A Red Shrimp, Farfantepenaeus brasiliensis (Latreille, 1817), Larvae Feeding Regime Based on Live Food

Red shrimp, Farfantepenaeus brasiliensis, larvae's response to different concentrations of live foods (diatoms Chaetoceros gracilis: 20–100 × 10 cells/mL; flagellate Tetraselmis chuii: 2–10 × 10 cells/mL and Artemia nauplii [NA]: 1–5 NA/mL) was investigated in three experiments. Experimental assessments were based on four variables: survival rate, weight gain, development index (DI), and resistance to salinity stress. A combination of C. gracilis 80 × 10 cells/mL, T. chuii 2 × 10 cells/mL, and Artemia 4 NA/mL provided the best experimental response. Specifically, F. brasiliensis larvae fed with the above-mentioned optimal concentrations of microalgae and Artemia grew faster and reached the postlarval stage in less time (168 h) than larvae in other feeding regimes evaluated. The effect of C. gracilis concentration on larval growth, survival, and the DI demonstrated that microalgae-based foods could be a highly productive alternative to more traditional aquaculture feeding regimes. The spatial distribution of Caribbean red shrimp, Farfantepenaeus brasiliensis, extends from North Carolina and the Florida Keys in the north to the Río Grande do Sul, Brazil in the south, and encompasses the southern Gulf of Mexico (including Yucatan), the West Indies, Bermuda, and the Caribbean coast of Central and South America (Perez Farfante and Kensley 1997). F. brasiliensis has been recognized as an excellent candidate species for aquaculture (Anguiano 1999) because populations remain abundant in the wild, growth rates under culture conditions are relatively good, and maximum adult size is large comparable to other penaeid species. Although this species could be effectively farmed, efficient larval rearing production techniques need to be developed. Penaeid larvae inhabit coastal waters where they prey on a variety of phytoplankton and zooplankton. Under laboratory conditions, cultivation of such plankton communities has proven unreliable and impractical. Hence, a limited array of food organisms, mainly selected strains of microalgae and Artemia NA, has provided the basis for indoor shrimp larvae production; although, nematodes and ciliates have also been exploited with moderate success (Leger and Sorgeloos 1992). Because shrimp larvae begin exogenous feeder by ingesting phytoplankton (Jones et al. 1997), several algae species were cultured for penaeid larvae culture. It included diatoms (e.g., Chaetoceros spp.), which are among the best food for early shrimp larvae stages, as well as other species e.g. flagellates such as Tetraselmis spp. to enhance the nutritional profile and to provide an adequate size range between 8-12 x 7-10 exclusive of the setae (Simon 1978; Brown 1991). Consequently, the use of two algal strains as a food source, generally a diatom and a flagellate, has been a popular option (Leal et al., 1985; Aquacop 1983; Gallardo et al. 1995). Although Tetraselmis spp. alone were successfully used for penaeid larvae (Aujero et al. 1983; Souza and Kelly 2000), a mixture of algae gained popularity due to the fact that a single algae could not fulfill all larval-stage lipid requirements. Lipids provide endogenous energy reserves during the embryonic and larval periods in decapods crustaceans (Kattner et al., 1994), because they possess little or no ability to biosynthesize n-3 highly unsaturated fatty acids, HUFA’s (Teshima 1997). Importantly for aquaculture, the composition of both C. gracilis and T. chuii contain these HUFA’s (Brown et al. 1997). Artemia, probably the most frequently-used food organism in aquaculture because of its high nutritional value (Sorgeloos 1980) and good fit with the raptorial habit of shrimp larvae, offers another viable source of HUFA’s (Emmerson 1980, 1984; Yufera et al. 1984; Lovett and Felder 1989; Rodriguez et al. 1994). The purpose of the present study was to determine the optimal feeding regime for F. brasiliensis larvae by testing the impact of various concentrations of C. gracilis, T. chuii, and Artemia NA on survival, growth and development index. The quality index was also calculated based on the resistance to salinity stress of the postlarvae harvested from the different treatments. 1. Material and Methods 1.1. Source of Larvae F. brasiliensis larvae used in each experiment were obtained from a single spawning of naturally inseminated females harvested from the wild. They were captured at a depth of 42 to 67 m near Isla Contoy, Quintana Roo, Mexico. Females were unilaterally eyestalk ablated to accelerate gonad maturation. Eggs were collected and placed in a small tank to obtain the nauplii that were harvested from the hatching tank at stage N1-2.