How to get ahead.......

[paris]

If you are a young tiger salamander larva looking to get ahead why not try CANNIBALISM?
Not only will you get A HEAD, but you will also get 2 arms, 2 legs, a tail and a torso! (

)


<font size="+1">ACT NOW SUPPLIES ARE LIMITED!!</font>*

<font color="ff0000">BEFORE</font>

<font color="0000ff">AFTER</font>

* <font size="-1">you only get so many siblings.....

</font>


DISCLAIMER:<font size="-2">the second picture is enlarged to scale-the scale being the silicone bead on this tank, this one has a little more than doubled its size in less than 2 weeks. during finals week i only fed them the cyclops-but luckily they ate them all(since i found out that cyclops were what killed my axolotls) i started out with 2 advanced tiger larvae and about 70 eggs-i now have 1 unhatched egg (going bad) and about 10 larvae! that's it-all the rest were eaten by this monster and the smaller cannibal-and the time that has elapsed between these pics is just 10 days! (at about 75F).</font>

<font color="ff0000">Odds in winning are 1 in 10</font>

 

[paris]

I wonder if you could take a correspondence course in cannibalism? here is a picture of the monster with a newly hatched larva next to it (note the naturalistic berber background)

to tell the truth i wasnt thinking the eggs were all going to hatch so quickly, so i hadnt planned on the necessity of preparing another tank for the 2 advanced ones.

 

[jesse]

ive heard that the morphology of canabalistic larvae is different. Is this true paris? are the adults morphology different too? it would be a great experiment to see what this cannibal turns out to be like

 

[paris]

yeah its true for the larvae, i cant remember if it carries over into adulthood-i believe it is covered well in 'the biology of amphibians'

 

[edward]

As I understand it the cannabalistic morph's development is triggered through population density (I'm going off memory here so I could be wrong) that includes multiple age classes or sizes.
There are some pictures of this form in Petranka's book.

Ed

 

[matthew]

Paris - what did you mean above by finding out that cyclops killed off your axolotls?

 

[jesse]

the cyclops can be farily large and can kill and eat small salamanders. THants why they are not really that recommended as a good food choice for small larvae

 

[jesse]

Hey paris, if you have any spare cannibalistic larvae, my home is always open to them

 

[tara]

ugh...I think this happened to my triturus as well. I figured the triturus who were living in their parent's tank were doing much better than the ones i was raising myself, because they were huge. I added the ones I had been keeping separate back into the parental tank...I have not seen them since but my two big guys keep growing and growing. stupid me.
T

 

[meghan]

(note the naturalistic berber background)
Paris...apparently because the setting is SO natural, it brings out the animal in it!

 

[sharon]

Sorry the new person here, maybe I missed out on a previous post?? How did you breed your tigers?

Sharon

 

[paris]

didnt breed em-went and got them from a pond-see post
http://www.caudata.org/forum/messages/13/15268.html?1084986285

 

[paris]

tara,
i am unsure of the reputation for triturus to eat their siblings, but the adults are good with their larvae (tend not to eat them i mean) sometimes its densities that drive cannibalism-one thing to note is that once a larva has been nipped by its siblings (again not necessarily a food item of choice in this situation-but more like "well HE LOOKED like a worm to me") then its energy that would otherwise go to growth must go into repair-and it will lag further behind the others and be smaller than the rest. certain species however are more prone to eating their own eggs, larva and siblings -even when they have the choice of different food. to note most cynops are in this category, i recently found 2 advanced larvae of japanese firebellies in the parents tank-this is easy to explain since the tank was very green i didnt get to see alot of what went on in there-but when i noticed they might be in breeding condition i poked my head in occasionally to look for eggs-since they are notorious for eating them-and never saw any-so that is why i am suprised to see the 2 i have-especially as i didnt have much they could have eaten in the tank with them (i would sometimes give live blackworms to the parents-but this food is sort of small for them) i am willing to bet that they had a few more siblings in there with them that helped to diversify their diet.

 

[richard]

One time ("in band camp"), I took an adult Axolotl out of his tank and set him in a bucket next to my bowl of babies... I woke up the next day and the huge adult was chilling in the tiny bowl with no more babies... I guess he saw them from his bucket and decided to jump across and get a snack in the middle of the night.

 

[jesse]

are you sure he jumped?

 

[tara]

Still I have a sneaking suspicion it is the large larva eating others. I have even seen him nipping at his(her/its) parents on more than one occasion. The adults are well fed, but that never stops them from snacking on the bloodworm/mysis shrimp I feed the larvae, they eat together and I have never once seen a parent attack a larvae. However, yesterday I did not feed the larvae. I came home today and my two smaller larvae had nips out of their tails (the smallest larvae doesn't even have a tail anymore - so he has been quarantined), BUT the largest one went unscathed. He is so EVIL. It also makes no sense because they are so well fed and so fat, there is all sorts of microlife in the tank so I figured that if they went a day without being fed they would still be able to scavenge. Clearly somebody did some scavenging.

 

[paris]

here is an interesting pic of the cannibals. i had put them in an ice cream bucket. now removed from their naturalistic berber background they appear to want to blend in with the white of the bucket. its a pretty drastic colour change -i can now see the gold sheen on their gills.

 

[tara]

Here are two links that provide info about this. Paris and I were discussing this just last night. I had a similar experience with Cynops orientalis larvae
http://pubs.nrc-cnrc.gc.ca/cgi-bin/rp/rp2_abst_e?cjz_z03-036_81_ns_nf_cjz4-03

http://www.indiana.edu/~pietsch/readout.html

 

[TJ]

Paris, you may find this info interesting:

ZOOLOGICAL SCIENCE 16: 303�E07 (1999) 16-2-21
Zoological Society of Japan

Faster Growth of Head Size of Pre-feeding Larvae in a Cannibalistic Population of the Salamander
Hynobius retardatus

Aya Nishihara-Takahashi*

Laboratory of Applied Zoology, Department of Agriculture,
Hokkaido University, Sapporo 060, Japan

ABSTRACT: Cannibalism is common in high density larval populations of Hynobius retardatus. Because cannibals are gape-limited, possessing a wider head (mouth) may be advantageous in these populations.
Field observations showed that the pre-feeding stage larvae were more vulnerable to cannibalism than feeding stage larvae in a high-density larval population. The data also showed that larvae with proportionally smaller head widths are more vulnerable to cannibalism than those with larger heads. Therefore, faster growth of head size during pre-feeding stage is predicted to be favored in a population with frequent cannibalism.
A laboratory comparison revealed that head growth (proportionate change in head width to body length) during the pre-feeding stage was greater in the larvae of a cannibalistic population than in those of a non-cannibalistic population. These results support the hypothesis that a wide head is an adaptation against
frequent cannibalism in larval H. retardatus.

 

[paris]

ok -well these is his aquatic graduation pics...that same big larvae posted up top-named hannibal- and in a few other spots has now become a land lubber.! he looks weird in the face still-as if he hasnt filled it out all the way yet -the next one to him in size is the one eyed one and its not showing any signs of leaving water.