Oryzias songkhramensis – Songkhram Ricefish
Oryzias songkhramensis was only described by Magtoon in 2010. The family name Oryzias is derived from the ancient Greek Oryza which means “rice”, a reference to the fact that they are common in rice fields. The species name songkhramensis is a reference to the catchment area of the Songkhram River in Thailand. To this, they owe their common name, Songkhram Ricefish.
Description
Oryzias songkhramensis does not grow very large. They reach a total length of about 2,5 centimeters. They are elongated in shape. The color of the fish is brownish on top. The belly is pale yellowish. A black dot is visible on the base of the pectoral fins. The edges of the caudal fin are trimmed with a black and pale yellow to orange band.
Similar species
This species is very similar to Oryzias mekongensis, Oryzias pectoralis and Oryzias minutillus, but research has revealed minor differences. These are some small differences in the bones and some visible differences.
- Oryzias songkhramensis: Black spot at base of pectoral fin. Black and faint yellow/orange bands on the outer edges of the caudal fin.
- Oryzias mekongensis: Black spot at base of pectoral fin. Black and bright orange bands on the outer edges of the caudal fin.
- Oryzias pectoralis: Black spot at the base of the pectoral fin. Black and bright orange bands on the outer edges of the caudal fin.
- Oryzias minutillus: No colored bands on the outer edges of the caudal fin.
Biotope
The distribution area of Oryzias songkhramensis includes part of the catchment area of the Mekong and Songkhram rivers.
They usually inhabit the channels, streams and rice fields with clear water. The substrate there consists of sand, detritus or mud.
Various other fish species and plants occur in the same habitat. Some species that were found there according to the description are, for example, Trichogaster trichopterus, Trichopsis vittatus, Rasbora rubrodorsalis, Channa striata and Machrobrachium lanchesteri. This is not to say that they make a good combination in the privacy of an aquarium! Plants found there include Nymphaea lotus, Jussiaea repens and Hydrilla verticillata.
Diet
The Songkhram Rice Fish is a small predator in the wild. They mainly feed on small insects, insect larvae, invertebrates, worms and zooplankton swimming in the water.
In the aquarium, it is not a picky eater. They eat flakes, small granules, frozen or live food, as long as it is suitable for their small mouth. Give them a varied diet to keep them healthy. Small live foods such as Daphnia and freshly hatched brine shrimp show their natural feeding behavior.
The Aquarium
This small, peaceful fish species is not very suitable for the community aquarium due to its small size. With only 2.5 centimeters, it is not easy to combine with other fish species. Oryzias songkhramensis is of course very suitable for a Nano aquarium.
Decorate the aquarium with sufficient vegetation. You can keep this species in a group with males and females.
The temperature of the water may be between 23 and 30 degrees Celsius. The pH may be slightly acidic to neutral from about pH 6.0 to 7.5.
Breeding Oryzias songkhramensis
Breeding Oryzias songkhramensis is not very difficult. You have the best chance of successful breeding in a special breeding tank or when you move the eggs as soon as they have been laid. The eggs are usually attached to fine-leaved plants such as Cabomba or Java Moss. You can also use spawn mops if you prefer to move the eggs instead of the parents.
When the female is ready to spawn, the males become darker in color. They then defend a small territory against other males. The female produces a few sticky eggs that stick to her. The male immediately fertilizes these eggs. The eggs will stick to the female for a while until she can deposit them on some fine-leaved plants.
Raising the fry
Usually the parent animals leave the eggs alone. The eggs hatch after one to three weeks. This depends on the temperature. The free swimming fry are not safe for the parents. If they get the chance, they eat the young. With a little luck, a few fry will survive in a densely planted aquarium.
In a breeding aquarium without parents, the chance of survival is of course a lot higher. You can feed the newly hatched young Oryzias songkhramensis with micro worms, vinegar eels and later with brine shrimp nauplii.
Be careful with the grouping of youngsters of different ages. The older fish hunt for the newly hatched young!
Author
John de Lange
Copyright images
Nonn Panitvong – Siamensis.org
Bounthob Praxaysombath – CC BY-NC-SA 4.0
Resources
Oryzias songkhramensis, A New Species of Ricefish (Beloniformes; Adrianichthyidae) from Northeast Thailand and Central Laos – Wichian Magtoon – 2010
Fishbase.se
