Urchin ID please

[jabberwock]

How do I tell if it is happy?

 

[Timfish]

Only way to tell if an urchin is happy is if it's leaving trails on the rock that have been scoured clean of all algae. Well, if it's spawning too, so two ways.

 

[OldRed1]

Only way to tell if an urchin is happy is if it's leaving trails on the rock that have been scoured clean of all algae. Well, if it's spawning too, so two ways.

There is some research to suggest that urchins spawn during periods of stress, so that may not be the best method to assess an urchin's happiness.

 

[Timfish]

There is some research to suggest that urchins spawn during periods of stress, so that may not be the best method to assess an urchin's happiness.

Trails of bare rock are a better indicator. Can you post links to the research? Water changes can certainly stimulate urchins to spawn but I have yet so see an urchin spawn after shipping or being moved to a new tank.

 

[OldRed1]

Trails of bare rock are a better indicator. Can you post links to the research? Water changes can certainly stimulate urchins to spawn but I have yet so see an urchin spawn after shipping or being moved to a new tank.

I should not have been so cavalier with the word "research," perhaps evidence would be a better word.

From researchers at Stanford: "Sea urchins are used as indicator organisms in public aquariums to determine if the system is functioning properly. This is because they are very "picky" about water quality. If the water is contaminated, the sea urchins will be the first to show signs of stress, spines laying down or falling off....A dying sea urchin will often spawn out and rot out, causing the others in the tank to spawn and die as well."

From an Urchin breeder: Stimulating urchins to spawn via stress is a viable way to collect sperm from males and eggs from females.

 

[jabberwock]

Thanks ya'll! Helpful tid bits of knowledge for me.

 

[jabberwock]

I have had it for 3 days. It is moving around its home base rock and reacted to water change and light this evening. So far so good.

 

[OldRed1]

I have had it for 3 days. It is moving around its home base rock and reacted to water change and light this evening. So far so good.

Another thought: From my own experience observing the creatures in my tank, I get a sense of their “routines,” in terms of their behaviors, patterns of movement, and so on.

With your own urchin, no doubt you will pick up on similar routines. If you observe your urchin suddenly deviating from these routines, then that’s a good indicator that something in your tank has changed. Not necessarily something bad, mind you. But it’s a good signal to check in on things.

 

[Timfish]

I should not have been so cavalier with the word "research," perhaps evidence would be a better word.

From researchers at Stanford: "Sea urchins are used as indicator organisms in public aquariums to determine if the system is functioning properly. This is because they are very "picky" about water quality. If the water is contaminated, the sea urchins will be the first to show signs of stress, spines laying down or falling off....A dying sea urchin will often spawn out and rot out, causing the others in the tank to spawn and die as well."

From an Urchin breeder: Stimulating urchins to spawn via stress is a viable way to collect sperm from males and eggs from females.

Sorry, but do you have less extreme examples of stress causing spawning than physically picking up an urchin and shaking it ? I certainly wouldn't consider a 5% or 10% water change as a source of stress for urchins, especially as spawning with water changes occurs only infrequently.

The laying down and especially dropping of spines certainly is an indicator of a stressed urchin. But with just one urchin in a system it could be disease, an injury in shipping, old age or lack of food. I can certainly see in a large aquarium having a group of urchins all react the same at the same time as an excellent indicator behavior and have used that myself in my systems wher I have multiple urchins. But far more frequently whith multiple urchins I only see one do poorly while the rest continue to thrive. With just one urchin there's has to be some other indicator for me to consider urchin spawning something other than "happy"

 

[OldRed1]

Sorry, but do you have less extreme examples of stress causing spawning than physically picking up an urchin and shaking it ? I certainly wouldn't consider a 5% or 10% water change as a source of stress for urchins, especially as spawning with water changes occurs only infrequently.

The laying down and especially dropping of spines certainly is an indicator of a stressed urchin. But with just one urchin in a system it could be disease, an injury in shipping, old age or lack of food. I can certainly see in a large aquarium having a group of urchins all react the same at the same time as an excellent indicator behavior and have used that myself in my systems wher I have multiple urchins. But far more frequently whith multiple urchins I only see one do poorly while the rest continue to thrive. With just one urchin there's has to be some other indicator for me to consider urchin spawning something other than "happy"

You make several great points, no question. And I agree the ‘evidence’ presented is on the extreme side. From an evolutionary standpoint, it makes sense that urchins might spawn in response to stress: the parent might die, but the species will continue.

As an aside, this thread made me research more about stimulated urchin spawning than I ever thought I would. It is disturbing how urchins are forced to spawn via injections of potassium chloride.