Feeding Frequency in Pacamã Larviculture

Abstract

The feeding frequencies on pacamã Lophiosilurus alexandri larviculture were evaluated. In the first phase, 10 days of active feeding, larvae with nine days post hatching (13.5 ± 0.7 mm) were stocked at density of 10 larvae L-1 in 5-L tanks each. The experimental treatments were: F2T (feeding 8h00 and 17h00); F2M (feeding 8h00 and 12h30); F3 (feeding 8h00, 12h30 and 17h00); and F4 (feeding 8h00, 11h00, 14h00 and 17h00). During this phase Artemia nauplii were used as food. In the second phase, during 15 days, juveniles were restocked in 20-L tanks at density of 2.2 juveniles L-1, and kept the same feeding frequencies of the first phase. Commercial dry diet containing 40% crude protein was used as food. No effect of feeding frequency on growth and survival, during both phases, was observed. However, survival decreases from the first to the second phase, showing the importance of the type of food. During the L. alexandri larviculture should be recommended twice a day feeding frequency.

Effect of Different Culture Conditions on Gene Expression Associated With Cyst Production in Populations of Artemia franciscana

“…However, their usefulness has still not been tested in an applied field, particularly with regard to the prediction of reproductive mode leading to diapause under controlled culture conditions. From a commercial point of view, controlled Artemia cyst production is important, given that the cysts have a high production value in fish larviculture, for example, in native marine or freshwater fish with a high commercial value, which is being developed in Central America ( Abdo-de la Parra et al, 2015 ; Palma-Cancino et al, 2019 ) and South America ( Fabregat et al, 2015 ; Luz and Portella, 2015 ; Dos Santos et al, 2016 ). In our study, we contribute new information with regard to this topic, by evaluating the expression level of eight previously described genes, in order to analyze their relationship with the diapause reproductive mode in a Chilean population characterized by high cyst production.…”

Development, nutrition, and rearing practices of relevant catfish species (Siluriformes) at early stages

“…However, no differences in survival were found when testing live prey densities ranging from 100 to 1600 nauplii larva −1 day −1 . Regarding feeding frequency, L. alexandri larvae can be fed Artemia nauplii two (at 8 and 17 h or 8 and 12:30 h); three (at 8, 12:30 and 17 h); or four (at 8, 11, 14 and 17 h) times a day, without differences in performance and survival (>89%) 178 . Therefore, the final choice of feeding regimens will depend on the hatchery operators.…”

“…Lophiosilurus alexandri early culture is successfully performed in freshwater with Artemia nauplii (Table 7). 49,53,176,177,178 However, the use of NaCl in the water is an interesting management technique during the initial phases of L. alexandri larviculture. In particular, larvae exhibit a CL 50-96h of 8.9 g NaCl L −1 at 8 dph and tolerate up to 10 g NaCl L −1 at 12 dph (four days after first feeding) (14.1-15.5 mm TL).…”

“…Regarding feeding frequency, L. alexandri larvae can be fed Artemia nauplii two (at 8 and 17 h or 8 and 12:30 h); three (at 8, 12:30 and 17 h); or four (at 8, 11, 14 and 17 h) times a day, without differences in performance and survival (>89%). 178 Therefore, the final choice of feeding regimens will depend on the hatchery operators. Natural zooplankton 181,182 and the fairy shrimp (Dendrocephalus brasiliensis, Brachiopoda) 183 can also be used with positive outcomes.…”