Dragon Snake Study, Plus a Cute Icon!

Hey folks! Thought I would share my most recent study on the diet of Dragon snakes that led me to conclude that tadpoles and frogs should be fed as the staple of their diet, with fish serving as a supplement only. :slightly_smiling_face: It’s pretty “wordy” and unexciting to read, but I enjoy sharing as much information here as I can and figured I’d leave it here for those that may be curious about the contents of the study. I added a cute icon I drew of a Dragon Snake to make it more interesting, though. :sunglasses:

Comparative Analysis of Nutritional Data Between Frogs and Fish in the Diet of Xenodermus javanicus

Study objective: This project determined the effects of species-specific diets on the snake species known as the Dragon snake ( Xenodermus javanicus ), using data collected through clinical observations, to compare the nutritional data of each prey species and improve captive husbandry methods.

Design: The data for this study was collected over the course of two years, from July 1st of 2020 to July 2nd of 2022. The prey species used in the study included Green Tree frog ( Dryophytes cinereus) tadpoles and frogs, American Bullfrog ( Lithobates catesbeianus ) tadpoles and frogs, western mosquitofish ( Gambusia affinis ), and variable platyfish ( Xiphophorus variatus). The prey species were distributed equally in corresponding size, quantity, and frequency throughout the study.

Twelve subadult Dragon snakes were split into three groups for the study; Group A, Group B, and Group C, respectively. Group A was fed a diet consisting exclusively of Green Tree frog and American Bullfrog tadpoles and frogs. Group B was fed a diet consisting exclusively of western mosquitofish and variable platyfish. Group C was fed an equally mixed diet, in which half consisted of frogs and tadpoles, and the other half consisted of fish.

Direct comparison of dietary data was made using individual dietary data (IDS) and clinical observations that recorded five categories of individual and group data: body condition, feeding response, behavior, alertness, and overall health.

Main results : After six months, notable differences in alertness and behavior emerged in Group B. Snakes in Group A and Group C appeared much more alert than those in Group B. Additionally, snakes in both Group A and Group C appeared more inquisitive about their surroundings. Snakes in Group A were the most reactive to stimuli compared to those in Group B and Group C. Almost all snakes in Group B had reduced reactivity compared to snakes in Group A and Group C. Snakes in Group B did not exhibit the same extent of curious behaviors recorded in Group A and C, and generally remained stationary in one location of their enclosure.

After one year, differences in body condition and further reduced alertness began to emerge. Snakes in Group A had slightly improved body condition, while snakes in Group B had noticeably reduced body condition. In Group C, the body condition in all but one snake had reduced. Snakes in Group B and C also appeared more sluggish and less alert compared to those in Group A. After two years, significant differences in all five categories were recorded between the three groups. Snakes in Group A had superior body condition to those in Group B and C. Snakes in Group A had maintained a strong feeding response, whereas those in Group B had a much weaker response to food, with some refusing a few of their meals. Snakes in Group A were significantly more alert and reactive than those in Group B, and slightly more so than those in Group C. Snakes in Group A also appeared healthier overall compared to those in Group B and C.

Conclusions : Results suggest that frogs and tadpoles are more nutritionally beneficial for Xenodermus javanicus , whereas fish do not meet the nutritional needs of the species. To improve captive husbandry and care, it is concluded that frogs and tadpoles should be fed as a staple of the diet of X. javanicus , and fish should only serve as a supplement to their diet.


It is sad that I still see people selling dragon snakes saying they can be switched to mice. Lord knows those animals probably died in their new homes.


It is incredibly sad. Their bodies are not designed to eat mice – it would be like trying to say you can switch a Kingsnake from eating mice to eating turnips, or that a human could be switched to eating glass or metal. It’s so upsetting.


Kudos to you @creaturesofnightshade for keeping up with the study. I know it was not fun to watch differences emerge, especially with Group B. Of course that’s how science processes, but it’s not necessarily pleasant in the moment. I assume that you now have all of your Dragon Snakes on the diet you’ve determined to be best for them. I’m curious as to whether you have noticed any positive changes as of yet in the Group B & Group C individuals who showed negative responses on their diets for purposes of the study. I hope they’ll make up the ground they gave up for the sake of their species. Being ectothermic, I know it’ll take them time if it happens. Have you noticed anything yet?


Question for you Nightshade -

Did you consider the presence of thiaminase in these fish species and account for it with any attempt at supplementation? Yes, I know that convention holds that these species do not have thiaminase, but reality is that they do have it, just in lower concentrations than in goldfish and the like. As such, there is the potential for long-term side-effect due to slow bioaccumulation of the enzyme, especially when dealing with an animal like Xenodermus that tend to have a very gracile body structure


Just occurred to me that I’m using your care guide in my research on this species! Appreciate the resource and the study you’ve done to help these thrive in captivity!


Yes, those in Group B and C are now on a diet of tadpoles and frogs exclusively. I am also adding supplements to their water (both the dragon snake’s and the tadpoles/frogs) to help them recover as quick as possible. They are already behaving more as I would expect a healthy dragon snake to – more alert, active, and curious. They definitely have more energy. I anticipate their body condition will improve relatively quickly. They should be at optimal condition within the next 6 months. :slightly_smiling_face:

Yes, I definitely think thiaminase is a major contributing factor. I wanted to add that to the study, but because I didn’t formally evaluate thiaminase levels (as I did not have the means to do so), I omitted it due to lack of evidence. I do hypothesize that thiaminase has a lot to do with the lack of nutritional benefit when feeding fish, even those that are considered to have a “safe” amount of thiaminase. Perhaps safe for other species, but for dragon snakes, not so much.