REPRODUCTIVE CYCLE OF SEA URCHIN
BASED ON LUNAR PERIOD ON BARRANG LOMPO ISLAND
By : Wilma J.C. Moka, S.Kel, Inayah Yasir, PhD and Prof. Dr. Budimawan, DEA.
ABSTRACT
The research on gonad maturity of sea urchin (Tripneustes gratilla and Diadema setosum) has been done
according to lunar period. The aim of this research is to know the growth rate of gonad maturity from two
species of sea urchin. Samples are taken from waters around Barrang Lompo Island during the new moon,
first moon, full moon, and third quarter in two moon’s cycles. The color, the weight, the length, and the
texture of were analyzed for recognizing the gonad maturity level of sea urchin by morphology
examination. The histology of the gonad is observed in the laboratory. Paraffin block and Haematoxylin
and Eosin (HE) method is use for the histological observation. The result shows that there’s no fixed
reproduction in one moon’s cycle.
Key word : Diadema setosum, Tripneustes gratilla, gonad maturity, lunar period
INTRODUCTION
Sea urchin (Phylum Echinodermata, Class Echinoid) is one of trade commodity that required by
many countries (Sukarno, dkk, 1983; Brice, 2008). The gonad is used as raw material for food.
But not only that, in Gondol, Bali, its gonad is used as a larvae food in fish culture (A. Giri, pers.
comm via email, 2009). In last ten years the number of sea urchin (Tripneustes gratilla) has
decreasing in Lombok Island (Azis dan Soegiharto, 1994). Is there any affect from global
warming? Or sea urchin already become overexploitation? It‘s unknown yet. However, it is need
a way to protect and prevent the sea urchin become extinct.
As others biota, reproduction and gonad growth rate of sea urchin also affected by environmental
factors. Researchs in some countries are show different results in growth rate of gonad based on
lunar cycle. Research in Fiji area shows that reproductive pattern of sea urchin is follow with
lunar cycle. It shows that Diadema savingnyi and Echinotrix diadema are spawn at full moon
while D. setosum and E. calamaris spawn at new moon (Coppard and Campbell, 2005). But Fox
(1922; 1924a, 1924b) in Randall (1964) said D. setosum in Suez area was spawn at new moon.
These researchs show that in different area reproductive pattern of sea urchin could be different.
There are five general sea urchin in Barrang Lompo Island; Diadema setosum, Tripneustes
gratilla, Echinometra mattei, Echinotrix calamaris, Messipilia globulus. But the two most
common species are Diadema setosum and Tripneustes gratilla that used as samples.
MATERIAL AND METHOD
Random sampling was done at seagrass bed until reef flat in ±1meter depth surround Barrang
Lompo Island, Spermonde Archipelago, South Sulawesi, Indonesia. Ten individuals were taken
of each species in every moon phase (the new moon, the first quarter, the full moon, and the third
quarter). Sampling was done in two time of the lunar period.
The gonad was taken out from its test for morphology examination. The color, the weight, the
length, and the texture were recorded. A little part of gonad was cut and put in the xylen in order
to make the gonad rigid and can stand until arriving at laboratory for histology preparation.
Histology preparation will use Hematoxilin Eosin (HE) test. Morphology examination and
histology preparation are use to know the gonad maturity level of samples.
Gonado somatic index (GSI) will analyze as supporting data. GSI is used to see relation of
weight gonad and weight of individual (Badawi, 1995).
Wg
GSI =
x 100%
W
GSI
Wg
W
: Gonado Somatic Index
: Weigth of gonad
: Weigth of individual
Sampling
Take the gonad
Morphology
Histology
Compare
Result
Figure 1. Research Methodology
RESULT
Gonad maturity level (GML) can be known based on comparing morphology examination and
histology examination.
Table 1. Gonado somatic index and and gonad maturity level of T. gratilla and D. setosum
Diadema setosum
Month
Tripneustes gratilla
Moon
Period
Number
of
sample
♂
♀
GML
GSI
♂
♀
♂
♀
GML
GSI
♂
♀
♂
Stage 2
&3
♀
5
0
6,07
0,00
Stage 2
&3
1
4
5,20
5,55
Stage 3
&5
Stage
5
Stage 3
Stage 2
&3
2
2
6,68
5,01
Stage 3
Stage
1&2
2,95
Stage 4
Stage 4
0
5
0,00
4,48
-
5,23
2,51
Stage 4
&5
Stage 4
3
7
4,31
6,48
Stage 4
&5
6
4,29
3,56
Phase
2;4 & 5
Phase
2&4
4
6
4,68
3,42
Stage
4; 5 &1
7
3
4,53
3,83
Phase
3&5
Phase
5,1
3
5
6,78
3,40
Stage 3
&5
Stage
5,1
5
5
3,26
2,92
Phase
3;4 & 5
Phase
4&5
4
5
5,64
6,15
Stage
3; 5 &1
Stage
1; 2;
3; & 4
31
28
22
34
I
New
Moon
4
1
3,12
5,42
Stage
3;4 & 5
Stage 3
I
First
Quarter
1
4
1,93
1,74
Stage
3
I
Full
Moon
1
4
4,11
2,19
I
Third
Quarter
2
2
6,21
II
New
Moon
7
3
II
First
Quarter
4
II
Full
Moon
II
Third
Quarter
TOTAL
Number
of
sample
♂
♀
Stage 1 : recovery; stage 2: growing; stage 3: premature; stage 4: mature stage 5: spent
-
Stage
4;5&1
Stage
4;5&1
Stage
4;5&1
Comparison among stages of gonad maturity level are seen from its percentation. Growing stage
and premature stage are combine into ‘pematangan’ stage in this percentation. The highest value
of ‘pematangan’ stage is reached in first quarter and full moon of moon phase in the first period.
The highest value of mature stage is reached in third quarter of moon phase in the first period.
The highest value of spawning stage is reached in new moon in the second period of the moon
phase.
GML Percentation
Pattern of T. gratilla GML Percentation
120
pematangan
100
matang
80
60
40
20
0
Gelap
1/2
Purnama 1/2 gelap Gelap
purnama
1/2
Purnama 1/2 gelap
purnama
Moon Phase
Figure 2. Pattern of T. gratilla gonad maturity level percentation
Gonad somatic index (GSI) can show the pattern of reproductive cycle. GSI will be increasing
along gonad maturity level, reached the highest value just before spawning and decreasing after
spawning (Badawi, 1995)
GSI Pattern of T. gratilla
5
Periode bulan I
Periode Bulan II
Average of GSI
4
3
2
1
0
Gelap
Setengah
Purnama
Purnama
Setengah Gelap
Moon Phase
Figure 3. Gonado Somatic Index (GSI) Pattern of T. gratilla
Pattern of gonad maturity level of D. setosum didn’t show any pattern. Most of the stages are in
the spawning stage.
Persentase TKG
Pattern of D.setosum GML Percentation
120
100
80
60
40
20
0
pematangan
matang
memijah
Gelap
1/2
Purnama 1/2 gelap Gelap
purnama
1/2
Purnama 1/2 gelap
purnama
Moon Phase
Figure 4. Pattern of .D. setosum gonad maturity level percentation
In gonado somatic index pattern it was seen that value of GSI is decreasing in the first period of
moon phase. But in the second period the GSI value is increasing.
GSI Pattern of D. setosum
7
Periode bulan I
Periode Bulan II
RATA-RATA IKG
6
5
4
3
Gelap
Setengah
Purnama
Purnama
Moon Phase
Setengah Gelap
Figure 5. Gonado Somatic Index (GSI) Pattern of D. setosum
Table 2. Environmental Factors on Each Moon Phase
Environmental Factor
Moon Phase
Period
Value
Temperature (0C)
New Moon
I
II
I
II
I
II
I
II
I
II
I
II
I
II
I
II
30
29
29
30
31
33
31
31
First Quarter
Full Moon
Third Quarter
Salinity (‰)
New Moon
First Quarter
Full Moon
Third Quarter
28
30
27
27
28
31
29
30
DISCUSSION
T. gratilla
During sampling, orange liquid produced from T. Gratilla aboral pore, it means the spawning
sign (Radjab, 2001). In morphology examination, it found that T. gratilla gonad is more juicy
and fragile than D. setosum gonad. There was no different colour among stages or between male
and female. Colour of gonad should be a sign of each stage in gonad maturity level (Darsono,
1986). This result makes some assumptions. First, the same colour could be result from the
environmental factors that affected the hormone. Second, the T. Gratilla is hermaphrodite. But
this can’t be sure because only one part from five gonad that used in histology preparation.
Result shows that gonad of T. gratilla in Barrang Lompo Island is have a trend growing and
spawning continously. Although the result show that trend, however, it can’t say that the cycle
follow the moon cycle since there was no one full cycle of fonad maturity level found during the
research period. It needs more research with longer time.
Gonado Somatic Index (GSI) measurement as a supporting data show comparison between
weight of gonad and weight of individual (Badawi, 1995). Although result show that GSI is not
significantly different among stage (p≥0,005), there was still diferent in GSI value in every
stages. According to Badawi (1995), weight of gonad will be heavier along growing stage until
mature stage. The maximum value will be reached just before spawning stage, and will decrease
along the spawning stage.
Therefore, it could be concluded that reproductive cycle of T. gratilla in Barrang Lompo Island
is not affected directly by moon cycle. This result confirms by Tuwo and Pelu (1997) said, that T.
gratilla in Barang Lompo Island have year cycle. In a year, there are four spawning time; JulyAugust, October, December-January and February. So the cycle didn’t affected by moon cycle.
But maybe there’s other factor.
Temperatures range among 29-310C. This measurement is quiet high but in small range.
Temperature at third quarter moon phase in the first and the second period of moon show are the
same, but gonado somatic index trend show differentiation. This data show that small range of
temperature does not affect to gonad maturity level. This result is agreed with Pearse (1974) in
Muthiga (2007) said, that temperature didn’t have affect in T. gratilla reproduction. The
assumption is temperature could give affect to reproductive cycle in temperate area. But in
tropical area like Indonesia, temperature with small range didn’t give any affect to reproductive
cycle.
D. setosum
Sampling of D. setosum was done in the same time with T. gratilla. However, D. setosum never
produce orange liquid like T. gratilla did. In morphological examination it can be seen that
gonad of D. setosum is quiet different from T. gratilla. Gonad of D. setosum is more rigid than
gonad of T. gratilla. Gonad of D. setosum also have extension of gonad between the straight five
gonad.
This research shows that there is no relation between one moon cycle with the gonad maturity
level of D. setosum. Histological examination shows that in two moon cycle period gonad of D.
setosum generally in spawning stage. But in this two period moon cycle growing stage and
mature stage still can be found.
This result is in correlance with Stephenson (1934), Mortensen (1937) and Pearse (1986b, 1970)
in Lawrence (2007) said, that there’s no moon periodicity in D. setosum reproduction. But this
result is not same with Lawrence (2007) that said process of gonadal growing of D.setosum
could finish in one to two months. Kobayashi and Nakamura (1967) in Lawrence (2007) also
said that D. setosum is spawning in both full moon and new moon.
CONCLUSION
Gonad maturity level of Tripneustes gratilla and Diadema setosum are not occur in one lunar
period (one moon cycle). But the result shows a trend there was a reproductive cycle.
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