389
20 Octopus maya
the animals do not ingest food during the first 5–7 days (Martínez et al. 2011). When
the internal yolk is consumed and the digestive gland is ready to digest external food,
the raptorial behaviour of hatchlings initiates. Despite that, under culture conditions
hatchlings are fed from day 1, because hatchlings coming from one spawn will be
between 1 and 5 days old, since embryos did not hatch at the same day.
Van Heukelem (1977) recommended feeding hatchlings with live food, mainly
palaemonids, amphipods or small crabs. Feeding O� maya hatchlings in massive
cultures with live feed is frequently impractical, although we also found that marine
gammarids certainly improve the growth rate and survival between day 1 and 15
DPH (6.9 ± 0.2 % day
− 1
; 92 % survival) when compared with animals fed Artemia
spp. adults (4.8 ± 0.2 % day
− 1
, 71 % survival) or freshwater gammarids (5.0 ± 0.3 %
day
− 1
, 41 % survival) (Baeza-Rojano et al. 2012). In an attempt to replace live prey,
several sources of protein were tested. A semi-humid squid paste-bound gelatin has
recently been developed and can be used as a main food of O� maya hatchlings and
juveniles (Rosas et al. 2008b; Rosas et al. 2012).
When an elaborated diet is used, a ration should be established. At the experimental level with individualized animals, an adequate ration of 30 % of WW day
− 1
was reported for this species (Quintana et al. 2011). However, in massive culture,
this type of ration is not precise, since it is not possible to assure that every animal
obtains the same amount of food. At present, hatchlings and juveniles are fed twice
a day (around 50 % WW each time) to avoid competition between them.
The type of tank and culture density for O� maya hatchlings were defined recently.
At our facility, hatchling culture is done in 7.5 m
2
dark tanks (5.0 × 1.5 × 0.4 m) at
a density of 50 individuals m
− 2
. Tanks are connected to a recirculatory seawater
(25 ± 1 °C) and aerated system that maintains oxygen, ammonia and nitrate levels at
5.5 ± 0.5, 0.2 ± 0.05 and 0.1 ± 0.01 mg L
− 1
, respectively. In such conditions, octopuses are fed twice a day and maintained for 60 days until they reach around 2 g WW.
In these tanks, survival can be variable and strongly dependent of the feeding rate.
Less than 2 rations day
− 1
per animal will produce high cannibalism and in consequence low survival. We have registered survivals lower than 10 % when not enough
food was offered to hatchlings. Refuges are also important to avoid cannibalism and
stress. Both for hatchlings and juvenile (until 10 g WW), Strombus pugilis conchs
are used as refuges at a proportion of three conchs per octopus.
20.4 Juveniles Ongrowing
At 60 days old, juveniles are transferred to outdoor 6 m diameter tanks (Domingues
et al. 2012). The octopuses are graded by size, reducing the high variability characteristic of O� maya hatchlings (Briceño-Jacques et al. 2010). Outdoor ponds are conditioned with greenhouse meshes that reduce the direct sunlight by 70 % (Fig. 20.3).
The tanks are connected to a recirculation seawater system coupled to protein
skimmers and 50 µm bag filters (one per tank). Squid paste is also used as food
during this octopus ongrowing stage, offering a mean of 3 rations per animal day
− 1
.
The culture density in outdoor tanks is 25 juveniles m
− 2
(700 juveniles per tank).
20 Octopus maya
the animals do not ingest food during the first 5–7 days (Martínez et al. 2011). When
the internal yolk is consumed and the digestive gland is ready to digest external food,
the raptorial behaviour of hatchlings initiates. Despite that, under culture conditions
hatchlings are fed from day 1, because hatchlings coming from one spawn will be
between 1 and 5 days old, since embryos did not hatch at the same day.
Van Heukelem (1977) recommended feeding hatchlings with live food, mainly
palaemonids, amphipods or small crabs. Feeding O� maya hatchlings in massive
cultures with live feed is frequently impractical, although we also found that marine
gammarids certainly improve the growth rate and survival between day 1 and 15
DPH (6.9 ± 0.2 % day
− 1
; 92 % survival) when compared with animals fed Artemia
spp. adults (4.8 ± 0.2 % day
− 1
, 71 % survival) or freshwater gammarids (5.0 ± 0.3 %
day
− 1
, 41 % survival) (Baeza-Rojano et al. 2012). In an attempt to replace live prey,
several sources of protein were tested. A semi-humid squid paste-bound gelatin has
recently been developed and can be used as a main food of O� maya hatchlings and
juveniles (Rosas et al. 2008b; Rosas et al. 2012).
When an elaborated diet is used, a ration should be established. At the experimental level with individualized animals, an adequate ration of 30 % of WW day
− 1
was reported for this species (Quintana et al. 2011). However, in massive culture,
this type of ration is not precise, since it is not possible to assure that every animal
obtains the same amount of food. At present, hatchlings and juveniles are fed twice
a day (around 50 % WW each time) to avoid competition between them.
The type of tank and culture density for O� maya hatchlings were defined recently.
At our facility, hatchling culture is done in 7.5 m
2
dark tanks (5.0 × 1.5 × 0.4 m) at
a density of 50 individuals m
− 2
. Tanks are connected to a recirculatory seawater
(25 ± 1 °C) and aerated system that maintains oxygen, ammonia and nitrate levels at
5.5 ± 0.5, 0.2 ± 0.05 and 0.1 ± 0.01 mg L
− 1
, respectively. In such conditions, octopuses are fed twice a day and maintained for 60 days until they reach around 2 g WW.
In these tanks, survival can be variable and strongly dependent of the feeding rate.
Less than 2 rations day
− 1
per animal will produce high cannibalism and in consequence low survival. We have registered survivals lower than 10 % when not enough
food was offered to hatchlings. Refuges are also important to avoid cannibalism and
stress. Both for hatchlings and juvenile (until 10 g WW), Strombus pugilis conchs
are used as refuges at a proportion of three conchs per octopus.
20.4 Juveniles Ongrowing
At 60 days old, juveniles are transferred to outdoor 6 m diameter tanks (Domingues
et al. 2012). The octopuses are graded by size, reducing the high variability characteristic of O� maya hatchlings (Briceño-Jacques et al. 2010). Outdoor ponds are conditioned with greenhouse meshes that reduce the direct sunlight by 70 % (Fig. 20.3).
The tanks are connected to a recirculation seawater system coupled to protein
skimmers and 50 µm bag filters (one per tank). Squid paste is also used as food
during this octopus ongrowing stage, offering a mean of 3 rations per animal day
− 1
.
The culture density in outdoor tanks is 25 juveniles m
− 2
(700 juveniles per tank).