Oxygen and Color

[Flippers]

H. rubra in anoxic conditions; brightness, chroma, red

I've been researching the Opae Ula and I came across an academic source, https://academic.oup.com/jcb/article/34/5/647/2547889, which highlights the results of decades of testing on wild-caught Opae Ulas. In the section, Chromatosomal Properties of H. rubra under Environmental Extrenes, the authors detail the differences in shrimp who have experienced anoxia, or an absence of oxygen. The study found that "significant differences were identified in chromosomal properties under many of the tested environmental extremes, such as brightness and chroma for H. rubra under anoxic conditions ... the overall "red" area fraction did statistically decrease after anoxia exposure" (653)

This study claims that a shrimp lacking oxygen will not be "red". Assuming this is true, and assuming that shrimp need high levels of oxygen to survive, should tanks have bubblers? Should we have more plants?

[Super Jess]

That is a really interesting study you linked. Thanks for sharing it!

I did note that all "shrimp were housed in separate 38 l aquaria under common conditions, including salinities maintained at 15‰, no circulating water or feeding, and minimal light exposure...baskets of porous volcanic rock to provide shelter as well as surface area for grazing on algae and microbes." So basically they were kept in the conditions that we maintain using the Mustafa Method.

To induce anoxia, "shrimp were...transferred to an anoxic environment (created by N2 bubbling) for 24 hours." So this is different from the control environment. I'm not sure what naturally occurring conditions would create an anoxic environment like that. Maybe someone can weigh in?

Edited to say: I wonder if some shrimp take more than 24 hours to acclimate and regain their color after a change in conditions like that? I wonder how low the oxygen got?

[Sasquatch]

Thanks for sharing the article! Interesting they had reproduction under conditions similar to the Mustafa method... hint hint

I was surprised the shrimp were stressed at only 90 degrees Fahrenheit I thought they would tolerate heat better being from Hawaii... better buy a fan for the summer haha

It also sounds like shrimp color is partly genetic. That’s good news for Mustafas orange shrimp program guaranteed to work!

[Flippers]

That is a really interesting study you linked. Thanks for sharing it!

I did note that all "shrimp were housed in separate 38 l aquaria under common conditions, including salinities maintained at 15‰, no circulating water or feeding, and minimal light exposure...baskets of porous volcanic rock to provide shelter as well as surface area for grazing on algae and microbes." So basically they were kept in the conditions that we maintain using the Mustafa Method.

I also noted that it was very similar to the methods described on this site!!

To induce anoxia, "shrimp were...transferred to an anoxic environment (created by N2 bubbling) for 24 hours." So this is different from the control environment. I'm not sure what naturally occurring conditions would create an anoxic environment like that. Maybe someone can weigh in?

Edited to say: I wonder if some shrimp take more than 24 hours to acclimate and regain their color after a change in conditions like that? I wonder how low the oxygen got?

I know that with betta fish we are advised to leave space between the lid and water line to allow for oxygen at the top...in addition to this, filters are recommended for all tropical fish as they not only cycle water but allow for a flow of constant oxygen. I'm wondering the correlation between additional oxygen and bright colors... I imagine that with the (underground) tide and the (relatively) large surface area of the pools, the wild Opae Ulas receive plenty of oxygen.

I was surprised the shrimp were stressed at only 90 degrees Fahrenheit I thought they would tolerate heat better being from Hawaii... better buy a fan for the summer haha

I was also surprised by this! I guess that water heats up a lot more slowly than air, so the temperatures in the water never have the opportunity to hit 90º before dark cools them again. Just a theory... Or, since heat rises, the Opae retreat to the bottom of the pools when it's warm?

It also sounds like shrimp color is partly genetic. That’s good news for Mustafas orange shrimp program guaranteed to work!

Yes, very exciting!

[crittersni]

I put a bubbler in my tank. I kinked the tube with rubber bands to keep the flow minimal so it doesn't overwhelm them. There are often a few hanging by it. They sometimes seem startled if hit by a bubble. Other times it seems like they're playing with it.

More have seemed more orange, but I still have a mix of colorless, and the orange ones go back and forth. Haven't really seen red yet, nor have they all been orange at the same time.

I had read (on this site?) that they like temps between 55 and 85. My A/C died during a recent heat wave, and I was concerned about them until air was restored. I bought a thermometer. Water approached 80, and they were swimming like crazy. PetSmart told me that frantic swimming is common in fish in overheated water. I put ice cubes in ziplock bags and floated them in the tank, as if I were adjusting the temp for new fish. I also prayed a lot! It brought the temperature and the swim speed down. The situation (fortunately) ended well.

[Mustafa]

So basically they were kept in the conditions that we maintain using the Mustafa Method.

Thanks for sharing the article! Interesting they had reproduction under conditions similar to the Mustafa method... hint hint

That's not a coincidence. Scott (Scott Santos whose lab we're talking about here...where the study originated) and I were in quite frequent email contact back then and he inquired about how I was keeping and breeding my shrimp. If I remember correctly he had powerhead filters in his tank back then and wasn't getting much if any reproduction. I told him to take the filters out, perform no water changes, and basically leave the shrimp alone, with some other details such as salinity etc., that I also share with everyone here. Shortly after he started seeing lots of reproduction. Scott is a great guy. He's moved on to other projects mostly, but he's always still willing to discuss issues surrounding these shrimp with me.

[Flippers]

So basically they were kept in the conditions that we maintain using the Mustafa Method.

Thanks for sharing the article! Interesting they had reproduction under conditions similar to the Mustafa method... hint hint

That's not a coincidence. Scott (Scott Santos whose lab we're talking about here...where the study originated) and I were in quite frequent email contact back then and he inquired about how I was keeping and breeding my shrimp. If I remember correctly he had powerhead filters in his tank back then and wasn't getting much if any reproduction. I told him to take the filters out, perform no water changes, and basically leave the shrimp alone, with some other details such as salinity etc., that I also share with everyone here. Shortly after he started seeing lots of reproduction. Scott is a great guy. He's moved on to other projects mostly, but he's always still willing to discuss issues surrounding these shrimp with me.

That's great! I wonder how many of the authors whose work I'm reading you know...

[Varanus]

This study claims that a shrimp lacking oxygen will not be "red". Assuming this is true, and assuming that shrimp need high levels of oxygen to survive, should tanks have bubblers? Should we have more plants?

I think not, given they seem so adapted to thrive in low oxygen environments they definitely have no need for high levels of oxygen.

[Flippers]

This study claims that a shrimp lacking oxygen will not be "red". Assuming this is true, and assuming that shrimp need high levels of oxygen to survive, should tanks have bubblers? Should we have more plants?

I think not, given they seem so adapted to thrive in low oxygen environments they definitely have no need for high levels of oxygen.

Hmmm... Low oxygen in an enclosed environment may have a different effect. Or perhaps it's not the absence of oxygen, but rather the introduction of N2 bubbling that stressed them into turning pale.