The  traditional method of species description is under discussion today.

The traditional taxonomic methodology is a museum task which includes the evaluation of body structures, the counting of fin rays but also the description of colour patterns. Therefore it is related only to the phenotype and does not consider genetic information. Furthermore, the behaviour is often not considered at all, because dead, preserved fish (museum specimens) play the major role in the process of description. But we know about significant differences in behaviour between different species, for example during courtship, which will undoubtedly play an important role in the future systematics. Thus  previous licorice gourami classification has to be regarded with considerable reservations.

Many areas of biology have already left behind these serious limitations of the earlier stages of science. For example, for the classification of flowering plants today, genetic information is often essential. The classification of birds has been turned upside down in a few decades by taking into account knowledge about DNA, but also by comparative studies on bird song. Therefore it is expected that new methods of taxonomy, which reveal the structure of genomes or consider behavioural patterns, will change the classification of licorice gouramis significantly in the future. Even today it is likely that, based on more accurate descriptions of behaviour, the parvalus-ornicaudata-group may have to be differentiated from the rest of the species.

Nevertheless, the classical   taxonomy based on phenotype, will remain an indispensable method of the description of plants and animals. If significant differences can be found by careful observation, this leads to the assumption that genetic differences also exist. In most ofcases, different appearance also indicates an internal diversity. And internal differences manifest in most cases an external diversity as well.

However, even under critical consideration of the limitations of phenological taxonomy, we would not doubt that it has been an indispensable method of biological description up to now. It will be helpful in the future as well. There is a need to upgrade it by including new methods  in ichthyology, but it will never be completely replaced.

(PF)