Suggested Guidelines For Maintaining Mutant Stocks

(Source: M. Halpern from Zebrafish Book 5th Edition)

Densities

With adequate water flow, stocks are routinely kept at densities of:
1 fish per 1/4 gallon `tanklet'-

25 fish per 5 gallon tank-

50 fish per 10 gallon tank-

150 fish per 30 gallon tank

Intercrosses

To obtain maximal numbers of identified heterozygotes, keep mutant working stocks as intercrosses from identified heterozygous parents. The wild-type progeny from several intercrosses should be pooled to maximize the genetic diversity of the stock. Use identified fish from one generation for experiments, while another generation of intercross progeny are growing towards sexual maturity. On average, make a new generation every 4‑6 months.| |

To maintain a mutant line, heterozygous fish should also be outcrossed to the wild-type main line. Ideally, the outcross stock should also be derived from group matings rather than a single cross. Identified heterozygous males can be used for freezing sperm.| |

Tank usage

Depending on the use of a given stock, estimate the number of tanks required for stock maintenance, mutant recovery, and experimental purposes:

Category 1: Working stock for maintenance and low level usage

3 X 5 gallon: 2 for identified heterozygotes, 1 for wild-type outcross

4 X 10 gallon: 2 to identify heterozygotes, 2 for growing fish to sexual maturity

Category 2: Recovering mutations from clonal fish

F1: 1 tanklet for original female, 1 X 10 gallon for first outcross (approximately 50 fish)

F2: 4 tanklets to hold fish being identified, 2 X 5 gallon initially for intercrosses

Category 3: Major working line

Tanks are needed for
intercrosses-

wild-type outcross-

double mutant stocks-

special backgrounds (i.e. gol^b1 for line-age or nic^b1 for physiology)

extra females for squeezing purposes-

identified single and double mutant heterozygotes

This means at least: 10 x 5 gallon, 5 x 10 gallon and 2 x 30 gallon.