SOME ECOLOGICAL PARAMETERS OF ARTEMIA PARTHENOGENETICA GAHAI AND THEIR USED IN RESOURCE EXPLOITATION

1
SOME ECOLOGICAL PARAMETERS OF ARTEMIA
PARTHENOGENETICA GAHAI AND THEIR USED IN
RESOURCE EXPLOITATION

• Author
• Sun Jingxian
• Dalian Fisheries University
• Dr. Jia Qinxian
• Research Center for Salt
• Lakes,Chinese Academy of
• Geological Sciences
• Academician. Zheng Mianpin
• Research Center for Salt
• Lakes,Chinese Academy of
• Geological Sciences

2
SOME ECOLOGICAL PARAMETERS OF ARTEMIA
PARTHENOGENETICA GAHAI AND THEIR USED IN
RESOURCE EXPLOITATION

• Theme
• Brine shrimp eggs is the indispensable ringent
  bait for the marine animal breeding
  .Gahai Salt Lake has an abundant Artemia
  resource, which should be utilized under
  reasonable exploitation.

• Based on the annual water temperature regime
  of Gahai Saltlake,
• forecasting the productivity of the
  population, estimating the
• potentiality of the resource exploitation.

3
MATERIALS

• Brine shrimp eggs collected from Gahai Salt
  Lake.
• The adults and larvae of Artemia hatched from
  dormant eggs.
• Bait Dunaliella sp., Phaeodactylum
  tricornutum and marine Chlorella sp.
• Salt water 60 salinity.

4
METHODS AND FORMULAE

• The setting of the experimental conditions
  Except for temperature, the conditions(salinity,
  bait or etc) were consistent with the nature.
• Temperature Between 16 and 34? at
  intervals of
• 2?,with errors of 0.3 (the temperature
  was controlled
• by ICL-216 temperature controller,
  see remark).
• Salinity Fixed at 60.
• Illumination Natural light.
• Breed density 1000 nauplii were added
  to each culture
• chamber filled with 2 liters of salt
  water (60).

5
Methods and Formulae (con.)
Threshold temperature of development(C) Constant
of effective accumulative temperature(K)

• Based on KN(T-C),finding the roots by using
  least square method.The
• equations are as follows

• Vj 1/Nj
• Vi (?Vj/n)1/(?Nj/n) n/?Nj
• k ( m r?ViTi??Vi?Ti) /m r?Vi2?
  (?Vi)2
• C (?Vi2?Ti??Vi?ViTi) / m r?Vi2?
  (?Vi)2
• R (?TiVi??Ti?Vi/m r) / SQR
  (?Ti2?(?Ti)2/m r)(?Vi2?(?Vi)2/m r)
• i 1,2,,m?r
• Degrees of freedom (df) m?r?r?2 )
  15?2?2?2 26
• where Nj -- development time (d) of the
  jth sample
• Vi -- mean development rate
  (d-1)
• Ti -- experimental temperature
  (?)
• k -- constant of effective
  accumulative temperature of a generation (C
• degree-days)
• r -- times of repetition at
  m experimental temperatures
• C -- threshold temperature of
  development (?)
• R -- correlation coefficient
• n -- number at each
  temperature.

6
Methods and Formulae (con.)
TEST OF LIFE TABLE

• Mean generation time (T), population net
  reproduction rate(Ro) ,intrinsic rate of natural
  increase (rm) , infinite rate of increase (?) and
  doubling population time (t) were calculated by
  the following equations (Wu et al.1991)

• T (?lxmxX)/ (?lxmx)
  
• Ro ?lxmx
  
• rm loge Ro / T
  
• ? exp(rm)
  
• t loge 2/ rm
• where X -- age (day)
• lx -- survival rate at X age
• mx -- output female offspring
  number per female
• adult at X age.

7
Methods and Formulae (con.)
THE DEFINITION FOR GENERATIONS

• Y f(X)
• The distributing time (X,day) as
  abscissa,the water temperature
• (Y,?) as ordinate, getting the
  regression equation f(X).
• Counting the temperature above the
  threshold temperature of
• development for larvae ,calculating the
  range of effective time 0,t

• Object function (A)
• The lower limit (a)
• The upper limit (b)
• Or set a0, get b set ab, get new b if bgtt,
  the calculation is finished,
• otherwise repeat calculation.
• where X distributing time (day)

8

• Using the mean effective accumulative
  temperature of a generation as an object function
  (A). The growth initiation time of the first
  generation as the lower limit. The upper limits
  were calculated with a definite integral
  equation. Subsequently, using the upper limit as
  the lower limit of the next generation, we
  calculated upper limits repeatedly to the time of
  the borderline of each generation in the range of
  0,t

9
RESULTS

• Temperature adaptability and requirement of the
  
• quantity of heat for development

• Life Table on Age Character

• Ecological Parameters and Water Temperature

• Population Productive Potential and Water
• Temperature

Generations and Water Temperature
Population Productive Potential
10
Result (con.)
Temperature adaptability and requirement of the
quantity of heat for development

• Table1 Influence of temperature on the mean
  development rate of Artemia

Temperature (?) Hatching(d) The larva(d) Whole life time(d) Mean generation time(d)
12 12.047.82
16 3.872.04 47.139.90 112.1342.70 85.66
19 2.951.65 30.315.75 96.3128.89 71.94
22 2.040.58 22.472.40 76.1714.47 60.70
25 1.520.59 17.801.42 61.0511.60 48.98
28 1.290.32 14.331.00 57.536.78 38.44
31 1.120.22 12.010.90 50.115.51 25.53
34 0.970.15 11.801.12 42.607.26 21.17
r 0.998 0.992 0.967
C(?) 9.94 10.33 10.28
K(?d) 22.912.08 261.2624.10 458.6857.6

• r -- correlation coefficient
  C -- Threshold temperature of development
• K -- Constant of effective accumulative
  temperature

11
Temperature adaptability and requirement of the
quantity of heat for development

• We recorded the development rate on each
  development stage of Artemia at 8 temperatures,
  as Table 1 shows. The close relationship between
  the mean development rates and temperature was
  shown by their correlation coefficient.
• We can clearly see that the development rates for
  hatching, nauplius, larvae, and adults were
  obviously shortened with elevated water
  temperature and so did the mean generation time.
• By calculations, the threshold temperature of
  development (C) and the effective accumulative
  temperature(K) for hatching were 9.94? and
  22.91?d, respectively. for the larva were 10.33
  ? and 261.26?d, respectively, and for a whole
  generation were 10.28? and 458.68?d,
  respectively.

12
Result (con.)
Life Table on Age Character
Table 2 Life table of Artemia on age character
Temperature(?) 16 19 22 25 28 31 34
eggs 1000 1000 1000 1000 1000 1000 1000
larvae 371.25 461.00 582.75 642.75 728.25 514.50 347.00
hypo-adults 108.5 185.75 352.75 340.00 413.00 232.50 67.00
adults 84.00 147.25 281.50 285.75 322.25 206.00 56.25
male 0 0 3 4 7 6 6.25
reproductive rate 65.21 79.08 86.65 160.09 157.70 129.70 38.5
population reproductive times 5.481 11.658 24.13 45.10 49.55 25.94 1.925
death rate before adult 91.6 85.275 71.85 71.425 67.775 79.40 94.375
Table 3 Daily reproductive rate of Artemia
19 ? 25? 34?
mean generation time(d) 71.9 49.0 21.2
reproductive rate 79.1 160.1 38.5
daily reproductive rate 1.10 3.27 1.81
13
Life table on age character

• Constructing a life table of Artemia at seven
  temperatures. The amount of eggs, larvae, adults
  were counted, and the survival rate, reproductive
  rate were recorded. (As Table2 shows)
• The death rate before adult marked the
  adaptability of the population to the
  environment. The death rate was high at either
  the higher or lower test temperature,low at the
  range of 22-28?. Fitting the death rate with
  temperature,we got the temperature range for
  development from larvae to adults.The range is
  10.10-39.56?.

14

Life table on age character

• The population reproductive times reflected the
  population potentiality of reproduction. Fitting
  the population reproductive times with
  temperature,we got that the population have
  potentialities of increase at the range of
  13.95-35.75 ?. The maximal potentialities of
  increase is at 24.85 ?.
• Putting the mean generation time and reproductive
  rate of each female Artemia together, we get
  daily reproduction. (As Table3 shows) Because of
  shorter generation time at higher temperature,
  daily reproduction was higher, and both total
  reproductive rate and daily reproduction reached
  the highest values at the optimum temperature.

15
Result (con.)
Some Ecological Parameters of Artemia and Water
Temperature
Table 4 Main ecological parameters of Artemia in
different temperature
Temperature rm(ind./?.d) T(d) Ro(Nt/No) ?(/d) t(d)
16 0.01774 85.66 4.572 1.0179 39.073
19 0.02999 71.938 8.652 1.0304 23.112
22 0.05091 60.702 21.995 1.0522 13.616
25 0.08578 48.980 66.811 1.0896 8.081
28 0.10842 38.444 64.602 1.1202 6.393
31 0.12749 27.530 33.441 1.13597 5.437
34 0.07643 21.171 5.043 1.0794 9.069
Regression equations Ro exp(-16.15491?1.56271X-0.03028X2 ) F(2.4)13.99 rm exp(-11.13956?0.59790X-0.01005X2 ) F(2,4)57.49 ? exp(-0.32958?0.02827X-0.00046X2 ) F(2.4)9.20 t 170.015311.3905X?0.1962X2 F(2,4)298.58 T 37.4685X exp(-0.1197X) F(1,5)2447.7 Ro exp(-16.15491?1.56271X-0.03028X2 ) F(2.4)13.99 rm exp(-11.13956?0.59790X-0.01005X2 ) F(2,4)57.49 ? exp(-0.32958?0.02827X-0.00046X2 ) F(2.4)9.20 t 170.015311.3905X?0.1962X2 F(2,4)298.58 T 37.4685X exp(-0.1197X) F(1,5)2447.7 Ro exp(-16.15491?1.56271X-0.03028X2 ) F(2.4)13.99 rm exp(-11.13956?0.59790X-0.01005X2 ) F(2,4)57.49 ? exp(-0.32958?0.02827X-0.00046X2 ) F(2.4)9.20 t 170.015311.3905X?0.1962X2 F(2,4)298.58 T 37.4685X exp(-0.1197X) F(1,5)2447.7 Ro exp(-16.15491?1.56271X-0.03028X2 ) F(2.4)13.99 rm exp(-11.13956?0.59790X-0.01005X2 ) F(2,4)57.49 ? exp(-0.32958?0.02827X-0.00046X2 ) F(2.4)9.20 t 170.015311.3905X?0.1962X2 F(2,4)298.58 T 37.4685X exp(-0.1197X) F(1,5)2447.7 Ro exp(-16.15491?1.56271X-0.03028X2 ) F(2.4)13.99 rm exp(-11.13956?0.59790X-0.01005X2 ) F(2,4)57.49 ? exp(-0.32958?0.02827X-0.00046X2 ) F(2.4)9.20 t 170.015311.3905X?0.1962X2 F(2,4)298.58 T 37.4685X exp(-0.1197X) F(1,5)2447.7
16
Some Ecological Parameters of Artemia and Water
Temperature

• Based on the observation of the process from
  hatching of eggs to death of adults, the life
  table of Artemia at seven temperatures were set
  up. The intrinsic rate of natural increase (rm) ,
  mean generation time (T),the reproduction rate
  (Ro), finite rate of increase (?) and the
  doubling time of population increase (t) of
  Artemia under different temperature were
  calculated. The results obtained are as Table4.
• The regression equations of the 5 parameters
  with temperature were listed in the table.

17
Result (con.)
Generations and Water Temperature

• Water temperature data from Gahai Saltlake,during
  1993-1994 and Jul-Aug in 1997.
• The total effective accumulate temperature is
  1225.66 ?d
• Mean accumulate temperature of generation is
  458.68?57.6 ? -- as an object function value(A)
• The theoretical number of generations is
  2.670.34 per year.
• The threshold temperature is 10?.

18
Generations and Water Temperature

• Fitting time distribution with water
  temperature and got equation
• Y 0.3066X?0.001179X2
  (F(2,6)99.94) (1)
• Y -100.3066X?0.001179X2
  (F(2,6)99.94) (2)
• where Y temperature(?) X
  generation time(d)

• Dividing the generation time

e(?)
?
?
?
10/7
25/4
26/8
?
23/10
10/8
30/11
17/3
Generation time (d)
Fig.1 The generations of Artemia and
environmental temperature in Gahai Salt Lake
? ? 1st to 3rd generations ? last
whole generation

•   The beginning time of each generation
• Generation?,Jul 10 Generation ? ,Aug 26
  The last whole generation,
• Aug 10.

19
Generations and Water Temperature
In order to determine the time borderlines for
each generation, we further fit time distribution
with water temperature and got equation 1,when
water temperature was above 10? got equation
2. The definition of the border line of each
generation time calculated from the definitive
integral equation was shown in Figure 1 When the
temperature was over 0? in equation 1, the range
of time was from 0 to 260(or from March 17 to
November 30). The 2nd 3rd generation began on
Jul 10, Aug 26, respectively. The last whole
generation began on Aug 10.
20
Generations and Water Temperature
Time of Reproductive Peak
?
?
?
?
?
3/8
17/7
18/6
1/9
12/9
20/4
27/10
30/11
17/3
Fig.2 The reproductive peak time of Artemia in
Gahai Salt Lake ? ? 1st to 5th reproductive
peak ? reproductive peak in last whole
generation

• The reproductive peak number is 4.690.43 per
  year.
• Peak of nauplii in first generation was on
  April 20th28th.
• Last reproductive peak on September 12th17th.
  
• Reproductive peak in last whole generation on
  september 1st. The nauplii hatched after
  September 1st can not complete the development
  from nauplii to adult, because of insufficient
  habitat effective accumulative temperature. (
  see remark)

21
Result (con.)
Population Productive Potential
BASED ON The changes of water
temperature with time(Eq.1) The
relationships between parameters and
temperature(Table.4) The rm ,Ro, T ,? and
t were converted into the relation of time
distribution.

• THE RESULT INDICATE
• July 11th to September 20th
  high productivity
• t lt30d
• rm gt0.02 d-1.
• July 11th to September 20th
  the best season for
• 
  commercial exploitation

22
CONCLUSIONS

• These methods of estimating the potentialities
  for exploitation are only available to the
  lake(like Gahai Saltlake) with broad area and
  deep depth.
• The generation of Artemia were closely in
  relation to water temperature.
• The diapause eggs of the last generation after
  the middle Sep can only be exploited
  appropriately.
• The eggs before the middle of Jul should be
  banned.

23
How to establish the strategy of exploitation

• Banning the exploitation of Artemia eggs --
  before the middle of Jul
• The first generation in a year comes
  from the overwintered eggs,and the population
  size is limit without complementary until
  sex-mature. In first generation,the peak of
  nauplii was on April 20th28th,the sex
  maturation was during the first twenty days of
  Jun. In order to keep the quantity of the
  population for sustainable increase,the eggs
  before the middle of Jul should be banned.
• Exploiting the diapause eggs appropriately --
  after the middle of Sep
• The last reproductive peak was on
  September 12th17th. Because the last generation
  provides the basis of producing first generation
  of next year,to assure enough eggs for the
  population of next year, the diapause eggs of the
  last generation after September 12th17th can
  only be exploited appropriately.

24
We also limit the time for exploitation by the
environmental variation model,which reflected
the annual variations of water
temperature,salinity and baits in Gahai
Saltlake.(the model will soon be published)
25
Thank you