ABSTRACT
Gambusia holbrooki es el pez de agua dulce con mayor distribución en Chile y el mundo, pero los estudios que abordan la morfología e histología hepática del pez son escasos. El hígado es utilizado para evidenciar efectos subletales de contaminantes ambientales y es preciso contar con una descripción histomorfológica del hígado para futuros estudios comparativos. El presente estudio tiene como objetivo describir patrones histomorfológicos del hígado de Gambusia holbrooki, para ello se colectaron 97 individuos adultos de los sistemas límnicos de los valles de Lluta y Azapa (Extremo norte de Chile), para observar patrones morfológicos comunes en ambas poblaciones, se utilizó técnicas histológicas de rutina e histoquímica. Las evidencias demostraron que el hígado contiene tejido pancreático y su arquitectura tisular es trabecular con mayor presencia de capilares sinusoides.
Gambusia holbrooki is the freshwater fish with the greatest distribution in Chile and the world. However, studies dealing with morphology and liver histology of fish are scarce. The liver commonly shows the sublethal effects of environmental pollutants and there should be a histomorphological description of the liver for further comparative studies. The present study aims to describe histomorphological patterns of the liver of Gambusia holbrooki. A total of 97 adult individual specimens were collected from the ecosystems in the valleys of Lluta and Azapa (Region of Arica and Parinacota), to observe patterns morphologically common in both populations. Routine histological and histochemical techniques were used for analysis. The evidence showed that the liver contains pancreatic tissue, and that tissue architecture is trabecular with greater presence of capillary sinusoids.
Subject(s)
Animals , Cyprinodontiformes/anatomy & histology , Liver/anatomy & histology , Pancreas/anatomy & histology , Chile , Fishes/anatomy & histologyABSTRACT
Objective The aim of this study was to investigate the masculinizing effects of progesterone ( PRO) exposure at different concentrations on the morphology of female mosquitofish (Gambusia affinis).Methods Immature female G.affinis individuals were put into static water with 0.5, 5, 50 and 500 nmol/L progesterone (n=56), respective-ly.In addition, control group and parallel groups were set up .After 42-day-long exposure, we measured four main indexes of the G.affinis:the body length, body weight, morphological changes in the anal fin 3rd fin and the 14, 15 and 16 verte-bral ribs.We also observed the state of ovarian development .Results The body lengths (BL) of experimental groups ex-posed at concentration of 50 and 500 nmol/L progesterone for 42 d showed significant differences , respectively ( P0.05).When exposed to 500 nmol/L PRO, the L, D and L:D values of the 14th, 15th and 16th vertebral ribs of the female G.affinis had very significant difference ( P<0.01 for all ) , respectively , indicating significant changes of morphological masculinization .Histological examination revealed that the developmental status of the ovaries of G.affinis in the experimental groups were to different degrees inhibited , and the nuclei appeared swelling in stage II and III oocytes . Conclusions The results of this study indicate apparent masculinizing effects of progesterone on immature female mosquit -ofish.