Global Veterinaria 10 (1): 22-25, 2013 ISSN 1992-6197 © IDOSI Publications, 2013 DOI: 10.5829/idosi.gv.2013.10.1.7179 Corresponding Author: Vahid Taghizadeh, Department of Fishery, Faculty of Fisheries and Environment Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran. 22 Effect of Water Hardness on Growth, Survival, Hematocrit and Some Blood Biochemical Indices of Kutum (Rutilus frisii kutum) Fingerlings Vahid Taghizadeh, Mohammadreza Imanpour and Abdolreza Jahnbakhashi Department of Fishery, Faculty of Fisheries and Environment Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran Abstract: The responses to water hardness augmentvariesfrom speciesto species. The aim of this research was to verify the growth, survival, hematocrit and some biochemical indices change in Kutum (Rutilus frisii kutum) fingerlingsin water with differentlevels of hardness. Fingerling fish (2±0.1 g) were randomlydistributed to trial units (three replicates per treatment) and kept in 15aquaria (20 fingerlings/aquarium). Fingerlingswere exposed to five water hardness amount (30, 70, 150, 300 and 600 mgLGCaCO ) at pH=8.45. At the end of trial, 1 3 FCR (feed conversion ratio), specific growth rate (SGR), final biomass, hematocrit, calcium, potassium, sodium, magnesium, glucose, cholesterol and total protein were concluded for each collection. Higher fingerlingsgrowth, survival, weight gain and final biomass were obtained 70 and 150 mgLG CaCO . Hence, this is the suggested 1 3 hardness range for growth and survival of Kutumfingerlings. Key words: Blood Biochemistry %Survival %Growth %Water Hardness %Kutum INTRODUCTION Skeletalgrowth in vertebrates is frequentlylimited the Kutum (Rutilus frisii kutum) is one of the economicall In particular, calcium, the primeval componentof the yimportant fishes of the Caspian Sea. They are mainly classified collagen matrix formingthe bonyskeleton of distributedin the southern part of the Caspian Sea, morevertebrates, is necessary to suitable growth and particularly in the region from Astara to Gorgan River and evolvement. Differencein the attainability of calciumin the migrate into rivers for spawning. Kutum have two life aquatic environmentplace constraintson the speed and histories; there are spring and autumn migratory scope of larval evolvement in fishes [3], can stunt growth populations. The fish spawn on aquatic plants and river and can place extra stresses on fish transplanted from a sands [1]. calcium-rich to a low-calcium environment. Totalhardness is the concentration of all divalent cations in water and Ca & Mg are the most common MATERIALS AND METHODS 2+ 2+ cations in nearly all freshwater systems. The suggested valuefor water hardness for fish culture in ponds is above 300 fingerling fish of Kutum produced at the 20 mgLG CaCO [2], principally because of itseffect Sijovalarea, Golestan, Iran were acclimated to laboratory 1 3 on phytoplankton growth and water pH control. conditions for 30 days before being randomly distributed However, Ca is necessary for fish for some biological into 15 experimental 70-L aquaria which supplied with 2+ processessuch as bone construction, blood freshwater from an urban system. The aquaria were coagulation, and multiple other cellular functions [3]. individually aerated and water temperature was controlled The internalsourceof Ca in fish is not easily accessible. at 23±1°C. Dissolved oxygen, pH and water temperature 2+ Hence, plasma Ca wascontrol by its ingestionwith food were continuously monitored. Photoperiod was 2+ or by branchial absorption [4]. maintained at 12-h light: 12-h dark cycle. obtainability of fundamental nutrients and minerals [5].