Belly colour development in Italian alpines

[froggy]

I have recently reared a large number of larvae of this species through metamorphosis. The diet has been about 80-90% BBS, with the rest comprising bloodworm and Daphnia, but all the morphs have yellow bellies with no hint of orange - even at 2 months post metamorphosis (see attached photo). Post morphing, aquatic juveniles have had bloodworm, earthworm, hoglice and whiteworm, while terrestrial juvies have had earthworm, whiteworm, springtails and crickets gutloaded with carotenoids. None of the animals have developed orange bellies.

Any idea what has gone wrong here?

C

 

[rethgar]

apuanus or inexpectatus? I assume the parent animals are a more normal (brighter)coluration...

I remember reading an article about alpine newt courtship techniques in low light conditions where visual cues are used less depending on light levels but don't remember anything being passed on to offspring.... so irrelevant (sorry!) Interesting article though :happy:

 

[froggy]

I'm not sure about the parents - Mark A bred them, so if he sees this maybe he can say what their bellies are like.

C

 

[Molch]

Huh...I don't really know why yours wouldn't be more orange.... mine are about the same age of yours. Their bellies started getting orange around the time they reduced their gills and their color has deepened after morphing.

One main difference is that I did not feed BBS past the first half of their larval development. I found that I had some deaths while feeding BBS, so I stopped those. As older larvae, they ate primarily Daphnia magna, with some whiteworms and chopped earthworms thrown in. Around metamorphosis, I also got blackworms, and they ate lots of those right around morphing, with chopped earthworms and Daphnia thrown in....

there are individual differences in belly color, however: some are deep orange, others a bit paler.

one wonders if factors other than diet play a role as well, e.g, genetics, temperature, size at morphing - I dunno...

 

[Azhael]

Hey, Chris. If i´m not mistaken the original parental group have red bellies. It´s strange that with a diet so rich in crustaceans they didn´t develop a richer color. Mine have the same yellow but then again mire were raised mostly on whiteworms and earthworms.
The most critical time for belly coloration is at the beginning of the development of the juvenile coloration, when the pigmentation in the belly is barely starting to appear. Perhaps they received less carotenes in that period? Mind you, with carotenes still in the diet, even after that period some color should have appeared.

Molch, there´s good indication that genetics play a role too, although the diet is certainly the primary and prerequisite factor. The genetics affect the brightness by means of influencing the ammount of xantophores. A yellow coloration is a clear sign of insufficient carotenes in the diet, nothing to do with genetics, in principle. If riboflavins have accumulated there´s no reason for carotenes to have not, except for a lack of them.

 

[Mark]

The parents have orange bellies, not a deep orange, just a light gold. Last years offspring that I kept (same as Azhael's batch) started off with yellow bellies which are now as orange as the parents. I have one of this year's (same as Chris') about to morph so I'll let you know what belly colour it develops on morphing. I think they will darken with time.

 

[froggy]

Thanks for all the comments. Forgot to say before, these are apuanus (inexpectatus is now a synonym on apuanus, anyway, I believe).
Well, there has been no reduction the amount of carotenoids available around metamorphosis. Lots of brine shrimp still, although bloodworms have made up more of the diet. Even so, I would have expected at least some more orange...

As they start to take on morph colouration the bellies are first of all a peachy colour and then go bright yellow. I'll let you know how they develop in the coming months, but I don't have high hopes for orange bellies! Next time I rear larvae, I will try feeding more Daphnia and see if that makes a difference...shame it's hard to culture in the soft water we have here....

Incidentally, those morphs look beautiful, Molch! I will show them to mine and hope it inspires them

C

 

[rethgar]

I knew the apuanus and inexpectatus sub species were the source of debate I.e. the same dub species separated by geographical area but didn't know if the genetics had been proven yet.
I will be interested to see how and if the colouration develops, keep us posted.

 

[Mark]

Chris, I checked the one I have from your batch this morning and it has a pale yellow belly too. It still has small gills but it's not far from morphing. I don't imagine it will develop an orange belly before it does. It ate mainly pond sweepings so it's had a very natural diet rich in daphnia etc.

This photo shows the belly colour of the parent animals - it's not red. And now the juveniles who started with yellow bellies last year have a very similar orange colouration.

I'll keep you posted.

 

[caleb]

Don't forget that the invertebrates have to accumulate carotenoids too (they come originally from plant sources) so some Daphnia or shrimp may be more carotenoid rich than others.

I know of one breeder who visits particular ponds to collect Daphnia that are especially red, and swears that this gives better newt colour.

Most of my juveniles come out slightly less orange than the animals in the original post, even when fed mostly on Daphnia in their larval stage. The stock they come from had bright red bellies.

The reddest alpines I've ever had were some cyreni that had a couple of months feeding almost exclusively on wild-caught gammarus at two years old. They were somewhere between orange and red, but the colour faded gradually over the years to something similar to Mark's picture.

 

[Molch]

it may not just be a question of whether they had carotenes in the diet, but also of how well they can absorb them. The latter could depend on other substances or conditions ... who knows? There seems to be a lot we have no clue about...

...could be a fascinating research project for a grad student somewhere.

 

[froggy]

I'm not too concerned as I know it doesn't seem to have any health impacts, but it's just odd that there doesn't seem to be even the vaguest hint of red! The Daphnia these ate were fed Spirulina powder, which is high in carotenoids, and the BBS were always freshly hatched nauplii with full yolk sacks, so I would have expected at least slight colouration. The Hypselotriton orientalis larvae that are growing up under the same regime seen to be developing red bellies, although it's quite hard to be certain at the moment.

I will make sure that they get carotenoids as juveniles, if I can, and see how that goes.

Mark - how quickly do your animals mature?

C

 

[fabian]

I will make sure that they get carotenoids as juveniles, if I can, and see how that goes.

C

Hi,
the best source for carotenoids in my experoence are gammarus, as Caleb posted above. I once turned a half grown pyrrhogaster with yellow body to a good orange/ red in two month by only feeding gammarus to him. My apuanus often have the same belly colouration as yours and start to get more orange if they are big enough to catch gammarus.
Greetz
Fabian

 

[Mark]

Mark - how quickly do your animals mature?

If well fed it takes just over a year from morphing for them to be mature enough to breed. They will breed even before they are fully grown. In my experience breeding always happens in the spring (March/April) so you are looking at spring 2013.

 

[Azhael]

Mark, i realize now i was thinking about one individual Alan had. It can be seen here, and it has a deep red:
Mesotriton alpestris apuanus
However, the other newt just below is very yellow indeed.

Gammarus really are superb in producing a deep red color in caudates. As Caleb says, their diets are also relevant, but still, they seem to produce better results than other crustaceans. My first, and so far only, I.a.cyreni seen in the wild had a deep red belly, just as bright as any H.orientalis. The trough he inhabited is full of Rivulogammarus. When i have a chance to go back there i´ll see if i can find others and check what their belly coloration is.

 

[Tudor]

Hi,
what means BBS?
And why don't you try to feed them whit defrosted Artemia?
Regards

 

[froggy]

BBS = Baby Brine Shrimp and refers to newly hatched Artemia nauplii. I have tried froen foods, but they only really start eating these close to metamorphosis. I will give the frozen Artemia a go - do you use frozen adult Artemia?

Thanks

C

 

[evut]

Can I also add a question about culturing and feeding Gammarus. I have looked them up and it seems that culturing these should be fairly simple but they can't be fed in planted tanks because they'll eat the plants...is that true?

 

[froggy]

They seem to be only culturable in outdoors tubs that stay quite cool. In small containers indoors they tend either to die quickly or not breed. They are only really a problem in planted tanks if the plants are not growing vigorously or you add huge numbers of shrimp at once. The other problem with them, as Morg will attest, is that ones that shrimp often escape newts or newts don't bother hnting for them if easier foods are available. This can lead to infestations that are difficult to eradicate. The shrimp will feed on eggs and young larvae and will also feed on food meant for the newts.

In my experience, the only newts that were any good at catching them were stream dwellers like Pachytriton (escpecially) and Paramesotriton. Other genera will eat them but aren't all that keen. Perhaps the frozen Gammarus that are available would work, though...

 

[Tudor]

BBS = Baby Brine Shrimp and refers to newly hatched Artemia nauplii. I have tried froen foods, but they only really start eating these close to metamorphosis. I will give the frozen Artemia a go - do you use frozen adult Artemia?

Thanks

C

Ok, Now I understand :happy:
Yes, I feed my newts with adult defrosted Artemia a week or two after they hatch (depend on how rapid they grow). Usually, they are able to eat a hole brine shrimp, or at least pieces of it. The nauplii (or BBS - I learn a new term -) are free of beta carotene, and is normal to be like this. Beta carotene are taken from the algae (like Cladophora, Chlorella, Scenedesmus etc) and just the adults Artemia have such a pigment because they feed with algae for weeks.
This is the reason that firs meal after the hatching is made of Cyclops and not Artemia nauplii. The Cyclops, even are carnivorous, have already beta carotene because they pray upon small species of Daphnia . Daphnia have beta carotene (because of the algae) which is transfered to Cyclops and the Cyclops are eaten by newts larvae. In this way, beta carotene are transferred to newts larvae from an early stage and at metamorphosis the amount of pigment is already enough to give the red belly.
This is the way I do.
Is not necessary the best way, but it works :happy: