Does Light / Dark effect Tarantula's diurnal cycle?

[atraxrobustus]

Does light and dark effect a tarantula's diurnal cycle? I know that most tarantulas are nocturnal as a rule, but does light effect their diurnal cycle such as with some species in kingdom Animalia (e.g. hamsters, etc.) to a point of not providing regular light/dark cycles might cause adverse effects?

 

[EtienneN]

Maybe it plays a small role in environmental cues for rainy/dry seasons, but tarantulas don’t sleep and as such don’t have any circadian rhythms. They can be kept in total darkness and thrive.

 

[cold blood]

as a nocturnal animal, they have no such cycle "needs" and therefore no such need for sunlight.

 

[atraxrobustus]

as a nocturnal animal, they have no such cycle "needs" and therefore no such need for sunlight.

But, when we use the term "Nocturnal" that implies some sort of a diurnal (to the degree that they're at least less active in the presence of light) cycle, and thus would imply a circadian rhythm, from my understanding of it.

 

[EtienneN]

Tarantulas live in the dark. There really isn’t a term out there that describes an animal that prefers living in the darkness all the time, so not having that word, we borrow from common parlance and say ‘nocturnal’

 

[cold blood]

But, when we use the term "Nocturnal" that implies some sort of a diurnal (to the degree that they're at least less active in the presence of light) cycle, and thus would imply a circadian rhythm, from my understanding of it.

it's simply something avoided. Leave the lights off permanently and they simply stay out more. I haven't lit my t room in about 5 years now aside from the flashlight I carry.

 

[atraxrobustus]

it's simply something avoided. Leave the lights off permanently and they simply stay out more. I haven't lit my t room in about 5 years now aside from the flashlight I carry.

Great, so then sticking them in a closet certainly won't adversely effect their health. I was a bit concerned.

 

[cold blood]

Great, so then sticking them in a closet certainly won't adversely effect their health. I was a bit concerned.

Go for it...won't be an issue.

 

[atraxrobustus]

Go for it...won't be an issue.

Though there does appear to be a diurnal of a sort. see this: http://britishspiders.org.uk/bulletin/040508.pdf

 

[viper69]

Does light and dark effect a tarantula's diurnal cycle? I know that most tarantulas are nocturnal as a rule, but does light effect their diurnal cycle such as with some species in kingdom Animalia (e.g. hamsters, etc.) to a point of not providing regular light/dark cycles might cause adverse effects?

I don't think anyone has published a peer-reviewed study on this in the recent past. Most T papers I find regarding behavior and physiology are before 1980, usually 60s/70s.

HOWEVER, a group of scientists did publish an abstract from around 2008 or so, and likely a paper after, detailing they detected a very conserved protein (conserved in mammals too) involved in circadian rhythm in SCORPIONS.

Given how conserved this protein, and its family members are, I'm sure this protein is found in Ts.

 

[Smokehound714]

several male aphonopelma are known for being diurnal wanderers, the iodius group is an example.

 

[Feral]

Does light and dark effect a tarantula's diurnal cycle? I know that most tarantulas are nocturnal as a rule, but does light effect their diurnal cycle such as with some species in kingdom Animalia (e.g. hamsters, etc.) to a point of not providing regular light/dark cycles might cause adverse effects?

Most spiders have circadian rhythms, including tarantulas. And "nocturnal" is definitely the appropriate word for a spider who is most active at night, the terminology has nothing to do with the ability to sleep. (Also, how we define "sleep" and apply the definition(s) to vertebrates and invertebrates is a whole other thing.) In 2017 a Nobel prize was awarded to the dudes who discovered what exactly produces circadian rhythms. It was assumed it came from some sort of central nervous system structure. But nope, spoiler alert- it's genetic. It's encoded on a specific gene that then controls the accumulation or dispersal of certain conserved proteins to produce the "internal clock" effect. (Probably the same protein @viper69 was thinking of, I'm guessing.) The black widow/Lactrodectus species are one of the few spiders that have no discernible circadian rhythm, making them arrhythmic. A couple of years ago we discovered three species of trashline orbweavers/Cyclosa species who have the shortest circadian rhythm of any animal ever studied, only 17-19 hours. (Wow, that's insane!) Circadian rhythm for navigational orientation has been studied in wolf spiders/Lycosa species among others. Avicularia avicularia were studied and determined to be crepuscular, not nocturnal. Many tropical forest dwelling species are actually crepuscular, incidentally with more activity at the dusk interval than the dawn interval. These crepuscular circadian rhythms were found to be weaker overall than grassland and especially desert dwelling species, whose exposure to much stronger light strengthens the circadian rhythms. It's been shown that avoiding exposed diurnal activity by having a strong circadian rhythm is an important water conservation tactic in many species of arachnid, including Aphonopelma species. I could not find any studies or data on the circannual rhythm of tarantulas specifically, but we've seen anecdotal evidence of it in some species who seem to need certain seasonal cues to trigger breeding receptivity. Induction of diapause through changing of daylight length has been shown to occur in at least a few other arachnids.

 

[viper69]

Most spiders have circadian rhythms, including tarantulas. And "nocturnal" is definitely the appropriate word for a spider who is most active at night, the terminology has nothing to do with the ability to sleep. (Also, how we define "sleep" and apply the definition(s) to vertebrates and invertebrates is a whole other thing.) In 2017 a Nobel prize was awarded to the dudes who discovered what exactly produces circadian rhythms. It was assumed it came from some sort of central nervous system structure. But nope, spoiler alert- it's genetic. It's encoded on a specific gene that then controls the accumulation or dispersal of certain conserved proteins to produce the "internal clock" effect. (Probably the same protein @viper69 was thinking of, I'm guessing.) The black widow/Lactrodectus species are one of the few spiders that have no discernible circadian rhythm, making them arrhythmic. A couple of years ago we discovered three species of trashline orbweavers/Cyclosa species who have the shortest circadian rhythm of any animal ever studied, only 17-19 hours. (Wow, that's insane!) Circadian rhythm for navigational orientation has been studied in wolf spiders/Lycosa species among others. Avicularia avicularia were studied and determined to be crepuscular, not nocturnal. Many tropical forest dwelling species are actually crepuscular, incidentally with more activity at the dusk interval than the dawn interval. These crepuscular circadian rhythms were found to be weaker overall than grassland and especially desert dwelling species, whose exposure to much stronger light strengthens the circadian rhythms. It's been shown that avoiding exposed diurnal activity by having a strong circadian rhythm is an important water conservation tactic in many species of arachnid, including Aphonopelma species. I could not find any studies or data on the circannual rhythm of tarantulas specifically, but we've seen anecdotal evidence of it in some species who seem to need certain seasonal cues to trigger breeding receptivity. Induction of diapause through changing of daylight length has been shown to occur in at least a few other arachnids.

There are a number of different genes responsible for encoding proteins that all contribute to circadian rhythm.

I studied these in school.

 

[Feral]

Yes, I guess technically I could have expanded my explainantion and noted the period, timeless, and doubletime genes with their coorsponding proteins PER, TIM, and DBT working together. That would have been a more accurate way to say it I suppose, but was it needed? I wasn't trying to over complicate things, just to give enough useful information to clear up some of the misunderstandings and errors and hopefully give people enough solid information to base their own judgements on. I certainly wasn't saying you were wrong in your previous post, I was only building on to what you had already said.

 

[Colorado Ts]

as a nocturnal animal, they have no such cycle "needs" and therefore no such need for sunlight.

Just this last summer, I read a research paper on Aphonopelma hentzi. You are right, they have no light requirements, they seem to possess a preferred temperature range.

So in the evening, as the sunsets and it cools off outside, they become active once the ambient temperature falls within their preferred range. As the night progresses and it get colder, they seek out their burrows as the temperature dips below their preferred temperature range. Then as the sun comes up in the morning and temperatures rise, they will come out briefly as the warming temperatures pass through their preferred temperature range.

 

[Feral]

Just this last summer, I read a research paper on Aphonopelma hentzi. You are right, they have no light requirements, they seem to possess a preferred temperature range.

So in the evening, as the sunsets and it cools off outside, they become active once the ambient temperature falls within their preferred range. As the night progresses and it get colder, they seek out their burrows as the temperature dips below their preferred temperature range. Then as the sun comes up in the morning and temperatures rise, they will come out briefly as the warming temperatures pass through their preferred temperature range.

I'm trying to find and read the study you're talking about, I'm interested. Is this it?

https://jeb.biologists.org/content/218/7/977.abstract

 

[Colorado Ts]

I'm trying to find and read the study you're talking about, I'm interested. Is this it?

https://jeb.biologists.org/content/218/7/977.abstract

I do recall reviewing that article, or at least reading the title and abstract....but no I don't think that is it.

I recall reading a research paper, and there was a discussion or a portion of the paper that pursued a correlation between ambient temperature and activity levels in species A. hentzi.

The article is on my computer at school. I'll go through my files tomorrow and post the title once I've located it.

 

[Colorado Ts]

I've been going through my files this morning and I cannot find that research paper...It's either in a strange file, or more likely it was a paper that I came across while researching. I may have read the paper for its primary content, but I may not have possessed the credentials or clearance that would have allowed me to download and retain a copy in my files.

I do recall that I was looking for information and documentation as to whether incubation temperatures had any impact on the sex ratios of Aphonopelma hentzi hatchlings. Is there a mean temperature that would produce a roughly 50/50 mix of males and females, while a deviation from this mean would produce more females in one direction and more males in another? That was my most recent literary research and it was while locating and reading documentation that I came across the article.

I'll keep looking...Sorry.

 

[SonsofArachne]

I have blackout curtains in my T room. I do keep a corner of one curtain lifted so there is a day/night difference, but that is mostly for scorpions and some mantids that are in there. I do feed/water with the lights on, but it doesn't seem to bother most of them, and the ones it does bother are the photo sensitive types that would be bothered by a flashlight too.