Lately there has been a lot of discussion about the generic assignment of a group of Central American cichlids all more or less closely related to the species originally described as Cichlasoma maculicauda REGAN 1905 and Cichlasoma synspilum HUBBS 1935. In order to decide to which genus these( and a few other) species belong, we first have to look at the availability of the proposed generic names. With availability I mean: can the names safely be used for any cichlid genus without breaking the rules of the International Commission on Zoological Nomenclature( ICZN). Vieja was described by Fernandez-Yepez in 1969. This Venezuelan author designated Cichlasoma milleri( a species also newly described by him) to be the type species for his new genus, as the rules of the ICZN require. Later it turned out that Cichlasoma milleri was a synonym of Cichlasoma maculicauda, rendering the latter as the name of the type species of Vieja. The meaning of this is that whenever Cichlasoma maculicauda were to be placed in a separate genus of its own, the name of that genus would have to be Vieja. Keeping it in Cichlasoma on the other hand would make the name Vieja a synonym of Cichlasoma, because the name Cichlasoma is of an older date( the priority rule). The story for Paratheraps is roughly the same. Proposed by Werner & Stawikowski in 1989( after their first description in 1987 failed to assign a type species) it has Paratheraps breidohri as its type species. Both names are thus available and may be used as generic names for( cichlid) species. Next question to be addressed is whether these two names are valid. As I said above, if maculicauda would have been kept in Cichlasoma, the name Vieja would become synonym. And synonyms are not valid. They cannot be used as valid names for cichlid taxa. Since Kullander( 1983) restricted the name Cichlasoma to 12 species of cichlid fish from South America, it seems illogical to assign the two Central American species at hand to this genus. The species maculicauda and breidohri will most likely never again belong to Cichlasoma for this reason. Lacking another available generic name for these species( older than the ones proposed by Fernandez- Yepez and Werner & Stawikowski) it follows that both species may safely be assigned to these two genera. The generic names Vieja and Paratheraps are thus also valid, their type species being Vieja maculicauda and Paratheraps breidohri respectively. Unless of course it would be shown that both species actually belong to one genus. In that case the younger of the two names( Paratheraps) would become a synonym of the older( Vieja). The discussion would end. All species concerned would have to be called Vieja. Some authors( mainly aquarists) are of this opinion. The problem is that these authors rarely give supportive arguments / evidence for their opinion. But this complicated matter may be solved in the near future. Recently some very interesting papers have been published on the phylogeny( interrelationships) of Central American cichlids. Oldřich Říčan and co-workers( 2008) studied most of the Central American heroine cichlids( including Paratheraps and Vieja) using both DNA and morphology. Molecular( DNA) and morphological characters are good indicators of relationships. Generic
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