Here you go:
February 20, 2005
Cichlid Breeding Terminology
by D. Jones (aka Number6)
Cichlid husbandry is the process of caring for and breeding the same species of cichlid to produce viable fry for one or more generations. The terminology for cichlid breeding has its roots in Genetic terminology but has evolved or been modified to convey a certain state of the genotype of a fish (Genotype is the genetic makeup of an individual). Cichlid breeders usually wish to begin with a male and female without genetic abnormalities in their genotype so they opt for wild caught specimens. This attempts to select quality parental stock. The appearance of the fish (phenotype) can be used to guess at the genotype quality, but this is just a guess. Fish that have been obtained from their natural habitats are labeled as wild caught (WC) or sometimes a manufactured term, F0 is used to differentiate for any fish ‘wild caught’ from the wild in say Florida or a similar environment other than the fishes natural habitats. The F stands for Filial (genetic sibling) and the zero denotes no relation. This is an assumption, and genetically speaking these fish may not have significantly different genotypes. This is the first deviation from true genetic terms. In genetic terminology, the parents are labeled with a P. According to genetic terminology, to have parental stock from known separate genotypes one should have two separate collection sites or two different variants. However, this is not a goal of good cichlid husbandry.
From a WC or F0, parental stock, fry from the crossing would be labeled as Filial generation (F1). The number following the F denotes the different generations involved in breeding. F1 is the first filial or filial-one generation. This identifies the offspring as the progeny after mating or genetically crossing two types of parents with different genotypes or phenotypes (the parents are known as the P generation). F2 is the second filial or filial-two generation, i.e. the progeny of self-fertile or intercrossing F1 individuals and so on. Members of this generation are two generations removed from the original parent generation. F2 individuals have been in bred one time.
In cichlid husbandry, any generation beyond F3 is often called tank raised to denote the likelihood of genetic similarity to other specimens that may be obtained from hobby breeders in the area. For example, 50 fry forms 25 pairs that in a single generation could produce 1250 new fish. The likelihood of obtaining siblings increases with each generation.
Questions arise when performing a back cross or an outcross. For example, back cross an F2 with an F1 of the same bloodline. It is thought that this is labeled an F3 as the fry are three generations removed from the wild. However, genetically speaking, the fry could not be labeled as such, as this enters the world of line breeding.
Similarly, when out crossing an F2, for example, to a new WC, the progeny are genetically an F1, however hobbyists are expecting the F# as a tool to identify generation removed from wild. The correct label would therefore be WC x F2. Another outcross would be an F1 crossed with an F1 from another bloodline. This does not produce F2. These fish are not inbred one generation. These could be labeled for cichlid hobbyists as F1 x F1. In Genetic terminology, they are actually F1 specimens being from parents of known separate genotypes.
The key to remember, labeling should benefit the buyer, not the seller. Label all fry as clearly and simply as possible and avoid areas of confusion. □
