Small Talk

The great shrimp experiment

August 14th, 2015

Not much is known about the Hawaiian red shrimp, opae `ula, but I’m excited to say I’m taking part in a scientific study to learn more about these fascinating critters.

Annette and me

Annette and me

At work, I met a woman named Annette Tagawa, a state aquatic biologist. She co-authored a book about the shrimp and the anchialine ponds they live in. (Click here to read that blog.)

We discussed our mutual enjoyment of opae `ula, and she and her co-author Mike Yamamoto invited me to volunteer in their continuing study of the crustaceans. I’m so happy to be asked!

I already have two tanks – a ten gallon and a five gallon. My batch originates from Hawaii Island (the original shrimp were purchased from Fuku Bonsai, when David Fukumoto still sold them.)

My 10 gallon.

My 10 gallon.

A berried shrimp in my 10 gallon.

A berried shrimp in my 10 gallon.

Mike (the shrimp team leader) asked me to take home a batch he harvested out of a pool in Ewa. I am to separate them into different color strains and observe their reproductive cycles.

Ewa opae `ula

Ewa opae `ula

"We are curious about the different color variations found among opae `ula in Oahu sinkholes. We do know that Hawaii Island and Maui opae `ula are mostly red, while Oahu opae `ula are often clear or banded, with a few other color forms, such as red, white, yellow, and orange. We think that part of the reason is the habitat: the black lava substrate of the Maui and Hawaii Island anchialine pools vs. the light colored limestone of Oahu sinkholes. Diet could also be a factor," he explains.

"Finally, there is the question about the influence genetics plays on the inheritance of color in these shrimp. We know next to nothing about this. Will white opae `ula produce only white young? Will red and white banded opae `ula produce clear and red young? I'm sure it will turn out to be much more complex than this, but the only way we can find answers is start with these simple questions," he finishes.

The task is to make observations regarding the Kona and Oahu opae `ula, particularly differences in behavior, breeding, and feeding between these two groups.

Freshly caught Ewa shrimp, pale from stress.

Freshly caught Ewa shrimp, pale from stress.

Annette brought me the shrimp, and they were all clear from the stress. "Like many aquatic animals, when they are stressed, they lose their normal coloration. The process of being caught from their tank or pool, transported in small containers, and maintained in unfamiliar surroundings have no doubt stressed them. In a bare tank, or in a tank with light colored substrate, they can also appear faded," Mike says.

I’ve enlisted Olivia in my hobby. She likes it, and likes doing things with me. (It’s mutual.) We set up a shrimp home and we're excited about being amateur scientists.

New shrimp bucket for the experiment.

New shrimp bucket for the experiment.

While I think this whole study is cool, one of the really fun side benefits is that the team will include her name as a contributor when it files a report on this. Maybe she’ll be doing science experiments for homework at that point, and if so, I should hope she gets an A on it!

Posted in child, pets | 7 Comments »

7 Responses to “The great shrimp experiment”

  1. Erika Enge:

    Diane, I was HOPING the "shrimp" in your headline referred to opae‘ula! I can't say I'm anywhere as deep into the topic as you are, but I've at least got more than just my toe in the brackish, anchialine pond of fascination with them.
    Thanks to your counsel, my handful of shrimpies appear to be thriving in their home within my home.
    It's just so calming to divert my eyes from the computer screen and watch them for a few minutes. Thank you!


  2. Ocean Lover:

    We've had ours in a vase for over 10 years easy! I know Annette......SUPER NICE girl!


  3. Diane Ako:

    Erika- I'm excited you're into this!!


  4. Kimo:

    Diane, I began my small opae'ula tanks a little less than a year ago and have been fascinated with these little guys. They started breeding in May, and my interest has picked up even more. I bought all the opae (at different times) from a small pet shop in Kapalama, so I'm assuming they're from the same population -- wherever that is. I have a 10-gallon on the kitchen counter, which receives a strong dose of late afternoon sunlight from the west-facing windows across the room. The rest of the day, the sunlight is indirect. This is the most successful tank, with recently born juveniles outnumbering the adults. I have a 5-gallon on my desktop, right next to a south-facing window. This colony is relatively new so no breeding yet. I have a 5-gallon and a 10-gallon (partially filled 18-gallon tank) in one of the bedrooms, next to a south-facing window. This 5-gallon is the oldest tank. I've seen a couple of berried females and a couple of tiny juveniles, so I think they've been breeding in this tank. This 10-gallon colony is relatively new and currently cycling through the diatom stage of ugly brown algae. I have a 2.5-gallon tank close to the west-facing windows. This is the only seawater+bottled water (1:1) tank in the collection. Anyway, re their color: I've noticed that the colony in the 2.5-gallon is the reddest of all. The red is bright and quite solid. The opae in the two 5-gallons are the next reddest, and the opae in the older 10-gallon are close behind. The opae in the new 10-gallon are dark brown, apparently reflecting the diatoms they're feeding on. Based on this very informal and unscientific observation, my guess is that color may be a function of degree of exposure to sunlight and diet. (Type of salt water may be a factor, too.) I'm sure other variables such as DNA impact color, but I haven't been able to observe this. Thus, I'm happy to learn about your study. I hope you'll keep us updated on what's happening. Mahalo for covering this topic!


  5. Lynell:

    You're so lucky you have huge aquariums! I just have 2 glass tiles with about a dozen in each.
    Thanks for the info on color. I thought the white ones were the girls. I have one tile that has reproduced after 2 years but the other (4 years now) are all just friends. And I added some that I got from a friend but no little ones.

    Hope you add frequent updates!


  6. Diane Ako:

    I'm so happy all y'all are excited about opae too!


  7. Duction:

    Nice article you have here, have you any updates on the breeding of selective colours and markings? I'm very interested in these shrimp too 🙂


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