waters and 50 not responding organisms during upper thermal limit hourly increase is 7.0-9.0
C for both red and green ophiuroid; but not the asteroid Fromia milleporella, with the deviation is 5.0-7.0
C.
4.2.2. Rate of changing temperature
From the experiments, Ophiomastix annulosa, Ophiarachna incrassata, and Fromia milleporella could survive at higher temperature during hourly upper
temperature limit 50 not responding organism between 36.0-37.0 C, 36.0-37.2
C, 34.0-35.8 C, respectively rather than daily upper temperature limit 50 not
responding organism between 34.0-35.0 C, 33.0-34.0
C, 32.0-33.0 C,
respectively. It can be assumed that these organisms could survive rapid temperature changes. It also happened with other organisms from other species,
class, and phylum e.g. bivalves Vasticardium sp whose 50 not responding limit during short term experiments hourly increase was more than 40.8
C and the upper limit was 42.0
C and medium term experiment limits daily increase were 35.0-36.0
C Morley, Widianari, and Juterzenka in prep. Table 15
. Nielsen 1990 opined that shorter exposure gives higher survival and longer
exposure usually lower survival. Table 15. Data of thermal limit from other tropic species Morley, Widianari,
Juterzenka unpubl. and prep..
Organisms Thermal Limit
C 100 not responding
Salinity Limit psu
100 not responding
Remarks Upper
Lower Decrease
Hourly Hourly
repeat Daily
Hourly Hourly
Leopard shell nE: 18
TE1: 25.0 TE2: 41.0
nC: 19 TC1: 25.0
TC2: 26.0 nE: 19
TE1: 26.0 TE2: 5.1
nC:
TC1: 26.0 TC2: 26.0
Moley, Widianari,
Juterzenka unpubl.
in prep.
Top shell nE: 18
TE1: 25.0 TE2: 40.0
nC: 18 TC1: 25.0
TC2: 26.0 nE: 19
TE1: 26.0 TE2: 10.0
nC:
TC1: 26.0 TC2: 26.2
Moley, Widianari,
Juterzenka unpubl.
in prep..
Table 15. Data of thermal limit from other tropic species Morley, Widianari, Juterzenka unpubl. and prep. continued.
Organisms Thermal Limit
C 100 not responding
Salinity Limit psu
100 not responding
Remarks Upper
Lower Decrease
Hourly Hourly
repeat Daily
Hourly Hourly
Perna viridis nE: 21
TE1: 25.0 TE2: 6.3
nC: 20 TC1: 25.5
TC2:26.0 Moley,
Widianari, Juterzenka
unpubl. in prep..
Vasticardium sp.
nE: 15 TE1: 25.0
TE2: 44.1 nC: 15
TC1: 25.0 TC2: 25.0
nE: 15 TE1: 27.4
TE2: 36.9 nC: 15
TC1: 25.8 TC2: 24.4
Moley, Widianari,
Juterzenka unpubl.
in prep.
The ability organisms to acclimate or adapt to changing environment is the most major factor that dictates whether these species or organisms could
survive or not in nature Stillman, 2003 in Barnes et al., 2010; Peck et al., 2009a. Exact lethal temperature limits are hard to determine for given organism because
the duration of exposure is very important Nielsen, 1990. The velocities of changing environmental stressors temperature and salinity under lab condition
gives a basic prediction for survival of marine ectotherms in the face of environmental change Barnes, 2010. When environmental conditions
temperature or salinity change rapidly change every hour, factors that dictate survival limit are resistance mechanisms and oxygen limitation. During slower
rates daily or weekly of environmental change, in this case temperature changes, factor that dictate survival are acclimatization and rate of utilization of
stored reserves. During climate change, environmental change can be annual, decadal or even longer. To cope with this climate change, the relevant rate of
warming adaptation and ecological mechanisms are the main factors dictating survival Peck et al., 2009a.
Prosser 1991 said that “lethal temperature is influenced not only by acclimation temperature and genetic makeup, but also by
age, hormonal state, diet, and environmental factors such as oxygen, salinity, and photoperiod”.
The thermal limit and body size does not really show a relationship with species Ophiomastix annulosa, Ophiarachna incrassata, and Ophiocoma cf.
dentata, and Fromia milleporella Figure 39, 40, 41, and 42. This also happened in upper thermal limit experiment with 34 tropical marine ectotherm species from
seven phyla living in intertidal and subtidal habitats from other tropical waters Singapore and Thailand by Nguyen et al. 2011. But these graphs showed that
upper thermal limit daily increase have lower limit than upper thermal limit hourly increase.
Figure 39. Temperature VS size of Ophiomastix annulosa in upper and lower thermal limit experiment hourly and daily increase and hourly
decrease.
5 10
15 20
25 30
35 40
45 50
12 13
14 15
16 17
18 19
20 21
22 23
24 25
26 27
28 29
30 31
32 33
34 35
36 37
D isc
d iam
e te
r m
m
Temperature C
Ophiomastix annulosa
hourly-upper-1 n=10 hourly-upper-2 n=6
hourly-lower n=10 daily-upper n=10
