Art by Alexander Vasiljev, Copyright © 2017


Friday, May 23, 2014


While studying and working with orchids in my past career, I was fascinated to watch how orchid flowering buds develop into one of the most structurally complex flowers in nature. Under favorable conditions, each orchid will take its time to open their flowers until reaching perfection.

Phalaenopsis flowers at different stages of development

During raising ranchu fry, I noticed similar tendency in developing tails. At first the tail is narrow and small, opening slowly into that desired shape. It is true, not every fry will have that "perfect" tail, but with little or no experience it is easy to overlook what is good, while culling at an early stage.

Tail development in ranchu fry. From left to right: 11, 16, 21 and 35 days from hatch

For me these were the first culls and despite of a lot of reading and studying many photos, I was hesitant. One thing I learned is NOT to look for all imperfections at once. Each stage of ranchu development will open to more strength or weaknesses. As a novice, I used a method of choosing and culling poor fish, instead of seeking out fish with high quality and leaving the rest behind. This method is more forgiving and I had a better chance of keeping good quality fish and not overlooking it. However, with this method it is harder to keep the quantity down and it is very easy to overstock. The fry is growing fast and more culls must be performed. It is a must to maintain the right stocking density! As the number of BBR is reduced, I will be able to implement the reverse selection method and choose the best quality ranchu out of the rest.

Looking ahead, I think it might become more difficult to select, when BBR will start transitioning into CBR. Besides the physical standards one must seek perfect swimmers that ranchu are famous for and don't forget to pay attention to each fish personality.

Thursday, May 22, 2014


Third cull is done with only 89 ranchu remaining from nearly 600 initial fry number. The focus is still on the tail shape. Now it is more or less easy to spot any imperfections, still looking from above.

After the baby ranchu reached one month of age since hatching, I stopped feeding newly hatched brine shrimp and switched them to TDO Chroma Boost B2 granules, supplementing it with Wolffia and a grounded mixture of Ranchu Lord and Hikari Purple pellets. I have also started to give them frozen brine shrimp and soon frozen bloodworms. BBR are growing very fast and need most nutritious diet to develop a good foundation.

35 days old ranchu, 1.2 inches (3 cm) long with perfectly developing tail 

Sunday, May 11, 2014


On their 24th day since hatching the ranchu fry are 6/8 inches (20 mm) long, demonstrating excellent growth rate. The tails are now much more developed, with more recognizable traits. This round I was trying to determine six more types of tail and body deformities, in addition to five that I was seeking out during my first cull ("First Cull - It's All About The Tail"). I had to pay maximum attention, since this time there were so many criteria to adhere to. For the first cull I had to go through approximately 600 fry of which I kept 40%. After the second cull I kept only 60%, which left me with 130 individuals but fairly nice looking so far. The next cull will happen sometimes next month. Below, are the diagrams of tail's defects outlined in blue for cull #2.

DESIRED tail shape and
degree of openness
Curved spine line and
misaligned tail
Tail has no split in
the middle
Tail core is too thick
and rigid

Tail is open but
Tail is split all the
way to peduncle

Tail is not open and
is asymmetrical
Tail side lobe tip
is deformed

Tail is not open. Red line
indicate desired angle
Tail core edges

regressed tail
Tail is not open, side lobes
extend too far back

Friday, May 9, 2014


Baby ranchu are not ready to be judged from the side until they are about 3 month old. But it is so exciting to see them taking the right shape. Twenty days ago they were barely animated larvae and now we are talking fish!

Side view of a ranchu fry on its twentieth day from hatching

Thursday, May 8, 2014


It is exciting to watch the ranchu fry grow. Almost every day, I notice changes in their look. At this time I feed them heavily with newly hatched brine shrimp as well as a mixture of ground pellet variety (Japan Ranchu Lord, Saki-Hikari Purple and Omega One Super Color Kelp) and Wolffia. The time between now and when they start changing color is EXTREMELY important. Their skull, skeleton and tail are forming now to become the foundation of a beautiful ranchu. If you miss this time, you miss the ranchu.

Ranchu on its twentieth day since hatching. The tail shape is coming through

Tuesday, May 6, 2014


It is time to give fast developing ranchu fry more room. Right stocking density is crucial for grooming healthy and well shaped fry. At this stage, when the fry is around 1/2 inch (1.5 cm) no more than 100 per 3.3 sq.ft (1 sq.m) is appropriate. As the fry grows the stocking density must be adjusted. Again, since my set up is quite minimalistic and I do not have room for more water containers, I used my 120 gal (454 L) pond to accommodate the next project - a larger size nursery for the ranchu fry.

All it took was four bamboo sticks, four rubber bands and a 400 micron mesh to make a net. The net was suspended from the bamboo frame in the pond, keeping the water depth inside the nursery of 4-5 inches (10-13 cm). I added an airstone and a hose to constantly supply clean water to the nursery, pumped from the UV sterilizer (see my previous post "Filter Box Addition and Improvements"). Water pours from the hose into a "diffuser", a bunched up fine mesh, to keep the water movement to a minimum.

Since newly hatched brine shrimp size is up to 400 microns, I chose 400 microns mesh to keep them from escaping. Any finer mesh would get clogged more often with algae and the rest of the derbies.

Saturday, May 3, 2014


Two weeks since hatching, this ranchu fry is close to what I am looking for at this stage. Still, all attention is on the tail. I am eager to see how the tail will develop in the near future.

Ranchu on its sixteenth day after hatching

Friday, May 2, 2014


Since the eggs hatched, I was culling any fry with deformed body as soon as I can identify it. But today, two weeks from hatching, I went through a major cull, ending up keeping only 40%.

The fry is now half an inch (13 mm) long. Even though the tail is now more or less defined, still, it is hard to detect its details and asymmetry between the tail lobes and shoulders, and the tail split. Today my goal was to select the fry with a straight body line and with the most open tail, which ideally should be 180 degrees, but not narrower than 160 degrees. The culling was done through looking from above. Below, I put together a few diagrams to illustrate what tail shape and development I was looking for. Misshaped tail is outlined in blue and should be the reason for disqualification. The photos are not of my actual fry and are used only for illustration purposes.

The next cull should be carried in about two weeks or when the fry reaches 6/8th of an inch (20 mm), and the tail is further developed with more details visible. I anticipate even greater reduction in numbers then.

Desired tail shape and
degree of openness 
Tail has no split in the middle

Single, regressed tail
Tail is not open. Red line indicates
degree of desired openness

Tail is not open and
is asymmetrical
Tail is open but asymmetrical 

Thursday, May 1, 2014


Two weeks old today since hatching. The tails are almost fully open and some are looking fairly nice. First big cull will need to happen this or next week.


Started last night and continuing this morning another spawn is taking place. Sixteen days past since the first spawn. This time ranchu are spawning in my new media - artificial "hairgrass" plants (see my previous post "Thoughts On Mops"). I have attached weights to each rosette and arranged them in a group on the bottom of the pond.

What I like about this substrate so far is that the eggs are spaced evenly, which is very important for their development. The plant's leaves are spread out in all directions exposing eggs to a good water circulation and supply of oxygen. This "mops" will be very easy to remove after the eggs hatch without sacrificing any fry. Lastly this medium doesn't seems to be catching any derbies. The ranchu seems to like my spawning "forest" too.

Ranchu eggs attached to an artificial plant