370
Studies carried out during the broodstock conditioning period of E� megalocyathus demonstrate that fecundity in these animals can be reduced while maintaining
the biochemical composition of the eggs, when food is scarce or when changes in
diet occur (Farías et al. 2011). These studies also show that Patagonian red octopus
can be conditioned without a crustacean diet and still maintain fecundity.
After laying the eggs, the females stop feeding and it has been suggested that this
behaviour generates population differences between genders since feeding habits
affect the age when they reach senescence and death (Ibáñez and Chong 2008).
The reproduction area at the Hatchery of Marine Invertebrate of Universidad Austral de Chile (HIM-UACh) consists of an isolated room of 5 × 6 m, with controlled
temperature and light. For the reproductive broodstock, 700 L (1.75 × 1.1 × 0.35 m)
tanks with sea water filtered at 1 µm and ultraviolet (UV) sterilized were used. Sea
water had the following characteristics: 29–31 psu, 11 ± 1 °C, 6–8 mg L
−1
of dissolved O 2 and lower than 1 mg L
−1
total ammonia. Light brightness was maintained
at levels below 50 Lx cm
−2
, while the temperature was controlled with a chiller
equipment.
The sea water was recirculated through deep-bed filters with anthracite as filter
material. Anthracite also has the property of retaining the dissolved ammonium.
Also, the water was subjected to a sterilization by UV lamps in order to reduce the
bacterial load.
The individuals came from the natural environment of Hueihue (Ancud, Chiloé,
X region, Chile). They were captured using a traditional method where divers trap
and place them in a floating fibreglass pond of 500 L which is tied to the boat. Then
they are landed and individually placed in mesh bags into 500-L tanks to prevent
their escape and damage between them, while being transported to the laboratory
at 12 °C and with oxygen injection throughout the entire journey of 2.5 h from the
capture area to the laboratory.
In the laboratory quarantine room, females are placed in acclimation ponds where
they are maintained for 48 h until recovery. Before placing the octopuses in breeding
tanks, they are sexed, measured and weighed. The animals are prepared for weighing by preparing a bath of ice-cold water at 2 °C for 3–5 min, which works as an anaesthetic that allows to measure and weigh the animals without harming them. Then,
they are placed on a scale to record their weight and, finally, total length is recorded.
19.3 Spawning Process
Egg layings collected from the wild (Ortiz et al. 2006, 2011), as well as layings obtained by broodstock conditioning (Fig. 19.2) in the laboratory (Farías et al. 2011;
Uriarte et al. 2011a, 2013; Gutiérrez 2012), confirm that this species presents absolute fecundity between 1,000 and 5,000 eggs per female (Table 19.2). On the other
hand, relative fecundity under controlled conditions is 1,101 ± 159 eggs kg
−1
female
(Gutiérrez 2012). Leporati et al. (2008) showed that other factors besides the size of
the female, such as seasonal changes in temperature, substrate availability for laying,
Í. Uriarte and A. Farías
Studies carried out during the broodstock conditioning period of E� megalocyathus demonstrate that fecundity in these animals can be reduced while maintaining
the biochemical composition of the eggs, when food is scarce or when changes in
diet occur (Farías et al. 2011). These studies also show that Patagonian red octopus
can be conditioned without a crustacean diet and still maintain fecundity.
After laying the eggs, the females stop feeding and it has been suggested that this
behaviour generates population differences between genders since feeding habits
affect the age when they reach senescence and death (Ibáñez and Chong 2008).
The reproduction area at the Hatchery of Marine Invertebrate of Universidad Austral de Chile (HIM-UACh) consists of an isolated room of 5 × 6 m, with controlled
temperature and light. For the reproductive broodstock, 700 L (1.75 × 1.1 × 0.35 m)
tanks with sea water filtered at 1 µm and ultraviolet (UV) sterilized were used. Sea
water had the following characteristics: 29–31 psu, 11 ± 1 °C, 6–8 mg L
−1
of dissolved O 2 and lower than 1 mg L
−1
total ammonia. Light brightness was maintained
at levels below 50 Lx cm
−2
, while the temperature was controlled with a chiller
equipment.
The sea water was recirculated through deep-bed filters with anthracite as filter
material. Anthracite also has the property of retaining the dissolved ammonium.
Also, the water was subjected to a sterilization by UV lamps in order to reduce the
bacterial load.
The individuals came from the natural environment of Hueihue (Ancud, Chiloé,
X region, Chile). They were captured using a traditional method where divers trap
and place them in a floating fibreglass pond of 500 L which is tied to the boat. Then
they are landed and individually placed in mesh bags into 500-L tanks to prevent
their escape and damage between them, while being transported to the laboratory
at 12 °C and with oxygen injection throughout the entire journey of 2.5 h from the
capture area to the laboratory.
In the laboratory quarantine room, females are placed in acclimation ponds where
they are maintained for 48 h until recovery. Before placing the octopuses in breeding
tanks, they are sexed, measured and weighed. The animals are prepared for weighing by preparing a bath of ice-cold water at 2 °C for 3–5 min, which works as an anaesthetic that allows to measure and weigh the animals without harming them. Then,
they are placed on a scale to record their weight and, finally, total length is recorded.
19.3 Spawning Process
Egg layings collected from the wild (Ortiz et al. 2006, 2011), as well as layings obtained by broodstock conditioning (Fig. 19.2) in the laboratory (Farías et al. 2011;
Uriarte et al. 2011a, 2013; Gutiérrez 2012), confirm that this species presents absolute fecundity between 1,000 and 5,000 eggs per female (Table 19.2). On the other
hand, relative fecundity under controlled conditions is 1,101 ± 159 eggs kg
−1
female
(Gutiérrez 2012). Leporati et al. (2008) showed that other factors besides the size of
the female, such as seasonal changes in temperature, substrate availability for laying,
Í. Uriarte and A. Farías