distinguishing characteristics

[mike b]

I was wondering is there any 100% foolproof way to distinguish cichlasoma dimerus from cichlasoma bimaculatum?

[Bas Pels]

If you happen to find any - does not have to be foolproof, slightly correct would suffice - post it

Kullander had described 12 species of Cichlasoma, which are very similar. Further, as these species might be a bit bariable, it will be virtually impossible to name them - unless tyou know the collecting locality

I got 6 C dimerum I brought back from Uruguay (coming from a logoon in the Rio Uruguay, ca 100 km north of Salto) and these will be nameble, even in case their latin name would change

[cichla]

dear Mike, dear all,
It is very easy to distinguish Cichlasoma dimerus and C. bimaculatum. Cichlasoma dimerus has 3 anal-fin spines versus 4 in C. bimaculatum. Cichlasoma dimerus is a member of the southern clade, C. bimaculatum blongs to the northern one.
Greetings, IS

[mike b]

looks like bimaculatum thanks cichla I found some pics on them in breeding dress and they looked exactly like mine I just wanted to verify for sure can you believe i bought these as cryptoheros myrnae at an auction about 2 years ago? they were fry then and at that size they pretty much all look the same it wasnt til I had them about 3 months that i realized the shape wasnt right for a cryptoheros anyway again thank you.

[Willem Heijns]

This an interesting one. The question was for "guaranteed" differences between Cichlasoma bimaculatum and Cichlasoma dimerus. Anal spine number is a good one; being a member of a clade is less easy to see.
But I wonder why the choice is/was between these two species. After all you bought them as Cryptoheros myrnae. In the genus Cichlasoma there are another ten candidates for your fish. And maybe even a few in Aequidens too. Any pictures?

[mike b]

I will try to get some pictures later today its just really hard because they just will not be still I had to net one out to count the anal spines the reason I wanted to get a positive ID is Ive got a pair in the tank so I might be getting rid of the rest and I wouldnt want to let a fish into the hobby without knowing for sure what it is, as far as aequidens thats what I thought at first but I havent found any aequidens pictures on the web that come close to resembling these fish so I guess Ill net one out when I get home today and try to post a pic

[mike b]

I'm not sure if this will post I'm using my phone to try to post the pics

[Paulo José Alves]

Hi

The name C. dimerus is used too easily in my opinion, there are naming of fish from Uruguay and from Peru for example as being C. dimerus, this is just not possible. I think this species is not as well defined as we might think. Actually, to define the species of the C. bimaculatum group, including the suposed southern clade, is really dificult and not certainly by the looks of them.

[mike b]

Im a little curious if the pics were good enough to be able to distinguish? any suggestions or confirmation as to what they are?

[mike b]

still wondering if anyone out there can give me a positive ID Ive actually had some interest but I dont want to sell or give away anything if Im not 100% sure what they are thanks again Mike