Identifying your Cichlasoma

[Mahlerfan]

A while back I posted that I was working on a guide for the hobbyist to identify the twelve species within the genus Cichlasoma. I intended to post the guide all at once but as it has not been easy to locate some species, I've now decided to do it one species at a time. The guide is not intended to be a scientific description of each species but as a layman's way to try to identify the Cichlasoma you may have swimming in your tank. Most of the work is based on S. Kullander's original and redescriptions of the species and on my own personal experience with these fish.

Knowing where a particular fish was caught and exported from would be the most useful factor in determing it's species, but as most are imported without locality data, I'm hoping this guide will be of some use to those wanting to know what fish they have. There is no one trait that will distinguish a particular species. You have to rely on a combination of several different characters in order to be able to tell the species apart.

The first species I'll start with is Cichlasoma boliviense. This one is not too hard to seperate from the other eleven species.

The combination of characters that distinguish Cichlasoma boliviense are -

A. 3 hard spines in the anal fin (as opposed to 4 or more that occur in 6 of 12 known species)

B. A caudal fin that has many small spots both on the upper and lower lobes of the fin (as opposed to large spots throughout the fin, small spots only on the lower half, or no spots at all)

C. Thin (as opposed to thick) to non existing black edging to the posterior edge of the scales on the head and anterior portion of the body.

D. Black spots on the scales of the posterior portion of the body.

 

[Mahlerfan]

It is interesting that the genus can be divided perfectly in two by counting the number of spines in the anal fin. Six species have three spines and six species have four (or in some individuals more.) The following two species - Cichlasoma bimaculatum and Cichlasoma taenia are both species with four spines in the anal fin. These two Cichlasoma are often confused with one another. They are similar, however both can be seperated from the remaing species with four anal fin spines by a number of characteristics, which will be more apparent as those species are listed. The real problem is distinguishing between these two species. The most apparently visible difference to the hobbyist will be the shape of the body. Cichlasoma taenia is a more elongated fish. I hope the rather poor photos I provide will allow that difference to be seen.

Cichlasoma bimaculatum




A. 4 spines in the anal fin.

B. Asymmetrical spotting of the caudal fin. Both upper and lower lobes of fin have spotting.

C. None to very thin black edging to the posterior portion of the head and body scales.

D. A relatively deep body shape as compared to Cichlasoma taenia.


Cichlasoma taenia





A. 4 spines in the anal fin.

B. Asymmetrical spotting of the caudal fin. Both upper and lower lobes of fin have spotting.

C. None to very thin black edging to the posterior portion of the head and body scales.

D. A relatively elongate body shape as compared to Cichlasoma bimaculatum..

 

[Mahlerfan]

Cichlasoma amazonarum



A. 4 anal fin spines.

B. Asymmetrical spotting of the caudal fin. Both upper and lower lobes well spotted.
.
C. Thin black edging to the scales of head and body.

D. A relatively deep body, as compared to Cichlasoma taenia.

E. Several rows of scales entering both the dorsal and anal fins.

Cichlasoma amazonarum may have the greatest geographical distribution of all the known species of the genus. With the exception of Bolivia, it occurs naturally throughout most of the Amazon basin. Because of this, it is a variable species. However one thing is consistent - the heavy scalation of the anal and dorsal fins, with several rows of scales entering both fins. No other 4 anal fin spined species has this feature. You may be able to see the rows of scales entering the dorsal and anal fins in the second photo I've provided, if you blow it up.

 

[dogofwar]

Great information...and great fish!

Matt

 

[Mahlerfan]

Thanks Matt.

 

[Mahlerfan]

The next group of Cichlasoma species I'll be listing are part of the Cichlasoma dimerus complex. 3 described species - Cichlasoma dimerus, Cichlasoma portalegrense and Cichlasoma pusillum, along with several undescribed forms (species?) make up this sub-grouping of Cichlasoma. These are the beauties of the genus. They are covered in metallic blue-green scales that make these Acaras among the most attractive of South American cichlids.

Cichlasoma pusillum




A. 3 anal fin spines

B. Asymmetrical spotting of the caudal fin. More closely placed spotting on the lower lobe. Upper lobe with bigger spaces between spots.

C. Thick black edging to the scales of head and body.

D. A more elongated body shape as compared to Cichlasoma dimerus and Cichlasoma portalegrense.

E. Enlarged suborbital spot (appears more like a line)

F. Varying amount of black spotting on the opeculum.

G. Anterior lateral stripe always expressed.

 

[Mahlerfan]

Cichlasoma dimerus






A. 3 anal fin spines

B. Caudal fin heavily spotted. Small spots on both upper and lower lobes of the fin.

C.Heavy black edging to scales of head and body.

D.Relatively deeper body shape as compared to C. pusillum.

E. Small suborbital spot. (depending on mood the spot may not be expressed at all)

F. Anterior lateral stripe always fainter than Lateral spot.

Cichlasoma dimerus is a very beautiful member of the genus. Although my photos don't capture it, they dispaly a very attractive blue to green color.

 

[Mahlerfan]

Cichlasoma portalegrense




A. 3 anal fin spines.

B. Caudal fin heavily spotted on lower lobe, with small tightly spaced spotting.
In upper lobe the spaces between the spots are larger and more prominent (look carefully at the caudal fin of the fish in the first photo.)

C. Heavy black edging to scales of head and body.

D. Relatively deeper body shape as compared to C. pusillum, but not quite as deep as C. dimerus.

E. Suborbital spot prominent, but not as large as in C. pusillum.

F. Anterior lateral stripe as dark as Lateral spot.

G.The head (in fully grown individuals) when viewed in profile, has a more rounded snout than either C. dimerus or C. pusillum.

Cichlasoma portalegrense is very similar to both C. pusillum and C. dimerus and to me, appears to be intermediate between the two. However Kullander keeps Cichlasoma portalegrense as a valid species because, unlike C. dimerus and C. pusillum, it has reduced dentition.

 

[Aquanero]

Very informative, I'd like to see this incorperated into the CA/SA profile thread. Great job.

 

[Mahlerfan]

Aquanero, thanks.
Cichlasoma is such a misunderstood genus in the hobby. I'm hoping this guide will be at least a little useful for anyone who would like to keep these fish.