Full text of DOI:10.1046/j.1444-2906.2000.00002.x

FISHERIES SCIENCE 2000; 66: 19–24
Original Article
Larval period and molting in the Japanese spiny lobster
Panulirus japonicus under laboratory conditions
1
1
2
3
Shintaro SEKINE, * Yasuhiro SHIMA, Hiroshi FUSHIMI, AND Makoto NONAKA
1
2
Japan Sea Farming Association, Minami-izu, Shizuoka 415-0156, Fukuyama University, Fukuyama,
3
Hiroshima 721-0292, and Department of Fisheries Resource Management, Tokyo University of Fisheries,
Minato, Tokyo 108-8477, Japan
SUMMARY: A total of 325 pueruli of the spiny lobster Panulirus japonicus was successfully reared
in the laboratory at Minami-Iku Station of Japan Sea-Farming Association, Shizuoka, Japan, during
1
989–1997. Of these pueruli, 136 individuals metamorphosed into the first juvenile stage. The dura-
tion of the phyllosoma stage ranged from 231 to 417 days (mean 319.4 days), and it has a tendency
to extend as the increase of water volume in the rearing tanks. The number of molting in the phyl-
losoma stage was 20–31. The body length of the last-stage phyllosoma ranged from 27.9 to 34.2
mm and the duration of the last stage was 11–26 days. The carapace length of the puerulus stage
was 6.0–8.0mm and the duration was 9–26days. The present data and those of previous studies
suggest that the body size and the duration of phyllosoma stage in captivity are affected by envi-
ronment as in the field. The duration of the puerulus stage is considered to be controlled basically
by water temperature and nutritional conditions in the phyllosoma.
KEY WORDS: growth, larval period, molting, Panulirus japonicus, phyllosoma.
INTRODUCTION
larvae were successfully reared to the puerulus stage, of
which 136 individuals metamorphosed into juveniles.
This study describes the growth and development of
P. japonicus phyllosoma and puerulus based on the results
of a series of experiments carried out at the station for 8
years. Comparisons of the duration of the phyllosoma
stage and the growth of phyllosoma between laboratory-
reared and wild-collected larvae are also discussed.
Rearing of Japanese spiny lobster, Panulirus japonicus,
larvae was reported for the first time in 1899 by Hattori
1
and Oishi. About 60 years later, Nonaka et al. succeeded
in rearing newly hatched phyllosoma to the second
†
4
2
molting stage by feeding Artemia nauplii. In 1981,
Inoue succeeded in rearing the larvae from hatching to
3
the last stage. Thus, many experiments had been prac-
ticed for about 90 years, but no one succeeded in rearing
phyllosoma to puerulus until 1988.
MATERIALS AND METHODS
Success in the larval rearing of the spiny lobster, P.
japonicus, from newly hatched phyllosoma to the pueru-
The observation in this study was tried on the above-
mentioned 325 puerulus and 136 juveniles derived from
the puerulus.
4
lus stage, reported in 1989 by Yamakawa et al. and
5
Kittaka and Kimura, was the first step in the advance-
Larval rearing methods were tried as follows.
ment of seed production techniques for the species.
Following these works, Minami-Izu Station of Japan
Sea-Farming Association (JASFA) started to improve
techniques for mass seed production of the spiny lobster
and succeeded in growing two larvae to the juvenile stage
in 1989. During the period 1989–1997, a total of 325
Rearing tanks
Two types of rearing tanks were used: specially designed
semispheric containers with diameters of 22, 30, 60 and
1
00 cm (hereafter referred to as 1, 5, 40, and 150 L tanks,
respectively) and commercial Artemia incubation tanks
with 55 cm in diameter (referred to as 80 L tanks). The
semispheric tanks were made from glass (1 L tank) or
acrylic resin (5, 40, and 150 L). The 80 L tanks were
made from polycarbonate resin.
†
We refer to the newly hatched phyllosoma as the first molting stage
and each ecdysis advances one molting stage.
Corresponding author: Tel: 03 52967539. Fax: 03 52967540.
Received 18 January 1999.
*

2
0
FISHERIES SCIENCE
S Sekine et al.
Rearing water
at a stocking density of 1.6–3 individuals/L. In 40, 80 and
50 L tanks, newly hatched phyllosoma were kept at den-
1
The seawater used for 1 L tanks was filtered with a
sities of 10–20 individuals/L. In the 150 L tanks, the
larvae rearing was discontinued from day 41 because the
large water volume of the tanks was difficult to manage
for the rearing, and the remaining larvae in the tanks
were transferred into 40 L tanks. They were moved again
to 5 L tanks because of decrease in number in the 40 L
tanks. The number of molting was counted with a casted
crust.
When the phyllosoma attained the puerulus stage,
each puerulus was immediately transferred to a 3 mm
mesh cage (10 ¥ 10 ¥ 7 cm), and reared at the same tem-
perature as in the water in which they metamorphosed
into puerulus.
0
.45 mm-mesh filter (TCG-045; Toyo Roshi Kaisha Ltd,
Tokyo, Japan) and sterilized with ultraviolet light (SS-
1
1
5G; Sen Lights Corp, Osaka, Japan). Phyllosoma in the
L tank were transferred daily to another tank contain-
ing fresh seawater. For the semispheric tanks of other
sizes and 80 L tanks, seawater was filtered through a 0.2
mm mesh membrane filter and then supplied to each tank
at the daily water exchange rate of about 20-fold.
In semispheric tanks except for 1 L, rearing water was
gently poured by air-tube fitted to air-stones and drained
through a central column covered with 1–3 mm mesh
net. In 80 L tanks, water was drawn from the drainpipe
and drained from the outlet at near surface through
1–2 mm mesh net.
Collection of wild puerulus
Rearing temperature
Wild pueruli were collected daily with five C-type col-
lectors at the wharf at Minami-Izu Station from Decem-
ber 1989 to December 1993. They were measured on
carapace length and reared until firstjuveniles to confirm
their species.
6
Water temperature in 1 L and 5 L tanks was set at three
o
different levels (i.e. 24 C throughout the experimental
o
o
period, 27 C throughout the period, and 27 C from day
o
of hatching to day 120 and 24 C from day 140 following
gradual lowering of temperature for 20 days (27–24 C
o
level). In 40, 80 and 150 L tanks, the third level of water
temperature (27–24 C) was applied.
o
RESULTS
Duration of the phyllosoma stage
Feeding
The number of puerulus obtained every year from 1989
to 1997 was 2, 5, 67, 1, 144, 6, 59, and 41, respectively,
totaling 325 individuals. Of those, the duration of the
phyllosoma stage was determined precisely for 271 indi-
viduals. The duration ranged from 231 to 417 days (mean
During the initial 4–6 molting stage, larvae were fed with
Artemia nauplii that had been enriched with Phaeo-
dactylum sp. for 24 h. They were fed once a day in 1 L
tanks, and twice a day in other tanks. When they were
just fed, the densities of nauplii in rearing tanks were
3
19.4 ± 40.9 SD days).
Table 1 shows frequency distribution of stage duration
3
000–4000 individuals per liter in 1 L tanks. In other
at a 20-day interval by tank size. In the 1 L tanks, 53 indi-
viduals metamorphosed into puerulus. The duration of
the phyllosoma stage was 231–315 days with a mean of
tanks, the densities were about 1500–2000 individuals
per liter.
In the following stages, minced ovarian tissues of
mussel were given together with Artemia reared with
Phaeodactylum sp. for 2–14 days.
The minced tissues of mussel were cubic and the
lengths of pieces were 0.5–2 mm. They were fed once a
day and the numbers of tissues were four–six pieces per
one phyllosoma. The reared Artemia were grown up to
2
79.6 days. The 35 individuals developed into the pueru-
lus stage in the 5 L tanks and the duration ranged from
34 to 356 days (mean, 299.8 days). In the 40 L tanks,
2
the 178 individuals reached the puerulus stage, and the
duration was 256–417 days (mean 336.1).
Thus a trend was observed toward an increase in dura-
tion of the phyllosoma stage with increase in tank size
0
5
.7–3 mm and fed once a day with the densities of about
0–1500 individuals per liter.
(
P < 0.01 by t-test). The variation range of the duration
of the phyllosoma stage, being 84, 122 and 161 days in
the 1, 5 and 40 L tanks, respectively, showed a trend
toward increase in proportion to the increase in tank size
except for the result in the 80 L tanks.
Rearing procedure
Relationship between rearing water temperature and
the duration of the phyllosoma stage is shown in Table
2. In the group maintained constantly at 27 C, the dura-
In 1 L tanks, one to 20 newly hatched phyllosoma were
kept. When they attained the 6–16 molting stage, some
of the phyllosoma larvae were transferred into 5 L tanks
o
tion was 291.0 days. In the group in which temperature

Period and molt in reared larvae of P. japonicus
FISHERIES SCIENCE
21
Table1 Frequency of the duration of phyllosoma stage in Panulirus japonicus
Duration (days) Capacity of rearing tank
1
L
5 L
40 L
80 L
Total
2
2
2
2
3
3
3
3
3
4
21–240
41–260
61–280
81–300
01–320
21–340
41–360
61–380
81–400
01–420
3
7
15
18
10
1
3
5
10
8
2
4
11
26
49
50
46
42
29
11
3
1
6
19
31
43
36
28
11
3
2
1
1
6
1
n
53
35
178
5
271
¯
x
279.6
299.8
336.1
320.2
319.4
Range
(231–315)
(234–356)
(256–417)
(290–366)
(231–417)
32
Table2 The duration of phyllosoma stage relating to rearing
temperature
Rearing
temperature
Duration of phyllosoma (days)
Average Min. Max. SD CV (%)
1
30
n
2
2
2
7°C
7–24°C
4°C
2
291.0 251.0 331.0 40.0
302 321.0 234.0 417.0 36.7
328.2 231.0 379.0 27.0
13.7
11.4
8.2
2
2
2
8
6
4
5
1
Coefficient of variance.
o
o
was set initially at 27 C and later lowered to 24 C, the
duration was 321.0 days. At a constant temperature level
o
of 24 C, the duration was 328.2 days. These results
22
clearly indicate that the duration of the phyllosoma stage
increased as the water temperature declined.
20
22 22 00
22 44 00
22 66 00
22 88 00
33 00 00
33 22 00
33 44 00
Number of molt during the phyllosoma stage
Duration of phyllosoma stage (day)
The number of molting ranged 20–31 (mean 26.9) in the
Fig. 1 Relationship between number of molting and duration
of phyllosoma stage in Panulirus japonicus, at two different water
temperatures. Data (ꢀ) and regression line (—) at 27–24°C
where y = 0.0544x + 11.73, r = 0.723, n = 63. Data (x) and
regression line (– –) at 24°C where y = 0.060x + 7.137, r =
1
L tanks and 26–30 (mean 27.4) in the 5 L tanks,
suggesting no obvious difference associated with the tank
size.
Relationship between the duration of the phyllosoma
stage and the number of molting is shown in Fig. 1. The
correlation coefficient was 0.92 for phyllosoma reared
0
.919, n = 6.
o
o
constantly at 24 C and 0.72 for those reared at 27 C ini-
o
tially and 24 C finally, suggesting a positive relationship
Phyllosoma in the last molting stage
between the two factors. Individuals with long periods of
the phyllosoma stage underwent more numerous
molting, and the interval of molting became longer at
the lower temperature so that the number of molting
decreased.
As shown in Fig. 2, the body length of 12 individuals of
the last phyllosoma stage ranged from 28 to 34 mm
(mean 31.3 ± 1.9 mm), with a size difference of 6 mm
between the smallest and the largest individual. The

2
2
FISHERIES SCIENCE
S Sekine et al.
Fig. 3 Frequency distribution of duration of the puerulus stage
in Panulirus japonicus.
Fig. 2 Frequency distribution of body length in the last stage
phyllosoma stage in Panulirus japonicus. n = 12.
duration of last phyllosoma is shown in Table 3 for 48
individuals reared in 1, 5, and 40 L tanks. It ranged from
Table3 Frequency of the duration in the last molting stage
of phyllosoma in Panulirus japonicus
11 to 26 days with a mean of 17.1 days.
Duration (days)
Capacity of rearing tank
1
L
5 L
40 L
Total
1
1
1
1
1
1
16
17
18
1
2
2
2
2
2
2
2
1
2
3
4
5
1
Puerulus stage
2
1
3
5
6
1
2
1
2
1
6
11
10
4
4
3
1
2
The duration of the puerulus stage in 135 individuals was
9
to 26 days with a mean of 12.6 days (Fig. 3). Ninety-
1
5
3
3
1
2
1
1
1
2
1
1
three per cent of these individuals metamorphosed into
juveniles for 9–15 days, and the remaining required
1
6–26 days to attain the stage. The puerulus stage was less
9
0
1
2
3
4
5
6
1
than 17 days for individuals which were reared in 40 L
tanks, while it was more than 17 days in some individu-
als reared in 1 L or 5 L tanks during the phyllosoma stage.
The carapace length of 93 puerulus was 6.0–8.0 mm
with a mean of 7.0 mm (Table 4). The carapace length
of 105 wild puerulus, which were collected daily with
settled collectors at the wharf at Minami-Izu Station
from December 1989 to December 1993, was slightly
greater than that of the reared specimens, ranging from
1
1
2
1
1
n
¯
x
24
16.8
18
18.1
6
17.3
48
17.1
6.4 to 8.0 mm with a mean of 7.31 mm.
DISCUSSION
5. The duration of the phyllosoma for reared individuals
4
was 307 days by Yamakawa et al. and 340 and 391 days
5
The number of molting, durations and body sizes of phyl-
losoma and puerulus from the data obtained in this study
and those given in the previous study are shown in Table
by Kittaka and Kimura. Oshima suggested that, on the
basis of the occurrence season of puerulus in the wild,
6
the phyllosoma stage would span at least half a year.

Period and molt in reared larvae of P. japonicus
FISHERIES SCIENCE
23
These are not contradictory to the results of the present
study.
present study, the duration of P. japonicus was 7.7 to 13.9
months (231–417 days) with a mean of 10.6 months
(319 days).
According to Booth and Phillips the duration of the
phyllosoma stage has been reported for the following
nine palinurid species/subspecies: P. argus, P. japonicus, P.
cygnus, P. interruptus, P. penicillatus, P. homarus rubellus,
Although the relation between the duration of phyl-
losoma and tank size is not clearly described, the dura-
tion seems to increase as the tank size becomes larger,
except for 80 L tanks as shown in Table 1. In this study,
the rearing methods were basically the same in each size
of tank, but we could not use entirely the same methods
in all trials. Therefore, more experiments will be needed
to confirm this tendency on the relationship between the
tank size and phyllosoma duration.
9
P. homarus homarus, P. polyphagus and P. marginatus. The
duration has been assumed to be 4–6 months for P.
homarus rubellus and 6–11 months for the remaining
seven species/subspecies without P. polyphagus. In the
The duration of tank-reared phyllosoma is longer
than those estimated for wild-collected samples in the
previous studies. Further investigations are needed to
confirm whether a definite difference exists between
individuals in captivity and those occurring in the sea,
although the great variation in duration of the phyllo-
soma stage found in both reared and wild may make it
difficult to determine the period clearly.
Table4 Frequency of carapace length in reared and wild*
puerulus
6
Carapace length of puerulus
mm)
Reared
Wild
(
6
6
6
6
6
7
7
7
7
7
8
.0
.2
.4
.6
.8
.0
.2
.4
.6
.8
.0
1
2
10
8
2
1
7
11
16
25
23
16
4
Johnson classified the phyllosoma of P. interruptus col-
9
1
0
lected from the wild into 11 stages. The work has been
used as a standard reference in the studies of the devel-
opment of palinurid phyllosoma, of the nine species/sub-
species mentioned above. His classification is based on
morphological characters, and permits size variations
within a stage and size overlapping between stages. Inoue
estimated 11 stages for P. japonicus phyllosoma on the
basis of his rearing experiments from hatching to the
17
24
13
3
3
3
n
93
105
¯
x
7.00
7.31
3
last stage. He pointed out that a single molting did not
*
Collected from the site of Minami-lzu Station JASFA.
necessarily result in development of the next stage and
Table5 Comparison of the duration and size of phyllosoma/puerulus in palinurid lobsters
Species
Authors Reviewers No. of No. of
Duration of
phyllosoma stage
Body length of
the final stage of puerulus length of
Duration
Carapace
stages
molts
(month)
(days)
of phyllosoma
mm)
stage
(days)
puerulus
stage
(
(mm)
Panulirus japonicus
This study
23 ~ 31*
234 ~ 417*
27.9 ~ 34.2*
9 ~ 26*
6.0 ~ 8.0*
6
Oshima
> 6
–
3
Inoue
11
6 ~ 9
29.64*
30.3*
32*
–
–
4
Yamakawa et al.
Kittaka and Kimura
29*
307*
340 391*
10*
13*
1 ~ 20
1 ~ 9
> 4 ~ 8
15
5
–
6.0 ~ 9.0
–
7
Nonaka et al.
8
Kanamori
9
Panulirus argus
Panulirus cygnus
Panulirus interruptus Booth and Phillips9
Booth and Phillips9
11
9
11
> 6
9 ~ 11
7.75
> 5*
> 7 ~ 8
Booth and Phillips
15
9
75
Booth and Phillips
9
Panulirus penicillatus Booth and Phillips9
11
10
Panulirus homarus
homarus
Booth and Phillips
Booth and Phillips
9
Panulirus homarus
rubellus
Panulirus polyphagus Booth and Phillips
9
4 ~ 6
9
> 2 ~ 4
*
Reared individuals.

2
4
FISHERIES SCIENCE
S Sekine et al.
that one stage might have several molting stages which
did not differ from each other in their morphological
traits.
ACKNOWLEDGMENT
The authors would like to thank Mr K. Watanabe, Mr S.
Suzuki and Mr K. Asami, Japan Sea Farming Associa-
tion, for their support to rear phyllosoma, and Dr K.
Hirose, Japan Sea Farming Association, for his valuable
suggestions and revision of this paper.
Classification of phyllosoma into stages can certainly
be made based on morphological characteristics. In con-
trast, the relationship between the stage of phyllosoma
and the molting stage remains largely unclear, as the
great variation in number of molting seen in this study.
Further examination is necessary in order to clarify
whether there is a constant relationship between stages
and molting stages. Characteristics that can represent
the growth and development of phyllosoma are at
present limited to the body length and molt-stage, yet
these two factors seem to be sufficient at least for practi-
cal purposes for the time being.
REFERENCES
1. Hattori T, Oishi Y. The first report of examination for hatching
of the Japanese spiny lobster. J. Imp. Fish. Inst. 1899; 1: 76–
1
31.
2. Nonaka M, Oshima Y, Hirano R. Cultured and ecdysis of spiny
The duration of puerulus stage in laboratory rearing
lobster at phyllosoma stage. Suisanzoshoku 1958; 5: 13–15.
4
was 10 days by Yamakawa et al., 13 days by Kittaka and
3. Inoue M. Studies on the culture phyllosome larvae of the Japan-
ese spiny lobster, Panulirus japonicus (V. Sievold). Special Report
Kanagawa Pref. Fish. Exp. St. 1981; 1: 1–91.
5
Kimura, and 9 to 26 days in this study. However, the
duration of wild-collected puerulus was reported to be
7
8
4
5
6
. Yamakawa T, Nishimura M, Matsuda H, Tsujigado A, Kamiya N.
Complete larval rearing of the Japanese spiny lobster Panulirus
japonicus. Nippon Suisan Gakkaishi 1989; 55: 745.
. Kittaka J, Kimura K. Culture of the Japanese spiny lobster Panu-
lirus japonicus from egg to juvenile stage. Nippon Suisan Gakkaishi
1
–20 days by Nonaka et al. and 1–9 days by Kanamori.
According to Booth and Phillips, the duration of pueru-
lus on the other palinurid species has been reported as
following: over 4–8 days (P. argus), 15 days (P. cygnus),
9
75 days (P. interruptus) and 2–4 days (P. polyphagus).
1
989; 55: 963–970.
The much shorter puerulus period in wild-collected
. Oshima Y. One consideration about metamorphosis period and age
of Japanese spiny lobster. Nippon Suisan Gakkaishi 1948; 13:
210–212.
puerulus seems to be attributable to the timing of their
collection immediately before metamorphosis. The
maximum duration of puerulus stage of P. japonicus was
7. Nonaka M, Fushimi H, Kageyama Y, Sasaki T. Notes on appear-
ance of puerulus (Panulirus) in Japan. Bull. Shizuoka Pref. Fish. Exp.
St. 1980; 14: 43–52.
2
6 days for reared individuals in this study and 20 days
7
for wild-caught ones. These indicate that some individ-
uals take a long period of the puerulus stage both in
captivity and in the natural environment.
8
. Kanamori K. Bioresources of Japanese spiny lobster at Susami area
of sea. I. Bull. Wakayama Pref. Fish. Exp. St. 1982; 36: 138–153.
. Booth JD, Phillips BF. Early life history of spiny lobster. Crus-
taceana 1994; 66: 271–294.
9
It is very likely that the body size of puerulus is influ-
enced solely by the environment they have lived in
during their phyllosoma stage, because puerulus do not
1
0. Johnson MW. The larval development of the California spiny
lobster, Panulirus interruptus (Randall), with notes on Panulirus
gracilis Streets. Proc. Calif. Acad. Sci. 1956; 29: 775–793.
4
,5,11
feed throughout the stage.
Consequently, the dura-
tion of the puerulus stage may be controlled by two
factors (i.e. water temperature and the nutritional con-
ditions during the phyllosoma stage).
1
1. Lemmens JWTJ. Biochemical evidence for absence of feeding in
puerulus larvae of the western rock lobster Panulirus cygnus
(Decapoda: Palinuridae). Mar. Biol. 1994; 118: 383–391.