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European Legislation

Axolotl Colony axolotl at indiana.edu
Wed Feb 18 16:46:21 EST 2004

Hello Neil,
I've read through the regulations in the .pdf file you mention in your  
email, and I've written down some of my thoughts (below).  It seems  
that our axolotls don't fit too nicely into several of their  
regulations.  I hope this helps.
Please do not hesitate to contact me if you have any more questions or  

Jill Gresens, ALAT
Assistant Director
Indiana University Axolotl Colony
Phone: 812-855-8260
Fax: 812-856-1838 (Attn: Axolotl)

_  _  _
In section 2.2, paragraph 2:  "In animals used for breeding, a state of  
near winter torpor...should be simulated...Restoration of  
pre-hibernation environmental conditions will induce activity and the  
mating behaviour".
This does NOT apply to axolotls!  If you have trouble mating them, you  
can alter their photoperiod (short-days then long-days to induce them  
to mate) but they should not be cooled to induce torpor, then warmed.   
We don't do any of these things for mating; we just put the animals  
together overnight.  No chemical or environmental manipulation is used.

Section 4.1: Social Behaviour: "...group housing of amphibians is  
Yes, axolotls may be housed in groups.  That said, when males are  
group-housed, they don't seem to be able to tell that they are housed  
with other males, so they will both deposit spermatophores regularly.   
This eventually causes a situation where a male is unable to produce  
spermatophores for a female (because he hasn't had a chance to  
replenish).  This reduces overall mating success, which is why we have  
discontinued the practice.  All of our males are housed individually  
now.  If you are going to group-house your males, we recommend that you  
isolate them for a few weeks prior to presenting them with a mate.   
This will allow the male to replenish his sperm supply, as well as  
become more sensitized to the presence of another animal in the tank  
with him.

Section 4.1: Social Behaviour: "Another function of holding amphibians  
in groups is to minimize fear responses"
This is true, but regular (gentle) handling will also help minimize  
fear.  Axolotls can become quite accustomed to being touched (and even  
stroked) when handled regularly.

Section 4.2 Environmental Enrichment
Floating plastic plants on the surface of the water and providing pvc  
pipes work very well, and are easily cleaned.  These things also help  
prevent group-housed animals from chewing on each other.

In section 4.3.1 they indicate that "airstones are not required for  
Xenopus", but they do not state any other exemptions from the policy.
They should not be required for axolotls or any other type of fully  
aquatic salamander species, either.  Their skin is delicate enough that  
I've seen skin-damage result from long-term aeration.  We do not filter  
or aerate our animals' water and we do not have trouble; they receive  
enough oxygen naturally through their gills/skin/lungs.  You can tell  
if an axolotl is oxygen-deprived by how often it surfaces to 'gulp' at  
the air.  If you see this happening more than every few minutes, you  
may consider ways to further oxygenate the water.  Otherwise, I don't  
recommend using air-lines.

Table 2: Minimum Space requirements for aquatic urodeles
We individually house our males in round plastic (food-grade) bowls.   
21.5cm diameter, 12cm deep.  The bowls hold approx. 2.5 liters of  
water. Water is replaced and the bowls are cleaned daily.  Our females  
are group-housed in larger containers: 26cm x 46cm and 14cm deep.
When kept at 15-22C, axolotls are quite sedentary animals, and will not  
move very much regardless of how much space they're given.  We  
frequently do a demonstration where 2 axolotls are placed side-by-side:  
1 in a 10-gallon tank, 1 in a small bowl.  Both animals always remain  
relatively still throughout the demo...the point being that the animal  
is just as 'happy' in the bowl as the 10-gallon tank.  Typically  
axolotls that move around alot are under stress from either poor  
water-quality, or from low oxygen content in their water.  When kept at  
warmer temperatures, axolotls can be more active and thus require more  
tank-space.  However, warmer water invites bacterial growth, and (if  
too warm) causes stress on the animals.
When looking at ideal housing situations for axolotls, always consider  
breeding and appetite. Our animals breed regularly, and eat well.   
Animals under stress do not do either.

Section 4.4 Feeding:  "Daily feeding is not advisable for adult  
animals, but once to three times weekly to satiation at each feeding is  
We recommend that adult axololts be feed small, daily meals.  Females  
especially need to be well-fed in order to have enough nutrients for  
adequate egg production.  Feeding weekly is too infrequent and will  
negatively impact health and spawning capability.  We recommend  
skipping at most 2 days between feedings.

On Wednesday, February 18, 2004, at 10:16  AM, Neil Yates wrote:

> Dear All   We need your help to try and modify European proposed  
> changes to cage sizes for Axolotls . The proposals are for a minimum  
> water surface area of 5000 sq cm and minimum depth of 20 cm for an  
> axolotl plus an additional 850 sq cm for each additional animal. This  
> is an increase of >5 times our current tank surface area and almost  
> twice the depth! We use Marine Biotech cages in a gentle circulating  
> system. The Axolotls appear quite happy and are breeding very well.  
> They give no indication that they need a bigger cage, apparently  
> waiting until food comes to them and just hanging around enjoying  
> themselves. We have had zero mortality in over 2.5 yrs. At least a 50%  
> fertilisation rate, indicating the general health of the animals.    
> Therefore:
> What size cages do you use?
> Why do you feel these are adequate from a welfare perspective - how do  
> they meet the animals needs?   If  I can obtain any additional support  
> to say that Axolotl welfare requirements have been met with smaller  
> cage sizes than those proposed, the draft cage sizes may be amended.   
> Can you help - please forward comments to me for collation.   DEADLINE  
> Friday 20 Feb 04   Many thanks
> Neil Yates & Andrew Johnson
> http://www.coe.int/T/E/Legal_affairs/Legal_co-operation/ 
> Biological_safety,_use_of_animals/Laboratory_animals/ 
> GT%20123%20_2001_%201%20E%20Amphibians%20final%20DRAFT.pdf
>     Neil Yates
> Director BMSU
> University of Nottingham
> Medical School
> Queens Medical Centre
> Nottingham
> NG7 2 UH
> Tel (0115) 970 9356
Jill Gresens
IU Axolotl Colony


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