Rearing System for Captive Breeding of Bobtailed Pygmy Squid

by: Richard Hilgers

This story has a convoluted beginning. It explains how I got involved in the design, manufacture and installation of a pygmy squid rearing system at the University of Wisconsin, Madison. You may find it fun reading, plus the pictures are interesting, too.  It's not every day we reef keepers talk about or even think about rearing squid in captivity. Yet, as you'll find out, this pygmy squid has been bred in captivity for quit some time. The story begins with an e-mail from my friend Anthony Calfo, author, coral propagator, speaker and all around nice guy.

In January of 2004, Anthony contacted me by forwarding a copy of his reply to an e-mail he received from Rob Toonen of Hawaii.  Rob is a research scientist at the University of Hawaii, author of several reef aquarium articles and, I found out later, also an all around nice guy.

Two professors at the Department of Medical Microbiology and Immunology, University of Hawaii, asked Rob to use his contacts in the aquarium industry to see if anyone knew of someone in Madison, WI with the ability to design, manufacture and install a system capable of housing the pygmy squid, Euprymna scolopes.  I'm not sure how many of Rob's contacts he e-mailed but one of them was my friend Anthony Calfo.  Anthony replied to Rob's e-mail and suggested I might be capable of the task.

When the e-mail came in, I read Anthony's reply and quickly scrolled down to read Rob's original message.  He talked about two professors who had accepted positions at the University of Wisconsin, Madison, to teach and continue their joint research on Euprymna scolopes, a pygmy squid. Excited, I immediately e-mailed Rob and he returned my e-mail indicating he would introduce me, via e-mail, to Professors Ned Ruby and Margaret McFall-Ngai.

On January 15, 2004, I received the first e-mail from Professor Ruby. My excitement grew exponentially. He and Professor McFall-Ngai were doing joint research on the pigmy squid's symbiosis with a luminous bacterium, Vibrio fischeri. After e-mailing back and forth for a couple of days it became clear to Ned and Margaret that the best way to convey their needs to me was through direct contact. I'd have to go to Hawaii to see first hand what they were currently using to hold and propagate the squid and talk to them directly about the needs of the squid. They offered me a round trip ticket to Hawaii and four nights hotel accommodations at a Waikiki Beach hotel. Less than a week later I was onboard a flight bound for Honolulu, Hawaii. I decided to extend my stay in Hawaii an additional four nights. The adventure begins.

Upon arriving in Honolulu I contacted Ned and we made arrangements to meet in the morning at their labs. I spent my first evening driving around Honolulu enjoying the beauty of an island State I thought I'd never visit.

  Easily one of the most recognizable landmarks in Hawaii is Diamond Head, the extinct volcano.  It's pretty imposing
  and cannot be missed.  Imagine seeing it for the first time in person. Awesome! The rest of the evening I spent
  trying to figure out the street layout so I could easily drive to Ned and Margaret's labs in the morning. I wanted to
  be prompt so, I found the lab that night and the correct one-way streets to get me there. I thought Madison was
  hard for visitors to find their way around but, Honolulu is worse.

  I arrived at their labs a few minutes early and was greeted by the receptionist via a buzzer and speaker system. Not
  just anyone can enter the Kewalo Marine Lab building.  The receptionist was expecting me and buzzed me to
  enter. Ned and Margaret were running a little late so, I went back outside to take in the morning sun, warmth and
  beauty. Ah, Hawaii in January, how nice.  Life is good!
 

  Meet Professors Ned Ruby and Margaret McFall-Ngai, formerly from the Department of Medical Microbiology
   and Immunology, University of Hawaii, Honolulu, Hawaii. They had accepted positions at the University of
   Wisconsin, Madison to continue their research on the pygmy squid. I found Ned and Margaret to be congenial,
   easy to talk to, intensely interested in their animals and concerned about duplicating their success using artificial
   seawater. At their Hawaii facility they were spoiled by having a continuous flow of fresh sea water supplying there
holding systems. It was a simple open system, fresh sea water in, waste water drained back to the ocean.

Spending time with Ned and Margaret was educational, entertaining and delightful. They are wonderful, easy going people who I found to be gracious hosts. Margaret began showing me around the labs and Ned soon joined us. We discussed their present system, the needs of the squid, the process of breeding the squid and the requirements of harvesting and hatching the eggs. It was all very interesting. We broke for lunch and I was treated to a delightful, secluded restaurant high in the mountains above Honolulu. We continued our conversation over lunch.

  Coming down out of the mountains after lunch, we stopped at several places for me to get pictures. The picture at
  the left is one of those shots: another view of Diamond Head with the city skyline in the foreground.

  Back at Kewalo Marine Lab, Ned and Margaret began expressing their concerns of switching from an open system
  to a closed system. Basically, an open system circulates sea water direct from the ocean to the system and back to the ocean carrying with it any waste products. A closed system circulates the same water over and over again. You must devise a filtration system to get rid of the build up of waste products or the sea water becomes toxic and will kill the animals you are trying to keep. I shared some ideas with Margaret and Ned of how reef keepers controlled or eliminated toxic waste products such as Ammonia, Nitrite and Nitrate. Also, we discussed, the need to add Calcium and PH/Alkalinity buffers to keep things in balance. I could see relief in their expressions as we talked. I could only hope our reef keeping systems would do the trick for the delicate squid. For me, this was uncharted territory. Yet, I was confident about designing a system that would allow them to keep up with their research in the Midwest, far from any ocean.

Back at my hotel that night, I tried to design a system with their criteria in mind. As excited as I was about the events of the day, my mind just would not work! I was on overload and had a whopping headache to boot. Finally, I simply fell asleep sitting up in bed. I awoke at 5am and began writing and drawing. It was as clear as a bell. I knew exactly what was needed and how to do it. After a shower and breakfast I headed for the lab. We were to meet at 9am and I was ready. Confidently I laid out my plans based on our conversation of the needs of the adult squid, the number of males and females they were likely to keep at any given time, plus a hatchery system for keeping the eggs aerated during the long incubation period (23 to 28 days depending on temperature of the water).

By 11am we were finished and I could tell they also believed my system would work for them. Now, I prayed that it would! I looked over at Margaret and she was smiling. I said, "Margaret, you look happy". She replied, "Dick, you don't know how happy we are that you are here." Well, I never told her this but, they weren't the only ones happy that I was in Hawaii in the middle of a Wisconsin winter. In a nutshell, that's how it happened. We were finished in two days and I still had six days left to enjoy Hawaii. I did enjoy myself even though my wife had to stay home because of the short notice. Here are a few more pictures from Hawaii and then I'll get to the actual installation of the system.

Construction Begins June 21, 04

Building the tanks and sumps was contracted out to Innovative Plastics, Inc. of Michigan. They did their usual high quality work that I have relied on since 1987.

Bobtailed squid are shy and hide in the gravel during the daylight hours. I suggested blue sides to the tanks to give the squid a sense of security. I knew the excitement that these critters were going to generate once they arrived in Madison. If we had the standard clear sides, people would be constantly peering at them from the side. This would hinder them from settling in properly and might affect their habits from feeding to breeding. Margaret and Ned agreed so, blue sides it is.

  The tanks for the females, were 72" x 32" x 12" and divided into eight compartments. Each compartment measured
  18" x 16" x 12" and could house up to two females. I named them, "The Female Condos". There would be two that
  size allowing them to keep up to 32 female squid. The male condos would be the same size cubicles but with only
  four compartments allowing room for only four males. You know how it is, put 32 females in the same room with
  four males, there's bound to be disagreements.  (Smile)

  This picture is of the hatchery tank. The squid readily breed in captivity and are provided a cave device made from
  PVC pipe into which they lay their eggs. This makes it easy for the researchers to collect the eggs and transfer
  them to the hatchery for incubation and collection of the newborn squid. I'm not going to attempt to explain the
  actual research being done but, it involves the squid's symbiosis with the luminous bacterium Vibrio fischeri, which
  the baby squid pick up in the first 24 hours of life from the environment and house in their light emitting organ.

            Abstract. "The symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri has a pronounced diel rhythm, one
            component of which is the venting of the contents of the light organ into the surrounding seawater each day at dawn. In this study, we explored
            the use of this behavior to sample the microenvironment of the light-organ crypts. Intact crypt contents, which emerge from the lateral pores of
            the organ as a thick paste-like exudate, were collected from anesthetized host animals that had been exposed to a light cue. Microscopy revealed
            that the expelled material is composed of a conspicuous population of host cells in association with the bacterial symbionts, all of which are
            embedded in a dense acellular matrix that strongly resembles biofilms described in other systems. Assays of the viability of expelled crypt cells
            revealed no dead bacterial symbionts and a mixture of live and dead host cells. Analyses of the ultrastructure, biochemistry, and phagocytic
            activity of a subset of the host cell population suggested that some of these cells are macrophage-like moluscan hemocytes."

A Work in Progress

  Here I am gluing PVC joints in the supply piping of the first unit. We are bringing up a one inch diameter supply
  pipe and branching off with cross fittings, reducing the supply to 1/2" pipe with a ball valve. The squid do not
  require high water volume turnover. Each compartment contains eleven gallons of water "(42 liters)" and with the
  flow rate I've chosen, 600 gph "(2300 l/h)", they're getting six water changes per hour. That is about what they had
  in Hawaii.

  This is the first of the female condos now ready for squid. Water is set at a specific gravity of 1.025, temperature is
  26 degrees Celsius or 78.8 degrees Fahrenheit: ideal conditions for these squid. The squid are endemic to the
  Hawaiian Islands and found in shallow water. They hide during the daylight hours by covering themselves with
  gravel. Students of the lab in Hawaii collect them at night, when they come out of hiding, by wading in shallow
  water along the shore using a flashlight and a hand held net.

The First Squid Arrive on Saturday, July 2, 04

We've Got Eggs

 Very often with cephalopods (octopus, squid and cuttlefish) the females come into captivity already impregnated.
  That's the case here. None the less, everyone in the lab was very excited when the first clutch of eggs was
  discovered. The research is being done with the baby squid so, this is an important event in the lab.
 

A Vibrant Squid in Full Color

  This picture depicts a squid that is displaying the vibrant colors of a healthy animal comfortable in his/her new
  home. The squid are fed live shrimp once a day. The shrimp currently used as food are the freshwater ghost
  shrimp. A source of marine shrimp is being sought because the ghost shrimp, if not eaten in a few hours will die.
  This can lead to a bio overload in the new system and cause stress on the squid. However, once the Nitrogen cycle
  occurs this should not be a problem.

One of the Greatest Pleasures of My Work

  It gives me a great deal of pleasure when someone comes in and admires the beautiful animals I work with. It might
  be the colorful reef fish, or a full blown reef tank of colorful corals or even the cute Bobtailed squid, Euprymna
  scolopes. These two students, Amber and Sarah, have been a delight to get to know. It's enthusiasm like theirs
  that makes my work a pleasure. Thanks girls!

The work is far from finished as this is the first of four systems. Two others are on line with saltwater circulating through them waiting to cycle. We didn't wait for the first system to cycle but took precautions to prevent a radical event. The life of the squid is the most important thing in the lab.

Anthony Calfo's websites: http://readingtrees.com and http://wetwebmedia.com.
Rob Toonen's website: http://www2.hawaii.edu/~toonen/publications.html

Photo Credits

All photographs were taken by the author except those noted otherwise.
 

Home Page

Questions - Comments - E-mail -->

We can be reached toll free - 888-745-0449