2017-11-26 Amazonas

trying standing water, air stones, small containers, large

containers, frozen spinach, and fresh spinach. To provide

the worms with stable water conditions, I used 2.4-gallon

(9-L tubs) with foam filters and airlifters. I couldn’t find

an airlifter that would work for a water depth of only

3.9–4.3 inches (10–11 cm), so I built my own mini air-

lifter out of a 0.5-inch (13-mm) tube, which I filled with

sand and closed at both ends with small wooden plugs.

After placing it in the oven for four minutes at 284°F

(140°C), I bent it around a cylindrical steel weight on

the kitchen counter. I quickly cooled it with the help of

a water sprayer. To make the injector, I drilled numerous

1.2-mm holes in the bottom end and covered them with

a short piece of 20-mm tube, into which I glued a 6-mm

tube as the nipple for the airline. The thicker tube was

sealed with O-rings on both ends.

Despite using this airlifter, the Microfex almost

died off, until I started giving them very large amounts

of food. Only when I left several large spinach leaves

floating in the tub did their numbers increase consider-

ably—they formed clumps on various spots on the leaves.

At last I had succeeded in producing enough to feed my

fishes a sufficient amount every day. After that I provided

the Microfex with plenty of blanched spinach and iceberg

or buttercrunch lettuce, and the worms developed well.

A tiny contaminant

I did not pay much attention when I discovered a few

small contaminants, since they had appeared occasionally

in my aquariums and in heavily algaed culture bottles on

the windowsill—I assumed they were Cyclops. My at-

tempts to culture them on the windowsill by adding other

foods, such as crushed fish food tablets, had all failed, so I

assumed they would not multiply or have much effect on

the worms. But I noticed that the water quality deterio-

rated quickly a few days after a water change, and the

Microfex populations leveled off or even declined.

So I began to change the water in the tubs every day.

The reproduction rate of the Microfex increased steeply,

but after two or three weeks it fell off again despite an

ample supply of food and clean water. I then removed

the food and animals from the tubs and cleaned them.

To my surprise, the entire bottoms of the tubs were

covered with Cyclops.

Over time, I realized that when the Microfex popula-

tion declined, the number of Cyclops increased. Strangely,

better hygiene did not decrease their numbers. On the

contrary, they seemed comfortable under these condi-

tions, as did the Microfex, and increased accordingly.

When the critters were removed, all it did was make

space for their offspring.

As they kept coming back stubbornly and continued

to multiply, I began to take a closer look at them under

the microscope. The body is white and on each side there

is a small pouch; the overall size is about 1 millimeter.

In addition to doing an online search, I asked questions

on several Internet forums. Most people said that they

were ostracods (seed shrimp), but they definitely are not.

Online information about microorganisms and arthro-

pods did not help.

On a goby forum, Jutta Bauer confirmed my suspi-

cion that they were a small Cyclops species. The small

bags on the sides are egg sacs, which only females carry.

Cyclops nauplii make an excellent rearing food due to

their small size. In addition, adult Cyclops are the favorite

food of Microphis deocata, the Rainbow Belly Pipefish

from India, one of my absolute favorite animals.

Culture trials

Apparently, it has not yet been possible to reproduce

these Cyclops in significant numbers. Since I already

knew that I was going to receive some Microphis from

AMAZONAS

Left: Drawing of

a Cyclops with

egg sacs.

Right: Microfex

can be cultured

in expanded

clay pellets used

in hydroponics

and commonly

sold as “Clay

Pebbles.”