Scientific Names : How do they work ?

by Francesco Zezza

FOREWORD: This information is not at all new, and you can likely find it in a lot of other places. All the same, I decided to take a moment and think on the “mysterious” scientific names and then report the whole matter to MCH visitors. This will NOT help you to better keep your fishes but, I feel, should be known by every clever cichlid keeper. Enjoy!

Convicts, Oscars, Peacocks … and also Teacup stingrays (yes, I’m carrying on with my studies on FW stingrays!), up to Sharks!!! Sharks, referring to small freshwater fishes and not to the majestic (cartillagenous fishes) kings of all the open seas, of course. There are a lot (too many!) common names in the aquarium hobby, but since I feel every aquarist should stay away from them, I will try to quickly review how a scientific name “works”! Maybe it will inspire someone to consider the idea of switching to scientific latin names; who knows?

The first name for a given fish is the GENUS name, i.e.: Copadichromis, beginning with a CAPITAL letter, and NEVER plural (no additional final “-s”) even when referring to more than one specimen.

The second name is the SPECIES name: i.e.: borleyi, almost always a Latin or Greek one, and then written in italics WITHOUT a capital letter at the beginning.

Binomial (genus/species) names are followed by the name(s) of the describer(s) and by the year of publication of the scientifc description. If another name and year appears afterwards in brackets, this means the fish has been previously described with a different name: i.e. Barbus tetrazona (Bleeker, 1855). The species name follows the “sex” of the latin GENUS name, such as (“male name”) Astronotus ocellatus or (“female name”) Rineloricaria parva. The same is true when the name refers to the describer: from a man’s name will result in: Cyrtocara moori, from a woman’s name, on the other hand, will result in: Labeotropheus trewavasae. Species names can also refer to the place (such as country, river, lake) of origin, such as brasiliensis (meaning from Brasil).

NOTE: to fully understand this “rule” you should at least be aware of the very basics of latin.

Sometimes the genus name is followed by abbreviations such as sp. cf. aff., these actually stand for:

sp. = means that a given species has not been described yet and is subject to be possibly changed in the future. Sometimes it is written like “Msobo”, beginning with capital letters to CLEARLY state this is NOT a scientifically “correct” name: Pseudotropheus sp. "Msobo". Generally speaking, anyway, it is written – God bless laziness – like Pseudotropheus Msobo.

aff. = means a SPECIES is “similar” to another one: Maylandia sp. aff. "Zebra" stands for an undescribed Maylandia close to the species zebra.

cf = means the GENUS, even if not fully described, is the genus it is  thought to be but it’s not a positive identification. I.e.: Maylandia cf. greshakei means the fish is SUPPOSED to be close to a greshakei, but it is NOT sure (possibly resulting, in the end, as being a closely related species).

The “type” names.

We’ll now, for the pleasure of knowing it, review the meaning of the terms: holotype, paratype, lectotype, syntype. This should help in understanding the scientific description of a given fish whenever we come to look at that kind of information:

·        Holotype: stands for the VERY FIRST described specimen of a given genus/species.

·        Paratype: are all the related ones (specimens of the same genus/species).

·        Syntype: each specimen is a “syntype” whenever the holotype or lectotype (see below) has not been designed.

·        Lectotype: lectotype is a syntype designed as the only type carrying a species name. All other specimens are, then, known as parallectotypes.

 If, by any reason, the holotype, lectotype, syntype were lost then a newtype can be designated.

Type population is the variety that holds the name of the geographical place where the type of a species belongs to. The Tropheus moorii caught in Mpulungu (formerly Kinyiamkolo) were the first Tropheus moori to be caught. So, the Tropheus moorii Mpulungu – as far as I know - has to be considered the “type population” for the genus Tropheus in the family Cichlidae.

I feel there’s no need to go any deeper. Nevertheless, I DO feel anyone should now be aware of why common names have to be feared like the devil and avoided in every serious cichlid (and not only) related discussion.

You may click here for an explanation of the scientific names of Lake Malawi Haps and mbuna.