Samps said:
Any info on them? Diet, water parameters, etc...??
Nice pics!
diet: depends on species and size. Generally, they eat small crustaceans from the substrate (snails, shrimp, aquatic insects and larvae, etc). Larger species also eat small fish like Killies. In theaquarium, live blackworms or pretty much any other small live food, frozen bloodworms and I have had success with frozen market prawn (tiny pieces), freeze dried krill and bloodworms, and even pellets and flakes with a couple of well acclimated "dolphins". As with any fish, VARIETY.
Water: avoid extremes. Mine have done well in nuetral PH, temp about 80F. But I believe some species may live in lakes with harder more alkaline water??
Behaviour: Varies a lot with species. All seem to be fairly aggressive and territorial, though they don't have the mouths to do a lot of damage to other fish. But, they will really harrass other mormyrids. I keep 4 different individuals in a 110 gal planted, there are skirmishes now and then, but they all have their palce and do fine (about 4"-7" range). They do like to hide and are mostly nocturnal (they seem to be most active in morning right before sunrise) IMO, the dolphins, specifically M. kannume or similar species, are the most interesting. Mine are VERY active, and NOT nocturnal. They are active day and night.. like a stingray. They do not hide... EVER. THey are EXTREMELY intelligent, will interact with you. I had one that after a year, would actually rub on my hand when I had my hand n the tank.. like a dog looking for attention. My dolphins seem to really like to harrass my bichers and fire eel and clown loaches, with occasional hit-and-run strikes at my arrow or other fish. Looks like mostly for FUN.
Can they be kept in groups? Hmm... I had 6 M. kannume. the divided themselves into 2 groups of 3. One dominant, one not. THe dominant group is thriving and active. The other group is down to one week individual who is not allowed to eat (the other group of 3 keeps him cornered in one little part of the tank). I suspect he will die soon. So what will become of the GANG of 3 I have left? we'll see. IN that group, there is one FAT, PEFECT, DOMINANT fish... but the other 2 seem to hold their own fine.
So, that's my experience with "dolphins". For the other species, not a whole lot to say. THey are interesting, cool looking, neat fish, but not nearly as fascinating or "interactive" as the M. kannumme.