The Predation of Artemia Nauplii by the Larvae of the Amazon River Prawn, Macrobrachium amazonicum (Heller, 1862), is Affected by Prey Density, Time of Day, and Ontogenetic Development

Abstract

The present study analyzed the effects of prey density, the time of day, and ontogenetic development on the predation of Artemia nauplii by the larvae of the Amazon river prawn, Macrobrachium amazonicum, as well as possible synergy among these factors. Larvae were raised in 120-L tanks with biological filter systems, and fed on recently hatched Artemia nauplii, using two feeding management protocols: (a) fed once per day at 2000 h (high density -HD) and (b) half of the ration provided at 2000 h, complemented at 0800 h the following day by a replacement of the nauplii consumed up to a maximum of the full ration (low density with replacement -LDWR). Each treatment consisted of six replicates. The consumption of nauplii was estimated prior to the feeding times. Consumption varied according to time of day, ontogenetic development, and feeding protocol. The larvae ingested more nauplii during the daytime at most developmental stages. Ingestion rates were similar during the day under both treatments, but at night the higher density of prey in the HD treatment caused a higher encounter rate and increased ingestion of nauplii by the larvae. Among the performance indicators only survival was greater in HD in comparison with LDWR; productivity and dry weight were similar. The results indicate a circadian trophic rhythm in M. amazonicum, with the encounter rate being an important mechanism for the capture of prey during the night. A second mechanism -probably the visual system -aids the perception of prey during the daytime. Based on these results, we suggest that feeding captive Amazon river prawn larvae only once a day would be appropriate and economically beneficial. Further work is necessary to determine the most effective time that this single feed should be applied.

Feeding and larval growth of an exotic freshwater prawn Macrobrachium equidens (Decapoda: Palaemonidae), from Northeastern Pará, Amazon Region

“…Similar results were observed for larvae of different species of crustaceans: Paleamon serratus (Yúfera and Rodríguez 1985a), Palaemonetes varians (Yúfera and Rodríguez 1985b), Metapenaeus ensis (Chu and Shing 1986), Scylla serrata (Zeng and Li 1992), Ranina ranina (Minagawa and Murano 1993), Panopeus herbstii (Welch and Epifanio 1995), Zysmata wurdemani (Zhang et al 1998), S. serrata (Suprayudi et al 2002, M. rosenbergii (Barros and Valenti 2003) and M. amazonicum (Maciel et al 2012). In most of these studies, higher rates of survival were associated with increased ingestion rates and a reduction in the duration of the intermolt.…”

“…By contrast, food limitations can compromise nutritionally depleted larvae, reducing the survival rate and increasing cannibalism (Jones et al 1997). The relationship between increased larval consumption of Artemia in response to an increase in the density of the latter had been previously observed for larvae of M. rosenbergii (Barros and Valenti 2003), king crab -Paralithodes camtschaticus (Epelbaum and Kovatcheva 2005) and M. amazonicum (Maciel et al 2012). Thus, the success of feeding during larval development depends on the efficient combination of food capture by the larvae and the nutritional quality of the food (Anger 2001).…”

Effect of salinity on the metabolism and osmoregulation of selected ontogenetic stages of an amazon population of Macrobrachium amazonicum shrimp (Decapoda, Palaemonidae)

“…Larvae were fed with Artemia sp nauplii beginning on the second day of cultivation due to the existence yolk in zoeae I bodies. From the 6 th day, humid diet was added to larvae diet twice a day (Maciel and Valenti, 2009;Maciel et al, 2012). Salinity was daily checked using a refractometer (Atago S/Mill-E), as well as siphonage of the tanks.…”

Growth, elemental and proximate biochemical composition of larval Amazon River prawn, Macrobrachium amazonicum, reared under different salinity conditions

“…Macrobrachium amazonicum, changes in elemental and proximate biochemical composition of larval biomass (contents of C, N, lipid, protein; all in % of W); C/N mass ratio; for further explanation, see Table 1. northern and northeastern South America as well as distinct hololimnetic clades in the hydrologically separated La Plata Basin and, possibly, in central Amazonia (Vergamini et al, 2011;dos Santos et al, 2013;Weiss et al, 2015). Although biologically relevant differences between separate populations have been found in reproduction, ecology, morphology, growth, larval development, physiology, and genetics (Dos Santos et al, 2013;Weiss et al, 2015;Boudour-Boucheker et al, 2016), there remains also a conflicting hypothesis proposing a single species with an enormous geographic distribution range (>4.000 km across) and an extreme degree of phenotypic plasticity, i.e., environmentally induced changes in biological traits (Vergamini et al, 2011;Maciel et al, 2014). A recent study (Soeiro et al, 2016) showed, however, that the early larval stages (I-IV) of two different populations of M. amazonicum (both from the lower Amazon region; one living in estuarine habitats with salinities >25, another one from a site characterized by fresh water), did not show any significant effect of the habitats of origin on salinity tolerance.…”

“…10-15 nauplii mL -1 ) were changed. A recent study revealed that a daily feeding interval and high food density (4-12 nauplii mL -1 ) allow for optimal larval survival and growth (Maciel et al, 2014). No food was given to the first zoeal stage because it is fully lecithotrophic ).…”