440
J. Iglesias and L. Fuentes
23.5 Paralarvae Feeding
23.5.1 Prey Size
Paralarvae can start feeding from the first day of life, but usually a greater number
of attacks are recorded 2 days after hatching at temperatures of 18–20 °C (Iglesias
et al. 2006). These authors also reported that larger Artemia (1.4 ± 0.4 mm) were
clearly preferred to smaller Artemia (0.8 ± 0.1 mm) at first feeding. Nevertheless, a
wide range of prey sizes has been used in research on paralarvae rearing. Navarro
and Villanueva (2003) used Artemia nauplii of 450–750 µm, in the first few weeks
of culture, while others (Moxica et al. 2002; Iglesias et al. 2004; Carrasco et al.
2005; Estévez et al. 2009) used Artemia of 2 mm length or bigger.
In order to investigate the effect of prey size on growth, Fuentes et al. (2009)
compared the use of small Artemia enriched for 24 h with Isochrysis galbana
(0.7 mm TL) with that of larger Artemia grown for 4 days with the same microalga
(1.5 mm TL) during a 30-day larval rearing experiment. There were no significant
differences in growth during the first 15 days, but growth was significantly faster
when larger Artemia was used as diet during the next 15 days of trial (Table 23.1).
Considering these results, for experimental larval rearing, it is recommended that
Artemia of 0.5–0.7 mm length are used for the first 15 days followed by Artemia of
1.5–2 mm length.
23.5.2 Paralarval Nutritional Requirements
Navarro and Villanueva (2000, 2003) considered that a lack of balance in lipid and
fatty acid composition and a deficiency in polyunsaturated fatty acids (PUFAs) of
the food supplied could be responsible for the high mortality and low growth during
O� vulgaris paralarvae rearing. Okumura et al. (2005) used Artemia supplemented
with flakes of A� personatus to increase the proportion of PUFAs in the diet. Seixas
(2009) and Seixas et al. (2010) fed Artemia enriched with different microalgae species rich in PUFAs, whereas Bersano (2003) and Estévez et al. (2009) used live
copepods and other zooplankton groups, respectively. Besides PUFAs, amino acids
seem to be another important component in the diet. Villanueva et al. (2004) found
that lysine, arginine and leucine represent about half of the total essential amino
acids in cephalopod hatchlings. In addition, Villanueva and Bustamante (2006) studied the importance of essential elements in the diet and detected a higher content of
copper in O� vulgaris hatchlings and wild juveniles than in Artemia-fed paralarvae.
An approach to meeting their vitamin A and E requirements in culture has been published by Villanueva et al. (2009). Further information on nutritional requirements
can be found in Chap. 5.
J. Iglesias and L. Fuentes
23.5 Paralarvae Feeding
23.5.1 Prey Size
Paralarvae can start feeding from the first day of life, but usually a greater number
of attacks are recorded 2 days after hatching at temperatures of 18–20 °C (Iglesias
et al. 2006). These authors also reported that larger Artemia (1.4 ± 0.4 mm) were
clearly preferred to smaller Artemia (0.8 ± 0.1 mm) at first feeding. Nevertheless, a
wide range of prey sizes has been used in research on paralarvae rearing. Navarro
and Villanueva (2003) used Artemia nauplii of 450–750 µm, in the first few weeks
of culture, while others (Moxica et al. 2002; Iglesias et al. 2004; Carrasco et al.
2005; Estévez et al. 2009) used Artemia of 2 mm length or bigger.
In order to investigate the effect of prey size on growth, Fuentes et al. (2009)
compared the use of small Artemia enriched for 24 h with Isochrysis galbana
(0.7 mm TL) with that of larger Artemia grown for 4 days with the same microalga
(1.5 mm TL) during a 30-day larval rearing experiment. There were no significant
differences in growth during the first 15 days, but growth was significantly faster
when larger Artemia was used as diet during the next 15 days of trial (Table 23.1).
Considering these results, for experimental larval rearing, it is recommended that
Artemia of 0.5–0.7 mm length are used for the first 15 days followed by Artemia of
1.5–2 mm length.
23.5.2 Paralarval Nutritional Requirements
Navarro and Villanueva (2000, 2003) considered that a lack of balance in lipid and
fatty acid composition and a deficiency in polyunsaturated fatty acids (PUFAs) of
the food supplied could be responsible for the high mortality and low growth during
O� vulgaris paralarvae rearing. Okumura et al. (2005) used Artemia supplemented
with flakes of A� personatus to increase the proportion of PUFAs in the diet. Seixas
(2009) and Seixas et al. (2010) fed Artemia enriched with different microalgae species rich in PUFAs, whereas Bersano (2003) and Estévez et al. (2009) used live
copepods and other zooplankton groups, respectively. Besides PUFAs, amino acids
seem to be another important component in the diet. Villanueva et al. (2004) found
that lysine, arginine and leucine represent about half of the total essential amino
acids in cephalopod hatchlings. In addition, Villanueva and Bustamante (2006) studied the importance of essential elements in the diet and detected a higher content of
copper in O� vulgaris hatchlings and wild juveniles than in Artemia-fed paralarvae.
An approach to meeting their vitamin A and E requirements in culture has been published by Villanueva et al. (2009). Further information on nutritional requirements
can be found in Chap. 5.