CICLO DE CRIANZA DE LA OSTRA PERLA Pinctada mazatlanica Y Pteria sterna

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/284802851
Breeding cycle of pearl oysters Pinctada mazatlanica and Pteria sterna
(Bivalvia:Pteriidae) at Bahia de la paz, Baja California Sur, Mexico
Article in Journal of Shellfish Research · January 1997
CITATIONS
READS
57
1,269
2 authors:
Pedro E Saucedo
Mario Monteforte-Sanchez
Centro de Investigaciones Biológicas del Noroeste
Centro de Investigaciones Biológicas del Noroeste
79 PUBLICATIONS 1,141 CITATIONS
57 PUBLICATIONS 887 CITATIONS
SEE PROFILE
Some of the authors of this publication are also working on these related projects:
RFVIIa View project
All content following this page was uploaded by Mario Monteforte-Sanchez on 06 September 2017.
The user has requested enhancement of the downloaded file.
SEE PROFILE
Journal of Shellfish Research. Vol.
16.
No.
].
103-110. 1997.
BREEDING CYCLE OF PEARL OYSTERS Pinctada mazatlanica AND Pteria sterna
(BIVALVIA:PTERIIDAE) AT BAHIA DE LA PAZ, BAJA CALIFORNIA SUR, MEXICO
PEDRO SAUCEDO AND MARIO MONTEFORTE
Centra de Investigaciones Biologicas del Noroeste, S.C.
P.O. Box. 12S
La Paz.
ABSTRACT
The breeding cycles of pearl
as part of a Pearl Culture
Program
in
B.B.S..
Mexico
oysters Pinctada mazatlanica and Pteria sterna were studied from June 1992 to
May
1993
Bahfa de La Paz. Gonad samples of 20 oysters of each species were collected monthly (480 over
and processed for histological examination. We studied the annual breeding cycle of both species, the sex ratio as
and the size of the oysters. The results obtained by histological analysis were confirmed by similar changes in a
gonadosomatic index. Gametogenesis was continuous throughout the year in both species. P. mazatlanica spawned once a year
(September), when water temperature reached 29.5°C. It is a protandrous hermaphrodite in which sex reversal was observed in oysters
the annual cycle)
a function of time,
100-mm shell height. The female:male sex ratio was 0.12:1. Gonad maturity was found in oysters larger than 39 mm. P.
spawned twice a year (February and May), when water temperature was 22.2 and 23.4°C. There was not enough evidence to
conclude that P. sterna was a protandrous hermaphrodite. If that were the case, sex reversal would have occurred in oysters larger than
larger than
sterna
50-mm
shell height.
KEY WORDS:
The female:male sex
ratio
was
0.38:1.
Gonad
maturity was seen in oysters larger than 40
Pearl oysters, breeding cycle, reproduction, repopulation,
INTRODUCTION
now
in a critical situation
because of overexploitation. The unconBahfa de La Paz for more than
little
and conservation
Oysters used
et al. 1994).
24°07'N, and
its
seasonal occurrence.
No
The objective of
this
is to
study
de-
in
Bahfa de La Paz.
in this
study were collected
in
1991
at Isla
Gavi-
La Paz, between 24°46' and
10°38' and 110°18'W (Fig. 1).
The selection of Caleta El Merito as the study area was made
because of its climatic, geomorphologic. and oceanographic con-
essential to
ditions,
1990, Garcfa-Dominguez
strategies.
the southwest coast of Bahia de
understand the reproductive biology of pearl oysters (Tranter
al.
P. mazatlanica, pointing out
ota and reared by extensive culture at Caleta El Merito, located on
The success of aquaculture of pearl oysters requires a proper
knowledge of the biology and ecology of the species. To understand the population dynamics of the wild stock and, more re-
1958a. Sevilla 1969. Rose et
only data avail-
a precise microscopic
MATERIALS AND METHODS
1983, Monteforte 1990. Monteforte 1991, Monteforte and
is
anatomy of
under bottom-culture conditions
repopulation, and recovery of the nacre resource has been emphasized on several occasions (Sevilla 1969, Dtaz-Garces 1972. Mar-
it
this study, the
who made
scribe the annual breeding cycle of the pearl oysters P. mazatlanica and P. sterna, obtained from extensive culture and kept
urgent need to apply strategies for conservation, extensive culture,
strategies,
1969),
at production through extensive culture and
induction to pearl formation, we are also searching for recovery
The presence of pearl oysters in the Baja California Peninsula
has played an important role in the social and economic development of the region, mainly in Bahfa de La Paz. Therefore, the
development of pearl-culture
(
development aiming
la
illegal extractions have continued,
impeding the natural recovery of broodstock.
cently, the
of males to females
In 1987, we started an applied research program on pearl oyster
culture and pearl induction at the Centro de Investigaciones Biologicas del Noroeste, in Bahfa de La Paz. Parallel to technological
1991. Monteforte and Carino 1992, Carino and Monteforte 1995).
At present, both species are under a legal ban decreed on the pearl
oyster fishery (Diario Oficial de la Federacion 1939) and are con-
Carino 1992, Saucedo and Monteforte 1994, Saucedo
Before
P. sterna.
description of the gonad
by 1940 (Sevilla 1969. Shirai and Sano 1979. Carino 1987.
Carino and Caceres-Martinez 1990. Monteforte 1990. Monteforte
tinez
is
ratio
with increasing age (Gervis and Sims 1992).
known about the reproductive biology of P.
each phase of the breeding cycle and
study has been done on P. sterna.
tirely
Federacion 1994). However,
However,
1:1
able were those of Sevilla
the natural stocks along the coast almost en-
sidered "species under special protection" (Diario Oficial de
and external processes). The
tends toward
mazatlanica and
trolled pearl fishery carried out in
400 years depleted
Bahfa de La Paz
internal
Mexico, natural populations of the native species Pinctada
mazatlanica (Hanley, 1856) and Pteria sterna (Gould. 1851) are
In
mm.
more
et al.
1
which were adequate
for the
development of the study.
detailed description of the area
is
provided
A
Alvarez-
in
Borrego and Schwartzlose (1979), Osuna-Valdez (1986). Murillo
1987), and Monteforte and Carino (1992).
1996).
(
There have been a number of studies of the reproductive biolthat most aspects
In April
ogy of the genus Pinctada. These studies reveal
of the breeding cycle of pearl oysters are common to all species.
to be functional protandrous hermaphrodites (maturing
cm
40-cm width, and 20-cm height) placed on a submerged
10-m depth. Sixteen cages were placed on the bottom of
the study area (eight per species), each one containing 30 oysters.
The initial size range varied from 39.5 to 136.5-mm shell height
They seem
as
males and changing
Correspondence
to:
to
females
at a certain size,
1992. 480 oysters (240 of each species) were trans-
ferred to bottom-culture conditions, using plastic pearl cages (70length,
shelf
regulated by
for P.
Pedro Saucedo. Centra de Investigaciones Biologicas
mm
at
mazatlanica (mean, 80.55; SD, 20.25) and from 41
.
1
to 89.2
SD. 12.30).
Twenty oysters of each species were collected monthly using
del Noroeste.
S.C. Division de Biologfa Marina. P.O. Box. 128. La Paz.
Baja California Sur, Mexico.
103
for P. sterna (mean. 66.12:
Saucedo and Monteforte
104
GI =
This
GW/
WWS
x 100
obtained by dividing the gonad weight of the animal (GW)
wet weight without shell (WWS). multiplied by 100. Finally,
the relationship between the GI and the monthly changes in (he
by
is
its
water temperature during the annual cycle was also studied.
RESULTS
Gonad Developmental
Stages
Gametogenesis was found
to
be a continuous process through-
out the annual cycle in both species. However, many of the stages
of the breeding cycle overlapped in time within the same gonad, so
their classification into
any gametogenic stage was sometimes
dif-
determine. The most important microscopic characteristics
of the gonad anatomy are described as follows:
ficult to
Indeterminate or Inactive
There
is
no evidence of gonad development. Instead, the gonad
consists mainly of connective tissue. Follicles are completely
empty and may contain some phagocytes. Gonads are not able to
be classified as to sex (Fig. 2A).
Developing or Near-Ripe
Figure
1.
Location of the study area (Caleta El Merito) inside Bahia de
La Paz, indicated bv
closed diamond.
The production of gametes begins. At first, follicles are small
and poorly developed. Oogonia in the ovary and spermatogonia in
the testis are mainly connected to the follicular wall (Figs. 2B and
As gametogenesis proceeds, different stages of gametes can
be observed. In the testis, primary and secondary spermatocytes
3A).
proliferate rapidly. In the ovary, connected
SCUBA
gear, and they
were preserved
in 10<7<-
formalin for 48
h.
Before dissection, the following shell measurements were taken
with plastic calipers (±0.01 mm) according to Hynd's expressions
(
1955): height or dorsoventral measurement, length or anteropos-
measurement, thickness, wet weight of the oyster with shell,
wet weight without shell, and wet weight of the visceral mass in
which the gonadal tissue is intermingled. This latter sample, alterior
ways excised between the labial palps, near the foot, and the intestine tube, was processed for histological examination. Samples
were embedded in paraffin, sectioned at 7 or 8 p.m. and stained by
the hemotoxylin-eosin technique.
pound microscope
at
They were analyzed with a com-
low magnifications (lOx and 40x) and were
some spermato-
zoa, or free oocytes with yolk and nucleolus, are
common
little
Maturity or Ripe
The gonad has grown and enlarged
mass,
and especially to
the gonads, we used
understand the seasonal changes occurring in
five broad gametogenic stages, using the schemes developed by
Sevilla (1969) for P. mazatlanica, and Rose et al. (1990) for P.
maxima. The stages
ripe. (4)
spawning, and
as a
compact and uniform
and hard to
follicles are distended
layer in the distal regions of the gonad.
The
follicular
lumen
is
mainly with polygonal-shaped free oocytes with yolk and
nucleolus (in the ovary) or with spermatozoa clearly defined by
Some isolated pockets of
developing oogonia or spermatids can be observed (Figs. 2D and
their eosinophilic tails (in the testis).
3C).
Spawning
(5)
spent.
We
also calculated the total female:male sex ratio of both species, the sex ratio as a function of time, and the sex ratio related to
It is
at right
was used
This phase is easy to detect because of the expulsion of gametes. Follicles are broken, distended, and partially empty. The
lumen
is
filled
with residual free oocytes or thin spermatozoa,
most adequate
considered the largest dimension of the
showing signs of regression
angles to the hinge
Spent
the size of the oysters. Shell height
oyster measured
which the individual
are: (1) indeterminate or inactive, (2) devel-
oping or near-ripe, (3) maturity or
indicator of growth.
in
distinguish. Connective tissue has been reduced to a small and thin
photographed through the microscope.
the breeding cycle of both species,
in the
During this stage, the amount of connective tissue rapidly
decreases and almost disappears.
follicles.
filled
To analyze
and some free oocytes
2C and 3A). At
or no yolk expand into the lumen (Figs.
the final stages of gametogenesis. spermatids and
with
as the
line,
excluding the
growth processes (Hynd 1955).
At the same time as histological analysis was done, a gonadosomatic index (GI) was calculated with the oyster's measurements
originally taken, using the equation proposed by Sastry (1970):
Follicles
(Figs.
2E and 3D).
have become extremely
thin,
and the lumen
is
prac-
empty, with some isolated pockets of residual oocytes or
spermatozoa. This phase is characterized by the rapid proliferation
tically
Breeding Cycle of Pearl Oysters
105
0>'
'
Figure 2. Sexual phases of male gametogenesis in P. mazatlanica and P. sterna. (A) Indeterminate phase in /'. sterna, showing empty follicles with
some phagocytes (ph); (B) early gametogenesis in P. sterna, in which small follicles (fo( contain spermatogonia (sg) connected to the follicular
wall, primary and secondary spermatocytes (sc) expanding toward the lumen, and some spermatozoa (sp) filling the center; (C) adyanced
in P. mazatlanica with distended follicles containing large amounts of
spermatozoa; (D) maturity stage in P. mazatlanica,
characterized by the presence of follicles packed ytith spermatozoa almost exclusively; (E) spawning in P. mazatlanica with broken and
partially
empty follicles containing residual spermatozoa Irs), and the presence of different kinds of phagocytes: (K) spent stage in P. sterna, in which
emptj and collapsed follicles contain high phagocytic activity; connective tissue is deyeloping again. Scale bar. 25 pm.
gametogenesis
Saucedo and Monteforte
106
Sexual phases of female gametogenesis in P. mazatianica and
Early gametogenesis in P. mazatianica showing poorly
developed follicles (fo) with small oogonia (og) connected to the follicFigure
3.
P. sterna. (A)
ular wall, lacking yolk and nucleolus, and auxiliary cells (ac); (B)
advanced gametogenesis
mazatianica, in which
in P.
immature
pe-
present in the follicle, together with
polygonal-shaped free oocytes (ocl with yolk and nucleolus; (C) maturity in P. sterna, containing mainly free-shaped oocytes filling the
duncle-shaped oocytes (po) are
lumen: ID) spawning
in
/'.
still
sterna, in
which
follicles
are thin and col-
lapsed, with residual oocytes (rol; (E) spent stage in P. mazatianica,
with residual oocytes showing signs of regression. Scale har, 25 uni.
of different kinds of phagocytes surrounding the gametes. The
connective tissue has started to develop again (Figs. 2F and 3E).
oysters were spent in October and
continued
in
November and
November. Gonad development
May. Mature oysters were
lasted until
seen from February to May.
P.
mazatianica
Sex Ratio
Breeding Cycle
The breeding cycle of P. mazatianica is shown in Figure 4. In
June and July, oysters at different developmental stages are common; a large number of them have started gonad development,
others have reached maturity, and another group
spent.
Spawning took place
in
was found
to
be
September and October, and most
This was completely skewed to the male sex. From the total
sample analyzed, 77% were male, 9% female, and the last 13%
were indeterminate. The female:male sex ratio was 0.12:1.
The sex
ratio related to oyster size revealed that P.
matured as male and tended
to
mazatianica
be a protandrous hermaphrodite.
Breeding Cycle of Pearl Oysters
£
107
Saucedo and Monteforte
108
706050
40302010-
JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR HAY
TIME (months)
J INDETERMINATE
Hi
Figure
SPAWNING
8.
£2
DEVELOPING
'//,
SPENT
J
MATURITY
JUL
AUG
OCT
SEP
NOV
DEC
JAN
FEB
MAR APR MAY
TIME (months)
Sexual gametogenic stages
in P. sterna
during an annual
Figure
10.
Temporal sex
ratio in P. sterna.
cycle.
Figure 9 shows the percentage of females and males. The sizerange analysis suggests that P. sterna can be a protandrous her-
and May, coincided with the two spawings observed in the year.
The GI and the water temperature had an inverse relationship.
maphrodite. Males were present from 40 to 85-mm shell height.
with a higher incidence between 40 and 55 mm. Females appeared
after 50-55
but were not represented in all of the size ranges.
DISCUSSION
mm
Their
maximum number was observed between 60 and 65 mm and
mm. Indeterminate oysters were present in all of the size
85 and 90
ranges (Fig.
9).
Figure 10 shows the sex ratio as a function of time. Once again,
the male sex was present over the entire annual cycle, but with a
higher incidence in January, February, and April during the spawn-
As suggested by Giese and Pearse
(1974). pearl oysters from
temperate regions generally exhibit discrete and regular breeding
seasons. Evidence found in this study indicated that P. mazatlanica
and
P. sterna
esis
was found
followed a clear annual breeding cycle. Gametogento be a continuous process throughout the annual
rest
cycle in both species. Changes observed in the reproductive activity of the oysters during the annual cycle were regulated mostly by
of the annual cycle. This behavior, unlike that of P. mazatlanica,
could indicate that this species is a multispawner.
seasonal changes in the water temperature. Earlier work done on
pearl oyster reproduction from different parts of the world con-
ings.
Females appeared from August on and were present the
firms Orton's rule:
GI
"if temperature conditions are constant or
nearly so and the biological conditions do not vary much, animals
The index seems
to describe adequately the reproductive activity of the oysters. The relationship between the index and the
).
reproductive activity of the oysters was relatively close (Fig.
1
The highest peaks
in the
values of the index, recorded in
and April, indicated the gonads
sexually ripe.
to
The lowest values of
be
in active
1
December
development or
the index, detected in
March
continuously" (Orton 1929 in Chellam 1987).
Tranter (1958b-d) observed a definite annual reproductive
will breed
cycle for Pinctada albina and Pinctada margaritifera from the
Strait, Queensland. Sevilla (1969) also found a breeding
Torres
cycle with continuous gametogenesis in P. mazatlanica from Bahia de La Paz. Mexico. Rose et al. 1990) noted the same pattern
(
maxima from Eighty-Mile Beach,
and Garcfa-Domi'nguez et al. (1996) made
of gametogeneis for Pinctada
Western Australia,
MALE
JUN
FEMALE
JUL
AUG SEP OCT NOV DEC JAN
TIME (months)
FEB MAR APR MAY
NDETERM
40-45
60-65
5D-55
45-50
55-60
75-60
TEMPERATURE
GONADOSOMATIC INDEX
80-85
70-75
65-70
85-90
SHELL HEIGHT (mm)
Figure
Figure
9. Size-related
sex ratio in P. sterna.
11.
P. sterna.
Relationship between the
(il
and the water temperature
for
Breeding Cycle of Pearl Oysters
similar observations for wild P. mazatlanica from Isla Espfritu
Santo. Baja California Sur. Mexico.
However, some differences in the overall pattern of gametogenesis of pearl oysters can be detected. P. albina breeds annually and
spawns once between April and
May
cember and from February
to April
ritifera also has a bimodal
spawning
gust and from
(Tranter 1958c), whereas P.
annually, but spawns twice, from October to De-
maxima breeds
September
(Rose
19901. P.
et al.
pattern,
from March
February (Tranter 1958d).
to
A
109
ranging from 72 to 176-mm shell height. A sex ratio of 1:1 was
observed for P. maxima from Eighty-Mile Beach. Western Aus-
200-mm
tralia, at
shell height
(Rose
et al.
1990).
For P. sterna, there was not enough evidence to conclude that
the species were protandrous hermaphrodites, although the female:
male sex
ratio
was
Females were present
0.38:1.
>50-mm
margato Ausmaller
capacity to change sex at
been reached. Previous descriptions of this
two spawning peaks, during June to
February, at Tuticorin Harbour (Chel-
species. Pinctada fucata, has
all
Apparently,
made by
members of
phenomenon have been
Wada (1953a), Tranter
Wada 1953) and
(1958a), and Rose
Pearse 1974).
for P. margaritifera;
During our study, P. mazatlanica bred annually and spawned
once, from September to October, when the water temperature rose
to 29-30°C. Histological evidence indicates a second short spawn-
change
may
(Cahn 1949. Tranter 1958a-d. Chellam 1987, Rose
Sevilla
1969) for P. mazatlanica;
(
(1990) for P. maxima;
et al.
Ojima and Maeki (1955)
in
The
and Tranter (1959) for
the Ostreidae, Teredinidae,
water temperature. Unfortunately, the monthly sampling used
for collecting the gonads did not allow us to detect this. P. sterna
by Tranter (1958b) for
spawned twice during the annual cycle. The
was
from
February to March, when the water
peak
temperature decreased to 24°C. The lesser peak was from April to
maximum
22.8°C. Once again,
the histological evidence suggests the possibility of a third spawning, during June or July. We believe that P. sterna is potentially
capable of spawning throughout the year, because mature gonads
the water temperature
of both sexes were present almost
dropped
all
year.
to
Rose
et al.
(
1990) found
mature oysters outside the main breeding period, suggesting
that P.
maxima is also capable of spawning all year.
The histological gonad analysis revealed that spawning
in P.
mazatlanica and P. sterna was not complete during the breeding
season, and a large number of residual gametes were present after
the
spawning
at
the spent stage.
We
found phagocytic activity
in
oysters of both species that had recently spawned, indicating the
presence of gonad regression. Tranter (1958c) and Rose
(1990) detected incomplete spawning and gonad regression
et
al.
in P.
albina and P. maxima. However, regression in P. sterna was inafter the first
complete
massive spawning
in
We
February.
the possibility of a second short breeding cycle in
suggest
which animals
avoid the spent stage and pass directly to gametogenesis after the
first spawning. Similar observations were made by Sevilla
1969)
(
for P. mazatlanica.
seem to be functional protandrous hermaphrowith sexes separated by time. However, bisexual phases may
Pearl oysters
dites,
same gonad, although they appear to be transitional
and nonfunctional, as suggested by Rose et al. (1990) for P.
occur
in the
maxima.
Two cases of hermaphroditism
both after
60-mm
were detected
shell height. Similarly,
in P. sterna.
Garcfa-Domfnguez
et al.
study,
we managed young
The
total
sex ratio
female:male sex ratio of 0.12:1 and the mean
were observed under 100
mm
confirmed
Isla Espfritu
males, the study
this.
mm. Garcfa-Domfnguez
found a different female:male sex ratio of 1.33:1
from
in P.
No
et
al.
females
(1996)
mazatlanica
Santo. However, although females outnumbered
was
39
to
49-mm
"weak
be explained by a
shell height for P. mazatlanica.
was reached
This size range,
corresponding to 8 months olds, was reached using organisms
reared by extensive culture. P. sterna maturity was detected at 40to
45-
mm
shell height,
ever, because P. sterna
corresponding to
is
1
1
months
a relatively small species,
male maturity can be attained
at
the pearl cages could have
somehow
we
olds.
How-
believe that
a lower size, and the density inside
inhibited
gonad maturity.
1978) found for P. fucata, a similar species in size, male
within
8 months and spawning at 9 months in Tuticorin
maturity
Harbour. Tranter (1958a) also noticed P. albina. another small
Chellam
(
and spawn at 4 months. Male maturity occurs
110-120 mm during the first year (Rose et al.
species, to be mature
for P.
maxima
at
1990). Full maturity
is
not attained by P. margaritifera until the
second year (Crossland 1957).
The GI was
method for estimating the
of
reproductive activity
pearl oysters. Resting on the assumption
that the ratio of body parts varies little with change in size of the
a useful quantitative
animal (Giese and Pearse 1974).
we were
able to measure the
relative reproductive condition of the oysters of different sizes
to
compare changes
in their
gonads
at different times. In
and
species
possessing little nutritive tissue in the gonads, like pearl oysters, an
increase in GI was interpreted as a buildup of gametogenesis. with
a decrease interpreted as spawning (Giese 1959). Because weight
and volume values increase by approximately the cube of linear
dimensions (Galtsoff 1931 ), care should be taken to equate dimensions
when volumetric and
linear
measurements
are used, as oc-
curred in this study.
However,
a limitation of the
GI
is that,
unless accompanied by
it could not be considered a reliable tool for
studying the
breeding cycle of pearl oysters and for understanding the seasonal
changes occurring in their gonads. For pearl-culture programs,
histology, coupled with gonad index measurements, is recom-
wild
was completely skewed to the male sex in both species, and therefore, they behaved as protondrous hermaphrodites. Particularly in
sex-reversal size detected at 100
may
oysters instead of adults,
especially in P. mazatlanica. a larger species.
P. mazatlanica. the
it
mechanism."
microscopic examination of the gonads, it indicates little as to what
is occurring within the gonads. Therefore, if used as a single
in
lanica.
this
at
1990).
et al.
other bivalves like
P mazat-
(1990) found two hermaphrodite specimens
In
in
Histological data demonstrated that male maturity
also bred annually, but
However,
and Pectinidae. and as hypothesized
P. albina.
hereditary sex-determining
P. fucata.
be brought about by stress
of sex reversal has been observed
ing could have occurred in June or July, triggered again by changes
in
(
for Pinctada martensii; Tranter (1958d)
sex can be reversible and
ability
mm.
genus Pinctada exhibit this
a certain size, after male maturity has
the
September and December to
lam 1987). The tendency for a bimodal spawning pattern has been
described for several marine invertebrates (Giese 1959, Giese and
May. when
shell
height, but males kept appearing with high frequency up to 85
carried out with larger individuals (adults).
method,
mended
for understanding the overall pattern of reproduction in
pearl oysters.
Other aspects of the reproductive biology of pearl oysters P.
P. sterna are yet to be studied. To improve the
techniques and strategies for spat collection, cultivation, growth,
mazatlanica and
and especially, the production of high-quality cultured
pearls, an-
Saucedo and Monteforte
110
nual and biannual
on the breeding cycle of pearl oysters are
trials
recommended.
dedicate this
work
to the
memory
of
(Grupo Ostras Perleras) of
Don Gaston
Vives,
pioneer of pearl culture in the world. The study was conducted as
part of an institutional program of the Centro de Investigaciones
(CIBNOR), Mexico.
Biologicas del Noroeste
invaluable help of the Pearl Oyster Research
ciate the
ACKNOWLEDGMENTS
We
(CONACYT-Mexico) since 1990, and the Sistema de InvestigaMar de Cortes (SIMAC-Mexico) since 1994. We appre-
dores del
It
has also been
funded by the International Foundation for Science (IFS of Sweden) since 1990, the Consejo Nacional de Ciencia y Tecnologfa
CIBNOR.
for all of the
Group
SCUBA diving
support during the in situ study. Special thanks to Victor Perez,
Horacio Bervera, Humberto Wright, and Sandra Morales. We are
M.C. Federico Garcia Domtnguez. CICIMAR,
also indebted to
who provided important assistance during the histological analysis.
Finally, we thank Dr. Ellis Glazier, CIBNOR, for the editorial help
on the English language manuscript.
LITERATURE CITED
Alvarez-Borrego, S. & R. A. Schwartzlose. 1979. Masas de agua del Golfo
de California. Ciencias Marinas 6:43-63.
Cahn. A. R. 1949. Pearl Culture
States
Department of the
DC.
ton.
Interior. Fish
californie.
1987. Le mythe perlier dans l'histoire coloniale de
AMAC
M. M.
Sud-
1990.
La
perlicultura en la Peninsula
siglo. Serie Cientifica (Special
Num-
l):l-6.
& M.
Bay of La
Mexico (1533-1914). Gems Gemol. 31:
Monteforte. 1995. History of pearling in the
Paz, South Baja California.
88-I0S.
Chellam, A. 1987. Biology of pearl oyster, pp. 13-21. In: K. Alagarswami
(ed.). Pearl Culture. Bulletin 39. Central Marine Fisheries Research
Institute.
Crossland, C. 1957. The cultivation of the mother-of-pearl oyster in the
Red
Sea. Aust.
Freshwater Res.
1994. Related to the Determination of
and Aquatic Species Under the Categories Endangered.
Threatened. Rare, and Under Special Protection. Norma oficial del
Globierno de los Estados Unidos Mexicanos, 2pp.
Diaz-Garces, J. 1972. Cultivo experimental de madreperla Pinctada mazatlanica
856, en la Bahia de
La
Paz, Mexico.
cional de Oceanografia. Mexico, D.F..
Memoriae IV Congreso Na-
November
17-19. pp. 429—442.
The weight-length relationship of the shells of the
hawaiian pearl oyster Pinctada sp. Am. Nat. 65:423—433.
Garcfa-Domfnguez. F., B. P. Ceballos- Vazquez & A. Tripp. 1996. SpawnGaltsoff, P. S. 1931.
ing cycle of the pearl oyster, Pinctada mazatlanica (Hanley, 1856),
(Pteriidae) at Isla Espintu Santo, Baja California Sur.
Mexico.
/.
Shell-
&
N. S. Sims. 1992. Biology and Culture of Pearl Oysters
Overseas Development Administration of the
Pteriidae).
United Kingdom. International Center for Living Aquatic Resources
Management, Manila, Philippines. 49 pp.
Giese, A. C. 1959. Reproductive cycles of
some west
coast invertebrates,
Withrow (ed.). Photoperiodism and related pheand animals. American Association of Science, Pub-
pp. 625-638. In: R.
nomena
in plants
lication
No. 55. Washington. D.C. 238 pp.
Giese. A. C.
&
J.
S. Pearse.
Invertebrates. Vol.
Hynd.
J.
New
S.
I.
A
and oogenesis in the pearl oyster Pinctada martensii (Dunker).
Kwansei Gakuin Univ. Ann. Stud. 3:12-14.
Osuna-Valdez,
I.
La
nia Sur.
1986. Evolocion Holocenica de la
Laguna de La Paz,
Autonoma de Baja
Califor-
Paz. 112 pp.
&
Reproductive cycle of the
Pinctada maxima (Jameson)
S. Harders. 1990.
silver-lip pearl oyster
(Mollusca: Pteriidae).
Sastry. A. N.
J. Shellfish
Res. 9:261-272.
1970. Reproductive physiology variation in latitudinally
separated populations of the bay scallop Aequipecten irradians.
Biol. Bull. 138:56-65.
Lamark.
P. & M. Monteforte. 1994. Breeding cycle of pearl oysters
Pinctada mazatlanica and Pteria sterna in Bahia de La Paz. South Baja
Saucedo.
California, Mexico. (Abstract Pearls "94).
J.
Shellfish Res. 13:348-349.
& H. Wright. 1994.
Repopulation of natural beds of pearl oysters Pinctada mazatlanica and
Pteria sterna in Bahi'a de La Paz. South Baja California. Mexico.
(Abstract Pearls '94). J. Shellfish Res. 13:349-351.
Saucedo,
Sevilla.
M. Monteforte, H. Bervera, V. Perez
P..
M.
L. 1969.
Contribucibn
al
conocimiento de
la
madreperla Pinctada
mazatlanica (Hanley. 1845). Rev. Soc. Me.x. Hist. Nat. 30:223-262.
Y. Sano Y. 1979. Reporte preliminar sobre los recursos de maShirai, S.
&
for
development of Pacific Natural Resources. Mei. Japan. Secretaria de
Pesca. Baja California Sur, Mexico. Internal Report. 55 pp.
1958a. Reproduction in Australian pearl oysters (Lamelli-
Tranter, D.J.
Pinctada albina (Lamark): Primary gonad development.
Mar. Freshwater Res. 9:135-143.
branchia).
Aust.
J.
revision of the Australian pearl-shells genus Pinctada
J.
Mar. Freshwater Res. 6:98-137.
1990. Ostras perleras y perlicultura: situacion actual en los
I.
Tranter. D.J. 1958b. Reproduction in Australian pearl oysters (Lamellibranchia).
II.
Pinctada albina (Lamark): Gametogenesis. Aust.
J.
Mar.
Freshwater Res. 9:144-158.
ity.
Aust.
Tranter. D.
Mexico. 77 pp.
View publication stats
Universidad Autiinoma de Baja California Sur, La Paz. 68 pp.
& K. Maeki. 1955. Some observations on the spermatogenesis
branchia).
Martinez. A. 1983. Prospeccion de los bancos de madreperla en el Golfo de
California de 1962 a 1965. M.Sc. Thesis. CICIMAR-I.P.N.. La Paz,
M.
Ambio
Ojima. Y.
Tranter. D.J.
S.
Acoelomated and Metazoans. Academic Press
(Lamellibrancha). Aust.
Monteforte.
California. Mexico.
J. 1987. Algunas caracterfsticas paleoceanograficas y cuerpos de
agua inferidos a partir de registros micropaleontologicos (Radiolaria)
en la Bahia de La Paz, Baja California Sur, Mexico. B.Sc. Thesis.
Pearse (eds). Reproduction of Marine
J.
York. 284 pp.
1955.
La Paz Bay, South Baja
Murillo.
1974. Introduction and general principles, pp.
3-21. In: A. C. Giese and
Inc..
valvia: Pteriidae) in
dreperla y su cultivo en aguas protegidas en Baja California Sur. Institute
fish Res. 15(2):297-303.
M. N.
natural
stocks of Pearl Oysters Pinctada mazatlanica and Pteria sterna (Bi-
Western Australian
1
Terrestrial
(Bivalvia:
11:13-18.
Panorama 38:28-35.
M. Carino. 1992. Exploration and evaluation of
Rose. R. A.. R. E. Dybdahl
Diario Oficial de la Federacion.
Gervis,
&
M.
1-135.
8:1
Decreed on Pearl Oyster Fisheries by the Mexican Government. Norma
Globierno de los Estados Unidos Mexicanos, 2pp.
1
AMAC
investigacion cientifica.
Federacion. 1939. Related to the Legal Permanent Ban
J.
la
oficial del
Hanley,
Number
1991. Las perlas. leyenda y realidad: un proyecto actual de
B.C.S.. Mexico. B.Sc. Thesis. Universidad
Cochin. India.
Diario Oficial de
M.
21:314-320.
de Baja California a principios de
ber
la
These de Maitrise en Histoire Universite de Paris VII, Jus-
& C. Caceres-Martinez.
Carino M. M.
entifica (Special
Monteforte,
Monteforte.
164 pp.
sieu.
Carino,
and Wildlife Service, Washing-
91 pp.
M. M.
Carino,
Fishery Leaflet 357. United
in Japan.
principales pafses productores y perspectivas para Mexico. Serie Ci-
J.
1958c. Reproduction in Australian pearl oysters (LamelliPinctada albina (Lamark): Breeding season and sexual-
III.
J.
Mar. Freshwater Res. 9:191-216.
1958d. Reproduction
in
Australian pearl oysters (Lamelli-
branchia). IV. Pinctada margaritifera (L.). Aust.
J.
Mar. Freshwater
Res. 9:509-523.
Tranter. D.
J.
1959. Reproduction in Australian pearl oysters (Lamellibranchia).
V. Pinctada fucata (Gould). Aust.
J.
Mar. Freshwater Res. 10:45-66.
1953. Biology of the silver-lip pearl oyster Pinctada
(Jameson). 2. Breeding season. Margarita 1:15-28.
Wada.
S.
maxima