Otos and plants

[Psy]

Large leafed plants and vertical flat rock surfaces (especially slate). Not essential, but likes bogwood and a large rounded substrate. Live plants seem essential to the long term survival of this fish.

Most videos and pictures though, show them being caught from leaf litter. Do they have access to submerged plants at other times of the year, or are most of us not crazy enough to put enough light on a tank full of leaves to ensure enough algae?

[dpm1]

My otos are frequently seen on the substrate and horizontal surfaces that grow algae or catch food. This is as well as ths expected flat , vertical surfaces including not just tank walls, wide leaf plants etc but also wood and Vallis.

I also have a fair few Hisonotus leucofrenatus 'Niger/Black otos' and these are even more likely to be seen on the substrate. A number are kept in a pygmy cory breeding tank where they spend almost their whole time in leaf little or on the sand, only rarely do I find them on the glass and that's usually when tank lights are on but the room is darkened.

I'm hoping to get some more sand over the coming weeks and rescape a couple of tanks. I may try the leaf litter in the tank with standard otos too and see what they make of it. I have noticed in the last they like to settle on 'dirty' substrate but the gravel in their currently is a little more coarse to suit Nanochromis tranveste cichlids and so food tends not to lay on the top as well, and algae doesn't grow on it as its still too fine to be immovable by the diggers.

[Jools]

Most videos and pictures though, show them being caught from leaf litter.

Can you point me in the direction of some of these?

Cheers,

Jools

[Shane]

This is really a dry season versus wet season thing. In the dry season when the water is low they are easily captured in huge numbers by seining leaf litter. I actually have some very nice video of collecting them in this manner. In the dry season they feed on the actual decaying leaf litter. I am sure it has almost no nutritional value (other than what they get from each leaf's biofilm), but they can eat all of it they want.

At one time I set up a 10 gallon leaf litter tank with oak leaves to test this. The Otos were quite happy and kept on good weight with only 1-2 feedings a week of wafers. The other 5-6 days they ate the leaves. I kept them this way for several months.

In the wet season they will move amongst the submersed plants and tree branches to feed near the surface where light can easily penetrate the water to cause algae to grow on these surfaces.

It is feast or famine for Otos. Fresh algae and plants in the wet season and decaying leaves in the dry season.

Aquarists do not usually give a lot of thought to the season changes, but in reality every planted tank is a wet season tank while tanks with just driftwood, stones, and leaf litter are dry season tanks. Both tank styles are natural reproductions of the same habitat at different times of the year.

-Shane

[dpm1]

They may go where the food is, however nowadays there is a trend for aquariums to be almost too clean and perfect and imo this is one instance where the overzealous nature of some keepers is actually forcing the fish away from their preferred food source.

I'm afraid the wet vs dry season argument of following the algae blooms to the surface layer and thus more plant stem oriented as waters rise cant be replicated in the vast majority of aquariums where even 50cm depth is often considered on the deep side. The light penetrates to the bottom regardless (unless very weak light/blackwater setup) and added to this is ambient light often from at least 2 or 3 sides if not all round..

This is one instance where a tank just cannot fully replicate nature. My otos and hisonotus simply prefer the substrate/horizontal flat surfaces, ideally with leaf litter, than feeding higher up - although it appears also to depend on tankmates as they are easy bullying targets (although ive had them with a betta which simply nudged them and corys out the way including lifting them off the floor to search underneath for food! Fish don't read rule books!)

They do however differentiate when resting (sleeping?). The otos still cling to plats, the hisonotus in general, and most certainly not in the pygmy cory tank, do not and stay rooted to the floor.