21 Octopus mimus
409
plete their development independently of external food (Villanueva and Norman
2008). Zúñiga et al. (2012) studied the mechanisms explaining how yolk reserve
modulates the adaptive capacity of O� mimus paralarvae, evaluating the thermoregulatory capacity, thermal selection and oxygen consumption in individuals acclimated at 20 °C. The study suggests that post-hatched paralarvae (1 DAH) are less
tolerant to extreme temperature, compared to 2–3 DAH individuals at the moment
when paralarvae are fully developed and the yolk is totally absorbed. In addition,
the paralarval thermal preference does not change with age. The temperature selected for paralarvae rearing was 22.8 ± 1.3 °C when they were exposed in a horizontal
gradient of temperature. The paralarvae age and their nutritional condition affected
the thermal tolerance range (TTR = Critical Maximum Temperature—Critical Minimum Temperature), with higher values for two and three DAH individuals (25 and
26 °C) than for 1 DAH (23.1 °C) and 4 DAH (22.7 °C).
Besides the adaptive implications and potential effects of the relationship between a lack of food and an increment of temperature on O� mimus paralarval survival in its natural environment, the results of Zúñiga et al. (2012) allowed the
definition of a critical period, starting once yolk reserve is absorbed at 20 °C and
after 4 DAH.
21.5 Ongrowing
In Antofagasta (northern Chile), the authors of this chapter have carried out different experiments focused on growth by feeding O� mimus using artificial food prepared with triturated fish flesh (54 %), fish meal (10 %) and clams compacted with
6 % non-flavour jelly all embedded in sausages (lamb tripe).
21.5.1 Tank Culture (Inland Facilites)
Octopuses with body weight less than 800 g were deployed at different densities
(5, 10, 15 individuals m
−3
) in metallic cages inside of raceway-type tanks made of
HDPE of 2 x 6 x 1.5 m with continuous water flow. Water was changed two to three
times, salinity was kept at 36 psu, ammonia at < 10 mg L
−1
and dissolved oxygen at
upper 4 mg L
−1
level. The latter was also enhanced using constant aeration. Lower
mortalities and higher growth were obtained at densities lower than 10 individuals
m
−3
. Octopuses preferred either fresh or frozen food, although they accepted the
artificial diet previously described (sausage-type food) which facilitates the management of octopus growth. Mortality was high in this culture system. The survival
average only reached 50 %. Growth was low and animals only attained a 70 % of the
initial weight in 60 days of culture.
409
plete their development independently of external food (Villanueva and Norman
2008). Zúñiga et al. (2012) studied the mechanisms explaining how yolk reserve
modulates the adaptive capacity of O� mimus paralarvae, evaluating the thermoregulatory capacity, thermal selection and oxygen consumption in individuals acclimated at 20 °C. The study suggests that post-hatched paralarvae (1 DAH) are less
tolerant to extreme temperature, compared to 2–3 DAH individuals at the moment
when paralarvae are fully developed and the yolk is totally absorbed. In addition,
the paralarval thermal preference does not change with age. The temperature selected for paralarvae rearing was 22.8 ± 1.3 °C when they were exposed in a horizontal
gradient of temperature. The paralarvae age and their nutritional condition affected
the thermal tolerance range (TTR = Critical Maximum Temperature—Critical Minimum Temperature), with higher values for two and three DAH individuals (25 and
26 °C) than for 1 DAH (23.1 °C) and 4 DAH (22.7 °C).
Besides the adaptive implications and potential effects of the relationship between a lack of food and an increment of temperature on O� mimus paralarval survival in its natural environment, the results of Zúñiga et al. (2012) allowed the
definition of a critical period, starting once yolk reserve is absorbed at 20 °C and
after 4 DAH.
21.5 Ongrowing
In Antofagasta (northern Chile), the authors of this chapter have carried out different experiments focused on growth by feeding O� mimus using artificial food prepared with triturated fish flesh (54 %), fish meal (10 %) and clams compacted with
6 % non-flavour jelly all embedded in sausages (lamb tripe).
21.5.1 Tank Culture (Inland Facilites)
Octopuses with body weight less than 800 g were deployed at different densities
(5, 10, 15 individuals m
−3
) in metallic cages inside of raceway-type tanks made of
HDPE of 2 x 6 x 1.5 m with continuous water flow. Water was changed two to three
times, salinity was kept at 36 psu, ammonia at < 10 mg L
−1
and dissolved oxygen at
upper 4 mg L
−1
level. The latter was also enhanced using constant aeration. Lower
mortalities and higher growth were obtained at densities lower than 10 individuals
m
−3
. Octopuses preferred either fresh or frozen food, although they accepted the
artificial diet previously described (sausage-type food) which facilitates the management of octopus growth. Mortality was high in this culture system. The survival
average only reached 50 %. Growth was low and animals only attained a 70 % of the
initial weight in 60 days of culture.