Search results for "Gambusia"

Experimental Study on the Diet of Mosquitofish (Gambusia holbrooki) under Different Ecological Conditions in a Shallow Lake

2004

We studied the diet of the eastern mosquitofish Gambusia holbrooki with in situ experimental mesocosms located in a shallow lake. Different nutrient concentrations (phosphorus and nitrogen) and fish population densities were tested. Our results confirm that it is a planktivorous species, with also a great ingestion of algae and detritus. Nutrient fertilization caused almost no changes in this species feeding behavior, but larger mosquitofish stocks induced a shift to zooplanktivory and a decline in detritivory. When macrophytes were present, the predation effect focused on zooplankton and plant-associated animals, otherwise predation on bottom macroinvertebrates increased. Females preyed up…

2002

We carried out enclosure experiments to assess the potential deleterious effects of the alien species common carp (Cyprinus carpio L.), mosquitofish (Gambusia holbrookii Gir.), and pumpkinseed sunfish (Lepomis gibbosus L.) on water quality and food web in a severely degraded floodplain wetland, the Spanish National Park Las Tablas de Daimiel. With addition of either carp or pumpkinseed sunfish, chlorophyll a and turbidity levels, as well as concentrations of total phosphorus and total nitrogen increased. The magnitude of this increase depended on fish species and was severest in the carp treatment. Mosquitofish did not significantly affect water quality. In the treatments with fish, cyclopo…

Fish communities and food web interactions in some shallow Mediterranean lakes

2003

Fish communities of five shallow Spanish Mediterranean lakes were studied and stomach content analysed to determine the foraging pattern of each species and the influence on the lake food web. Lakes ranged from 0.5 to 2300 ha with less than 3 m mean depth, while the trophic state varied from mesotrophy to hypertrophy. We fished during summer 2000 and 2001, and for one lake also during spring 2002. Almost no piscivores species were recorded and in general omnivorous species dominated independently of lake trophic state. Fish dietary differences were found among lakes and prey availabilities. Maximum fish biomass and diversity were found in the Albufera lake, where mugilids (Mugil cephalus an…

Microplastics ingestion by the exotic fish Gambusia holbrooki in two Mediterranean coastal lagoons

2020

Gambusia holbrooki es un pequeño pez Poecílido, de origen norteamericano que fue introducido a principios del siglo XX en humedales de la Península Ibérica para el control biológico de los mosquitos. Actualmente presenta poblaciones en muchos humedales y está considerada como una de las principales especies invasoras en la península. Estos peces se alimentan principalmente de invertebrados, pero son también susceptibles de ingerir y acumular residuos de microplásticos que presentan tamaños similares al tamaño de algunas de sus presas habituales. En el presente estudio analizamos los contenidos del tracto gastrointestinal de ejemplares adultos de esta especie, procedentes de dos lagunas cost…

Experimental Study on Diflubenzuron: Degradation in Freshwater and Bioconcentration in Mosquitofish Following Chronic Exposure

2013

ISSN: 2152-2197 ; ESSN: 2152-2219. Editeur commercial : Scientific Research Publishing; International audience; Diflubenzuron (DFB, trade name dimilin® 25 WP) is a chitin synthesis inhibitor widely used against forest insect pests in Algeria. Prior to implementation of these products as chemical agents for mosquito control, knowledge on their potential effects on non-target organisms and its behaviour in water are needed. Therefore, the present study was focused on DFB and aimed to use an HPLC procedure developed previously in order to obtain information on its degradation in freshwater and its bioconcentration in adult females of the fish Gambusia affinis (Cyprinodondiformes, Poeciliidae),…

Invasion success despite reduction of genetic diversity in the European populations of eastern mosquitofish (Gambusia holbrooki)

2006

The introduction of a few individuals to new, isolated habitats (founder effect) is expected to reduce the genetic variability of a population. At the beginning of the last century a few eastern mosquitofish (Gambusia holbrooki) individuals were introduced to Southern Europe from North America to control malaria‐carrying mosquitoes. We studied the effect of this severe bottleneck on genetic variability in four populations of eastern mosquitofish introduced to Spain and Italy in the early 1900s and compared them to a native population in North America. Using amplified polymorphic DNA–polymerase chain reaction (RADP–PCR) we found a strong reduction of genetic diversity, in terms of both numbe…

La eutrofización en los lagos someros mediterráneos: aplicabilidad de la DMA y un caso de estudio experimental en mesocosmos

2013

Este trabajo se centra en su mayor parte en el estudio de los efectos más directos de la eutrofización en los lagos someros mediterráneos y en el funcionamiento ecológico de este tipo de lagos cuando son sometidos a un incremento en la carga de nutrientes y a la presencia de peces. El trabajo también aborda el estudio de las metodologías más apropiadas para la evaluación de estos lagos mediante la aplicación de la Directiva Marco Europea del Agua (DMA). Este trabajo tiene dos secciones principales, siendo cada una parte de dos proyectos europeos que incluían lagos someros de distintas localidades europeas:(1) El proyecto SWALE que pretendía establecer las diferencias en el funcionamiento ec…