; her gills are fluffy, her girth is better, and she’s always active, and she’s almost 36 inches now. She does use her tiny arms to try and assist her turns. She seems to play with our cat when the cat bats the side of her tank. Can’t think of anything else interesting at the moment, but she still remains sweet natured.

    • avatar

      Hi Sandra,

      Thanks for the update on your very interesting (and unique) siren. It would be a good idea to add a screen cover to the tank and secure it with cage clamps…. Some of the protective slime rubs off when the animal escapes, which can leave it open to bacterial/fungal infection.

      Best, Frank

  5. avatar


    Very interesting. I just captured a lesser siren – Siren intermedia nettingi in a trap that I made. I would like to observe it for a few months before releasing later this summer. I have it in a 10 gallon aquaria with a nice pump and filter unit. Substrate is small gravel. My question pertains to water changes – I am using distilled water and not tap water. Is one preferred over the other?

    • avatar


      Interesting…did you use an eel or minnow type trap?

      Do not use distilled water, as it may cause important salts/minerals to leach out of the animal via osmosis. Most tap water is fine if treated with instant de-chlorinating drops (sold for use with tropical fish); bottled spring water can also be used. Be careful with gravel…when feeding from the bottom, the siren may ingest gravel and suffer an impactionlarge river stones or finer substrates, as described in article are usually a better choice. please let me know if you need more info, best, Frank

  6. avatar

    Hey Frank, we use tap water with Reptisafe, a dechlorinator designed specifically for amphibians ans reptiles. It helps with their electrolyte balance 🙂 good luck 🙂

  7. avatar

    Hi.o have lesser siren(girl) for about 2 months.water conditions are good I feed her right but I just noticed 2 red bumps.one one head and one on middle body.tthey small, red bumps sticking out.what are that? Did you ever see something like that? Will it go away?

    • avatar

      Hello Pauline,

      Sorry for the delay…missed the post somehow; nice to hear you are interested in this species. I have not seen that on sirens…can range from parasite to small injury that is being walled-off, bacterial infection. Since most are wild caught, parasites can be expected…many are well-tolerated if the animal is in good health. Unfortunately, diagnosis treatment can be difficult..perhaps best to watch for now, but if condition seems to worsen let me know and I’ll check for experienced vets in your area, please keep me posted, frank

  8. avatar

    Hi Frank,

    We have two sirens (not sure how old they are or sex). They used to be great eaters, always eating their night crawlers and krill. However, one of them has stopped eating and has developed white blotches on its body. I researched bacterial infections in axolotls and they suggested Holtfreter’s salt solution and wondered that your thoughts were. Thanks for being such a great resource!

  9. avatar

    Hi Frank,

    We have two sirens (not sure how old they are or sex). They used to be great eaters, always eating their night crawlers and krill. However, one of them has stopped eating and has developed white blotches on its body. I researched bacterial infections in axolotls and they suggested Holtfreter’s salt solution and wondered that your thoughts were. Thanks for being such a great resource!

    • avatar

      Hello Emily,

      I thought I answered this …recall writing but do not see my response …sorry if it did not post. I’ve used methylene blue (article here) but am not experienced with H. solution…used often though, as I recall. best to split animals if that has not been done. Please let me know if you need more info on meth blue, or help in finding an experienced local vet. Pl keep me posted, best, Frank

  10. avatar

    Hi Frank,

    Thanks for your advice! I bought the methlyene blue. Should I follow the directions on the bottle? They are for fish and fish eggs. Do you have a dilution and soaking amount that we should try?

  11. avatar

    Hi. I got a little African side neck turtule as a gift. I put him together with lesser siren and albino closed frog.siren is acting “slow motion ” and not sweeming around… I worrie. Shout I give a turtule away? I love my siren. I want the best for her…it seams like putting a turtule is stressing her out..

    • avatar

      Hello Pauline,

      Yes , remove the turtle…it will stress the frog and siren, and will begin biting at them in time. Turtles also produce a great deal of ammonia with waste products, which is deadly to amphibians. That species gets quite large, needs UVB exposure and a high calcium diet…let me know if you need more info on care, best, Frank

  12. avatar

    HI. I give turtle to reptile pro store. I had him for 2 days. Siren and closed frog still not being them self’s. Not hunting… Slow…siren berly wants to do anything. They look the same(no skin changes or anything) all the fish are doing great.(2 angel, 2 tetras, Cory,spotted catfish,pletko, rope fish) water is 77 f, pH and ammonia normal. I don’t know…are they stressed… Or got salmonella from turtle? I heard turtle cary ssalmonella..

    • avatar


      All reptiles and amphibians probably carry Salmonella as a normal part of their gut flora…usually only causes a problem when they are sick from other causes, kept in unclean conditions, etc. With all those animals I’d check your ammonia regularly, make sure you do frequent partial water changes. Frog and siren will eventually try to eat most fish..cory and similar can become stuck in throats, due to spines. Best, frank

  13. avatar
    paulina sabatowicz

    Hi, me againiI think siren and frog my got bacteria infection or fungus…. There r tiny white spots around her left gills. Frog looks fine but it doesn’t… Is methane blue gonna help? Should I cut a dose by half? How long soaking?

  14. avatar

    Frank…thanks for this info. My husband and I are full time volunteers for our National Parks, seashores, forests etc, currently assigned to a Wildlife Refuge in SC. We are charged with the care and maintenance of a Siren. Yesterday, after returning to work from our 4 day weekend, I could not find the Siren anywhere in the tank….I found this strange because I can usually see some part of him, but I am new to this game and didn’t question it further, until this am when our Ranger returned from a day off and I questioned him about the Siren. He said he had not seen him either in his last day on (2days previously). We then attempted to find the Siren. My Ranger found him all right, on the floor behind the aquarium. I didn’t even know they could do that ! Thankfully, he was still alive and returned to the tank. We are hoping he won’t be to stressed out. My question is this: I have been feeding the Siren a large Pinky every couple of days…is this diet enough for him? Should he be receiving a more varied menu? The Siren is about 27 inches in length.

    • avatar

      Hi Jan,

      Yes, they wander at night and are escape artists, be sure to secure top with screen clips or as best suited for your tank. Keep an eye out for red areas on the skin…loss of the protective slime, coupled with minor abrasions, can lead to bacterial/fungal infections. Adding Stress Coat or a similar product may be useful, but not necessary if animal appears normal.

      They will scavange carcasses of mammals in the wild, perhaps take a small rodent that attempts a swim, but small whole animals are not regularly taken; they shouldn’t be given pinks often…maybe once every 6 weeks or so. Pinky-rich diets given to other amphibians and reptiles that have not evolved to feed solely upon mammals have led to liver disease, fat deposits in eye, kidney problems (White’s treefrogs, tiger salamanders, basilisks). Diet should be based on small whole fish (shiners, minnows best..goldfish ok on occasion but not often); earthworms, crayfish (I remove claws) if available, small whole shrimp on occasion. Large insects can also be offered..crickets, silkworms, roaches.

      Some will accept trout chow or commercial turtle pellets...both excellent food sources as well.

      Please keep me posted, enjoy and thanks for your work with NPS, frank

  15. avatar

    Thanks Frank….yesterday I kept a close eye on him. When I first arrived in the am I found him upside down, could see little hind legs. Two things….#1: I know Sirens do not have hind legs. # 2: I was scared he was gone. So I nudged him and he immediately started moving around. I then pulled a reptile book
    (well, 2 actually) and my husband and I feel pretty strongly it is a Congo Eel and not a Siren. Yesterday was a feeding day, but he would not eat. Played with his food, chomped on it and left it alone. I tried another fresher in the later afternoon and he judged it, moved it around, let it rest on top of his head, but did not eat. My husband noted a few scratches. I noted, when he was playing with the pinky, he only opened his mouth half way.

    Sorry it took me so long to respond to your request Frank: Here are the comments you requested.

    Since that above posting, the “Siren” had one feeding, and he did eat and was acting like his old self. As I only work on TH, FR,SAT (feeding day is Sat), I did not see him for a bit. The other volunteer reported to me that he seemed fine. When I returned that next Th, I found the lid to the aquarium open. The Eel was still there, but I was obviously concerned. I brought that fact to the attention of the volunteer. She knows the importance of leaving that lid down (especially now). She did not remember leaving the lid open, and I assumed she would pay more attention to that aspect. This week I was off on TH and returning Fr, immediately checked on our charge. I could not see him anywhere. The next day I looked again, enlisted the help of some other volunteers, moved the scenery around a bit…no Conger Eel. I questioned the other volunteer, said she had not seen him since Tuesday, but that she does not specifically look for him every day. A quick check with our boss revealed that he had not removed the Eel. It seems as if another escape has occurred, but the lids to the aquarium look intact. We have searched everywhere. Can you suggest some possible destinations? Thanks for your time Frank!

    • avatar


      It will most likely push beneath whatever cover is available, they do not climb, but no real way to hazard a guess as to location.

      Screen aquarium lids secured by lid clips are the only way to keep them contained…in time, they push against hinged lids and escape.

      You can read about the 3 amphiuma species here; click on species name for details.

      As mentioned, pinkies are not appropriate as a steady, long term diet. Care of amphiuma is well-established, and longevities of 20-30+ years are known, so I’m not sure why husbandry was not researched by folks primarily responsible for the animal…please feel free to have folks in charge post here for proper care info…they can email if professional whatever prevents posting on site (zoo folks often email rather than post, etc). Again, when appetite declines and animal appears ill, a vet exam is necessary if water quality (pH, ammonia levels) is as it should be. Please let me know if you need more info, best, Frank

  16. avatar

    Hi Frank, thanks for all of your informative posts, it has been a great learning experience for a former reptile phob.

    This morning, after 12 days, the Conger was again visible IN the tank. Last Saturday another volunteer and I had moved everything around in the tank looking (unsuccessfully) for him. So I don’t know what to think, if he was out or not. I assume he would not have been able to get back in?

    Either way I was glad to have him back. A new Ranger comes to work here next week or so, and I am going to share your information with her.


    • avatar

      Hello Jan,

      I would set the tank up differently, providing only 1 suitable hiding place, if finding/observing the animal is a problem. Let me know if you need info, best,. Frank

  17. avatar
    paulina sabatowicz

    My lesser siren I “shredding” her tail…like there are pieces missing from her tail…it seems to be healing now but will the end of her tail regrow? Why she is losing end of tail? She lives with 2 rope fish..clowed frog and 2 angels and 1pletco

    • avatar

      Hello paulina,

      Tails do re-grow, but infections can be dangerous…watch for red skin. Plecos have the odd habit of latching onto fishes that have thick mucus coverings, such as freshwater Stingrays, and consuming the mucus…this could be going on at night, and may damage siren’s skin as well.. Ropefish may bite off pieces at night also, and will attack the gills; clawed frogs will also pull off the gills in time. best to separate the siren, as the stress will also affect long term health.

      Check your ammonia levels also, as high levels will cause tissue to break down..you’d likely see other symptoms, but all the species you have put out quite a bit of ammonia. Please let me know if you need more info, best, frank

      Check amonia

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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