Infusoria in Aquaculture

Protozoan-Infusoria

as Alternative Live Food in

Aquaculture

Sefti Heza

Dwinanti

Department of Aquaculture

Sriwijaya University

Protozoa -

InfusoriaProtozoa merupakan binatang yang paling banyak di dunia

Infusoria merupakan kelompok terbesar di Phylum Protozoa, di mana anggotanya sekitar 8.000 species

Infusoria adalah sekumpulan jasad renik sejenis zooplankton (FLAGELLATE, CILIATE, AND TENTACULIFEROUS PROTOZOA)

Umumnya berukuran antara 40-100 mikron

Infusoria sebagai pakan alami digunakan sebagai makanan pertama (first feeding) bagi larva ikan yang mempunyai bukaan mulut kecil

Secara visual warna infusoria adalah putih dan hidup menggerombol sehingga akan tampak seperti lapisan putih tipis seperti awan.

• Infusoria is a collective term for minute aquatic creatures like:-

1. Ciliates 2. Euglenoids3. Protozoa 4. Unicellular Algae

that exist in freshwater ponds.

• In modern formal classifications the term is considered obsolete; and the microorganisms previously included in the Infusoria are mostly assigned to the Kingdom Protista.

Ciri-ciri dari Ciliata antara lain :

Memiliki bulu getar (silia) di seluruh tubuh yang berfungsi untuk bergerak, menangkap makanan, menimbulkan arus air untuk pernafasan;

Kosmopolitan

planktonik (Tintinnidae/memiliki kantung kitin sebagai pelindung (lorica)

mempunyai 2 inti yaitu makronukleus & mikronukleus

Habitat di lingkungan berair

Hidup bersimbiosis & parasit

Reproduksi asexual (pembelahan biner) dan sexual (konjugasi).

Yang termasuk ciliata adalah Paramaecium caudatum, Didinium narutum, Calpodium capulum.

Yang termasuk flagellata adalah Euglena viridis, Pandorina sp, Chilomonas sp.

Dalam akuakulture Paramecium and Stylonychia adalah infusoria air tawar sedangkan yang di air laut adalah Fabrea and Euplotes

Stylonychia

Paramecium

Fabrea

Euplotes

Ciliated protozoans may be important for first-feeding fish larvae because:1) ciliates often dominate such communities and are more abundant than copepod nauplii in coastal waters(Kamiyama 1994);2) most of the ciliates in the plankton are of a similar orsmaller size than copepod nauplii (Taniguchi 1978).3) Protozoans can grow often just as well on inert foods, which is easier for aquaculture purposes

Marine ciliates are conventionally divided into loricate (tintinnid) and aloricate (naked) forms (Sanders 1987, Kamiyama 1994).

Naked ciliates may be more important food for fish larvae than tintinnids, because naked ciliates occur in considerably larger numbers than tintinnids (Pierce and Turner 1992).

The advantages of Fabrea salina as an alternative for rotifers or brine shrimp larvae were summarized by De Winter, 1975 as follows:i) It is one of the few truly “pelagic” ciliatesii) It has the appropriate dimensions as a live food: depending onculturing conditions its size can vary from 50 - 500 μmiii) The smooth cell wall and the absence of appendages facilitate itsuptake by the predatorsiv) The generation time is very shortv) As a particle feeder it can be cultured on live algae as well as inertfoodsvi) According to the literature data its nutritional value for fish larvaeseems to be excellentvii) As many other protozoans it forms a tough cyst membrane whensubmitted to unfavorable environmental conditions. The cysts can bekept viable for a certain period of time without losing their hatchability.

Generally, for infusoria culture, lettuce, cabbage and banana peels are commonly usedas media as they stimulated growth of organisms. Take a glass jar or aquarium, filled withde-chlorinated filtered water and add 2 to 3 banana peelings. Cover the container witha cloth to prevent the entry of mosquitoes and files. Keep the container in a cool placewhere natural diffused light is available. After 2 to 3 days the water will turn milky andalso emit foul smell. This is due to the multiplication of a large number of bacteria causingdecay of banana peelings. A film of slime will be formed on the water surface. In about4 to 5 days, the water will turn clear, becoming transparent with light yellowish colour.This is because of the floating spores of infusoria in the air which have settled on thewater surface break up and disintegrate. The culture is now ready for feeding the earlystages of fish larvae. Once the culture reaches the peak density, it must be harvested, ifnot, the density will suddenly fall due to lack of space and oxygen depletion. After 50 %harvesting, add 2 to 3 drops of milk and again fill the glass jar with fresh water. Theculture will sustain for a week. Infusoria can also be cultured by above method by puttingbruised lettuce leaves or take some dry paddy husk and boiled it in water and take thesolution for culture. Infousoria can be collected using 0.12 mm fine mesh cloth from foulsmelling water bodies.

Ciliate Culture

Initially, several ciliates were considered for culture, and Fabrea salinashowed to be more reliable in culture than Strombilidium sp. and Strombidiumsp and is, therefore, the focus of this paper. Algae (Isochrysis and Rhodomonas ) provided as food was cultured with Gulliard’s F/2 in the laboratory. All of the experiments were carried out for seven days in 2 LErlenmeyer flask initially containing 1 L of chlorinated then dechlorinated, 1μm filtered seawater (32 - 34 ‰). the normal range was 25 - 30°C. The trialswere conducted under continuous light ranging from 1,240 to 1,680 lux. Dailycounts for organisms were performed in triplicate using Sedgwick-Rafter slideson a compound microscope; Samples for water quality measurements including ammonia,temperature, salinity, dissolved oxygen, and pH were taken daily from eachreplicate.