ZOOPLANKTON PRODUCTION IN AQUACULTURE Assoc. Prof. Serpil SERDAR Ege University, Faculty of Fisheries

Plankton: the aggregate of passively floating, drifting, or somewhat motile organisms in pelagic zone PhytoplanktonZooplankton ChlorophyceaeRotifera PrasinophyceaeArtemia BacillariophyceaeCopepod HaptophyceaeDaphnia ChrysophyceaeCyanophyceaeCryptophyceae

Phylum: Rotifera Classis: Seisionidea Classis: Bdelloidea Classis: Monogononta These species is distributed fresh water, brackish water and marine water and nearly 90 % rate live in fresh water. Rotifera phylum is the most important zooplankton group in aquatic systems includes 3 classis, 120 genus and approximately 2000 species.

Keratella cochlearis Keratella longispinaAsplanchna priodonta Philodina acuticornis Brachionus calyciflorusBrachionus rubens Freshwater rotifer species

Morphlogy Rotiferlerde vücut baş, gövde ve kuyruk olmak üzere 3 bölgeden oluşmaktadır. The body of most rotifers is divided into three portions: head, trunk and foot. The head carries a corona which is surrounded by cilia

The rotifer Brachionus plicatilis is divided into two types so-called L and S types by morphological, physiological and genetical characteristics L type - Brachionis plicatilis µm S type - Brachionis rotundiformis µm SS type - Brachionis rotundiformis µm

-They have distinguishing characteristics such as size, body shape and shape of their anterior spines -Digestion rate of L-type is 1.7 times is more than S-type - Optimal water temperature S-type 28-35ºC L-type 18-25ºC - The lowest water temperature limit S-type 20 ºC L-type 10 ºC -S-type diploid female 25 (2n=25) chromosome haploid male 12 (n=12) chromosome -L-type diploid female 22 (2n=22) chromosome haploid male 11 (n=11) chromosome

L- biotypes ( µm) SM biotypes ( µm) S and SS biotypes ( µm) B. plicatilis B. manjavacas B. ʹ Nevada ʹ B. ʹ Austria ʹ B. ibericus B. ʹ coyrecupiensis ʹ B. ʹ almenara ʹ B. ʹ tiscar ʹ B. ʹ cayman ʹ B. ʹ towerinniensis ʹ B. rotundiformis B. ʹ lost ʹ L, large; SM, medium; S and SS, small and super small. The numbers indicate the approximate range of adult’s body length in each group

REPRODUCTION Asexual and sexual reproduction in Brachionus plicatilis *Amictic female produces 20 or more eggs in 7-10 days *Mictic female produces 1-3 eggs in the same period

Why does start formation of resting egg? * Suddenly change of temperature and salinity in the culture medium * Reduce of culture medium quality *Change of food type, quality and quantity * High population density * Genetic structure of rotifers

Mictic and amictic female * After parthenogenetic reproduction, amictic female produce diploid eggs which are oval shape and grey colour and after hatching, amictic or mictic female emerge * After meiosis, mictic female produce haploid eggs which are round shape, grey colour and half of amictic egg size. After hatching, male rotifer emerge *After meiosis, mictic female produce fertilized eggs (diploid) which are oval shape, brown or orange colour cytoplasm and small part of egg has transparent space

Rotifer species have contributed to the successful hatchery production of more than 60 marine finfish species and 18 species of crustaceans. Brachionus plicatilis is one of the most popular and important species

Culture history of B. plicatilis Early 1950srotifer population rapid and suddenly increased in eel ponds (Mizukawari phenomena) 1964daily tank transfer method improved 1960mass culture techniques explored 1965discovered to be excellent food for red sea bream larvae 1967discovered that baker’s yeast is a suitable food source 1970sbaker’s yeast was used extensively in mass culture

* Rotifers are ideal as a first exogenous food source due to their small size *Slow swimming speed and habit of staying suspended in the water column * Ability to be cultured at high densities *High reproductive rate *Their swim speed is suitable to larvae for catching easily without huge cost * isolation from natural area is easy *you can culture in a small scale tank in a high density *Amount of calorie content is approximately 4x10 4 cal and it can easily be enriched with fatty acids or vitamins can be easily *Due to parthenogenesis cycle, continuously produce new generation and population increase rapidly *Reaching egg formation in a short time Why rotifer is important for early feeding in aquaculture?

Culture conditions *Although Brachionus plicatilis is known for its ability to tolerate a wide range of salinity between 1 %0 and 97 %0, optimal reproduction can take place at salinities below 35 %0. *The choice of the optimal culture temperature for rearing rotifers depends on the rotifer type; L-strain rotifers (18-25ºC) being reared at lower temperatures than S-type rotifers (28-35ºC). Temperature (°C) Time for embryonic development (days) Time for young female to spawn for the first time (days) Internal between two spawning (hours) Length of life (days) Number of eggs spawned by a female during her life Rotifers can survive in water containing as low as 2 mg/l of dissolved oxygen. The best growth rates occur approximately at a temperature between 20 and 35 °C, a salinity of %0 and a pH of

*Brachionus calyciflorus and Brachionus rubens are the most commonly cultured rotifers in freshwater mass cultures. *They tolerate temperatures between 15 to 31°C. *The optimal pH is 6-8 at 25 °C, *Minimum Oxygen levels are 1.2 mg.l -1. Culture conditions of freshwater rotifers

FEEDING Nannochloropsis oculata Chlorella sp. Dunaliella tertiolecta Tetraselmis suecica Isochrysis galbana Monochrysis lutheri The rotifer is the planktonic suspension feeders. These organisms filter small particles (2-20 µm) out of the water column by means of a ciliated corona located on the anterior portion of the body. Microalgae is commonly used as feed, often together with baker’s yeast and artificial diets (Culture Selco® and Roti-Rich). Filtration and ingestion rates are influenced by food type, mainly the presence or absence of a cell wall, critical cell density, cell size, type of rotifer, and culture conditions such as water temperature, salinity and O 2. The most common phytoplankton species in rotifer feeding Marine species Freshwater species Scenedesmus costato-granulatus Kirchneriella contorta, Phacus pyrum, Ankistrodesmus convoluus A rotifer can eat 200 cells/minute under optimal conditions

Rotifer (ind./ml) Baker’s yeast g/ g/ g/ < 0.5 g/10 6 Rotifer density. ml -1 Culture Selco ® g/ g/ g/ g/ g/ g/10 6

Culture Systems * Batch * Semi-continuous * Continuous

The first method (long term) produces an enrichment of the tissues, as it is continuous along the entire culture period The second system is a short term enrichment. It implies the harvesting and rinsing of the rotifers and the preparation of a separate enrichment tank Rotifer biochemical composition is of primary importance for larval nutrition. The lipid and essential fatty acids profile is relatively modifiable by dietary manipulation. Baker’s yeast and some microalgae species support high population growth but the rotifers produced are nutritionally deficient or poorly balanced in the lipid fraction as larval food. In order to achieve an appropriate content of essential fatty acids, rotifers can be enriched with microalgae, handmade, marine oil emulsions, prepared microparticulated feeds and commercial products.

Conceiçao, L. E., Yufera, M., Makridis, P., Morais, S., Dinis, M.T Live Feeds For Early Stages of Fish Rearing. Aquaculrure Research, 41, Fulks, W., Main, K.L., Rotifer and Microalgae Culture Systems. Proceedings of a U.S.-Asia Workshop. Hawaii, pp.3-52 Fu, Y., Hirayama,K., Natsukari, Y. 1991a. Genetik divergence between S and L type strains of the rotifer Brachionus plicatilis O.F.Müller. J. Exp. Mar. Biol. Ecol., 151, Fu, Y., Hirayama, K., Natsukari, Y.1991b. Morphological differences between two types of the rotifer Brachionus plicatilis O.F.Müller. J. Exp. Mar. Biol. Ecol., 151, Gomez A., Serra M., Carvalho G.R. & Lunt D.H. (2002) Speciantion in anvcient cryptic species complexes: evidence from themolecular phylogeny of Brachionus plicatilis (Rotifera). Evolution 56, Hindioğlu, A., Serdar, S., (2001). The Effect of Different Dilution Rates on Rotifer (Brachionus plicatilis Müller, 1786) Culture TÜBİTAK, Tr. J. of Veterinary and Animal Sciences, 25: (English abstract). Lavens, P., Sorgeloos, P Manual on the production and use of live food for aquaculture. FAO Fisheries Technical Paper, 361. Lubzens, E., Tandler, A., Minkoff, G Rotifers as food in aquaculture. Hydrobiologia. 186/187: Lubzens, E Raising rotifers for use in aquaculture. Hydrobiologia 147: Moretti, A., Fernandez-Criado, M. P., Cittolin, G., Guidastri, R Manual on Hatchery Production of Seabass and Gilthead Seabream, Volume 1. FAO Fisheries Technical Paper Serdar, S., Hindioğlu(Lök), A. (1999) Advantages and disadvantages of resting egg formation in rotifer (Brachionus plicatilis (O.F.Müller 1786)) culture. Journal of Fisheries and Aquatic Science, Vol 16, No:1-2: (English abstract). Serdar, S., Hindioğlu(Lök), A., (1999) Resting egg formation of rotifer (Brachionus plicatilis Müller, 1786) at different salinities. Journal of Fisheries and Aquatic Science, Vol 16, No:3-4: (English abstract). Serdar, S., Lök, A., (2002) Effects of temperature on resting egg formation in the rotifer (Brachionus plicatlis, Müller, 1786) culture. Journal of Fisheries and Aquatic Science, Vol:19, No:1-2:13-17 (English abstract). famille%20Asplanchnidae1/famille%20Asplanchnidae1.htm References