of the sperm has several advantages in aquaculture production,
especially for hatcheries, through synchronization of gamete availability, allowing provision of sperm outside the reproductive season, permitting simplified broodstock establishment, and
facilitating sperm transport between facilities [23, 24]. Cryopreservation also makes it possible to create genetic resource banks [25]
that are repositories for selected strains and endangered species,
where the material is secure of diseases, natural disasters, and contamination [22, 23, 26]. Subsequently this sperm with specific
characteristics can be used in genetic programs and preservation
strategies.
Although the cryopreservation of oyster sperm can help production and conservation activities, it is clear that the maternal
genome needs to be preserved as well. Oocytes have been more
difficult to cryopreserve, and oysters are not an exception
[27, 28]. An alternative is to cryopreserve embryos or larvae,
which has been demonstrated to produce viable offspring in the
case of the Pacific oyster (Crassostrea gigas) [29].
1.3 Target Species
Paracentrotus lividus is a regular sea urchin that is widespread in the
Mediterranean Sea and eastern Atlantic intertidal and subtidal
coasts from Scotland to Morocco. It is one of the main edible
species around Europe, although not the only one.
Holothuria forskali is a sea cucumber and can be found at
shallow depths in the eastern Atlantic Ocean and the Mediterranean Sea. This edible sea cucumber has a cylindrical body and can
grow to 30 cm long.
Mytilus galloprovincialis is the most widespread mussel species.
In addition to an important ecological role in filtering seawater,
mussels are among the most farmed mollusks, and the annual
harvest is close to two million tonnes per year [2].
Crassostrea angulata (Portuguese oyster) is an example of a
species for which genetic resources can disappear. Portuguese oyster natural populations collapsed due to the onset of pathologies
and poor remediation and management measures [30]. Creating
mechanisms that allow reducing the loss of biodiversity is crucial.
One tool that allows preserving the genetic profile and improves
the reproductive technologies is cryopreservation.
2 Materials
2.1 Cryopreservation
of Sea Urchin
(Paracentrotus
lividus) Sperm
1. Polystyrene rack, height 7.8 cm above the liquid nitrogen
surface (see Fig. 1) (for cryopreservation at an approximate
cooling rate of ~11
C/min).
2. Styrofoam box with a lid (capacity 1–2 L).
Cryopreservation of Marine Invertebrates
415
especially for hatcheries, through synchronization of gamete availability, allowing provision of sperm outside the reproductive season, permitting simplified broodstock establishment, and
facilitating sperm transport between facilities [23, 24]. Cryopreservation also makes it possible to create genetic resource banks [25]
that are repositories for selected strains and endangered species,
where the material is secure of diseases, natural disasters, and contamination [22, 23, 26]. Subsequently this sperm with specific
characteristics can be used in genetic programs and preservation
strategies.
Although the cryopreservation of oyster sperm can help production and conservation activities, it is clear that the maternal
genome needs to be preserved as well. Oocytes have been more
difficult to cryopreserve, and oysters are not an exception
[27, 28]. An alternative is to cryopreserve embryos or larvae,
which has been demonstrated to produce viable offspring in the
case of the Pacific oyster (Crassostrea gigas) [29].
1.3 Target Species
Paracentrotus lividus is a regular sea urchin that is widespread in the
Mediterranean Sea and eastern Atlantic intertidal and subtidal
coasts from Scotland to Morocco. It is one of the main edible
species around Europe, although not the only one.
Holothuria forskali is a sea cucumber and can be found at
shallow depths in the eastern Atlantic Ocean and the Mediterranean Sea. This edible sea cucumber has a cylindrical body and can
grow to 30 cm long.
Mytilus galloprovincialis is the most widespread mussel species.
In addition to an important ecological role in filtering seawater,
mussels are among the most farmed mollusks, and the annual
harvest is close to two million tonnes per year [2].
Crassostrea angulata (Portuguese oyster) is an example of a
species for which genetic resources can disappear. Portuguese oyster natural populations collapsed due to the onset of pathologies
and poor remediation and management measures [30]. Creating
mechanisms that allow reducing the loss of biodiversity is crucial.
One tool that allows preserving the genetic profile and improves
the reproductive technologies is cryopreservation.
2 Materials
2.1 Cryopreservation
of Sea Urchin
(Paracentrotus
lividus) Sperm
1. Polystyrene rack, height 7.8 cm above the liquid nitrogen
surface (see Fig. 1) (for cryopreservation at an approximate
cooling rate of ~11
C/min).
2. Styrofoam box with a lid (capacity 1–2 L).
Cryopreservation of Marine Invertebrates
415