Beiträge von FranciscoB

Only one animal, or as a group in a very large tank. In their natural habitat, adults are schooling fish, and in addition to that, they are migratory as part of their reproductive seasonality. They do so in large shoals.

Perhaps the INTRAspecific aggresion we see in aquaria (almost always too small) does not occur as much in nature, or, alternatively, it may play a role in the social context of migratory behavior.

But in commonly sized aquaria, more than one specimen will almost always result in a lot of picking and hierarchy fights, usually to the demise of a lesser specimen (small or less self assured).

It is great that these fish exhibit little to no- INTERspecific aggression, and generally are rather tame towards other fish, both larger and smaller. Mine (20-25cm) is very docile (though seeks food very aggressively) and friendly, and a delight to have (meet him/her below). She/he likes to be pet on the top of the head.

Hi Axel,

+1 about the (otherwise good pictures) not showing well the issue.

In my opinion, the exophthalmy (googly eye) may not be related at all with the tumor-like ailments, nor the flashing that you are observing on your fish. I think they are separate issues happening at the same time.

Regarding the growths, I am afraid that indeed, it may be what is often called 'fish tuberculosis'. Very likely, this came into the tank with the recent introduction of the platys, even if those may not have displayed it. I say that, assuming that your aquarium had the rest of the fish for a long while in good health, prior to the platys; I don't know the history so I may be wrong. My opinion is that 'fish tuberculosis' is a general term used to describe ailments caused by actually a number of different agents, and not a single causing microorganism. If viral, there is no effective treatment. If bacterial, it should be treatable but you may need a combination treatment, as the actual agent is not known to you.

Regarding the googly eyes - In my experience this can occur from either a physical injury to the eye (somewhat uncommon), but is more frequently due to chronically insufficient water changes leading to accumulation of nitrate to high levels (beyond 20ppm). The fact that two fish showed it argues against physical injuries separately on each. Again, you know the history of water changes and nitrate in the tank, but I would recommend to check that. I have been able to improve the health and appearance of googly eyed fish I have rescued, just by providing excellent water quality via frequent and large water changes as a routine (for me, no less than 50-70% weekly). It takes months but it does recede, even in cases of whitish films over part of the eye.

A different observation is that the ideal conditions for long term health of the altum and Manacapuru angels and that of the platys are at odds. Softer, lower pH versus harder, higher pH. It is true that both are adaptable (especially the platys), but they are not an ideal combination. Something to think about for the long term. Better to look for vivid colors among more compatible species.

I hope others are able to better diagnoses, especially treatment suggestions. Good luck!

Francisco

Very nice!

Thanks for posting this.

Very cool! Thanks for sharing.

One possible explanation; there could be others - If the rain water collects water that has ran over the roof of a building, the roof material has every chance of altering the pH of the collected water. Rain water collected in the open (not after running over a roof) should not be affected and provide a good comparison.

I meant to say - "...and the fish continue to NOT eat my plants."

My planted Metynnis spp. aquarium continues to go strong, and the fish continue to now eat my plants. Three M. maculatus in this tank are 22 years old, and the single M. lippincotianus in the picture is ~ 4 years old. I had to take out three fish to another tank, due to excessive harassment of the adult males to the single adult female. Eventually they will be put back together in a larger tank.

If you like Sagesalmier (Metynnis, Myleus, Myloplus, Tometes, etc.), and have found ways to keep them in planted tanks, please do post images! Many of my colleagues keep telling me it is not possible. What do you think?

Cheers, Francisco.

Wonderful!

Thanks so much for sharing!

Hi All,

I appreciate and respect your views and agree with them, up to a point. And I very much thank your for showing your fish and sharing your experiences, which I value highly.

Yes, I would rather have a large school of Hemiodus in a very large tank. However, for me, that is not possible for several reasons:

Regarding the Hemiodus-

1) I have only seen these fish for sale twice in my life, once at a "natural" aquarium in Cali, Colombia, and the next time was when I bought these fish (x4) at a store in New Jersey. Never again. Increasing the size of the school seems i possible, both because of where to get from, and because the size of the tank; 2) Under my care, they have grown from ~ 5cm to ~ 14 cm in close to 3 years, and have actually become calmer during that time; 3) when I bought them, they had injuries in their "noses", indicative of bumping into walls at the store tanks; the last time I saw any "nose" damage on my fish was at least 2.5 years ago, a few months after I got them. They are now larger, healthier, and calmer, they don't scatter around when I approach, and instead, come forward inquisitively to receive the food I offer or the taps on the glass they have learned to recognize as rewards; 4) If I were seeing any evidence of the fish not doing well, I would conclude that indeed they should not be kept in the 125gal tank I have. However, I don't see any evidence of that being the case. 5) Unfortunately, a tank larger than 6 feet (180cm) is just not possible at this time, unless it is built in place, and frankly, there are other priorities ahead of that.

Regarding the Semaprochilodus (I believe this is what you refer to as 'night tetra') -

This fish is currently 8-9 inches (20-23 cm), and also came to me as a baby (~6.5cm, photos attached). This fish eats from my hand daily and acts as a well-trained puppy. Never does it crash around, becomes startled or anything like that.

Yes, I do know both Hemiodus and Semaprochilodus are schooling fish. In fact, Semaprochilodus are migratory too, which is something even the largest of aquaria cannot offer. I also know that Semaprochilodus can grow to a foot in length (30cm), as I have seen them as a food fish in Colombia, but I also know that it is not he bulk of them who reach that size, and that it takes a number of years to reach that size (about a decade to a foot long fish). But I don't see anything wrong about having them in a tank, which although not as big as it could be, it is not too small or cruel, so long as they look happy, act happy, look healthy, and have the signs of health to go with it. One day, hopefully soon, I will have a larger tank, but it does not seem to me their current situation is cruel or harmful to them, although it is certain that I could not have more fish in there.

This is very different from the often seen large Astronotus in a 40gal tank, or red tail catfish in a 55, or the adult goldfish in a much too small aquarium.

Again, with many thanks and respectful camaraderie.

Francisco

Hi SailFin and Ralf,

Thanks for your messages and for posting beautiful images of your tanks, of your Hemiodus gracilis, and for sharing your experiences.

I completely agree that I will need a larger tank than my 180cm (125gal). Unfortunately for now, that is what I have. The fish continue to do well, and to grow, although now at 7-7.5" (~14cm), they probably won't get any larger.

They have actually became calmer as they have grown, now being quite chill, and allowing me to do water changes without much fuss. I do need to be careful, as they are big and fast. They eat almost from my hand.

In October of last year I lost one to a tragic mistake on my part. Accidentally I left one of the lids of the tank open overnight, and the smallest of the four jumped out (photo atached). I was devastated and frustrated appreciating my error. Alas, things happen. It was the smallest, then a bit over 6 inches. The three left (2nd photo attached) have grown since by about a half an inch and are all at about the same size. They are my favorite fish.

I guess not that many people keep them but they are very much worthwhile the effort. Super gentle, active and very beautiful. Cheers!

Hi Basti,

These are not books but icthyological works on various groups within the very large genus Crenicichla. Some are useful to aquarists like myself, but are aimed at actual icthyologists. At least the 1st includes pictures of live specimens, which may be useful to you. I believe the links should be live, as they are for me. Enjoy, Francisco. [One day, "the book on Crenicichla will be available!]

1-

[HTML] Phylogenomics of pike cichlids (Cichlidae:  Crenicichla ) of the  C. mandelburgeri  species complex: rapid ecological speciation in the Iguazú River and high ...

L Piálek , E Burress , K Dragová, A Almirón, J Casciotta … - Hydrobiologia, 2019 - Springer

2-

[HTML] A review of the species of  Crenicichla  (Teleostei: Cichlidae) from the Atlantic coastal rivers of southeastern Brazil from Bahia to Rio Grande do Sul States, with…

SO Kullander , CA Lucena - Neotropical Ichthyology, 2006 - SciELO Brasil

3-

[HTML] A new pelagic predatory pike cichlid (Teleostei: Cichlidae:  Crenicichla ) from the  C. mandelburgeri  species complex with parallel and reticulate evolution

L Piálek , J Casciotta , A Almirón, O Říčan - Hydrobiologia, 2019 - Springer

Beautiful. I love the background wall !

I.t looks awesome now and will much more so as the plants continue to develop.

Congratulations Roswitha. Very nice tank with lots of potential.

Good luck with it and I look forward to seeing it populated and landscaped!

Cheers, Francisco

My single wild Pterophyllum dumerillii (long-nosed angelfish)

Species epithet should be "thoracatum" - Hoplosternum thoracatum, the Port Hoplo.

Has the genus name now been changed to Megalechis?

Beautiful fish. Thanks for sharing!

Absolutely v=beautiful. Never had them, but always wanted them. Not seen often for sale, at least in the USA.

Beautiful! Thanks for sharing.

They have almost completely changed from their juvenile colors (lots of white specks) to quite close to the adult coloration.

I wish you continued good luck and success with them!

Francisco

For silver dollar enthusiasts -

In an interesting paper [Pagezy & Jegu 2002. Bull.Fr.Peche Piscic. 364: 49-60, free online], the authors describe the feeding ecology and cultural appreciation for the fish ("kumaru" - large silver dollars) and the fishery for them in the Wayana region of French Guyana.

Image 1 shows the 3 fish taxa discussed (names of genera not all up to date).
Image 2 shows the aquatic plant the fishes show the highest association with: Mourera fluviatilis (Podostemaceae), a recurrent element in the ecology of many herbivorous Serrasalmidae.

Image 3 shows depictions by Wayana children (ages 8-13) of the fishery, showing both bow-and-arrow, and standard line and hook fishing.

Figs 2 and 4 show awareness by the children of consumption by the fish of Podostemaceae plants on the rocks, whereas Figs 5 and 6 show awareness by the children of fish consumption of terrestrial fruit falling in the river from riverine fruit trees.

Rarely do we see such a vivid depiction of both the fish ecology and the cultural appreciation for them by the locals!
I enjoyed the article very much. Hopefully you will like it the excerpt too.

Hi All,

As currently established based on morphological revision (Schultz 1967), and fairly recent molecular phylogenetic analysis (Anderson 2016), there are 3 accepted species of angelfish in South America: P. scalare, P. altum, and P. dumerillii. (See also Baensch & Riehl books).
By far, the majority of what is seen in the hobby are P. scalare, including variants and commercially bred strains, and a few P. altum available from importers. Relatively rarely do we see Pterophyllum dumerillii, the Long-nosed Angelfish. Although not rare in its natural habitat, it is less common and very rarely available. [It is still sometimes referred to by its junior synonym, Pterophyllum leopoldi, described within my lifetime. Caltesnau’s name, honoring Dumerill, has precedence by over 100 years!]
I came across a single left-over wild-caught young fish at Absolutely Fish in NJ in 2017, and purchased it immediately. I knew it was special. It has grown to become a very beautiful fish as you can see in the pictures. It is very assertive, doesn’t bother others and doesn’t put up with crap from anybody. Notice the distinctive features: 1) long snout, caused in part by, 2) the total absence of pre-dorsal notch (continuous line of forehead), 3) the presence of the dark, blotch (not a stripe) between the mid-body and the posterior black vertical stripes.

Does anybody have specimens? Would you show them here? Heck, images of any other Angels would be cool too. Something you are proud of.

Cheers!

These guys love their seaweed, and the dollars used to like lettuce but no longer. I also believe nori is better for them, cheaper for me, less polluting, and closer to things they may eat in nature despite being marine. Also, this way they don't eat the aquarium plants.

Four tanks - 1) Silver dollars (Metynnis , 3 spp.), 2) Flagtail + friends, 3) M. boesemanni rainbows (young, growing up), 4) Congo + lemon + cardinal tetras (young, growing up). As shown, competition with bushy-nose plecos can be fierce, even if those get their own treats at night.

Cheers,

Francisco