Handbook of Nature-Study · Lesson XLI · Topic 3: Fish study
41. The stickleback
Goal: Your child can recognize a stickleback by the spines on its back and describe how the father builds and guards a nest.
You'll need
- A still, weedy pond or ditch that holds water all year
- A dip net and a clear jar or white dishpan
- A hand lens
- Nature notebook
What's in the book
The leading thought (the smallest common fish; the father builds a nest of the alga called frog-spittle), the method (dip deeply in a stagnant, partly shaded pond; in May several may build a nest in an aquarium) and nine questions about the spines, fins, color, eyes, mouth, how it uses each fin, how it eats, and its nest.
The lesson, step by step
When and where
Spring and early summer, in quiet, weedy ponds, ditches and slow streams that never dry up; in the north and along the coasts. Comstock collected them in early May, when males build nests. Safety: an adult stays within arm's reach near any water. Stay off steep or slippery banks and never wade in fast water.
Keep the big idea in mind
Read this to yourself:
The stickleback is the smallest of our common fish. It lives in stagnant water. The father stickleback builds his pretty nest of frog-spittle which he watches very carefully.
Frog-spittle is the green, slimy, stringy alga that floats in ponds.
Dip for fish
Comstock's method:
Take a dip net and dip deeply; carefully examine all the little fish in the net by putting them in a Mason jar of water so that you can see what they are like.
If you catch a fish to look at, use a small net, keep it in a clear container of water from the same stream, in the shade, for no more than 10 to 15 minutes, then let it go exactly where you caught it. Wet your hands before touching a fish, or better, don't touch it at all. Check your state's rules first; some places need a fishing license even to net small fish.
Count the spines
How did the stickleback get its name? How many spines has it? Where are they situated? Are they always carried erect?
The common brook stickleback has five spines, as Comstock says; other kinds have three or nine.
Watch it swim
When the stickleback is swimming what are the positions and motions of the dorsal, anal, tail and pectoral fins?
Describe the mouth. Does it open upward, straight ahead or downward?
The nest
Do you know how the stickleback nest looks? Of what is it built? How is it supported? Is there one door or two? Does the father or mother stickleback build the nest?
Read the answers in a book, or look for a small ball of weed guarded by a dark fish. Comstock suggests keeping several in an aquarium to see a nest built. That is only for a family already keeping a proper aquarium, set up by an adult; otherwise watch and let them go.
Let them go and tell back
Return the fish to the same spot. Ask your child to tell you what is special about the father stickleback. Then share the leading thought.
Nature notebook
Draw a stickleback large, with every spine counted. Draw its nest beside it from a book picture or your own finding.
Afterwards
Visit the same pond in a week or two and dip again. Are the males darker or more colorful now?
Tip
Even the father's spines are tiny, but keep fingers out of the jar and let the fish be.