Feasibility of compensatory growth in early juveniles of "red claw" crayfish Cherax quadricarinatus under high density conditions

The aim of this work is to study the feasibility to induce compensatory growth in Cherax quaricarinatus crayfish at an early stage of development under high density, the typical conditions of nursery phase. An advantageous characteristic of this species is the capacity to face temporary starvation, especially at early stages of development. This would help to design feeding strategies avoiding overfeeding, and diminishing operating costs in aquaculture. In this sense, during the last 8 years it was analyzed in this species the application of intermittent feeding, known as unfavorable feeding condition followed by daily feeding (favorable feeding condition). This alternative feeding protocol was used in the present study to trigger compensatory growth. Juveniles weighing 0.07 ± 0.01 g were distributed in 2 feeding regimes: C (control): juveniles fed daily during 60 days, and IF (intermittent feeding): juveniles deprived of food for 4 days and then fed for the following 4 days, these 4 days’ cycles were repeated during the first 20 days, on day 21 they were daily fed until day 60. Juveniles were stocked in each tank under 0.0096 crayfish/cm2 density, and zootechnical and biochemical parameters were evaluated throughout 60 days. A very suitable and similar survival (~ 65%) was maintained between feeding regimes, and the previously unfavorable feeding condition did not promote greater aggression among juveniles. There was a small compensatory response, but no recovery occurred probably because the favorable feeding condition was too short to trigger a strong compensatory response. Hyperphagia and improvement of feed conversion were not observed in juveniles of IF, suggesting that the high density was the key for these primary compensatory mechanisms to be absent. The competition for food, could have affected and changed the priority in allocating energy resources for accelerated growth. Lipids and glycogen content from body mass were strongly depleted after unfavorable feeding condition, but there was almost a 100% recovery during favorable feeding condition. We suggest that this response was detrimental to body mass as a priority and as a strategy for juveniles to extend survival during the ‘double’ nutritional stress caused by intermittent feeding and high density. The applicability of this alternative feeding strategy during an intensive production system can be viable, however, some changes must be considered in order to trigger compensatory growth. We suggest that a long-term of the favorable feeding condition could trigger a strong compensatory response if the high density tested in the study is maintained. We believe that juveniles of the current study had to face two nutritionally stressful factors: food restriction and high density. This could change the priority in allocation of energetic reserves and then the other suggestion would be to reduce the density if the same alternative feeding protocol is maintained.Fil: Stumpf, Liane. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Sarmiento Cárdenas, Paul Nicolás. Universidad Nacional de Colombia; ColombiaFil: Timpanaro, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Lopez, Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Crecimiento compensatorio en juveniles de la langosta de agua dulce pinzas rojas Cherax quadricarinatus (Decapoda, Parastacidae) y sus aplicaciones al cultivo

Un adecuado manejo alimenticio es determinante en el éxito en la acuicultura, dado que el consumo de alimentos influye directamente en el crecimiento y en la conversión alimenticia de los organismos. En una producción semi-intensiva e intensiva, los costos de alimentación representan hasta el 80 por ciento del total y por esta razón un manejo alimenticio alternativo al habitualmente empleado (alimentación diaria) puede ser una estrategia viable para reducir dichos costos. Explorar el crecimiento compensatorio en los organismos después de una reducción en la cantidad de alimento suministrado es una herramienta que puede ser utilizada para dicho fin. Los juveniles tempranos de la langosta de agua dulce Cherax quadricarinatus presentaron la capacidad de compensar tanto un moderado como prolongado periodo de restricción alimenticia (alimentación intermitente)y los mecanismos involucrados fueron la hiperfagia y la mayor conversión alimenticia. La recuperación del crecimiento fue total o parcial, dependiendo de la extensión del periodo de alimentación diaria post-restricción (periodo de recuperación). La aplicación de un período de recuperación fue imprescindible para inducir la capacidad compensatoria en esta especie. De los factores que modulan el crecimiento compensatorio, se observó que las dietas altamente proteicas no afectan dicha capacidad, así como las tres temperaturas ensayadas (inferior a la óptima, óptima y superior a la óptima, para el crecimiento de la especie). La talla tampoco afectó dicha capacidad, pero, influye en la severidad de la respuesta del periodo restricción y consecuentemente en el tiempo de recuperación. La restricción no causó severas alteraciones en la estructura, composición bioquímica y actividad de las enzimas digestivas de la glándula digestiva, lo que refleja que estos juveniles no presentarían deficiencias nutricionales. La alta supervivencia observada en los juveniles que compensan es otro indicador de que tanto la restricción alimenticia como la propia compensación no causan posteriores daños en el organismos

Compensatory Growth in Juveniles of Freshwater Redclaw Crayfish Cherax quadricarinatus Reared at Three Different Temperatures: Hyperphagia and Food Efficiency as Primary Mechanisms.

Feeding restriction, as a trigger for compensatory growth, might be considered an alternative viable strategy for minimizing waste as well as production costs. The study assessed whether juvenile redclaw crayfish Cherax quadricarinatus (initial weight 0.99 ± 0.03 g) was able to compensate for feeding restriction at different temperatures (23 ± 1, 27 ± 1 and 31 ± 1 ° C). Hyperphagia, food utilization efficiency, energetic reserves, and hepatopancreas structure were analyzed. Three temperatures and two feeding regimes (DF-daily fed throughout the experiment and CF- 4 days food deprivation followed by 4 days of feeding, intermittently) were tested. The restriction period was from day 1 to 45, and the recovery period was from day 45 to 90. The previously restricted crayfish held at 23, 27, and 31 ± 1 ° C displayed complete body weight catch-up through compensatory growth following the restriction period with depressed growth. The mechanisms that might explain this response were higher feed intake (hyperphagia), and increased food utilization efficiency. Hepatopancreatic lipids were used as a metabolic fuel and hepatosomatic index was reduced in the previously restricted crayfish, but recovery at the same level of unrestricted crayfish occurred after the shift to daily feeding. The highest temperature affected adversely growth, feed intake, food efficiency, and metabolism of crayfish, whereas the lowest temperature and feeding restriction induced a more efficient growth of the crayfish

Recovery growth of Cherax quadricarinatus juveniles fed on two high-protein diets: Effect of daily feeding following a cyclic feeding period on growth, biochemical composition and activity of digestive enzymes

Recovery growth of C. quadricarinatus juveniles was evaluated during a daily feeding period that followed a cyclic feeding period, by the analysis of the biochemical composition and structure of the hepatopancreas, and the activity of digestive enzymes. Two different diets were evaluated: diet A (49% crude protein) and diet B (38% crude protein), and juveniles were subjected to one of the following feeding regimes for each diet: DF, under which they were daily fed throughout the experimental period (120 days); and 4F/4D, under which they were fed for 4 days followed by 4 days of food deprivation in repeated cycles from day 1 to day 45, and daily fed from day 45 to day 120. Juveniles under the 4F/4D regime showed compensatory growth and reached the same body mass of control juveniles (i.e. complete catch-up growth) at the end of the experiment. This physiological response was not affected by the two high-protein diets tested, and it may be at least partly explained by an improved food conversion ratio, a similar ability to digest and absorb nutrients and an increased efficiency in protein digestion with respect to control juveniles. The 4F/4D regime had no negative effects on the nutritional state and health of red claw crayfish, which confirms the high tolerance of the species to food deprivation. The present results are important from an economical point of view since they show that it is possible to significantly reduce the amount of food offered in culture systems, and consequently reduce production costs, without affecting juvenile growth.Fil: Stumpf, Liane. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Tropea, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Lopez, Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Effect of temperature on biochemical composition, growth and reproduction of the ornamental red cherry shrimp Neocaridina heteropoda heteropoda (Decapoda, Caridea).

The effect of water temperature on biochemical composition, growth and reproduction of the ornamental shrimp, Neocaridina heteropoda heteropoda, was investigated to determine the optimum temperature for its culture. The effect of embryo incubation temperature on the subsequent performance of juveniles was also evaluated. Ovigerous females and recently hatched juveniles (JI) were maintained during egg incubation and for a 90-day period, respectively, at three temperatures (24, 28 and 32 °C). Incubation period increased with decreasing water temperature, but the number and size of JI were similar among treatments. At day 30 of the 90-day period, body weight and growth increment (GI) at 24 °C were lower than those at 28 and 32 °C. On subsequent days, GI at 24 °C exceeded that at 28 and 32 °C, leading to a similar body weight among treatments. These results suggest growth was delayed at 24 °C, but only for 30 days after hatching. The lipid concentration tended to be lowest, intermediate and highest at 28, 32 and 24 °C, respectively, possibly as a consequence of the metabolic processes involved in growth and ovarian maturation. Protein and glycogen concentrations were similar among treatments. Both the growth trajectory and biochemical composition of shrimps were affected by the temperature experienced during the 90-day growth period independently of the embryo incubation temperature. During the growth period, shrimps reached sexual maturity and mated, with the highest proportion of ovigerous females occurring at 28 °C. All the females that matured and mated at 32 °C lost their eggs, indicating a potentially stressful effect of high temperature on ovarian maturation. Based on high survival and good growth performance of shrimps at the three temperatures tested over the 90-day period it is concluded that N. heteropoda heteropoda is tolerant to a wide range of water temperatures, with 28 °C being the optimum temperature for its culture

Embryonic and larval development of the caridean shrimp Palaemon argentinus (Decapoda, Caridea): Effects of salinity and diet

The caridean shrimp Palaemon argentinus is a species of commercial and ecological interest. Its numerous larval stages, the lack of knowledge on their nutritional requirements, and their ability to survive in a wide range of salinities raise questions on the optimum conditions for larval rearing in captivity. The present study was aimed at evaluating embryonic development under different salinities and larval development under different combinations of salinities and diet regimes, in order to define alternative, cheaper culture conditions. We tested salinities usually encountered by the species in natural habitats (0.1, 1 and 5 ppt) and a highly protein-inert diet (Tetracolor®) as a potential replacement for live food (nauplii of Artemia salina). The incubation period and fecundity were similar among salinity treatments. Overall, the number of survival days and percentage of zoeae that moulted two, three and four times were higher when embryogenesis occurred at 5 ppt and when larvae were exposed to 5 ppt. These results suggest that the conditions experienced by embryos affect the performance of the first larval stages, and probably reflect the lower energetic requirements of zoeae to osmoregulate as water and haemolymph osmolarity become closer. On the other hand, larval performance was better when fed A. salina nauplii than Tetracolor®. The latter may not cover the nutritional requirements of zoeae or may have low digestibility due to insufficient enzymes in the undeveloped larval digestive system. Based on the present results, we conclude that a salinity of 5 ppt combined with a diet consisting of Artemia sp. nauplii is optimal for larval culture at early stages.Fil: Tropea, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Stumpf, Liane. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: López Greco, Laura S.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Spatial and temporal distribution of brachyuran crab larvae in Ibiraquera Lagoon, southern Brazil

This study investigated the abundance and composition of brachyuran crab larvae in the four subsystems of Ibiraquera Lagoon throughout the year. A colder and drier period was detected, contrasting with warm months during which salinity varied depending on rainfall and whether the sand bar was open or closed. The mean density of brachyuran zoeae was 540 ± 96 (SE) larvae · 100 m-3. Mean density was significantly (p<0.05) higher in three subsystems during April. Saco Lagoon (the outer subsystem) exhibited significantly higher (p<0.05) mean density in July, August, October, November and December 2004. Larvae from the families Portunidae, Menippidae, Panopeidae, Ocypodidae and Varunidae were found in Ibiraquera Lagoon. Neohelice granulata Dana, 1851 was the most abundant species. The high abundance of initial stage larvae showed the importance of Ibiraquera Lagoon as a nursery ground for crab species.Este estudo investigou a abundância e composição de larvas de Brachyura nos quatro subsistemas da Lagoa de Ibiraquera ao longo de um ano. Foi detectado um período frio e seco em contraste aos meses quentes, quando houve variação na salinidade em função das chuvas e da barra estar aberta ou fechada. A densidade média de zoés de Brachyura foi de 540 ± 96 (EP) larvas · 100 m-3. Abril apresentou densidade média significativamente (p<0,05) superior em três subsistemas. A Lagoa do Saco (o subsistema mais externo) apresentou densidade média significativamente (p<0,05) superior em julho, agosto, outubro, novembro e dezembro de 2004. Larvas pertencentes às famílias Portunidae, Menippidae, Panopeidae, Ocypodidae e Varunidae foram encontradas na Lagoa de Ibiraquera. Neohelice granulata Dana, 1851 foi a espécie mais abundante. A alta abundância de larvas em estágio inicial mostrou a importância da Lagoa de Ibiraquera como um berçário para espécies de caranguejos

Total lipids in the hepatopancreas of the redclaw crayfish <i>C</i>. <i>quadricarinatus</i> throughout the experiment.

<p>Temperature regimes: 23±1°C, 27±1°C and 31±1°C; feeding regimes: DF (juveniles fed daily throughout the experimental period) and CF (juveniles fed for 4 days followed by 4 days of food deprivation, intermittently during the first 45 days of the experimental period, and fed daily from day 45 to day 90), and days of the experiment: day 1 (beginning of the experiment), day 45 (the end of restriction period), day 60, 75 and 90 (recovery period). Letters “a,b,c” indicate significant differences interaction between feeding regime and time. Letters “A,B,C” indicate significant differences interaction between temperature and time.</p