Postlarvae of the cauque prawn Macrobrachium americanum were reared for 4 months under laboratory conditions at 20°C and 33°C. Four hundred 50‐d‐old postlarvae were stocked into eight 70‐L aquaria. A balanced commercial feed containing 40% protein was supplied daily at 9–20% of body weight during the first 2 months and at 3–5% of body weight during the final 2 months. Live brine shrimp Artemia spp. were also provided as food. The growth of the cauque prawns was greater at 33°C than at 20°C but did not differ significantly over the study period. Knowledge of cauque prawn rearing requirements under artificial conditions is important for the production of juveniles as stock for large‐scale prawn culture.

En México la mayor parte de los escasos los trabajos de las espe­cies microscópicas, pese a que poseen una gran importancia ecológica, económica y propie­daes de interés para el sector salud. En la zona de estudio, Área Natural Protegida Ejidos de Xo­chimilco y San Gregorio Atlapul­co, Ciudad de México, este es­quema se repite, encontrándose pocos trabajos sobre las microal­gas de los canales de Xochimilco y ninguno sobre San Gregorio Atlapulco. El objetivo del pre­sente trabajo fue elaborar un in­ventario de las microalgas de los canales de estas dos áreas. Para el caso de Xochimilco, se hizo una revisión bibliográfica exhaustiva, que abarcó de enero de 1933 a diciembre de 2014. Para el caso de San Gregorio Atlapulco, de­bido a que no había estudios previos, se realizó un muestreo en enero del 2013 en 17 estacio­nes distribuidas en toda la zona, con una red de arrastre de aber­tura de malla de 54 μm y con una botella van Dorn. Las muestras se preservaron con formalina al 4 % y con lugol al 1% respectiva­mente, obteniendo un total de 34 muestras. Se generó un listado de 370 especies de microalgas para toda el Área Natural Protegida, de las cuales, 36 % pertenecieron a Clorofitas; 24 % a Euglenofitas; 24 % a Diatomeas, 12 % a Ciano­procariotas, 3 % a Dinoflagelados y 1 % a Cromofitas, con 27 nuevos registros para San Gregorio Atlapul­co. Entre las especies registradas, Microcystis aeruginosa y Peridinium willei forman florecimientos algales tóxicos, por lo que se hace necesa­rio monitorear estos ecosistemas para prevenir sus efectos noci­vos, además de continuar con los estudios ficoflorísticos de la región. Archivo XML (SciELO)

Postlarvae of the giant Malaysian prawn Macrobrachium rosenbergii were reared for a 120‐d period under laboratory conditions at 20°C and 33°C. We stocked 480 50‐d‐old postlarvae in eight 70‐L aquaria. A balanced commercial feed containing 40% protein was supplied daily at 20% to 9% of body weight during the first 2 months and at 5% to 3% of body weight during the final 2 months. Live brine shrimp Artemia franciscana were also provided as a supplemental food. The growth of the giant Malaysian prawn was significantly greater at 33°C than at 20°C. Basic knowledge of giant Malaysian prawn rearing requirements under artificial conditions is important for the production of juveniles as stocks for large‐scale prawn culture.

Postlarvae of the giant Malaysian prawn Macrobrachium rosenbergii were reared for a 120‐d period under laboratory conditions at 20°C and 33°C to calculate survival. Ninety‐six 50‐d‐old postlarvae were stocked in eight 70‐L aquaria. A balanced commercial feed containing 40% protein was supplied daily at 20% to 9% of body weight during the first 2 months and at 5% to 3% of body weight during the final 2 months. Live brine shrimp Artemia franciscana were also provided as a supplemental food (10 organisms/L). Survival was 81% at 33°C and 67% at 20°C. The difference was statistically significant (P < 0.001) throughout the study period. Basic knowledge of rearing requirements under artificial conditions will be important for the production of juveniles as stock for large‐scale prawn culture.

We analyzed the combined effects of population density and presence or absence of shelters on growth and physiological performance of the crayfish Cambarellus montezumae. Three different densities-64, 144, and 208 crayfish per m 2 -with and without shelters were used. Growth; survival; metabolic rate; tissue glucose; and total lipid, triglyceride, nitrogen, and energy content were measured. Animals stocked at 64 and 144 per m 2 with shelter reached the highest body weight; those in groups without shelter had elevated levels of glucose (p < .05). Animals stocked at 144 per m 2 retained the most nitrogen and energy (p < .05). Overall, the combination of medium density with shelters produced the best performance.