Hatching Requirements of Daphnia magna Straus, 1820, and Daphnia pulex Linnaeus, 1758, Diapausing Eggs from Iranian Populations In vitro

Authors
Department of Fishery, Gorgan University of Agricultural Sciences and Natural Resources, Shahid Beheshti Street, Gorgan, Islamic Republic of Iran.
Abstract
Considering the crucial importance of Daphnia species in aquaculture, in particular for artificially- cultured sturgeon fry, a comprehensive study on the hatching requirements of their diapausing eggs seemed to be inevitable in order to obtain the ideal hatching technique. To do so, the ephippial eggs were collected from live food ponds in the cultivation and breeding centre of Gorgan and after isolation, were kept in dry and wet conditions at 4°C for 2 months in darkness. Following the pre-incubation period, the ephippia in each group were subdivided into two parts each treated with NaOCl 1% and distilled water. The effect of temperature levels (20, 25, and 30˚C) and photoperiod levels (12L: 12D, 24L: 0D) on hatching percent and the rate of egg hatching were investigated in artificial daphnia medium (AdaM) for 15 days. Results indicated that wet pre-treatment of Daphnia magna diapausing eggs with 1% NaOCl solution and subsequently exposure to continuous illumination at 20 and 25˚C was effective to reach the maximum number of hatchlings and the maximum egg hatching rate (P< 0.05). Exposure of the wet diapausing eggs of Daphnia pulex to 12 hours illumination and 25ºC without soaking in NaOCl 1% maximized the number of hatchlings and the rate of egg hatching (P< 0.05).

Keywords


1. Aghaei Moghadam, A. 1999. A Survey on the Relationship between the Appetite of Sturgeon Fry (Acipenser persicus) and Dominant Population of Zooplankton in Rearing Ponds of Shahid Rajaii Sturgeon Breeding and Cultivation Centre. MSc. Thesis, Spring 1999, Agricultural Sciences and Natural Resources University of Gorgan, 132 PP.
2. Brendonck, L., Centeno, M. D. and Persoone, G. 1996. The Influence of Processing and Temperature Conditions on the Hatching of Resting Eggs of Streptocephalus proboscideus (Crustacea: Branchiopoda: Anostraca). Hydrobiologia, 320(1-3): 99-105.
3. Carvalho, G. R. and Wolf, H. G. 1989. Resting Eggs of Lake-Daphnia. I. Distribution, Aboundance and Hatching of Eggs Collected from Varying Depths in Lake Sediments. Freshwater Biol., 22: 459-470.
4. Davison, J. 1969. Activation of the Epphipial Eggs of Daphnia pulex. J. Gen. Physiol. 53: 565-575.
5. De Meester, L. and De Jager, H. 1993. Hatching of Daphnia Sexual Eggs. I. Interspecific Differences in the Hatching Response of D. magna Resting Eggs. Freshwater Biol., 30: 219-226.
6. Frankland, B. and Wareing, P. F. 1966. Hormonal Regulation of Seed Dormancy in Hazel (Corylus avellana L.) and Beech (Fagus sylvatica L.). J. Exp. Bot. 17: 596-611.
7. Gyllström, M. and Hansson, L. A. 2004. Dormancy in Freshwater Zooplankton: Induction, Termination and the Importance of Benethic-pelagic Coupling. Aquat. Sci., 66: 274-295.
8. Hairston, N. G. Jr., Hansen, A. M. and Schaffner, W. R. 2000. The Effect of Diapause Emergence on the Sysonal Dynamics of a Zooplankton Assemblage. Freshwater Biol., 45: 133-145.
9. Herzig, A. 1974. Some Population Characteristics of Planktonic Crustaceans in Neusidler Sea. Oecologia, 15: 127-141.
10. Irigoien, X., Harris, R. P. and Verheye, H. M. 2002. Copepod Hatching Success in Marine Ecosystems with High Diatom Concentrations. Nature, 419: 367-369.
11. Kluttgen, B., Dulmer, U., Engels, M. and Ratte, H. T. 1994. ADAM: An Artificial Fresh-water for the Culture of Zooplankton. Water Res. 28: 743-746.
12. Lutz, R. V., Marcus, N. H. and Chanton, J. P. 1992. Effects of Low Oxygen Concentrations on the Hatching and Viability of Eggs of Marine Calanoid copepods. Mar. Biol. 114: 241-247.
13. Maier, G. 1990. Spatial Distribution of Resting Stages Rate of Emergence from Diapause and Times to Adulthood and to the Appearance of the First Clutch in 3 Species of Cyclopoid copepods. Hydrobiologia, 206: 11-18.
14. May, L. 1987. Effect of Incubation Temperature on the Hatching of Rotifer Diapausing Eggs Collected from Sediments. Hydrobiologia, 147: 335-338.
15. Niani, A. 1998. A Survey and Determination of Sexual Ripening in Female Broodstocks of Russian Sturgeon (Acipenser guldenstadti) in Southwest Coast of Caspian Sea (Autumn Russian Sturgeon). MSc. Thesis, Agricultural Sciences and Natural Resources University of Gorgan, 114 PP.
16. Nielsen, D. L., Brock, M. A., Crossle, K., Harris, K., Healey, M. and Jarosinski, I. 2003. The Effect of Salinity on Aquatic Plant Germination and Zooplankton Hatching from Two Wetlands Sediments. Freshwater Biol, 48: 2214-2223.
17. Onbé, T. 1978. Sugar Flotation Method for Sorting the Diapausing Eggs of Marine Cladocerans and Copepods from Sea-bottom Sediments of Ise Bay and Uragami Inlet, Central Japan. Bull. Japan. Soc. Sci. Fish. 44, 1411p.
18. Pahlevani, M. H. 1999. Evaluation of Quantitative and Qualitative Characters in Cotton Genotypes under Rainfed and Rainfed with Complementary Irrigation Conditions. MSc. Thesis, Isfahan University of Technology, 86 PP.
19. Pancella J. R. and Stross, R. G. 1963. Light Induced Hatching of Daphnia Resting Eggs. Chesapeake Sci., 4: 135-140.
20. Pinfield, N. J. 1968. The Promotion of Isocitrate Lyase Activity in Hazel Cotyledons of Exogenous Gibberellin. Planta, 82: 337-341.
21. Schwartz, S. S. and Hebert, P. D. N. 1987. Methods for the Activation of the Diapausing Eggs of Daphnia. Freshwater Biol, 17: 373-379.
22. Tsitsials, A. and Barry, M. 2002. Optimizing Hatching Conditions for Australian Daphnia Ephippia. Verh. Internat. Verein. Limnol., 28: 1460-1463.
23. Vandekerkhove, J., Declerck, S., Brendonck, L., Conde-Porcuna, J. M., Jeppesen, E. and Meester, L. D. 2005. Hatching of Cladoceran Resting Eggs: Temperature and Photoperiod. Freshwater Biol., 50: 96-104.
24. Vandekerkhove, J., Niessen, B., Declerck, S., Jeppesen, E., Conde-porcuna, J. M., Brendonck, L. and De Meester, L. 2004. Hatching Rate and Success of Isolated Versus Non-isolated Zooplankton Diapausing Eggs. Hydrobiologia, 526: 235-241.
25. Vandekerkhove, J., Vanhove, M., Declerck, S., Jeppesen, E., Conde Porcuna, J. M., Brendonck, L. and De Meester, L. 2004. Use of Ephippial Morphology to Assess Anomopod Richness: Potentials and Pitfalls. J. Limnol. 63: 74-84.
26. Vanhaecke, P., Cooreman, A., and Sorgeloos, P. 1981. International Study on Artemia. XV. Effect of Light Intensity on Hatching rate of Artemia Cysts from Different Geographical Origin. Mar. Ecol. Prog. Ser. 5: 111-114.
27. Wolf, H. G. and Carvalho, G. R. 1989. Resting Eggs of Lake-Daphnia. 2. In situ Observations on the Hatching of Eggs and Their Contribution to Population and Community Structure. Freshwater Biol., 22: 471-478.
28. Yurista, P. M. 1997. Bythotrepes cederstroemi Diapausing Egg Distribution and Abundance in Lake Michigan and the Environmental Cues for Breaking Diapause. J. Gt. Lakes Res., 23: 202-209.
29. Zarska-Maciejewska, B. and Lewak, S. 1976. The Role of Lipases in the Removal of Dormancy in Apple Seeds. Planta, 132: 177-181.
30. Zenkevich, L. A. 1962. The Animal Life (Zhizń Zhivotnykh). Volume 2, Chapter 7, Phylum Arthropoda.