Study on Growth of Silver Carp (Hypophthalmichthys Molitrix) fed by Diatoma Microalgae in Pond

Abstract

The common method of fertilizing to increase live food (microalgae) in Hypophthalmichthys molitrix ponds has disadvantages, including the fact that fertilizers increase the population of microalgae of all types (toxic and non-toxic) without human control and thus can cause growth. Unwanted to become harmful algae. This study was carried out at the same time with the beginning of the summer season and breeding of silver carp, with the aim of enriching the microalgae composition of warm-water fish breeding ponds located in Mazandaran province. Growth rate was calculated according to the treatments. 100 young of 90g Silver Carp were stored in each pond. Experiments were performed in circular concrete ponds with a diameter of 6 meters and a water height of 1 meter. Different microalgae compositions (1: 70% chlorella, 30% diatoma, 2: 70% diatoma, 30% chlorella and 3: control of natural algae composition of the area) were fed during the experiment. In this study, the growth rate of Silver Carp in different densities of Diatoma and Chlorella algae was evaluated in combination with different percentages in the pond environment and at the end of the experiment, survival percentage, fish growth rate, specific growth rate and average daily growth were calculated. Ponds whose fish were water-enriched with Diatoma microalgae with a density of 70% had higher growth (survival rate, fish growth rate, specific growth rate and average daily growth). Also, according to this study, since one of the condition for having a healthy farmed fish is to have a healthy and proper nutrition, so it is necessary to increase the share of edible microalgae Diatoma in the breeding environment of these fish to produce more and higher quality of these fish.