Effects of water hardness and turbidity on growth and fecundity of freshwater Cladoceran, Moina macrocopa (Straus, 1820)

Water hardness and turbidity are important parameters in zooplankton culture, especially for Cladoceran affecting growth and reproductive parameters of the plankton. Effects of water hardness and turbidity on growth and fecundity of the Cladoceran, Moina macrocopa, was investigated by culturing and feeding them on green algae Scenedesmus quadricauda. Experimental treatments for hardness were 0, 20, 40 and 80mg/I as CaCO_3 and for turbidity were 0, 20, 40 and 80 NTU (Nephelometric Turbidity Unit). Experiments were carried out in 500m1 flasks with initial density of 15 individuals per flask in randomized complete block design with three replicates. After 10 days, we found that M macrocopa, had the maximum population density (370.5-365.0 individuals per flask), maximum specific growth rate (SGR) (0.35/day), and the shortest population doubling time (Dt) (1.98 days) at 0 and 20mg/1 CaCO_3, all with significant differences compared to other treatments (P<0.05). In contrast, we observed the maximum population density (296-325.5 individuals per flask) at turbidities of 0 and 20 NTU, maximum SGR (0.33/day) and the shortest Dt (2.10 days) at turbidity of 0 NTU, with significant differences compared to other treatments (P<0.05). The highest fecundity of Al macrocopa was obtained at 213mgil as CaCO_3 and turbidity of 0 NTU which significantly differed with other treatments (P<0.05). Overall, we showed that AI macrocopa in freshwater with hardness less than 20mg/l as CaCO3 and turbidity less than 20 NTU had better growth and fecundity performance. The species can be used to evaluate habitats where water hardness and turbidity is higher. Mass culture of the species based on its growth and reproduction under these optimal conditions could provide suitable zooplanktonic biomass for feeding of fish larvae

Effects of salinity, temperature, light intensity and light regimes on production, growth and reproductive parameters of Apocyclops dengizicus

The effects of salinity, temperature, and light conditions on production and development, longevity, survival and sex ratios of the cyclopoid copepod, A. dengizicus were determined. Seven different salinity levels (5, 10, 15, 20, 25, 30, 35 psu), four temperatures (20, 25, 30, 35 °C), three different light intensities (33.3, 85.3, 162.1 μmol photons/ m^2/ s) and light regimes (24:0, 0:24, and 12:12 h light:dark regime) were employed. The highest production was achieved under 20 psu salinity. The optimum temperature required for the maximum reproduction and shortest development time was 35 °C. The production was highest (p<.05) and development rate of A. dengizicus was shortest (p<.05) under the lowest light intensity (33.3 μmol photons/ m^2/ s). Continuous light (24:0 h LD) showed positive effects on growth and production. Light regimes 24:0 h and 12:12 h LD yielded the highest total production and growth (p<.05), with highest (p<.05) survival percentage. This study demonstrated that A. dengizicus can tolerate wide range of environmental conditions and can be cultured for commercial live feed purposes as well as toxicity studies

The effect of different diets on production and population specific growth rate of the freshwater Cladoceran Ceriodaphnia quadrangula (Muller, 1785)

In this study, effects of five different diets including green algae, Scenedesmus quadricauda, mixture of S. quadricauda and baker's yeast, cattle manure, poultry manure, mixture manure (cattle + poultry, 1:1 ratio in weight) were examined on density, specific growth rate and doubling time of freshwater Cladoceran, Ceriodaphnia quadrangula population, at two high and low levels of food density with three replications. The results showed that the maximum population density (184 individuals/50ml), maximum specific growth rate (SGR) (0.18/day) and minimum doubling time (Dt) (3.85 days) were obtained when C. quadrangula fed with S. quadricauda at high density (50×104 cell/ml). In addition, the minimum population density (7.3 ind/50 ml), minimum SGR (0.019 /day), and maximum Dt (36.2 days) resulted from C. quadrangula fed on cattle manure at low diet density (5mg). In this research, maximum (800±34.6µm) (Mean ±SE) and minimum (521±31.6µm) body length of C. quadrangula measured when fed with cattle manure at low diet density and S. quadricauda at high diet density, respectively. In conclusion, the results of current study illustrated that S. quadricauda as diet gave better performance for rearing of C. quadrangula compared to other diet treatments

Effect of different diets on fecundity, development time and body size of freshwater copepod Eucyclops serrulatus

The effect of five different diets consisting of green algae Scenedesmus quadricauda, cereal plant meal (wheat+white+canola+barley), fish food meal, mixed manure powder (chicken manure+cattle manure), and baker's yeast (Saccharomyces cerevisiae) were investigated on fecundity rate, larval development time and body length in freshwater copepod Eucyclops serrulatus. A complete randomized design was employed using an individual gravid female in 50ml vials at 26ºC water temperature. The maximum fecundity was obtained in copepods fed on fish diet (18.6±1.08, eggs /female; mean±SD) followed in order by baker's yeast (17.3±3.19), cereal plant meal (13±2.45), Scenedesmus (9.3±0.41), and mixed manure powder (8.6±0.82). The larval developmental time of copepod E. serrulatus was significantly different in copepods fed on examined diets. The mean shortest naupliar time (8.3±0.81 days) and copepodit time (1.0±0.70 days) were observed in copepods fed on fish food meal with a significant difference compared to other examined treatments. In addition, length and width of naupliar, copepodit, and adult of copepod E. serrulatus increased when copepods fed on fish diet and baker's yeast

Short communication: Age and growth of king nase, Condrostoma regium (Cyprinidae), from Bibi-Sayyedan River of Semirom, Isfahan, Iran

Age determination is an important step in fisheries management. The cyprinid fish Chondrostoma regium (Heckel, 1843) is widely distributed in Tigris-Euphrates basin and the Mediterranean basins of southeastern Turkey and the northern Levant. In Iran, it is found in Karun and Karkheh Rivers, the Hoor-al-Azim Marsh and also in Zayandehrud River and Bushehr basin. This species is not found in other basins of Iran. However, there is little information about its habitat requirements. ... The aim of the present study was to investigate the length-weight relationship and age and growth of C. regium population in Bibi-Sayyedan River of Semirom, Isfahan as a tributary of Tigris basin in Iran

Effect of temperature and photoperiod on the growth and fecundity of a freshwater cladoceran, Moina macrocopa (Straus, 1820)(Branchiopoda: Anomopoda)

Temperature and photoperiod are important parameters in zooplankton culture, particularly in cladoceran culture due to their significant effect on growth and reproduction. Effects of temperature and photoperiod on the growth and fecundity of a cladoceran, Moina macrocopa was examined by culturing and feeding it with green algae Scenedesmus quadricauda in 500 ml conical flasks. Treatments used for temperature (°C) and photoperiod were 25, 30, 35 (°C) and 12:12, 24:0 and 0:24(light:dark hours), respectively. The maximum population density (310.5 individuals/flask), maximum specific growth rate (SGR) (0.387 individuals /day), shortest population doubling time (Dt) (1.79days) and highest fecundity (8.5 offsprings/ female) obtained at 30(°C). Correspondingly, the maximum population density (320.7 ind/flask), maximum SGR (0.538 ind/day), shortest Dt (1.28 days) and highest fecundity (7.54 offsprings/ female) determined at 24:0 light:dark photoperiod. Overall, this research showed that growth and reproduction of M. macrocopa at 30 (°C) and 24:0 light:dark photoperiod gave significant performance (P<0.05) compared to other examined treatments. Mass culture of this species under the mentioned conditions of temperature and photoperiod could provide suitable live food for use in fish larvaiculture

Nutritional value of freshwater mesozooplankton assemblages from Hanna Dam Lake, Iran, during a one-year study

Nutritional value of freshwater mesozooplankton, fatty acid (FA) and amino acid (AA) compositions were determined in the middle of each season for a one-year period from May 2009 to February 2010 in Hanna Dam Lake, Isfahan, Iran. FA and AA composition significantly (P<0.05) varied in relation to the seasonal changes of water quality, phytoplankton and zooplankton community. The content of saturated fatty acids (SAFA), mono unsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) ranged from 22.4-29.0%, 30.9-40.4%, 11.8-20.9% of dry weight (DW), respectively. The major SAFA were 16:0 (13.7-17.0 % DW) and 18:0 (4.9-7.0 % DW), whereas contents of MUFA were mainly 18:1n-9 (13.8-16.2 % DW), 16:1n-7 (6.9-13.6% DW), and 18:1n-7 (5.7-10.6% DW). The major PUFA were 18:2n-6 (2.6-11.7 % DW), 18:3n-3 (2.4-3.1% DW), 20:5n-3 (3.9-4.8% DW), 22:6n-3 (0.73-0.99% DW), and 20:4n-6 (0.56-0.73% DW). As for the ratios of n-3:n-6, the values were 0.70:1, 2.54:1, 2.10:1, and 1.73:1 in spring, summer, autumn and winter respectively. The mean essential amino acid (EAA) and non-essential amino acid (NEAA) were 28.7 and 71.3 %; 31.0 and 69.0 %; 31.63 and 68.4 %; 34.5 and 67.0 % of total amino acid in spring, summer, autumn and winter, respectively. The amount of tyrosin, isolucine, lucine, arginine, cysteine, aspartic acid, glycine and proline were higher in mesozooplankton population at summer and autumn compared to winter and spring

Effect of temperature and photoperiod on production and morphometric characters of a freshwater Cladoceran, Ceriodaphnia quadrangula (O. F. Muller, 1785)

The most important factors controlling cladocerans production, growth, and morphometric characters are temperature, food quantity and quality and photoperiod. Effects of temperature and photoperiod on production, and morphometric characters of cladoceran, Ceriodaphnia quadrangular, were examined by culturing on green algae Scenedesmus quadricauda in 250 ml conical flasks (150 ml water). Treatments used for temperature (˚C)and photoperiod (light hours:dark hours) were 20,25,30 (˚C) and 12:12,24:0 and 0:24, respectively. The maximum population density (5.51 ind./ml) obtained at 24:0 and 30 (˚C), while maximum body length (731 µm) and maximum body width (491 µm) obtained at 0:24 and 20 (˚C). Correspondingly, the maximum adult (61 %), maximum neonate (39 %) and young (9 %) in population under culture conditions of 0:24, 12:12,24:0 (L: D) and 20 (˚C) obtained, respectively. Overall, this research showed that growth and reproduction of Ceriodaphnia Quadrangula gave better performance at 25 (˚C)and 24:0, light: dark photoperiod

Gut contents study of white leg (Litopenaeus vannamei) shrimp during a culture period from earthen ponds in Delvar of Bushehr

In this research, gut contents of white leg shrimp Litopenaeus vannamei were investigated for 113 days culture period at earthen ponds in Delvar of Bushehr, by sampling every 15 days. Results showed that artificial food had highest weight percentage in gut contents (foregut, midgut, and hindgut) following in order by detritus, zooplankton, phytoplankton, and macrobenthic. In the beginning of culture period, macro-bentic were observed in larval gut contents while other food items were throughout culture period. The maximum occurrence of detritus in gut contents was at 26 and 40 days-old larvae while highest phytoplankton was obtained at 86-days-old larvae in end of culture period. The zooplankton had approximately similar amounts throughout culture period in different parts of gut, while macro-benthic only observed at 26-old-days larvae with maximum amount at foregut and midgut. The mean highest gut fullness attained at foregut (0.95 %) and lowest at hindgut (0.20 %). The dominant color of gut content was green-brown in all parts of gut that could be due to consumption of natural pond products. This study illustrated that most consumed food items in L. vannamei was prepared by natural pond foods. In addition, detritus and plankton have most important in L. vannamei during culture period