Why did my urchin die so fast??

45reef

New Member
Just as observation, I found that my Pencil Urchin LOVES Romaine lettuce. I put it in on a clip for my Yellow Tang, and the urchin always seems to find it & latch on to get his fill. I;ve had him for almost a year and he;s doing great.
 

lion_crazz

Active Member
Originally Posted by noodlemmy
I think someone asked the salt question before and I forgot to answer... sorry! I use Instant Ocean.
Emily
Yes, that was me Emily. This is probably just an odd coincidence, but Instant Ocean is supposedly very harmful to sea urchins. It has been theoried that sea urchin's mortality rate in water mixed with Instant Ocean is close to 90%.
"The mortality of sea urchins in water made from Instant Ocean is about 90%, and in water made from Coralife salt the mortality rate is about 80%....The two salts, Instant Ocean and Coralife, that made artificial seawater with the lowest survivorship of larvae consistently have heavy metals concentrations hundreds to hundreds of thousands times those found in natural seawater."
 

bang guy

Moderator
The mortality rate of Urchin Larvae and the Mortality rate of adult Urchins are totally unrelated.
noodlemmy - you really need to buy your own test kits. I recommend ALK, Calcium, Phosphate, and Nitrate. ALK and Calcium are critical tests in my opinion.
Ammonia, PH, and Magnesium are useful for problem solving but don't need to be tested if everything is doing well.
 

lion_crazz

Active Member
Originally Posted by Bang Guy
The mortality rate of Urchin Larvae and the Mortality rate of adult Urchins are totally unrelated.
noodlemmy - you really need to buy your own test kits. I recommend ALK, Calcium, Phosphate, and Nitrate. ALK and Calcium are critical tests in my opinion.
Ammonia, PH, and Magnesium are useful for problem solving but don't need to be tested if everything is doing well.
You don't think they could be related at all? I know adult sea urchins can withstand the much higher levels better than larvae, but don't you think it affects them negatively at all?
 

ophiura

Active Member
Inability to adapt to synthetic salt mixes has been postulated as a possible reason why seastars, in particular, have such poor survival rates within the first month of introduction to our systems.
Larval urchins have long been favored for toxicity and development studies in part because of their ease of culture and also because of their similarity - very very close similarity - to human development in its early stages.
In general the study of larval urchins may only be of limited relevance to adult urchins, but it is worth noting. However, I would imagine a lot of people have success keeping the urchins in varioius salt mixes. I would imagine that Instant Ocean is commonly used in scientific labs culturing urchins for such studies.
I would say there still might be some correlation with synthetic salt mixes in general being an issue, but these case I have NO doubt about whatsoever. The specific gravity in general is fatally low, and with no acclimation, there was little hope.
 

lion_crazz

Active Member
Yep, that is what I thought Ophiura. Thanks
I was not claiming that this was the case here, I just thought it was an odd coincidence that it happened to Instant Ocean salt as well.
 
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