My River tanks

[Tony T.]

Try after the tutorial from Martin, thanks







New home for Gastromyzon sp SK01

In these pics what are those tiny white spots all over the body? From the front they seem to rise out away from the skin [similar to tubercles or papillae?].

[Hendra]

I believe the white (little) spots is tubercles

[Graeme Robson]

Superb!!



Graeme.

[Tony T.]

Thanks. Make me wonder do tubercles appear on other Gastromyzon species?

[Hendra]

I think tubercles also found at another species of Gastromyzon, esspecially at snout and dorsal part of head of mature specimens. In Inger and Chin paper (about Gastromyzon spp), all described species have tubercles.

If you interested I can send you the file.

[Tony T.]

I send you PM for detail so please check

[Martin Thoene]

OK guys, time for out-of-the-box thinking again. In my Hillstream article I go a lot into my personal theories on the body shape of these fish. Reading information on aerodynamics leads me to believe that all these sucker-type fish have body shapes honed to produce an effect in fast flowing water.

Theoretically, you would think that the smoother the fish's body was the "slipperier" it would be in the water flow right? Same thing with planes....smoooooth. Except there are some aircraft that have some weird detailing on their wing surfaces........



This is a Gloucester Javelin. The small vertcal protrusions on the wing's upper surface are known as "Vortex Generators". Each one creates small vortices of air over the wing and increases the speed of the laminar flow across the suface. Effectively, this helps with wing lift at high angles of attack, but also increases the air retention to the shape of the wing, increasing control for the pilot. The air more closely follows the aerodynamic shape of the plane.

Now if you look at a Gastromyzon compared to a Beaufortia......




Gastromyzon are a lot "taller" in profile than a Beaufortia. Maybe the water flows over Beaufortia easier because of the low-profile, effectively a low chord wing shape? Gastromyzon are of a heavier chord shape (i.e. thicker cross-section in profile) and maybe this creates a laminar flow seperation? By having little "bumps" on the body I would theorize that they must create vortices and force water to cling more to the shape, ultimately exiting behind the fish with less drag and tending therefore to lessen the tendency to move the fish from its intended resting place.

You can get weird effects from dimples rather than protrusions too.....golfballs.....

http://www.aerospaceweb.org/question/ae ... 0215.shtml

I get up close and personal with vortex generators almost every working day. I do a lot of refuelling on Cessna 172s and 182s with them fitted.
The fuel filler is just out of picture on the right.

Anyhow, that's my 50c. They may have a biological function in Gastromyzon (don't know what) but my bet is they are of aero (read hydro) dynamic benefit.

Martin.

[Tony T.]

It depends on whether or not both sex of Gastromyzon have similar tuberculation pattern. For some cyprinids such as Barilius and Zacco only males have large and numerous tubercles while females have much less, and they are known to fight other males a lot, often violently. In this case it can be easily seen that tubercles are used for fights.

[Martin Thoene]

It depends on whether or not both sex of Gastromyzon have similar tuberculation pattern. For some cyprinids such as Barilius and Zacco only males have large and numerous tubercles while females have much less, and they are known to fight other males a lot, often violently. In this case it can be easily seen that tubercles are used for fights.

Inger and Chin, 1961 quotes various species having tubercules, some definitely nuptial in nature around the head area. These tend to be bigger in males during breeding activity and in some females present or absent.
I'm looking at these body tubercules as something different. Based on what i know and see of Gastromyzon territorial battles there's no real use of these features as weapons.

Head tubercules, particularly in Pseudogastromyzon seem to have great significance because it's always the male with the best "rack" that seems to be the one breeding in an aquarium environment. He is dominant by his obvious "maleness" and is the one that the females choose to mate with. I've seen sub-dominant males doing courship dances with females, but never seen one be accepted. They always go for the best looker.

Martin.

[Tony T.]

Do females in OD have body tubercles too? It would be interesting if such swimming aid is missing on one sex.

On the other hand maybe for hillstream loaches tubercles are more for display than actual use? In Schistura I had seen males with enlarged cheek use their cheeks to hammer their opponents during disputes of similar species, so we know at least one use of the enlarged cheeks i males. Schistura fights can be quite violent, however, with actual damage on both side.

[mamaschild]

Absolutely gorgeous loaches

If I could talk my hubby into having a tank with just rocks in it and not full of plants, I would definately have a bunch of these guys. I love the way they swim, and the patterns I've been seeing lately are wonderful.

[cybermeez]

Nice chubby Hillstreams! That Kalimantan Gastro is stunning!

[Hendra]

My first concept is to replicate the natural habitat of them, there is no any waterplants found in Gastromyzon spp niche since the water very rapid, but I got a nice experience from adding some plants in Gastro tank yesterday.

Casually, I added some Piptospatha grabowskii in one of my river tank, the plants is from another (planted) tank which was my first river tank ( I already remove the R/T manifold and changed the setting to be just planted tank ). Since the plants have algae at the surface of the leafs, some Gastromyzon didn’t want to neglecting the chance to got some yummy vegetable snack since they only consume bloodworms everyday.






They look quite happy with the vegetables, so I try to put a small rock (from another tank) which have green algae at its surface in Gastromyzon tank. After several time I found the surface of the rock become clean, only small amount of algae left.

Pic of comparison between the “clean” rock and algae rock.




So, I put a bigger rock. The result is ALL Gastromyzon sp. come together to this rock and its become an “algae party”.

The party move from the right algae rock (the same rock with little “clean” rock in pic above) to the left one.
















View from top.









Another “Sunday Algae Party” at another tank.












This experience give me an idea to make algae culture, perhaps some rocks in water container, with the help of sunlight can provide nice foods for Gastromyzon spp.

The tank where the plants and rocks come from. Have planning to re-setting the layout with some driftwoods.

[Mike Ophir]

beautiful photographs....all the more reason to get a big river tank!


Mike

[shari]

Very cool party!