A family consists of offspring from a single pair mating between an adult female and an adult male. Rearing multiple families is critical in order to maintain diversity within our refuge population. Due to facility space limitations, the FCCL has found 40 larvae/L an adequate middle-ground for stocking larvae, which typically takes a total of eight families to reach this target density. Therefore, family size becomes a significant factor to consider when culturing fish because offspring from one mated pair can have a negative impact on the survival of offspring from another mated pair. The FCCL is taking steps toward promoting survival of individual families by conducting trials using small culture containers that can rear single families at a time, this method could reduce competition between families and increase the survival of each individual family. Co-culturing families is standard practice in aquaculture, evaluating this aspect is critical in order to increase efficiency in the production and maintenance of cultured Delta Smelt. The FCCL is carrying out trials to assess this factor by individually incubating an equal number of eggs from one, four or eight family groups, parentage analysis will assess the survival of each family in these groups.