Why would weight of ragworms increase over time at different salinities?

[Jakerm1995]

To provide some context for this question:

I have 4 seawater treatments at different salinities. At 50% seawater there was a 51% increase in weight over a one hour period. At 75% seawater there was a 26.9% increase in weight over 1hr. 100% seawater = 6.18% increase over 1hr. Finally at 125% water, there was a 7.25% decrease in weight over 1hr. I understand this has to do with osmolarity. The species in question are euryhaline osmoconformers, I have a very vague idea, but would very much appreciate some assistance in understanding what is happening here 😅 

Any help is welcomed and appreciated! Thanks for taking the time to read this post.

[exchemist]

1 hour ago, Jakerm1995 said:

To provide some context for this question:

I have 4 seawater treatments at different salinities. At 50% seawater there was a 51% increase in weight over a one hour period. At 75% seawater there was a 26.9% increase in weight over 1hr. 100% seawater = 6.18% increase over 1hr. Finally at 125% water, there was a 7.25% decrease in weight over 1hr. I understand this has to do with osmolarity. The species in question are euryhaline osmoconformers, I have a very vague idea, but would very much appreciate some assistance in understanding what is happening here 😅 

Any help is welcomed and appreciated! Thanks for taking the time to read this post.

What does 125% water mean? 

[Jakerm1995]

1 minute ago, exchemist said:

What does 125% water mean? 

125% Seawater* Sorry typo  I can't seem to edit it. Btw I am still yet to complete those calculations so I apologise for not following up your replies. 

[exchemist]

9 minutes ago, Jakerm1995 said:

125% Seawater* Sorry typo  I can't seem to edit it. Btw I am still yet to complete those calculations so I apologise for not following up your replies. 

How can you have 125% seawater? 

But, to give you a clue about what may be going on, it is common to see burst earthworms after heavy rain. Why do you think that might be?  

 

Edited March 21, 2022 by exchemist

[Jakerm1995]

15 minutes ago, exchemist said:

How can you have 125% seawater? 

But, to give you a clue about what may be going on, it is common to see burst earthworms after heavy rain. Why do you think that might be?  

 

It's just the salinity. I have posted a picture of the different seawater treatment concentrations, so you can sort of understand what I mean :'D I hope this helps. Thanks again for your help!

19 minutes ago, exchemist said:

How can you have 125% seawater? 

But, to give you a clue about what may be going on, it is common to see burst earthworms after heavy rain. Why do you think that might be?  

 

As for your earthworm comment, what do you mean by burst earthworms? Sorry for all my stupid questions 😅

[exchemist]

9 hours ago, Jakerm1995 said:

It's just the salinity. I have posted a picture of the different seawater treatment concentrations, so you can sort of understand what I mean :'D I hope this helps. Thanks again for your help!

As for your earthworm comment, what do you mean by burst earthworms? Sorry for all my stupid questions 😅

Aha, so it's seawater equivalent , i.e. in ionic strength, not real seawater.

Regarding the burst earthworms - and your expanding ragworms - If you have a more concentrated solution and a weaker one, either side of a membrane that allows water molecules to pass through, but not the ions,  what tends to happen? 

 

[Jakerm1995]

10 hours ago, exchemist said:

Aha, so it's seawater equivalent , i.e. in ionic strength, not real seawater.

Regarding the burst earthworms - and your expanding ragworms - If you have a more concentrated solution and a weaker one, either side of a membrane that allows water molecules to pass through, but not the ions,  what tends to happen? 

 

Hey, sorry for the delay. So to answer your question, I assume that it's just that water will pass through to the more concentrated solution from the weaker one? 

[exchemist]

3 hours ago, Jakerm1995 said:

Hey, sorry for the delay. So to answer your question, I assume that it's just that water will pass through to the more concentrated solution from the weaker one? 

Exactly. Water will flow to the more concentrated side from the more dilute side.

So if the membrane is the skin of a worm, and the ionic strength on the inside is approximately that of seawater, what will happen to the worm if it is placed in a solution with lower ion concentration? 

[Jakerm1995]

20 hours ago, exchemist said:

Exactly. Water will flow to the more concentrated side from the more dilute side.

So if the membrane is the skin of a worm, and the ionic strength on the inside is approximately that of seawater, what will happen to the worm if it is placed in a solution with lower ion concentration? 

Sorry again, busy days atm :'D Thanks again for all the help! The water will enter the worms cells through the skin and, thus, the worm will get bigger? Sorry if that sounds stupid ahah

[exchemist]

24 minutes ago, Jakerm1995 said:

Sorry again, busy days atm :'D Thanks again for all the help! The water will enter the worms cells through the skin and, thus, the worm will get bigger? Sorry if that sounds stupid ahah

Yes. And if, like an earthworm, it does not have very elastic skin, it will go pop eventually. But apparently (I did not know this) ragworms have elastic skin and can stretch without being damaged. Also it seems they can tolerate quite a significant dilution of their body fluids and still function. 

Does that explanation fit the data you have been given?

 

[Jakerm1995]

On 3/23/2022 at 8:56 PM, exchemist said:

Yes. And if, like an earthworm, it does not have very elastic skin, it will go pop eventually. But apparently (I did not know this) ragworms have elastic skin and can stretch without being damaged. Also it seems they can tolerate quite a significant dilution of their body fluids and still function. 

Does that explanation fit the data you have been given?

 

Hey, apologies yet again for the delay. I've had a friend moving in and also one staying with me. Little time to focus on my studies, which isn't good really considering my deadlines. This piece is due in tonight, so I am really going to focus now and get it done. That explanation fits yes, so I appreciate your help a lot. I may need some additional help on the maths side of things, if I ever meet you, I owe you beers for all the help! 

[exchemist]

2 hours ago, Jakerm1995 said:

Hey, apologies yet again for the delay. I've had a friend moving in and also one staying with me. Little time to focus on my studies, which isn't good really considering my deadlines. This piece is due in tonight, so I am really going to focus now and get it done. That explanation fits yes, so I appreciate your help a lot. I may need some additional help on the maths side of things, if I ever meet you, I owe you beers for all the help! 

Well it's 2235 in London, now and I'm tired after a 2hr choir rehearsal (performing Haydn's Creation on Saturday) so I'm off to bed. I think you've got the idea by the look of it now, so hope you manage to work the rest  of it out.