Autum Molt Cycle.

[Crabber85]

I've been keeping track of my group's molt cycles for about five years now and a pattern emerged they tend to do the majority if not all of their molting between Sept-30th and about the second week of April and this six month long session of back to back molts really kicks off right around the Autumnal equinox and starts to wind down close to the Vernal equinox and during this time of molting my tank gets very very quiet.

For about two or three weeks before they start they eat and drink like little piggies which was my first real que as to what was going on and then they disappeared underground with only one or two being visible on the surface at any given time and that has been the normal pattern for a very long time.

[wodesorel]

Makes sense so they'll be up for the breeding season.

[Crabber85]

@wodesorel, yeah that does make sense its hard to believe I've been at this most of my life and hadn't made the correlation sooner.

For the longest I just thought that the shortened daylight and cooler temps that fall and winter brings were the major triggers for causing them to enter a state of hibernation so to speak but then I started keeping track of the lunar cycles and so for forth and realized that it was the equinox's signaling them apparently even indoors and having their tanks light with artificial sunlight for as close to twelve hours a day as I can manage they can still feel when the earth is on a certain point in its axis.

That got me to thinking that maybe hermitcrabs are kind of like birds and they can sense the magnetic fluctuations that coincide with the vernal and autumnal equinox's and that triggers them into a season of back to back molting and also serves as a trigger to slow down their molt frequency for the warmer months which would be breeding season.

I'm still looking into all the science using other crustacean cousins of the land hermitcrab who have had more time in research done on them to see if my assumptions are correct or just in my head.lol

[wodesorel]

Mine can sense incoming storms, so I've no doubt that being indoors doesn't cut them off completely with whatever has been hardwired into them for survival.

The only downside is there isn't a lot of literature on critters closely related to hermits that also live on land. If it's not a cash crop, it's not studied!

[Crabber85]

It is definitely sad that more legitimate research hasn't been done and that's a question I've seen a lot when others with less knowledge want to be absolutely sure that what they are being told is backed up with valid science and so they immediately ask for a link to any thing written by someone with a degree on the subject and my response has always been "The information we have available to us now has mostly been learned through the observations of hermitcrab owners past and present and is being presented as a collective knowledge base mostly based on incidental or anecdotal evidence because hermitcrabs and most other crustaceans are considered to be insects by the academic world not much real hard scientific research has been done on them."

I'm of the opinion that we only know about thirty percent of all the information on land hermit crabs because of a lack of actual research and because of that new information will still likely be forthcoming over the next twenty years as we slowly discover more about them the deeper we get into the topic.

[wodesorel]

Insects are better studied!

I think the problems comes down to the fact they don't fit into a category. Too land for the marine sciences, not an insect so of no interest to entomologists. They're sort of out there on their own with no real "value" to people studying specific biomes, since they cross boundaries.

[Crabber85]

Yeah insects are better studied so I guess that's a bad analogy to be using.lol

I can't agree with you more hermitcrabs are largely overlooked by the sciences and its not fair they need to be taken more seriously but in all reality it will probably continue to fall to folks like us to do the hard work and document our findings for the future generations of crabbing enthusiasts and that makes communities like this invaluable resources because for as far as I dare see ahead we are all we have.

[Laurie LeAnn]

Mine molt around Jan-Feb..before it was Dec- Jan.. now this mating..that was in the summer..now we're hitting winter..

[Crab_Coalition]

Mine molt around Jan-Feb..before it was Dec- Jan.. now this mating..that was in the summer..now we're hitting winter..

If any of this is true, then how does each tank condition play ba part ij that?

What does a tightly sealed humid tank impact a mesh tank and how much outside air they receive?

Does this behavior occur despite each tank condition? I think to do a true test study there would need to be a study on tank or crabitat impact including the region where the crab reside because based on what I have read on this forum about crab behavior, or molting, etc there seems to be many variables and adaptation to tank conditions cannot be discarded because , at their essence, hermit crabs are one of the ultimate survivors in an adapt-or-die scenario which is their reality every day of their life.

Would love to read feedback on this and thus broaden my own understanding as well as maybe provide another voice to the issue.

[Crabber85]

It's been well documented that lunar cycles do have a direct effect and even trigger wild land hermit crabs into molting and a portion of said lunar cycles are lunar eclipses and equinoxes which seem to have some impact on crustaceans including the land hermit crab and being in a controlled enclosure doesn't necessarily totally negate the effects that these events have on them.

You can read about the research that was done in this area in a book called the biology of the land crab it was done some thirty odd years ago but the science is still valid.

Some species of land hermit crab come from equatorial regions which basically means they don't naturally experience the shortened days of fall and winter because the days and nights are always the same year round on the equator so something else must trigger them like full moons and astronomically speaking a full moon actually exerts more gravitational force on the earth which is why the tides are higher and lower on average than on any other night and we know the moon plays a significant role in triggering molts so it must be that hermitcrabs of any species whether in a controlled environment or not can feel the enhanced gravitational effect of the full moon add to that the fact that when the norther hemisphere is entering the fall the planet is actually rotating back on its axis causing the norther hemisphere to come closer to the moon and further away from the sun which causes the cooler and then colder weather as we reach the zenith of our backward rotation in the dead of winter.

This all adds up to an enhanced gravitational effect from the moon on the earth which is why full moons that occur during the winter have an exaggerated effect on the tides versus during the summer months where their effect is still strong but not quite so as in the winter months.

I guess what I'm saying is there are so many variables that contribute to initiating a molt season and we only know of just a few that its really hard to narrow it down to just one.

[wodesorel]

The really interesting thing is that hermits in Germany will produce zoea year round, while in North America it's only a summer thing. We've talked about it before here and the only thing we could think of was that it had something to do with barometric pressures since they're on the same latitude as many of us crabbers over here, so the daylight would be exactly the same.

[Crab_Coalition]

It's been well documented that lunar cycles do have a direct effect and even trigger wild land hermit crabs into molting and a portion of said lunar cycles are lunar eclipses and equinoxes which seem to have some impact on crustaceans including the land hermit crab and being in a controlled enclosure doesn't necessarily totally negate the effects that these events have on them.

You can read about the research that was done in this area in a book called the biology of the land crab it was done some thirty odd years ago but the science is still valid.

Some species of land hermit crab come from equatorial regions which basically means they don't naturally experience the shortened days of fall and winter because the days and nights are always the same year round on the equator so something else must trigger them like full moons and astronomically speaking a full moon actually exerts more gravitational force on the earth which is why the tides are higher and lower on average than on any other night and we know the moon plays a significant role in triggering molts so it must be that hermitcrabs of any species whether in a controlled environment or not can feel the enhanced gravitational effect of the full moon add to that the fact that when the norther hemisphere is entering the fall the planet is actually rotating back on its axis causing the norther hemisphere to come closer to the moon and further away from the sun which causes the cooler and then colder weather as we reach the zenith of our backward rotation in the dead of winter.

This all adds up to an enhanced gravitational effect from the moon on the earth which is why full moons that occur during the winter have an exaggerated effect on the tides versus during the summer months where their effect is still strong but not quite so as in the winter months.

I guess what I'm saying is there are so many variables that contribute to initiating a molt season and we only know of just a few that its really hard to narrow it down to just one.

I will definite look into grabbing that book or reading up on it more. The reason for my question is because I had crabs that remained molting for months and this was during the summer season so if what you or the book is saying is true, then my crabs will only stay on the surface another another week, maybe 2 or even less before they ALL or a majority of them go back down again?

Interesting theory that should definitely be talked about. Thank you.

[Crabber85]

This is something that I have been studying for years and it seems that there are more than a dozen possible triggers for causing hermitcrabs to initiate a molt season, some think that these triggers are associated with the hermitcrabs biological programming which does make sense because this set of genetics based rules has been passed down over a thousand generations of land hermit crabs as an adaptation to enhance their survival by ensuring that they only do the majority of their molting when breeding season has passed.

Breeding season in the wild is from April to October and can be marked by the mass migrations of hermitcrabs and other land crabs marching to the sea to mate and spawn which in some species of hermitcrabs is the only time each year that they even see a beach because a large portion of the known species live inland for most of the year.

What gets me is when we get in hermitcrab species from regions below the Equator they seem to adapt to the routine or schedule that's already been established in our tanks by our older hermitcrabs and for me my PP's are the schedule setters so my Ecuadorians who experience all of their seasons in reverse our winter is their summer seem to do just exactly as the PP's and molt around the same time so this suggests that maybe the scent associated with the molt inducing hormone also plays a large role in triggering mass molts between species regardless of what their wild molting schedules happened to be.

Like I said this topic is so complicated that right now we can't really say for sure which one thing is the predominate trigger.

[mlakers]

My theory on this involves the rainy season vs. the dry season. Hurricane season ends in October and the Caribbean gets much drier. The risk of flooded sand from storms goes way down so being below the surface to molt after October is safer and more comfortable. Similarly, during the rainy season the humidity would be up and mass migrations would be safer/easier on the gills (and they know to head for the trees when the barometric pressure indicates an impending storm).

[Crabber85]

@mlakers, that's a very interesting theory because I have noticed during the warmer muggy southern summer months that my group tends to be topside a lot and then when the weather starts to change getting cooler and drier they seem to all go down around the same time so what your saying makes a lot of sense.

Here in the South its not uncommon to have our humidity in the upper nineties for weeks on end just because of the way the jet stream seems to funnel all of this excess moisture out of the Gulf of Mexico right across my state and with that extra moisture comes lots of thunder storms and this past summer was one of the wettest ones we've had on record, we had rainy weather all day every day for what seemed like two or three months during the spring and summer and my group was extremely active because the air was so saturated outside the house that it was directly effecting the humidity levels in the house and therefor the humidity of my enclosure I even had to open up an extra spot in the plastic wrap on my lid to allow more air flow into the enclosure because the humidity was staying in the upper nineties on its own.

My mother even made the statement that the floor in the house felt wet because of all the rain we'd had, I mean the air in the house was actually sticky from all the moisture.