Lab Report: Food Behaviourism in Japanese Red Belly Newts
Abstract
The current experiment sought to determine the food of choice by Japanese Red Belly Newts. Fifteen Japanese Red Belly Newts were introduced into three sets of tanks. Food was introduced into the tanks in the first tank (control group) was given blood warms while in the other two tanks, beef hearts, blood worms, and crickets were introduced. We found out that salamanders become very active, aggressive, and territorial when it came to securing food for themselves in the tank. At the initial stages before realizing any food was added into the tank, the salamanders were quite calm and subdued. However, after some time, when the salamanders realized that their favourite food had been introduced into the tank, they acted upon it. This, in turn, alerted the others in the tank to be alert and fight for the food. The results showed in total, four beef heart, two bloodworms and one cricket were consumed.
Introduction
Feeding Japanese Red Belly Newts 2-3 times weekly is sufficient to ensure their survival, growth and development. Their common diet includes suitably sized prey items, including bloodworms (frozen or fresh), earthworms, maggots, shrimp, insect larvae as well as slugs. In every feeding session, 3 or 4 prey items are enough for every Japanese Red Belly Newt (Wake & Deban, 2000). Care for Japanese Red Belly Newts includes feeding them properly, and it does involve their food choices. In the current experiment, I am concerned about learning which of the food is the most ideal for these amphibians by deducing observations when feeding them on different kinds of food.
Though my interests are expansive, I have always remained fascinated by the sight, feeding and behavior of newts and salamanders. My fascination in newts and salamanders began when I was a child. I once asked by parents if I could keep and breed as many species as I could, but they always denied me the opportunity because my little sister could not stand them. I started breeding them secretly at the age 14 in a small tank behind our house. My focus on their husbandry and conservation grew sharper when I visited the zoo for the first time. In time, I wrote an article to document and share my experience with the rest of the world. The passage of the last decade has not dulled my eagerness for these captivating amphibians, and I can propose them to both beginning and advanced herp enthusiasts.
The declining numbers of these amphibians around the world is also a course of concern for any herp keeper; it is different in my case. There is a need to collect information on the numbers, means of feeding and educate the public on the need to rescue Japanese Red Belly Newts and other amphibians. Many species are well shielded by law in the United States of America (USA) and in the United Kingdom (UK) as opposed to many other places around the world; this needs to change. There are various well-organized conservation efforts, some using volunteers and some full-time employees.
Newts are impeccably suited to aquariums with plenty of live plants, and remarkable displays that are easily arranged. Plants aid to ensure the water quality is high, and the multiplex environments they create enhances life for both the amphibians and newt-owner (Wake, 2009). Most amphibians are known to be docile creatures, but Japanese Red Belly Newts are different. They are always nosing about for food, surveying, and connecting with tank-mates. They even swim to the side of the aquarium in anticipation for food when one enters the room to feed them.
The current experiment involved observation of 15 newts in their environment (tanks). In tank one, containing newts serving as the control group where served only bloodworms, which is their food of choice. The newts in second and third tanks were served beef hearts, blood worms, and crickets so as to establish which type of food they preferred over the alternatives served. In each case, only one piece of food was given to control over consumption of the food liked by the newts. Observations were done for twenty-five minutes in all the cases. The central hypothesis that we sought to test is whether the salamanders were to prefer crickets over beef hearts and blood worms
The experiment was conducted in the university laboratory in which three tanks were set up. Tank one served the control tank while the other two served as our experimental tanks. After some consultations and extensive reading of previously done studies, we found out that the preferred foods for the Japanese Red Belly Salamanders are blood worms, small crickets, and beef heart. To monitor food aggression and territoriality, we rated salamander behavior from a scale of 1-10 in regards to the aggressive behavior shown during feeding time. We used Excel 2010 plotting the plot the graph of salamander aggression against eating.
We had a total of 15 Japanese Red Belly Salamanders in three tanks. In the first tank, the newts acted as our control group. They were fed on bloodworms only. This is the food that considered as their food of choice in the natural habitat. The salamanders in other two tanks were served beef hearts, blood worms, and crickets in turns to determine the type of food they preferred over the alternatives given. In each feed, a single piece of food was offered to void over consumption by the salamanders. Each tank was observed for 25 minutes.
Observations
In tank two, there was a lot less movement witnessed initially when food was placed in the tank with the salamanders. When the movement began, it was very vigorous. Once they realized the food was in the tank, they began to fight over the food. One of the salamanders ate the dead cricket after 9:25 minutes. Three other salamanders engaged in a fierce fight after 14:40 minutes had already elapsed with one salamander on top of the beef heart while the other two salamanders attacked it to get to the food.
After 15:50 minutes, another bloodworm was introduced into the tank and after 16:59 minutes, another cricket was added into the tank. After twenty minutes 20 minutes, the smallest salamander in the tank ate the beef heart; thirty seconds later, two of the salamanders began to fight over the blood worm. The fighting was vigorous. The bigger salamanders attacked the smallest salamanders over the food. At this time, four salamanders were fighting over the food. At the 24th minute, one salamander out of the four that were fighting reigned and ate the bloodworm. After 24 and 45 seconds, the biggest salamander in the tank snatched away a beef heart that the smallest salamander had (unsuccessfully) tucked away. In to total, one cricket, two beef hearts and one blood worm were eaten in tank two.
In tanks three, a similar approach was deployed. However, a different set of salamanders were observed. At 0:00 minutes, a beef heart, blood worm, and cricket introduced into the tank. The amphibians remained unaware the presence of food for nearly ten minutes. At the tenth minute, the newts realized that food had been introduced into the tank after which movement became more apparent and vigorous. Twenty-five seconds later the newts fiercely began fighting over the beef heart. After a fierce fight, two of the salamanders gave up and left the beef heart for only one salamander. At 11:25 minutes, more fighting resumes but no salamander actively attempts to reach out for the food.
After quarter had elapsed, there was nothing of significance to record. The salamanders seemed to be disinterested in the food. This compelled a repeat of step at this stage to aid in capturing more observations. At 0:00 minutes, additional food was introduced into the tank. The newts were swimming in the tank just like normal. After 3:28 minutes, the bloodworm added was eaten, with no significant fight over it. Two minutes later, the salamanders showed renewed interest in the food that has been introduced into the tank. Two of the salamanders approached the beef heart, but no action was witnessed until the seventh minute. After 7 minutes, three of the salamanders approached the blood worm; one was exceedingly rambunctious and fought with its competitor subduing it. Being rambunctious had its payoff; the most boisterous salamander won the beef heart and ate it.
After 15 minutes had elapsed, the salamanders once again calmed down. No salamander took an interest in the crickets placed inside the tank. The beef heart once again was the most popular choice among the salamanders, with blood worms coming in second. In total, two beef heart consumed, one bloodworm and zero crickets were consumed.
In the control tank, the salamanders were only fed blood worms; which is their food of choice according to documents examined earlier. The salamanders in the control tank did not eat the blood worms provided for them, even after the fact that they were not fed for three days.
Results and Discussions
After 25 minutes of observations of the newts in the three tanks, we found that the salamanders prefer to eat the beef heart over any of the foods provided within their tanks. We rated aggressive behavior when it came to food on a scale of 1-10. We found out that salamanders become very active, aggressive, and territorial when it came to securing food for themselves. At the initial stages before realizing any food was added into the tank, the salamanders were quite calm and subdued. However, after some time, when the salamanders realized that their favourite food had been introduced into the tank, they acted upon it. This, in turn, alerted the others in the tank to be alert and fight for the food. When additional food was added, it was noted that the salamanders’ activity increased exponentially, and they even actively engaged in fighting. It was observed that the salamanders ultimately preferred to eat the beef heart over the blood worms and crickets that also were provided for them to consume. Comparatively, in our control experiment, the newts did not consume the blood worms even after saying without food for three days. This was interpreted to mean that blood worms are not the favorite food for the salamanders. This affirms that our hypothesis was refuted. More evidence can be drawn from the two tanks in which beef heart was consumed highest followed by crickets as attested in figure one and two.
Figure one shows the variations in the first and the second feeding time. The salamanders, during the first feeding session, were more active for very few minutes, as attested by the increase in X-axis (time) and the latency in the Y-axis (Percentage of Salamander eating). Contrary, during the second feeding session, the salamanders fought for the food more actively as attested by the steep rise in the percentage of salamanders (Y-axis) eating the food in a short period.
In figure two, the percentage of salamanders feeding during the first and the second sessions also varies. The percentage of salamanders that ate in the second session is twice that fed in the first session.
Conclusion
Our hypothesis that the salamanders would prefer the crickets over the beef heart and the blood worms was not supported. From our observations, the salamanders much preferred the beef heart even over the bloodworm, which was equally surprising as that, is their supposed food of choice.
Recommendations
Future experiments will need to have more similar sets of tanks to aid in in comparisons of the results. This will aid in drawing of more conclusive results.
References
Wake, D. B., & Deban, S. M. (2000). Terrestrial feeding in salamanders.Feeding: Form, Function, and Evolution in Tetrapod Vertebrates. Academic Press, San Diego, CA, 95-116.
Wake, D. B. (2009). What salamanders have taught us about evolution?Annu. Rev. Ecol. Evol. Syst., 40, 333-352.
