Effect of temperature, salinity and algal food concentration on ... - NOPR

Indian Journal of Geo-Marine Sciences Vol. 41(4), August 2012, pp. 369-376

Effect of temperature, salinity and algal food concentration on population density, growth and survival of marine copepod Oithona rigida Giesbrecht Santhanam P* & Perumal P1 School of Marine Sciences, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, India. 1 Department of Biotechnology, Periyar University, Salem-636 011,Tamil Nadu, India. *[E-mail: [email protected]] Received 07 June 2011; revised 02 August 2011 In the present study the copepod, Oithona rigida was reared successfully fed with different algal diets such as Chlorella marina, Coscinodiscus centralis, Skeletonema costatum and Chaetoceros affinis in the hatchery condition. The total mean production of different stages of O. rigida viz., nauplii, copepodid and adults were: 21120.79, 8205.6 and 4949.9 L-1 respectively. Maximum density (3679.3 L-1) of nauplii was attained on 11th day of culture. The egg diameter of O. rigida was reported as 0.003 mm, just hatched nauplius (Nauplius I) and last nauplius (Nauplius VI) were 0.098 and 0.184 mm respectively. The length of early copepodid and the adult female and male were 0.312; 0.745 and 0.699 mm respectively. It is inferred that the water quality parameters such as temperature, salinity and algal prey essentially influenced the population, growth and survival of O. rigida in captive condition. The density obtained during the two months culture period indicated that, O. rigida is more sufficient for commercial seed production of fish and crustacean larvae. [Key words: Copepod, Oithona rigida, nauplii, culture, Chlorella marina]

Introduction Copepods nauplii are recognized as prime food by many fish, they elicit a feeding response, they are appropriate size and they may provide nutritional benefits if they have been feeding on phytoplankton1. They have a preponderance of phospholipids rather than triacylglycerols, as well as ratios of fatty acids that more closely approximate the natural diet of marine fish larvae2. The unique swimming movement of copepods makes an attractive food source, as they induce a positive feeding response in finfish3. Current aquaculture practices provide adequately for the critical needs of some fish species with well developed technology for the production of rotifers and Artemia as live food. For some other species of fish these are not suitable as food2. Research laboratories in various parts of the world have been working towards the effective cultivation of marine copepods for use as an alternative food in aquaculture. Marine copepods are being promoted as an inevitable live feed for fish and crustacean larvae4,5. The collection of copepods from wild is a time consuming job and the availability of required species in required numbers is also never sure. Therefore much attention has been focused in recent years on continuous mass

culture of copepods and they provide a sufficient supply. Moreover the cyclopoid copepod, Oithona rigida is less sensitive and more tolerant to wide environmental conditions and also has a higher productivity than calanoids and can be fed on variety of food items. Recognition of the potential advantage in culturing the copepods, the present study was made to investigate the conditions required improving large scale culturing systems. Experiments are being conducted to determine the density, growth and survival of O.rigida in response to temperature, salinity and algal food concentration. The present study was aimed to standardize the most effective water quality conditions for increasing the scale of intensive production of O.rigida to enable reliable supply of animals with minimum expensive and maximum automation. Various workers have attempted to culture different species of copepods and many such investigations were made in temperate waters6-9. In India, very few information is available10 on culture of brackishwater cyclopoids and used them in mariculture hatchery system. The aim of this study was to develop a system for the cultivation of a cyclopoid copepod, O.rigida which occurs more common in tropical waters.

370

INDIAN J. MAR. SCI., VOL. 41, NO. 4, AUGUST 2012

Materials and Methods Zooplankton samples were collected from Vellar estuary (Lat. 11° 29’; Long. 29° 46’), southeast coast of India, during night at 09:00 pm, by using scoop (plankton) net with 158 µm mesh. Halogen lamp was used to attract the copepods towards the mesh since it has phototactic behavior. The collected samples were immediately transported to laboratory and thoroughly rinsed to reduce the contamination from other zooplankters. From the samples, O .rigida was identified under microscope using the key11. After the conformation, 300-312 gravid females of O. rigida were isolated and stocked in an oval shaped, flat-bottomed fiberglass tank (0.54 m dia, 0.81 m length) filled with 100 litre filtered seawater and vigorous aeration was given. Seawater was filtered through a membrane filter (1 µm). Water quality parameters such as temperature, salinity, pH and dissolved oxygen were maintained in the ranges of: 26-30°C; 28-34‰; 7.5-8.5; 5.0-7.5 mL/l respectively (during rearing period) fed with a daily ration of mixed algae viz., Chlorella marina, Coscinodiscus centralis, Skeletonema costatum and Chaetoceros affinis in the concentration of 50,000 cells/mL. The cultures were harvested at every 12 days by gentle siphoning. The generation time of O .rigida under optimal conditions is about 10-12 days at 26-30°C and having 6 naupliar and 6 copepodite stages including the adult. Finally the adult gravid female copepods were used to restart stock culture. Water quality parameters such as temperature, salinity, pH, dissolved oxygen and the population density, growth and survival of nauplii, copepodite and adults were observed daily. For biological observations 3 samples of 1ml was taken and counted the different stages of copepods for average results. A separate experiment was carried out to estimate the effect of temperature, salinity and food concentration on density, growth and survival of O.rigida. Different temperature ranges such as 15-20°C and 21-25°C was maintained for the entire experimental period. Temperature fluctuation can be maintained by using air conditioning. Temperature above 25°C was maintained through water bath. An immersion heater in the water bath can be used to control temperature ambient. Water should be stirred using an air stone so that a layer of heated water does not form at the surface and overheat the animals. Water level within the animal

containers should be slightly higher than that of the heater water bath. This cause’s gentle stirring of the water in the animal containers as the surface loses heat to the atmosphere and convection currents were established. A range of salinities 15-20‰ and 21-27‰ were used for salinity studies. These salinities were achieved by diluting seawater with distilled water. The concentrations of unicellular algae quantified by cell counts using a Sedgewick counting chamber under compound microscope. Different cell concentrations of 10,000 cells/mL and 30,000 cells/ml were used for the present experiment to examine the food concentration effect. Phytoplankton samples were collected from the Bay of Bengal, Parangipettai coast using a plankton net (48 µm) and live cells of Coscinodiscus centralis, Skeletonema costatum and Chaetoceros affinis were isolated by repeated centrifugation method12. Isolated phytoplankton were stocked separately in 1000 ml conical flask containing filtered seawater at 28°C temperature, 30‰ salinity and 7000-9000 light intensity and fertilized with mixed culture medium12. Chlorella marina was obtained from Central Institute of Brackishwater Aquaculture (ICAR, Govt. of India, Chennai) and maintained separately fed with Conway’s medium. Results A favourable result on population density, growth and survival of O. rigida was obtained in the temperature range of 26-30°C, salinity 28-34‰ and food concentration of 50,000 cells/mL. Over 12 days operation, the culture system produced an average of 1760.06 nauplii/l, 658.8 copepodid/l and 412.46 adults/l on the 12th day. Maximum mean density of O.rigida was recorded as 3679.3 nauplii/l, 2016.3 copepodid/l and 1832 adults/l on 10, 12 and 12th day(s) of culture respectively. For the entire culture period (2 months), the total mean production was 34276.29 ind./l. comprising 21120.79 nauplii, 8205.6 copepodids and 4949.9/l (Fig. 1). Daily production adut of copepod was given in Table 1. Growth (body length) and survival of the O. rigida was estimated and the detailed results on daily growth of different stages of copepod are given in Table 2. Of these egg diameter of O. rigida was 0.003 mm, just hatched nauplius (nauplius I) was 0.098 mm, last nauplius (nauplius VI) was 0.184 mm. Length of early copepod was 0.312 mm.

SANTHANAM & PERUMAL: EFFECT OF TEMPERATURE, SALINITY AND ALGAL FOOD CONCENTRATION

371

Table 2—Daily mean growth (mm) of O. rigida Duration of rearing (hours)

Fig. 1—Total mean production of O. rigida at maximum temperature, salinity and food concentration. Table 1—Daily mean production of copepod, O. rigida Days

Nauplii (L-1)

Copepodite (L-1)

Adult (L-1)

0 1 2 3 4 5 6 7 8 9 10 11 12

0 51.66±1.53 62.33±1.53 577.6±7.1 1172±2.52 1694±4.58 2154.3±4.51 2788.3±3.05 3098±1 3380.7±3.51 3679.3±4.16 1478.3±7.23 984.3±4.50

0 0 0 0 190.3±1.53 218.6±1.53 296.7±4.51 365.7±4.04 690.7±1.53 1056.7±5.86 1478.3±10.41 1892.3±4.04 2016.3±5.69

312±2 306.3±0.58 104.6±3.05 88±1.73 59±1 12±2 0 0 0 399.7±2.55 781±3.61 1055.3±7.6 1832±6.24

After the 5th copepodid, the adult formed. Length of adult female and male O. rigida was 0.745 and 0.699 mm respectively. Maximum survival of 87.4%, 90.5% and 89.2% were observed at the temperature of 26-30°C, salinity ranges between 28-34‰ and food concentration of 50,000 cells/mL respectively. During temperature ranges between 15 and 20°C, the density of O. rigida declined steadily and the nauplii production was started at 4th day onwards (Fig. 2). Average production of nauplii, copepodite and adult were 640.7, 213.4 and 68.8 respectively. Maximum mean density of 1500.8 nauplii, 783.3 copepodite and 112.8 adults were observed on 11th, 12th and 15th day/(s) onwards. However, in temperature ranges between 21 and 25°C, the maximum nauplii, copepodite and adults were observed in the density of 1934.1, 1129.8 and 204.8 during 11th, 12th and 14th day respectively Table 3. The density of O. rigida in the salinity ranges between 15-20‰ was shown in Fig. 3. Average density of nauplii, copepodite and adults were 730.7, 341.9 and 92.6. Maximum average density of 2269

Nauplii stages Length (mm)

Copepodite stages Length (mm)

0

-

-

24 0.20 0.22 0.19 0.21 24 24.02 24.04 24.03 24.05

0.105±0.001 0.109±0.005 0.129±0.0015 0.152±0.002 0.161±0.0015 0.193±0.003 -

48

-

0.314±0.002 0.362±0.024 0.443±0.0015 0.524±0.0011 (Female) 0.503±0.0005 (Male) 0.609±0.0005 (Female) 0.603±0.0015 (Male) 0.745±0.0025 (Female) 0.699±0.001 (Male) (Adults)

12th day

Fig. 2—Effect of temperature on density of O. rigida.

nauplii, 1020.2 copepodite and 208.4 adults were recorded at 10th, 12th and 11th day respectively. Recorded mean density of nauplii, copepodite and adults of O. rigida at salinity ranges of 21-27‰ were 1265.5, 486.6 and 147.8 respectively. Here the maximum density of nauplii (2978.4) was observed on 9th day of the experiment followed by copepodite (1516.2) and adult (512.6) at 12th and 11th day onwards. The mean density of O. rigida generally increased with improving food concentration (Fig. 4).


372

Table 3—Daily average growth of O. rigida at different temperatures Duration of rearing (hours) 0 24 0.20 0.22 0.19 0.21 24 24.02 24.04 24.03 24.05

Nauplii stages Copepodite stages Length (mm) Length (mm) 15-20°C 0.09±0.0002 0.108±0.004 0.115±0.007 0.133±0.0005 0.159±0.0001 0.174±0.0014 0.223±0.05 0.258±0.002 0.306±0.016

48

-

12th day

-

13th day

Nauplii stages Length (mm) 0.10±0.0003 0.104±0.0012 0.117±0.016 0.134±0.0003 0.152±0.0005 0.180±0.0002 -

0.337±0.006 (F) 0.312±0.04 (M) 0.464±0.001 (F) 0.439±0.021 (M)

-

0.524±0.003 (F) 0.501±0.013 (M) Adults

-

-

Copep stages Length (mm) 21-25°C 0.239±0.004 0.248±0.013 0.314±0.0005 0.464±0.0013 (F) 0.437±0.002 (M) 0.518±0.0014 (F) 0.489±0.0030 (M) 0.607±0.0002 (F) 0.583±0.0012 (M) Adults

Fig. 3—Effect of salinity on density of O. rigida. Fig. 4—Effect of algal food concentration on O. rigida density.

Production of nauplii, copepodite and adult O. rigida at 10,000 cells mL-1 food concentration was comparatively lower than at two higher food concentrations. Here the average production was 683.2 nauplii, 102.7 copepodite and 39.67 adults. Total mean production was 9907.1 nos./l. In 30,000 cells/mL algal food concentration, the density was higher than 10,000 cells/mL and lower than 50,000 cells/mL. While the total mean production

were 15924.3 nos./l. comprising of 12041.6 nauplii, 3077.8 copepodite and 804.9 adults. Average production was 1003.5 nauplii, 256.5 copepodite and 67.10 adults. Growth of O. rigida showed that a temperature range between 15 and 20°C was reduced the growth and extended the development time. Here the nauplii I appeared after 24.20 hrs with the length of 0.09 mm


and the Nauplii VI metamorphosis at 74.84 hrs with body length of 0.74 mm. The body length of copepodite I and adult female and male were 0.223 mm, 0.524 and 0.501 respectively. Adult O. rigida observed at 13th day of experiment. Growth was slightly increased in the temperature ranges between 21 and 25°C, here the Nauplii (NI) was hatched after 24hrs with the length of 0.10 mm and body length of NVI is 0.180 mm. The length of CI and CV was 0.239 mm, 0.518 mm (Female) and 0.489 mm (male). Adult female and male copepods length was found as 0.607 and 0.583. Copepod, O. rigida showed the least growth at the lowest salinity of 15-20‰. While the body length of NI and NVI was 0.092 and 0.164 and they appeared on 24 hrs and 48.82 hrs respectively. The CI and CV length were 0.271 and 0.576 (Female) and 0.561 mm (Male). Length of adult female and male were 0.705 and 0.659 respectively. Growth in the salinity ranges between 21-27‰ was 0.10 (NI), 0.182 (NVI), 0.302 (CI), 0.598 (CV female), 0.571 (CV male), 0.726 (adult female) and 0.678 (adult male) (Table 4). The present result on growth in response to food concentration was clearly indicated in low food concentration of 10,000 cells/ml, the copepod growth was decreased Table 5. Length of NI, NVI, CI, CV (female) and CV (male) were 0.074, 0.177, 0.219, 0.495 and 0.481 mm. Adult female and male length was 0.584 and 0.563 mm respectively. In case of 30,000 cells/mL, the length of NI and NVI was found to more as 0.098 and 0.172 mm. The CI and CV were

appeared with the length of 0.269, 0.573 (female) and 0.560 (male). While the body length of adult female and male copepod was 0.698 and 0.683 mm respectively. The survival of nauplii, copepodite and adults of O. rigida were proportional to temperature, salinity and food concentration. Least survival of 32%, 21.8% and 16.7% were observed in the temperature range between 15 and 20°C, salinity of 15-20‰ and food concentration of 10,000 cells/mL respectively. Higher survival was noticed with optimum temperature, salinity and food concentration (Table 6). Discussion In the present study gravid females of O. rigida were used to start the culture. Nauplii were not used due to the problem in separation. Present study was similar to Schipp et al. and Stottrup et al.7-13. In the present observation, the maximum production of 3,676 nauplii was recorded followed by 2010 copepodites and 1825 adults/l. Production rate of copepod, O. rigida exceeded than those reported for Acartia sp.14. They reported the maximum densities in Acartia tsuensis cultured in outdoor tanks viz: 1136 nauplii, 588 copepodites and 280 adults/l. Similarly Schipp et al.7 was reported in Acartia spp. Drillet et al.15 stated that many important and novel parameters that could help the improvement of copepod cultivation techniques. They recommended that scientific research to understand catabolic lipid pathways in various copepod species as this would

Table 4—Daily average growth of O. rigida at different salinities Duration of rearing (hours)

373

Nauplii stages Copepodite stages Length (mm) Length (mm) 15-20‰

Nauplii stages Length (mm)

Copepodite stages Length (mm) 21-27‰

0 24 0.20 0.22 0.19 0.21 24 24.02 24.04 24.03 24.05

0.092 0.10±0.0005 0.103±0.0004 0.117±0.0001 0.136±0.002 0.164±0.0005 -

0.10±0.003 0.104±0.0001 0.117±0.0001 0.134±0.0004 0.152±0.0002 0.180±0.0032 -

48

-

12th day

-

0.239±0.0004 0.248±0.0013 0.314±0.0015 0.464±0.0005 (F) 0.437±0.0012 (M) 0.518±0.0004 (F) 0.489±0.0005 (M) 0.607±0.0012 (F) 0.583±0.0004 (M) Adults

0.271±0.002 0.326±0.0002 0.405±0.0013 0.500±0.0005 (F) 0.480±0.004 (M) 0.576±0.005 (F) 0.561±0.0021 (M) 0.705±0.0005 (F) 0.659±0.0013 (M) Adults

-


374

Table 5—Daily average growth of O. rigida at different food concentrations Duration of rearing (hours)

Nauplii stages Copepodite stages Length (mm) Length (mm) 10,000 cells/mL.

Nauplii stages Copodid stages Length (mm) Length (mm) 30,000 cells/mL.

0 24 0.20 0.22 0.19 0.21 24 24.02 24.04 24.03 24.05

0.074±0.015 0.099±0.004 0.109±0.0005 0.118±0.001 0.138±0.0002 0.151±0.0005 0.177±0.003 -

0.219±0.0012 0.264±0.020 0.292±0.0001

0.098±0.005 0.103±0.0005 0.114±0.013 0.137±0.0014 0.154±0.002 0.172±0.0003 -

48

-

-

12th day

-

0.334±0.0005 (F) 0.317±0.0014 (M) 0.495±0.0005 (F) 0.481±0.0014 (M)

13th day

-

0.269±0.041 0.326±0.015 0.392±0.0005 0.486±0.0001 (F) 0.473±0.0001(M) 0.573±0.0024 (F) 0.560±0.015 (M) 0.698±0.0025 (F) 0.683±0.014 (M) Adults

0.584±0.005 (F) 0.563±0.0003 (M) Adults

help developing inexpensive food items for copepods which are able to bio-convert fatty acids. Also the need for understanding mating process, sex changes, sex ratio and chemical communication between copepods seems obvious and the amount of effort should be needed in these areas. Temperature is considered to be the most important factor affecting the density, growth, development time and survival of O. rigida. The density of copepod increased when the temperature was maintained in the range of 28 to 32°C7,16,17. Authors have stated that the size and biomass of the copepod, Acartia clausi was influenced by the temperature. However, it has been reported that the decrease in prosome length was associated with the increase in biomass of A.tsuensis18. Katona19 stated that the low temperature of 14°C prolongs the development as it might inhibit the molting rate in neritic copepod Eurytemora herdmani. Temperature may also influence on the growth of the copepod. The time for development of O. rigida from egg to adult depend upon the temperature. In the present study, O. rigida were taken the times at 26-30°C, to develop from NI to CI was 72.84 hrs and development time decreased as the temperature increase, which compares favourably with previous reports20,21 and also in agreement with earlier findings5 in calanoid copepod Acartia

Table 6—Effect of temperature, salinity and algae on survival of copepod Parameter Temperature 15-20°C 21-25°C 26-30°C Salinity 15-20‰ 21-27‰ 28-34‰ Food concentration 10,000 cells/ml. 30,000 cells/ml. 50,000 cells/ml.

Survival (%)

32 58.6 87.4 21.8 56.2 90.5 16.7 60.8 89.2

plumosa. Development time of Paraeuchaeta elongata copepodites22 and Sinocalanus tenellus nauplii23 decreased with increasing temperature beyond the limit. Landry24 stated that the development is also controlled by a series of biochemical reactions, the rates of which are regulated by temperature. In the present study, the time taken at 15-20°C to develop NI to CI was 96.88 hrs, it is indicated that the low temperature prolonged the development time. In the present study, phytoplankters were found to maintain the optimum pH which was conducive for good biomass and growth. Similar findings were


earlier reported25,26. Dissolved oxygen concentration maintained in the optimum level (5-7.5 mL/l.) during the entire culture period was found to have influenced the better growth and good density of culturing species. Aeration is required in copepod culture system, in order to help maintain microalgae in suspension promote better algae distribution and avoid anoxic areas in the tank27,28. Salinity was found to influence the production rate of copepod. It was maintained between 28 and 34‰, which were found to be an ideal salinity regime for the maximum production of O. rigida. Decrease in salinity (15-20‰ onwards) resulted the reduced density and the species were disappeared in the culture tank when the salinity decreased below 9‰10-13. Maximum production of nauplii was attained on 10th day of culture and it could be noticed that the nauplii production decreased from the 11th day onwards, which may be due to the metamorphosis of nauplii into the copepodites29. Variations in salinity also affect the growth and development time, with lower salinity producing slower development times. Presently low growth and extended development time was observed in low salinity of 15-20‰. It was suggested that physiological stress, due to the additional osmoregulation and respiration demands at these salinities resulted in a suppression of growth rate23. Food is another very important factor to support the good growth and density of copepod in culturing system. Abundance of nauplii, copepodites and adults of O. rigida increased in proportion to the increased food concentration and combination. The candidate species O. rigida had a generation period of 10-12 days depending upon the temperature and the availability of food. In the present experiment, the successful rearing of copepod, O. rigida has been accomplished by providing a mixture of foods such as C.marina, C.centralis, S.costatum and C.affinis with high concentration, which resulted in higher biomass30,31. Decreased population was observed earlier besides the shortage of food32. Good quality and rich nutritive value of food organisms such as C.marina, C.centralis, S.costatum and C.affinis can also responsible for good results in the biomass of O. rigida7-33. In response to being supplied with high concentration of algal food, the copepods had the highest survival rate. But in low food concentration survival was comparatively low because of the food scarcity7. Despite the fact that better results might be

375

obtained by designing a mixed diet for O. rigida34. Authors stated that intensive copepod production normally relies on feeding a combination of algae. Intensive mass culture of copepods has been attempted with several species with varying success by several workers in abroad27,35,36. The copepod survival at 26-30°C was greater (87.4%) in the present study it is clearly understood that the copepod O. rigida as tropical species can tolerate a wide range of temperature. While in low temperature they cannot show any development and metabolism, it clearly has a less pronounced effect on survival than salinity21. In the present study, maximum growth, density and survival of O. rigida performed best in optimum salinity and survival generally decreased with reduced salinity. This was agreed by37 who stated that the maximum density of A.bifilosa in the Mundaka estuary (Spain) occurred at 30‰ salinity. No cannibalism was observed in the present culture. But Stottrup et al.23 and Ohno et al.38 have reported earlier that declined nauplii production after 7th day in Acartia culture was due to the cannibalistic behaviour of adults and copepodites. Information from this study can be used to develop an improved copepod culturing systems. Culture system of copepod O. rigida have been developed and standardized with favourable conditions. Experimental results on effect of temperature, salinity and food concentration on density, growth and survival of O. rigida indicated to judge the levels of temperature, salinity and food concentrations required to produce a certain number of animals under laboratory conditions. Present study also indicated that the economically practicable and more numbers of copepod, O. rigida can be used as live-food for the mass rearing of fish larvae and they can be considered to be the most promising candidate species for mass culture and the population densities after 2 months of culture approximated to several hundred adults. copepodites and several thousand nauplii per litre capacity should be sufficient to feed the fish larvae until metamorphosis. References 1

2

3

Luis E C Conceicao, Manuel Yuera, Pavlos Makridis, Sofia Morais & Maria Teresa Dinis, Live feeds for early stages of fish rearing, Aquaculture Research., 41 (2010) 613-640. Rippingale R J & Payne M F, Intensive cultivation of a calanoid copepod, Gladioferens imparipes A Guide to Procedure, (2001) (60 pp). Doi M, Toledo J D, Golez M S N, Santos M & Ohno A, Preliminary investigations of feeding performance of larvae

376

4

5

6 7

8

9

10

11

12 13

14

15

16

17

18

19

20

21

22


of early red-spotted grouper, Epinephelus coioids, reared with mixed zooplankton. Hydrobiologia, 358 (1997) 259-263. Watanabe T, Oowa C, Kitajima C & Fujita S, Nutritional values of live organisms used in Japan for mass propagation of fish: A review. Aquaculture, 34 (1983) 115-143. Sunyoto P, Diani S & Supriatna A, Experimental culture of Acartia plumosa: A copepod for use in marine fish hatcheries. NAGA, 18 (3) (1995) 27-28. Stottrup J G & Norsker N H, Production and use of copepods in marine fish culture. Aquaculture, 155 (1997) 231-247. Schipp G P, Bosmans J M P & Marshall A J, A method for hatchery culture of tropical calanoid copepoda, Acartia spp. Aquaculture, 174 (1999) 81-88. Payne M F & Rippingal R J, Evaluation of diets for culture of the calanoid copepod Gladioferens imparipes. Aquaculture, 187 (2000) 85-96. Puello-Cruz A C, Mezo-Villalobos S, Gonzalez B & Voltolina D, Culture of the copepod Pseudodiaptomus euryhalinus (Johnson 1939) with different microalgal diets. Aquaculture, 290 (2009) 317-319. Merrylal James C, & Martin Thompson P K, Production of copepods in outdoor culture tank. Symposium on Coastal Aquaculture Cochin India, (1986)1275-1280. Kasturirangan L R, A key for the more common planktonic copepods of the Indian waters, CSIR Publication 2.., (1963) 87 pp. Gopinathan C P, Live-Feed culture-Micro algae. Bull Cent Mar Fish Res Inst, 48 (1996) 110-116. Stottrup J G, Richardson K, Kirkegaard E & Jorgenpihl N, The cultivation of Acartia tonsa Dana for use as a live food source for marine fish larvae. Aquaculture, 52 (1986) 87-96. Ohno A & Okamura Y, Propagation of the calanoid copepod Acartia tsuensis in outdoor tanks. Aquaculture, 70 (1988) 39-51. Drillet G, Fouel S, Sichlau H M, Jepsen M P, Hojgaard K J, Joarder K A & Hansen W B, Status of recommendations on marine copepod cultivation for use as live feed. Aquaculture, doi:10.1016/j.aquaculture. (2011) 2011.02.027. Landry M R, Population dynamics and production of a planktonic copepod, Acartia clausi in a small temperate lagoon on San Juan Island, Washington. Int Revue Ges Hydrobiol, 63 (1978) 77-120. Uye S I, Population dynamics and production of Acartia clausi Giesbrecht (Copepoda: Calanoida) in inlet waters. J Exp Mar Biol Ecol, 57 (1982) 57-83. Lee W H, Ban S, Ikeda T & Matsuishi T, Effect of temperature on development growth and reproduction in the marine copepod Pseudocalanus newmani at satiating food concentration. J Plankton Res, 25 (3) (2003) 261-271. Katona S K, Growth characteristics of the copepods Eurytemora affinis and E. herdmani in laboratory cultures. Helgolander Wiss. Meeresunters, Bd., 20 (1970) 373-84. Yoon W D, Shim M B & Choi J K, Description of the developmental stages in Acartia bifilosa Giesbrecht (Copepopda:Calanoida). J Plankton Res, 20 (1998) 923-942. Chinnery F E & Williams J A, The influence of temperature and salinity on Acartia (Copeoda:Calanoida) nauplii survival. Mar Biol (Berl.), 145 (2004) 733-738. Ozaki K & Ikeda T, The effect of temperature on the development of eggs and nauplii of the mesopelagic copepod

23

24

25 26

27

28

29

30

31

32

33

34

35

36

37

38

Paraeuchaeta elongata. Plankton Biol Ecol, 44 (1997) 91-95. Kimoto K, Uye S & Onbe T, Growth characteristics of a brackishwater calanoid copepod Sinocalanus tenellus in relation to temperature and salinity. Bull Plankton Soc Jpn, 33 (1986) 43-57. Landry M R, The relationship between temperature and the development of the life stages of the marine copepod Acartia clausi (Giesbr.). Limnol Oceanogr, 20 (1975) 854-857. Matsudaira C, Culturing of a copepoda, Sinocalanus tenellus. Inform. Bull Plankton Soc Jpn, 5 (1957) 1-6. Omori M & Ikeda T, Methods in marine zooplankton ecology, II Edn. John Wiley and Sons, Pergamon Press, New York, (1984) pp 256. Marinho da Costa R & Fernandez F, Feeding and survival rates of the copepods Euterpina acutifrons Dana and Acartia grani Sars on the dinoflagellates Alexandrium minutum Balech and Gyrodinium corsicum Paulmier and the Chryptophyta Rhodomonas baltica Karsten. J Exp Mar Biol Ecol, 273 (2002) 131-142. Støttrup J G, Production and nutritional value of copepods. In: Støttrup J G & L A McEvoy (Eds.). Live feeds in marine aquaculture. Blackwell Science, Oxford, UK. Chapter 5, (2003) 145-205. Doi M, Singhagraiwan S, Singhagraiwan T, Kitade M & Ohno A, Culture of the calanoid copepod, Acartia sinjiensis in outdoor tanks in the Tropics. Thai Mar Fish Res Bull, 5 (1994) 27-36. Tackx M & Polk P, Feeding of Acartia tonsa Dana (Copepoda, Calanoida): Predation on nauplius of Canuella perplexa T. et A. Scott (Copepoda, Harpacticoida) in the sluice-dock at Ostend. Hydrobiology, 94 (1982) 131-133. Kiorboe T, Mohanraj F & Riisgard H V, In situ feeding rates of planktonic copepods comparison of foam methods. J Exp Mar Biol Ecol, 88 (1985) 67-81. Klein Breteler W C M & Gonzalez S R, Influence of cultivation and food concentration on body length of calanoid copepods. Mar Biol, 71 (1982) 157-161. Corkett C J, Techniques for breeding and rearing marine calanoid copepods. Helgolander Wiss, Meeresunters, Bd., 20 (1970) 318-324. McKinnon A D, Duggan S, Nichols P D, Rimmer M A, Semmens G & Robino B, The potential of tropical paracalanid copepods as live feeds in aquaculture. Aquaculture, 223 (2003) 89-106. Sorensen F T, Drillet G, Engell-Sorensen K, Hansen W B & Ramlov H, Production and biochemical composition of eggs from neritic calanoid copepods reared in large outdoor tanks (Limfjord, Denmark). Aquaculture, 263 (2007) 84-96. Cortney L Ohs, Kelly L, Chang Scott W Grabe, Matthew A DiMaggio & Erik Stenn, Evaluation of dietary microalgae for culture of the calanoid copepod Pseudodiaptomus pelagicus, Aquaculture, 307 (2010) 225-232. Villante F, Ruiz A & Franco J, Summer zonation and development of zooplankton populations within a shallow mesotidal system: the estuary of Mundaka. Cah Biol Mar, 34 (1993) 131-143. Ohno A, Takahashi T & Taki Y, Dynamics of exploited populations of the calanoid copepod Acartia tsuensis Aquaculture, 84 (1990) 27-39.