Iriaterina Werner – Iriatherina werneri
Representatives of the fresh waters of Australia and nearby islands are infrequent guests of our aquariums. Even on the crest of popularity, the number of species contained by aquarists of the USSR barely exceeded twenty. Now in Russia there are even fewer.
Meanwhile, among the many medium-sized fishes of this region there are genuine pearls that can decorate any aquarium. These, of course, are Iriatherina werneri.
Iriatherina werneri Herman, Meiken was described in 1974 by specimens caught near the town of Merauke by the river Irian Jaya in New Guinea. This river was considered the only habitat of this species. However, in 1978, Dr.G.Allen discovered and described similar fish in the Jardine River in the north of the Cape York Peninsula Australia.
He gave the found name the name Iriatherina jardinensis. As it turned out, later, it was about the Australian population Iriatherina werneri.
There are two populations of the species – Australian and New Guinea, which differ in body color. For fishes from Australia, the main body background is silver, and for individuals from New Guinea the body is painted olive-brown.
Australian fish were imported to the USSR. First breeding report Iriatherina werneri appeared in the August issue of T.F.H. 1983, by H.J.Richter.
In the USSR, the first mass breeding carried L. Kuskov, and the first mention in the literature dates back to 1986. I first saw Iriatherina werneri in 1986. in Leningrad from M. Tsirling, however, it was not possible to purchase fish.
Only in 1988 I managed to exchange two females and one male for Hemigramus bleheri. At that time I could not find any literary data on the parameters during breeding.
I had to experiment. It was only much later, when the breeding was already mastered, that several A.N.G.F.A. magazines came into my hands. Fishes of Sahyl, where data were given on some water parameters.
So the hardness ranged from 7 to 19 dH °, pH 5.2-7.6, temperature 23-30 ° C. Interestingly, Dr.G.Allen, describing the habitat conditions of Iriatherina werneri, results in very low pH values of 5.2-5.8.
This suggests that the water in these places is extremely soft. He caught fish in the calm backwaters of the Jardine River, which are rich in vegetation, mainly lilies.
Content: These fishes need thickets of plants, which for greater comfort of the fish should be located on the sides and along the back wall of the aquarium in order to leave a wide strip along the front wall for their free swimming. The presence of floating plants is also welcome.
Dark soil is desirable. For decorating, you can still use snags and stones.
Aeration and filtration of water up to 2-3 volumes per hour are also obligatory, as well as its regular substitution at least once a week for 25% – 30%.
These are peaceful schooling fish with interesting behavior. Very mobile, moving rapidly, sometimes hovering in a shady corner in the midst of plants.
When frightened hiding in the thickets of plants, where they become almost invisible. They love to play in the stream coming out of the filter water.
Iriaterines float in the upper and middle layers of water. They can be kept in the general aquarium with any peaceful fish of a suitable size, but they should not be kept together with active species of fish that can bite off the ends of the long rays of the fins of the males.
Now I’ll tell you in more detail about my attempts to achieve stable mass breeding of Iriatherina werneri. First, I put my pets in a 40-liter aquarium.
Water was hardness 4-5 dH °, pH 6.8-7.2, temperature in the range of 24-28 ° C. There was no soil in the aquarium; Javanese moss was used as a plant and spawning substrate.
The fish were fed once or twice a day, in the summertime with small cyclops and daphnia in winter – Nauplii Artemia salina. The fish very quickly adapted to these conditions and felt great. Very soon, I noticed the marriage dances of the male.
Spawning ritual Iriatherina werneri It is a truly magnificent sight and deserves a separate description. The sexually mature male occupies the site of the aquarium near the small-leaved plant and jealously protects it from other males.
Skirmishes occur almost constantly, but I did not notice the damage to rivals. When a female appears in the field of view of the male, he straightens his first dorsal fin like a sail in a strong wind and moves toward it.
The second dorsal and anal fin at this time make quick movements up and down.
These movements remarkably resemble the fluttering flight of a butterfly or moth. If the female is ready to spawn, she goes to the male, and the pair side by side moves toward the bundle of small-leaved plants, in the thick of which spawning occurs.
Now back to my attempts to achieve mass breeding Iriaterina Werner (Iriatherina werneri). Very soon, in the depths of a bunch of Javanese moss, I discovered caviar. The moss was removed from the aquarium with the parents and transferred to another capacity of 26 liters.
The water parameters were saved. The first fry appeared after 6-7 days, they were very small and kept at the water’s surface at an acute angle to it.
This is where the hardest thing began. I could not manage to pick up starter feed for them.
Paramecium caudatum was tested in pure culture, all types of rotifers from reservoirs near Krasnoyarsk (Filinia, Philodina, Keratella, Brachionus, Asplanchna), and even pure microalgae culture (Chlorella). The result was the same, the fry appeared in large numbers and died after one or two days.
Reflecting on the reasons for my failures, I suggested that perhaps the cause of mortality of fry is related to the parameters of water. As I mentioned, at that time I only knew about Iriatherina werntri that Australia is the birthplace of this fish.
It was logical to assume, given the rather arid climate of this continent, that, at least during certain periods of the year, water hardness increases significantly. I decided to move in this direction and began to artificially increase the hardness of the water.
Calcium chloride was used for this. When the stiffness was raised to 15-17 dH °, it became clear that I was on the right track. Now the picture was completely different.
As usual, on the sixth day the first fry appeared. It was in January, the temperature outside -25 °, -28 ° C, all the lakes were covered with ice and snow.
An infusorium shoe (Paramecium caudatum) was given as a starter feed, and Semilac infant formula was additionally given. Two weeks later, the fry began to eat Nauplii Artemia salina.
As a result, managed to feed more than 50% of the fry. So beautiful Iriatherina werntra firmly settled in my collection.
During this time, I have accumulated quite interesting observations. So they feel equally well in both old and fresh water. Adult fish successfully live with hardness from 4 to 30 dH °, and pH from 6.0 to 8.5.
However, if you maintain a stiffness of 15 dH ° and above, then the fish practically do not get sick. No less interesting is the data on the effect of low temperatures on Iriatherina werneri. So once a week-old fry without a loss suffered a temperature of + 16 ° C for almost two days.
Adult fish at this temperature became lethargic and stopped feeding, but their death was also not observed. It is interesting to note that during these two days not a single fry appeared from the roe, however, as the temperature rose to 20 ° C, the hatch continued.
As a result of long-term observations, a method of mass breeding Iriaterina Werner, which I propose to the reader. For spawning used glass aquariums with a capacity of 30 liters.
The optimal sex ratio is three females per male. To obtain a large number of even-age fry, at least 10-15 females should participate in spawning. As a spawning substrate, I prefer to use Javanese moss.
Water should be hardness 15-17 dH °, pH-7.0-7.5, temperature 24-28 ° C. I use Artemia salina nauplii 80-90% of the diet and 10-20% chopped Tetra as feed for adult fish phyl. Fish spawn almost daily, each female lays several eggs.
On the sixth day from the moment of registration of the first spawning episode, the substrate must be transferred to another container, where the fry will be hatching and growing. All water parameters should be the same as in the spawn. If this is not done then the producers will destroy most of the offspring.
The next day, the first fry hatch out; they are very small and immediately begin to feed. The starter feed is a mixture of 70% Paramecium caudatum and 30% Philodina acuticornis odiosa, which I breed at home. In addition, 1-2 times a day, the fry receive the smallest artificial food (50% decapsulated eggs Artemia salina and 50% Tetra phyl).
As the hatching of new fry continues for seven days every day, it is necessary to continue to give starting feeds even when the first fry have already taken larger feed. After 10-14 days, the fry begin to feed on Artemia salina nauplii, the first signs of sex difference appear after six weeks.
The first spawning occurs at the age of eleven weeks.
This method of maintenance and breeding Iriaterina Werner (Iriatherina werneri) allowed me not only to maintain for six years my collection at the level of at least 100-120 copies, but also to breed annually the required number of fish for sale.