Growth, mortality and migratory pattern of white shrimp (Litopenaeus vannamei, Crustacea, Penaeidae) in the Carretas-Pereyra coastal lagoon system, Mexico

The growth, mortality and migration pattern of the population of Litopenaeus vannamei Boone 1931 in the Carretas-Pereyra coastal lagoon system, Mexico, were studied. The shrimp spatial distribution and abundance were analyzed in relation to salinity, water temperature, and substrate. A total of 2 669 shrimps was collected at 22 sites sampled monthly from March 2004 to August 2005. Juvenile shrimps of L. vannamei were present in the coastal lagoon system throughout the year, reaching densities from 0.001 to 0.302 ind/m². The estimated daily growth rate was 0.06 to 0.27 mm carapace length (CL). No significant seasonal differences were appreciated. Weekly total mortality (Z) was between 0.04 and 0.34. Recruits, juveniles and sub-adults displayed a bimodal distributional pattern regulated by the prevailing conditions during the dry season. The peak abundance of juvenile stages occurred in December-January and March-May. The abundance presented an inverse correlation with salinity (r=-0.42; p<0.05) and a positive correlation (r=0.44; p<0.05) with silt content. No clear correlation was distinguished for emigration size with season of the year or water temperature. Rev. Biol. Trop. 56 (2): 523-533. Epub 2008 June 30.

Se estudió el crecimiento, la mortalidad y el patrón de migración del camarón Litopenaeus vannamei Boone 1931 en el sistema lagunar costero Carretas Pereyra, México. La distribución espacial y la abundancia fueron analizadas con relación a la salinidad, temperatura y substrato. De marzo de 2004 a agosto de 2005 se recolectó un total de 2669 camarones con un muestreo mensual en 22 sitios. Los jóvenes se hallaron todo el año en el sistema lagunar costero, con densidades entre 0.001 y 0.302 ind/m². La tasa de crecimiento diaria fue de 0.06 a 0.27 mm longitud del cefalotórax (CL) y no se apreciaron diferencias significativas entre estaciones. La mortalidad total (Z) semanal estuvo entre 0.04 y 0.34. Reclutas, jóvenes y subadultos presentan un patrón de distribución bimodal regulado por las condiciones prevalecientes durante la estación de estío. Los valores máximos de abundancia de los estadios juveniles se presentan en diciembre-enero y marzo-mayo. La abundancia presentó una correlación significativa inversa con la salinidad (r=-0.42; p<0.05) y positiva (r=0.44; p<0.05) con el contenido de limo. No se distinguió una clara correlación entre la talla de emigración, la estación del año y la temperatura del agua.

Growth, mortality and migratory pattern of white shrimp (Litopenaeus vannamei, Crustacea, Penaeidae) in the Carretas-Pereyra coastal lagoon system, Mexico.

The growth, mortality and migration pattern of the population of Litopenaeus vannamei Boone 1931 in the Carretas-Pereyra coastal lagoon system, Mexico, were studied. The shrimp spatial distribution and abundance were analyzed in relation to salinity, water temperature, and substrate. A total of 2669 shrimps was collected at 22 sites sampled monthly from March 2004 to August 2005. Juvenile shrimps of L. vannamei were present in the coastal lagoon system throughout the year, reaching densities from 0.001 to 0.302 ind/m2. The estimated daily growth rate was 0.06 to 0.27 mm carapace length (CL). No significant seasonal differences were appreciated. Weekly total mortality (Z) was between 0.04 and 0.34. Recruits, juveniles and sub-adults displayed a bimodal distributional pattern regulated by the prevailing conditions during the dry season. The peak abundance of juvenile stages occurred in December-January and March-May. The abundance presented an inverse correlation with salinity (r = -0.42; p<0.05) and a positive correlation (r=0.44; p<0.05) with silt content. No clear correlation was distinguished for emigration size with season of the year or water temperature.

Reproductive biology of Oreochromis niloticus (Perciformes: Cichlidae) at Emiliano Zapata dam, Morelos, Mexico

The reproductive season of tilapia was studied by monthly samplings at Emiliano Zapata dam, Morelos State, Mexico. From February 1999 through February 2000 a sample of 50 fish was taken from the commercial catch (castnet, 6.5 cm of mesh size). The observed sex ratio was 1:1.29 (females:males) (2=10.26; p<0.05). The tilapia reached maturity at 151.3 mm (females) and 152.0 mm (males) of total length. Rainy (August) and dry (February) seasons were determined as the breeding period. Fecundity variation was better correlated with length (r=0.7473; p<0.002) than with weight (r=0.7395; p<0.002). The fecundity ranged between 243 and 847 oocytes per fish, with egg diameter from 300 to 3 700 µm. Intensive breeding activity in August and February coincide with phytoplankton biomass increase

Se analizó la biología reproductiva de la tilapia en la presa Emiliano Zapata, Morelos, México. Para esto se realizaron muestreos de febrero 1999 a febrero 2000. Se tomaron 50 organismos mensuales de la captura comercial obtenidos con una atarraya de 6.5 cm de luz de malla. La proporción sexual fue de1:1.29 hembras:machos (2=10.26; p<0.05). La madurez sexual se alcanza a los 151.3 mm (hembras) y a los 152.0 mm (machos) de longitud total. Se detectaron dos épocas de reproducción para la especie: durante la estación lluviosa (agosto) y durante la estación de secas (febrero). La fecundidad relativa presentó mayor correlación con la longitud (r=0.7473; p<0.002) que con el peso (r=0.7395; p<0.002). Por otra parte, el intervalo para la fecundidad osciló entre 243 y 847 ovocitos por pez, con diámetros de 300 a 3 700 µm. Asimismo, la actividad reproductiva de la especie en Agosto y Febrero, coincide con el incremento de biomasa fitoplanctónica

Reproductive biology of Oreochromis niloticus (Perciformes: Cichlidae) at Emiliano Zapata dam, Morelos, Mexico.

The reproductive season of tilapia was studied by monthly samplings at Emiliano Zapata dam, Morelos State, Mexico. From February 1999 through February 2000 a sample of 50 fish was taken from the commercial catch (castnet, 6.5 cm of mesh size). The observed sex ratio was 1:1.29 (females:males) (chi(2)=10.26; p<0.05). The tilapia reached maturity at 151.3 mm (females) and 152.0 mm (males) of total length. Rainy (August) and dry (February) seasons were determined as the breeding period. Fecundity variation was better correlated with length (r=0.7473: p<0.002) than with weight (r=0.7395; p<0.002). The fecundity ranged between 243 and 847 oocytes per fish, with egg diameter from 300 to 3 700 microm. Intensive breeding activity in August and February coincide with phytoplankton biomass increase.

[Intracellular pH changes induced by sclerosing agents in peritoneal fibroblasts]. / Alteraciones del pH intracelular en fibroblastos peritoneales inducida por factores implicados en la esclerosis peritoneal.

UNLABELLED: Sclerosing encapsulating peritonitis secondary to peritoneal dialysis has been associated to acetate-containing dialysis fluids, hypertonic glucose and disinfectants. Physiopathologic mechanisms of fibrotic proliferation that implicate those agents are not totally explained. With an experimental approach using cultured peritoneal fibroblasts, we have studied intracellular pH changes and Na+/H+ antiporter activity under cells perfusion with peritoneal dialysis liquids containing acetate, lactate, hypertonic glucose and interleukin-1. All experiments were performed at extracellular pH 7.4 and physiologic HCO3/CO2 concentration. RESULTS: 35 mM acetate produced a huge intracellular acidosis (ipH = 6.80 +/- 0.08). Lactate effect was less important (6.95 +/- 0.07), with a slow ipH recovery in about 30 min in both cases. IL-1, 10(-6) M also reduced ipH to 7.10 +/- 0.03. Acidosis was linked to Ca2+ outflow via Ca/H exchange and was blocked with Cd 20 nM. Extracellular Na = 0 and amiloride totally inhibited ipH recovery after acetate, lactate, or interleukin-induced acidosis. Hypertonic glucose perfusion increased ipH (7.31 +/- 0.06) for 5-7 min. This increase was also inhibited by amiloride or extracellular Na absence. Na+/H+ exchanger activity increased to 58%, and kept activated after ipH recovery. In conclusion, acetate, hypertonic glucose and IL-1 showed the common effect of stimulating the sodium-proton exchanger by different mechanisms, giving a possibility of potentiation. Activated Na+/H+ exchanger may act as a signal-transduction increasing fibroblast proliferation and explaining the cellular mechanism of sclerosing peritonitis.

Reproductive aspects of Oreochromis niloticus (Perciformes: Cichlidae) at Coatetelco Lake, Morelos, Mexico

Sex ratio, size at maturity, maturity stages, fecundity and egg diameter of Oreochromis niloticus from Coatetelco Lake, Morelos State, Mexico, were studied from January to December 1993. Sex ratio (male:female) was approximately 1:1.02. Length at maturity was 117 mm (males) and 120 mm (females). The fecundity ranged between 104 and 709 eggs, with egg diameter from 1,000 to 3,000 microns. The gonadosomatic and hepatosomatic index indicate that the species breeds during summer and winter.

Reproductive aspects of Oreochromis niloticus (Perciformes: Cichlidae) at Coatetelco Lake, Morelos, Mexico.

Sex ratio, size at maturity, maturity stages, fecundity and egg diameter of Oreochromis niloticus from Coatetelco Lake, Morelos State, Mexico, were studied from January to December 1993. Sex ratio (male:female) was approximately 1:1.02. Length at maturity was 117 mm (males) and 120 mm (females). The fecundity ranged between 104 and 709 eggs, with egg diameter from 1,000 to 3,000 microns. The gonadosomatic and hepatosomatic index indicate that the species breeds during summer and winter.

[Changes in heroin administration route and frequency of human immunodeficiency virus infection]. / Cambios en la vía de administración de la heroína y frecuencia de infección por el virus de la inmunodeficiencia humana.

BACKGROUND: Self-administration of drugs by different intravenous routes may induce a reduction in the organic complications of drug addiction (DA). The aim of this study was to evaluate the changes in the way of drug administration in a series of DA individuals in the province of Cádiz, Spain, and the evolution of the frequency of infection by the human immunodeficiency virus (HIV) in these patients. METHODS: The reports of all the drug users from the province of Cádiz admitted to the Detoxication Unit of the Hospital Punta de Europa in Algeciras, from January, 1989 to July, 1993 were reviewed. At the time of admission many data were evaluated, fundamentally the main route of drug administration, and anti-HIV seropositivity. RESULTS: Seven hundred ten drug users were included in the study. Ninety-seven percent used mainly heroin. The route of drug administration on admission was intravenous in 56.1%, pulmonary in 39.7%, inhalatory in 3.2% and oral in 0.8%. Forty-one point seven percent patients were seropositive for HIV. The frequency of the use of the intravenous route throughout the semesters analyzed was I/89: 85.7%, II/89: 89.6%, I/90: 80%, II/90: 80.8%, I/91: 59.8%, II/91: 50%, I/92: 44.9%, II/92: 39%, I/93: 34.3% (p < 0.00001). The use of the respiratory route significantly increased. The percentage of anti HIV positivity in the drug users evaluated was 67.4, 80.8, 56.4, 46.9, 40.7, 34.1, 30.6, 36.3, 23.2% (p < 0.00001), respectively for the same periods. The decrease in the use of the intravenous route and the reduction in anti HIV seropositivity demonstrated a correlation coefficient of 0.91 with a confidence interval from 0.62 to 0.98 (p < 0.05). CONCLUSIONS: The decrease, over time, in the use of the intravenous route for heroin administration in the collective analyzed was significantly associated with a decrease in HIV infection in these patients.

[Serum adenosine deaminase in human immunodeficiency virus infection. Its relationship with CD4+ lymphocytes and beta 2-microglobulin]. / Adenosina desaminasa sérica en la infección por el virus de la inmunodeficiencia humana. Su relación con los linfocitos CD4+ y la beta 2-microglobulina.

BACKGROUND: The activity of the deaminase adenosine enzyme (ADA) has principally been related with the functionalism and replication of the T lymphocytes. Its serum behavior and possible clinical use in infection by the human immunodeficiency virus type 1 (HIV-1) was studied. METHODS: A multicenter study in which the serum values of ADA were examined and compared with those of two reference markers (CD4+ lymphocytes and beta 2-microglobulin) in 35 presumably healthy donors used as controls, in 60 intravenous drug users (IVDU) seronegative for HIV-1, in 69 HIV-1 asymptomatic seropositive intravenous drug users (HIV-1+) and in 48 patients with AIDS. RESULTS: The serum values of ADA were as follows: control group 10.9 +/- 4.2 U/I; IVDU group 17.6 +/- 7.4 U/I; asymptomatic HIV-1+ group 32.7 +/- 10.2 U/I, AIDS group 46.2 +/- 18.2 U/I. Differences between the different groups were statistically significant in themselves and in relation to the control group. A negative correlation was observed (r = 0.47, p < 0.01) with the number of CD4+ lymphocytes and a positive correlation was found with respect to beta 2-microglobulin (r = 0.76, p < 0.001). The values of serum ADA activity in patients with AIDS and tuberculosis (47.4 +/- 17.2 U/I) were not significantly higher (p < 0.05) to those of patients with AIDS without this second infection (45.9 +/- 19.3 U/I). CONCLUSIONS: Serum deaminase adenosine may be a useful evolutive marker for human immunodeficiency virus type 1 given that its activity increases significantly in infected patients in agreement with the grade of immunodeficiency and its values correlate well with those of reference markers (CD4+ lymphocytes and beta 2-microglobulin).