From Incubation Systems
HATCHING JARS made from plastic: Used successfully for over 20 years by federal, state and professional hatcheries and fish producers here and abroad, this McDonald type hatching jar become the standard of the fish farming industry. It can be used for a wide variety of species like: Salmonids, Thymallids, Coregonids, Acipenserids, Percids, Cyprinids etc. Made of clear, high impact, easy to clean plastic, this uniquely designed hatching system enables uniformely distributed water to rotate fish eggs ever so gently and evenly. It works very simply as water from the supplying hose is directed down to the open-ended feeder tube in the center of the jar. The tube (diameter 3 cm = 1.25 in.) easily accommodates the prefered water flow so that the eggs at the base are rotated uniformely and precisely.
The jar has a height of 45.8 cm (18 in.) a diameter of 16 cm (6.25 in.) and a volume of 6.86 l (232 oz.). It weighs only 2.5 pounds (1.1 kg). A circular filter/mesh screen prevents eggs from spilling out of the jar, while the large spout (length 7.5 cm = 3 in., width 5.3 cm = 2 in.) at the top lets hatched fish swimm out at just the right time. Now you can virtually duplicate nature's way of hatching eggs with this durable, seethrough incubator jar. So next time you want your eggs 'over easy', make sure you are using this hatching jar.