In a colourful world
While the morphological variation was important in the creation of koi as they are today, the expression of color is certainly central to defining koi as ornamental. It is true to say that without colour koi would never have developed. Skin pigment cells produce the various colors. Erythrophores and xanthophores contain carotenoid pigments and produce various shades of red or yellow. Melanophores are black and contain melanin. In addition, further hues like green and light blue are formed due to the superposition of pigment cells in the skin.
Figure 1. A single zebrafish melanophore imaged by time-lapse photography during pigment aggregation. Because black pigment cells are connected to the central nervous system they can react to the environment sensed by the fish. Click this image to see how the pigment cells of a tilapia respond to a drop of adrenalin, simulating fight-or-flight response, thus causing stress in the fish which in turn triggers the pigment aggrigation..
Jumping fish and swimming speed
Many koi owners have experienced a fish flapping on the lawn because it jumped out of the water. Many have spent fruitless hours trying to revive these suffering fish in the hope of a miracle happening. We want to blame someone for this mishap and are quick to find the culprit, usually a protection net that was carelessly closed over the tank, or worse, failure to use the net at all. They call that negligence.
There may be other reasons for fish jumping. Rushing, bubbling water is one. A waterfall, or water bubbling from air stones or return pipes dangling near the pond edge ...
Media and the Diffusion Depth of the Biofilm.
The diffusion depth presented impacts on the evaluation of removal rates and treatment performance of MBBR carriers (biofilm media). Dr. Markus Geiger and Bernd Rauch from Multi Umwelttechnologie AG discuss important aspects to consider.
This technical article points out the importance of oxygen diffusion depth of the biofilm. The ideal requirements can be fulfilled by thin, disc-shaped and porous carriers. This has impact on the design of biological filters irrespective their application whether for wastewater treatment, recirculation aquaculture systems (RAS) or domestic koi ponds.
The Mutag BioChip™ media for moving bed biological filters.
Aquaculture professionals, breeders and koi communities use Mutag BioChip™ as biofilter media for best water quality and large savings on OPEX
The Mutag BioChip™ speeds up pond filters with 3,000 m² of active surface area per m³ of filter media for the steadily growing nitrifying microorganisms for reducing the ammonia which is produced by the fish.
Ever since I got involved with koi shows the seeming endless chore of water changes was a concern of mine. Not only was it a labour intensive task requiring constant attention and management; it also was a very wasteful act. On more than one occasion we
Gas bubble trauma or Gas bubble disease
Some time ago I received this email:
Hi - I am from Malaysia and a fairly avid koi hobbyist. I would like to seek clarification of DO saturation limits. In page 89 of your book, you have stated 300% as saturation limit with minimum as 6 ppm.
This article discusses the practical use of airlifts in aquaculture and garden ponds. A little beter understanding of how it works will make it easier to apply more efficiently. First we look at the history and theoretical framework and then the practical application.
We are all like that. We want the best that our money can buy. Sometimes we simply want the best car to drive out from behind our walled properties into the street. But when we sit back and consider the options, our senses override our pride. The money in our pockets speaks.
StabHi Organic Substrate are pebbles that has been tested to stabilize the pH while biological nitrification processes continue.
Used StabHi to increase the pH, alkalinity and hardness of aquaria and fish ponds all at the same time. The biological processes in aquaria and fish ponds need the correct levels for pH and alkalinity to function properly. Equally important is to maintain the hardness by adding calcium and magnesium ions.
PVC Gate Valves have a proven track record of more than 40 years for being reliable, serviceable and economical in areas where the control of fluids at low pressure is required.
They find application in a wide range of industries from cooling towers to agriculture, from waste water control to nuclear plants.
Popular in the fields of aquaculture and koi ponds, these low pressure valves are space saving and do not require unions. They can be fixed or replaced without upsetting the pipe work. Simply undo the bolts, slip the offending part out and replace it.