Piranhas Forum banner
1 - 7 of 7 Posts

10,481 Posts
Discussion Starter · #1 ·
P-fury members: This spawning record pertains to the species S. spilopleura. The photographs, including the accompaning juvenile photo appears to be [in my opinion] that of S. spilopleura CF also called S. medinai by hobbyists. I will later send photos from this document to add on for this article. These photos have been recycled often by TFH.

Spawning Piranhas by Emanuel Ledecky, Cincinnati Aquarium [Condensed version by Frank Magallanes, OPEFE, January 27, 2003].

A 300 gallon unlandscaped tank at the Fleischman Memorial Aquarium housed 3 adult piranhas. These were a gift of the Shedd Aquarium and were probably the result of an earlier successful spawning described by Bill Braker. For reasons given in his article, Braker had identified them as Serrasalmus spilopleura and the accompaning photographs matched the Cincinnati fish exactly, but remains uncertain because many of this group, however, is very confusing. 2 of the 3 fish were about 7 inches in total length, the 3rd about an inch shorter. All fish showed heavy scar tissue and repeated damage and regeneration. Their unpaired fins were almost non-existent. In an attempt to give them greater security and improve the appearance of the tank, driftwood and aquatic plants were added. Still some fin-nipping went on. I decided to add other fishes to act as a distraction, but one does not simply add other fish to a piranha tank. Up this point live fishes, mostly bluegills and goldfish, were part of their diet and were quickly attacked and devoured. Guppies were totally ignored, apparently too small and beneath the piranhas' notice. A large firemouth cichlid was then tried. One day a piranha met his his charge and bit off this nose!

At the time I happened to have a surplus of Tilapia sparrmannii and tried these alert and cagey fish next. These did well and all survived. More valuable fish such as Exodon paradoxus and Cheirodon axelrodi were then added. The community thrived and the strategy worked to some extent. The piranhas still chewed each other occasionally, but their fins began to regenerate. Stips of beef heart became the main part of their diet. During the winter the water temperature fluctuated from 67 to 76 F. The fish occasionally chased each other and were observed to assume a tight head-to-tail position, circling as if attempting to bite each other tails. This behavior in itself is not unusual, as head-to-tail circling, tail slapping, and similar displays are seen in a number of different species, even among fish of the same sex or those too young to breed. I suspected more was happening. The color of all the piranhas deepened. Instead of silver, the body color became smoky gray and the fins almost black. The circling became more frequent; sometimes all three fish participated.

February 11, while making a check after the close of the aquarium, I noticed two piranhas, one smaller than the other, side by side in midwater. Finding two piranhas so close together and not helping themselves to a piece of their neighbor is most unusual. As I watched, the fish slowly rose by beats of their pectoral fins. Just beneath some floating water sprite they tilted sharply upward, came close together, trembled, and parted. A cascade of eggs was falling through the water and was almost instantaneously devoured by the Exodon and the parents themselves. These eggs were scooped into a tray and I noticed little translucent globules on the roots of the floating water sprite. There they were in numbers, clustered like plums on a tree!

Methylene blue and an air stone was added to the tray and our hard water cut one-half with snow water. In 24 hours embryos could be seen moving in the eggs, and a day later they began to hatch. The young hung belly up in a horizontal position by a thread extending from their yolk sacs. They became quite active; by nine days after hatching, when almost half an inch long, all fry were free-swimming. From the beginning, brine shrimp were eaten and in only a few days young white worms were eagerly accepted.

I prepared the tank for another spawning by adding a large water hyacinth with long trailing roots and a piece of unwound rope. A month later to the day after the first spawning, on March 11, the piranhas again spawned. Both the water hyacinth and the rope were ignored, the eggs were again deposited on the roots of the water sprite, with some adhering to a piece of driftwood.

There appeared to be no guarding by the parents and the eggs were left undisturbed. A short time later all the eggs were gone. I was now fairly certain that the spawning pattern differed from previously published acccounts. I was so certain I predicted the next spawning time and date. On April 10 the third spawning took place, again in the late afternoon. This part of my prediction proved true. I had, however, been too authorative with only limited experience. In this and other subsquent spawnings the water hyacinth roots were used, and the fish prepared the site by chewing some of the rootlets off, forming sort of a hollow near the center.

Observation of many spawning runs did not clarify the sexes of the fish. Even though I placed my wife at another angle to the spawning pair and we both watched intently. Neither of us could tell which fish actually released the eggs. The motion, speed, and the close proximity of the vent areas made it impossible. The smaller fish was darker, more angular, and had less fin damage. During spawning its anal fin overlapped the vent of the larger fish in a manner similar to that of the male Metynnis. It was assumed, then, that the smaller fish was the male. Later spawnings themselves differed from the one I first observed. The pair not only turned upward but sometimes continued into a loop with half roll, spraying eggs when completely upside down. Sometimes, between runs, the female mouthed the plants containing eggs. She was also observed to stand in a vertical position while jerking her head. The male would then come alongside. A number of times the fish broke from this position, circled each other, and the returned. Eventually they came side by side and repeated the trembling loop-roll. The eggs that did not stick were eaten by both parents and the other fish. Those that did attach were not bothered, although both parents mouthed them. On one occasion a large bunch of Myriophyllum was anchored in the gravel and this and the otherplants were unharmed until the fish went into their pre-spawning display. The Myriophyllum was then cut off and floated to the surface and the piranhas spawned on it.

The pattern just described was never seen again and was probably very atypical. Many more eggs were attached when the parents prepared the site and, surprisingly, the male guarded them. He remained slightly below the nest with his head toward it, driving away intruders and at intervals executing a swimming movement which sent fresh water toward the eggs.

The fourth spawning was about a month later, on May 17. Then on May 28, only 11 days later, the fish were observed in prespawning activities. Later, the male was observed standing in atypical "on guard" position. Sure enough, closer inspection of the plants revealed eggs. Subsequent spawnings were at intervals of 24, 18, and 7 days. What happened to my carefully worked out schedule? There are several possibilities of which the most probable is that the male spawned with the second female, though definite proof is lacking. On August 13, the known breeding female was wounded during courtship. A short time later she was floating head down at the surface, still alive but with the whole rear portion of her body chewed off. The poor creature was sacrificed and preserved and since that time no further spawning has occured. The remaining piranhas have lately appeared to have darker coloration, and I have high hopes that once again our aquarium will boast a breeding pair of these beauties.

Emanuel Ledecky, Cincinnati Aquarium

9,941 Posts
Unvaluable info!
Tanks again!
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.