Home | Amphibians | A Huge, Aggressive Salamander – the Natural History and Care of the Greater Siren

A Huge, Aggressive Salamander – the Natural History and Care of the Greater Siren

Greater SirenHello, Frank Indiviglio here.  Salamanders 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 laticauda.  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

Please write in with your questions and comments. 


Thanks, until next time,

Frank Indiviglio

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

    Hello Mike, Frank Indiviglio here.

    Thanks for the kind words, much appreciated.

    Best regards, Frank Indiviglio.

  3. 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!

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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?

  10. 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

  11. 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 :)

  12. avatar

    Hi Sandra,

    Thanks…Reptisafe is a good choice, Best, Frank

  13. 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?

  14. 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

  15. 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!

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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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