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Rio Rivers …

AKA: cichlids – and other inhabitants – of Rio de Janeiro pools, fountains, and creeks.

by Francesco Zezza

·         Foreword: I like geophagine cichlids … I find them both entertaining (to look at) and interesting to “study”. My interest in these fishes led me – in the past – to grow (from small juvenile to adults) six Geophagus brasiliensis simply to see them turning into six adult males (30 cm/one foot each)! And then again I tested all my patience limits when I faced the ridiculously slow growth rate of six (once more) Geophagus crassilabris; actually kept in my “new world cichlids” tank …

·         Introduction: To the best of my knowledge almost all geophagine cichlids live in South-America over an area which extends from the Amazon forest (and related areas) to the extreme south (Uruguay and Argentina). The only notable exception is – again as far as I know – Geophagus crassilabris (originating from Panama). This extremely wide distribution area allows, on one hand, each fish-keeper to choose the “earth-eaters” he prefers (or best fit his tap water) and on the other hand asks for a careful consideration of their water needs. It’s perfectly clear – or at least it should be - that it is NOT wise to mix in the same tank fishes originating from the Amazon forest and from – let’s say – Uruguay. I’m not referring to water chemistry only but also to the difference in water temperature. It should be understood that the temperature during winter months in the southermost part of South America drops really low and - in some extreme cases - even close to zero. 

My experience with Geophagines.

1.        The very first step has been - as previously said – keeping Geophagus brasiliensis (or at least that’s the label they were carrying when I got them … as a matter of fact the “Geophagus brasiliensis complex” is one of the most complicated taxonomic issues of all South-American cichlids). Great care should be taken when dealing with them in order to obtain fishes of a certified origin - as much as you can. This was NOT the case of my fishes having being sold to me as six juvenile Gymnogeophagus rhabdotus … further reading taught me that young specimens of those two species can be easily misidentified. Things become clear with aging when G. brasiliensis attains – also from my personal experience – a T.L. of about 30 cm while G. rhabdotus remains much smaller. To make things worst my fishes turned into six (just my luck!) males! The tank they were kept in – at that time it was my biggest unit – was a “generous” 300 lt (gross capacity, of course) shared with two loriicarids..  I think it’s easy to guess the “riots” and fights taking place in there …

2.       the second step is still on the go and refers (once more six specimens) to Geophagus crassilabris I received (a bit larger than fry) in 2001. After four years, the larger one, being sized approximately 15 cm. started to show some noticeable colours. Beyond their frustrating slow growth rate these fishes are perfect tank-mates for almost every new world tank set-up: not aggressive or territorial (although I haven't noticed any spawning activity up to now, which may change things a bit), not messy or bully to other tank-mates (in my case characins, loricariids and other cichlids), they do dig (looking for food morsels (in the same way malawian sand-shifters do) but their moderate size helps to avoid the awful “sand storm” I was used to deal with in the past.

I’ve never witnesses a spawn of these fishes (I mean geophagines) but it’s reported that they do so using a huge variety of breeding habits: mouthbrooders, egg-layers (either in open space or in caves), and also the so called “larvophiles” this meaning eggs are laid (on a substrate) and then larvae are “mouth-guarded”. Most part of parental bonds end up in a maternal / biparental family even though the male was reported to take care of the whole brood. I have no idea about the spawning habits of the Geophagine species I have kept up to now, which is still a challenge for me. May be I’m doing (or did) something wrong, even unwillingly, thus preventing these beauties from spawning … we’ll see!!!

At any rate, at least for Geophagus crassilabris it’s quite certain that they have to be considered as maternal mouthbrooders, while Geophagus brasilensis (all members of this complex) are said to be substrate spawners.

It’s said (see last paragraph for actual reference) “eartheaters” do better in small groups (up to 10 specimens), are easy to breed and generally speaking are not that fussy about water parameters their request being: water temp around 25° C (except Gymnogeophagus), NO2 and NH3 close to 0; NO3 < 50 mg/lt, while a high O2 level is considered a helping hand … nothing too “exotic” then ! Regrettably many of them grow big (up to 30 cm/one foot) and tan size has to be chosen accordingly.

As stated before the brood care is rather complex and differs between different genera - you can refer to the book at the end of this article for further information on this issue.

·         What’s going on in Rio: Despite the fact Rio de Janeiro is quite far away from the Amazon forest (it takes hours to fly from Rio to Manaus, the latter city being the capital of the Amazon state) it is STILL part of Brasil … and if you consider the distribution of Geophagines it is NOT that strange to find these fishes thriving in pools, small lakes, channels, creeks and the rest of water bodies around the city. If You take a look at George’s report on AFC 2005 meeting you’ll see there’s Geophagus whose “geographic locality” says Cabo Frio and as far as I know Cabo Frio in not that far from Rio de Janeiro… In the “Lagoa Rodrigo de Freita” (Rodrigo de Freita’s lagoon)– a large, even if polluted to a certain extent, fresh/brackish water body - stretching from just below the Corcovado hills till the city of Rio – these cichlids, but not only, are eagerly “searched” – by means of “hand launched” nets – for human consumption… Of course, it may well be that the fish I saw are not native in this - relatively small - part of Brazil but still it was the first time I saw them in anything but a tank and I tend to believe that their natural biotope will not be much different than the one I saw in Rio.

·         Intruders: of course there are also “black spots” to say so - I refer to fish which are definitely “non-native” and still enjoy the warm carioca’s climate. The most noticeable of them are goldfishes and / or koi carps with the latter including some remarkably large specimens found – among the rest – in the pond of the so called japanese garden in the Jardim botanico.

·         Actual specimens (genus/species; cichlids/non cichlids) found around Rio and some guesses on the way they live, referring to what is said to happen in their natural habitat: enough for now – with the "warning" that I’m going to show you more than cichlids – let the show begin.

I found – in Rio at least – the eartheaters living in generally shaded environments, shallow and warm waters, moderate to almost no water flow, with almost no plants living in the water in stunning contrast with the gorgeous vegetation living along the banks (ferns of different types are, among others, in sight). The water looks brownish with lot sof leaves and branches (and not only) in it. I’d then bet on an acidic to neutral water chemistry …

Following pictures (please note that all were shot from above the water level, while some were taken from a distance) are all depicting cichlids. One thing you should note is the tiny particle size of the substrate. This kind of substrate is easily dug / shifted / moved / chewed by the fish when looking for food. It is this habit that earned them the common name of “Eartheaters”. In the end of spring / beginning of summer) there were a lot of pairs guarding their fry. Unfortunately, because of late season the hatching stage was already completed so I didn't have a chance to get more information on their spawning mode ie. " mouthbrooding vs substrate spawning. If I was asked to take a guess, taking into consideration the biotopes I found them, I would bet on the latter !

Creek bottoms, like the one shown above are made of debris, sand, silt, decaying leaves and branches which makes stirring easy for the parents and extremely pleasant to the fry. The parents move the substrate with the moves of their fins and thus food particles are re-suspended for the fry which feed on it.

More pics (above) dedicated to cichlids, the main features of this environment (in this moment the area is in full sun) are – once again – the same. Note the fish in squared yellow frame.

Let’s go on …

Could I refrain from mentioning / showing loricariids? Of course not … both of them are, likely, large specimens of Hypostomus plecostomus, thriving – as usual – in the dark, secretive places available. The second one (see image below, fish raising from the bottom) attained the remarkable T.L. of, about, 60 cm (two feet)!!!

I have to admit that the last picture (see above) puzzles me a bit.. Some of the fish shown in it are - without a doubt - livebearers and this fact doesn’t completely fit to the description of the environment I made earlier. Livebearers are said to do better in neutral to moderately alkaline waters. Thus, there are two options :

A)     the water – at least this body of water - is in the neutral pH range

B)      the livebearers (could it be?) are, once more, “intruders”, artificially added there by man.

It was a pity that this was – above all – a business trip and I was lacking all my reagents and / or measurement devices … TOO BAD! Any way I feel that those pictures still show a lot.

This is a pair, regrettably the water was really brown and the place was in the shade to allow fry to be seen, but – believe me! – they were a huge “waving cloud” …

·         Others inhabitants: there were a lot (dragon fly, butterfly, frogs, but also small white herons, squirrels, tiny monkeys and more …) but – here - I’d like to “introduce” only the best looking turtle I’ve seen so far: Phrynops hilarii

Whose “taxomic data-sheet” is (should be) like this:

Kingdom           Animalia

Phylum             Chordata

Subphylum       Vertebrata

Class                Reptilia

Order              Testudines (Linnaeus, 1758)

Family              Chelidae (Gray, 1825)

Genus               Phrynops (Wagler, 1830)

Species            Phrynops hilarii (Duméril and Bibron, 1835)

It’s reported to attain a full size of about 40 cm, to stand quite well cold weather and water (hybernating when water temp goes below 10° C). It’s found in a wide area including Uruguay, Paraguay, Argentina and Southern Brazil living in soft bottomed, not too clear water (ponds, lakes and others) with plenty of aquatic vegetation. The pH of this water is reported to be 6.5 or even lower.

Back to geophagines, now …to give you the reference I was talking about :

·         Book(s): the real “bible” of any dedicated earth eater keeper is (at least to me) the book “South American Eartheaters” by Thomas Weidner, edited by Cichlid Press. Given the chance to own one book on Geophagines, this should be your choice …

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