Marked reared turbot, Scophthalmus maximus (L.) (594) were released onto an exposed beach nursery ground together with marked wild fish (438) of approximately the same size (4–6 cm TL) and were sampled at intervals for 38 days. A consistent ratio of marked wild: unmarked wild indicated that marking did not increase mortality. The wild 0‐group turbot population size was estimated at 1540 at the time of release, indicating that hatchery‐reared individuals could theoretically make a significant contribution to the local population size. However, the absolute and relative catches of the marked, reared fish were lower than those of the marked wild fish, and no reared fish were caught after 23 days. The higher mortality rate was attributed to both a smaller size and their hatchery‐reared origin. The population dynamics of the 1994–1995 year‐classes of wild turbot were also studied. Recruitment of post‐larvae (3 cm) to the beach started in March and continued until October. Population size peaked over the August–October period. Juvenile turbot remained on the nursery beach until June of the following year when they presumably emigrated to deeper water. During this 15‐month period their length increased from 3 to 12–15 cm.

RESUMENPara determinar la dieta de la lechuza de campanario (Tyto alba Scopoli, 1769) fueron colectadas 592 egagrópilas desde Enero hasta Diciembre de 2010, en la Estación Experimental del Instituto Nacional de Investigaciones Agrícolas, Calabozo, estado Guárico, Venezuela. Adicionalmente, en el sitio se registró la precipitación mensual durante la época seca y de lluvia. En el laboratorio, cada una de las egagrópilas fue medida para determinar tamaño y peso. Posteriormente fueron procesadas en seco para estimar la cantidad total de presas consumidas, especies en algunos grupos, número promedio de presas/egagrópila y las relaciones entre: número de presas consumidas y peso de las egagrópilas; y número de presas y la precipitación. Los promedios de peso, longitud y ancho de las egagrópilas fueron: 3,6 g ± 1,5, 2,7 cm ± 0,6 y 1,8 cm ± 0,4, respectivamente. La dieta de T. alba incluyó 847 presas, las cuales estuvieron conformadas por roedores (Zygodontomys brevicauda, Sigmodon alstoni, Holochilus sciureus y Oligoryomys sp.) (99,30%), aves (Cuculidae y Passeriformes) (0,23%) y murciélagos (Mollosus sp.) (0,47%). El promedio de individuos por egagrópila fue 1,5 ± 0,4. El peso de las egagrópilas fue proporcional a la cantidad de presas (r = 0,4377; P = 0,000). El número de presas consumidas y la precipitación estuvieron relacionados de manera inversa (r = -0,7304; P = 0,007), la composición de la dieta de la lechuza no varió en ambos periodos. T. alba mostró ser un cazador potencial de roedores, útil en control biológico de roedores en el cultivo de arroz en Venezuela. ABSTRACTIn order to determine the diet of the Barn Owl (Tyto alba Scopoli, 1769), 592 pellets were collected from January to December 2010 at one month interval, at the National Institute of Agricultural research's experimental center, in Calabozo, Guárico State, Venezuela. In addition, precipitation records during the dry and rainy seasons were obtained at the field research site. In the laboratory, each pellet was measured to determine size and weight. Then, each pellet was dry-processed to estimate total amount of consumed prey, species in some groups, the average number of prays per pellet and the relationship between the number of consumed preys and pellet´s weight and between number of preys and rainfall. Mean weight, length and width of pellets were: 3.6 g ± 1.5, 2.7 cm ± 0.6 and 1.8 cm ± 0.4, respectively. The owl´s diet included 847 preys, comprised by rodents (Zygodontomys brevicauda, Sigmodon alstoni, Holochilus sciureus and Oligoryomys sp.) (99.30 %), birds (Cuculidae and Passeriformes) (0.23 %) and bats (Mollosus sp.) (0.47 %). The average number of individuals per pellet was 1.5 ± 0.4. Pellets weight was directly related to number of prey (r = 0.4377; P = 0.000). Number of consumed prey and rainfall were inversely related (r = -0.7304; P = 0.007), however, diet composition was not affected by either rainy or dry season. T. alba showed to be a potential hunter of rodent and it can be useful as a biological agent against invasive rodent spe...

Neotropical Entomology 37(5): 591-596 (2008) Prostigmata and Mesostigmata Mites Associated to Litter from the University Park UCLA, Lara State, VenezuelaABSTRACT -Richness and abundance of Prostigmata and Mesostigmata mites inhabiting litter from a gallery forest in the university park at the Universidad Centroccidental Lisandro Alvarado (UCLA), Lara State, Venezuela were studied. Mites were captured using a pitfall trap along an 1800 m-transect from November 2000 to December 2001. Higher richness and abundance were registered for Prostigmata with 18 genera in eight families. In Mesostigmata, 11 genera included in six families were found. Of the 2085 Prostigmatan mites collected, 69.6% belonged to the Eupodidae genera Eupodes and Linopodes. Of the 398 Mesostigmata collected, 40.7% belonged to the Laelapidae; four genera of this family were found, being Hypoaspis and Cosmolaelaps the most abundant, with 28.6 and 8.0% of the Mesostigmata collected, respectively. Further studies, including Cryptostigmata, are required to improve the knowledge about the acarofauna diversity of soil-litter strata of the study area.KEY WORDS: Eupodes, Linopodes, Hypoaspis, Cosmolaelaps, richness, abundance RESUMEN -Se estudió la riqueza y abundancia de los géneros de ácaros Prostigmata y Mesostigmata habitantes de la hojarasca en un bosque de galería del Parque Universitario de la Universidad Centroccidental Lisandro Alvarado (UCLA), Estado Lara, Venezuela. Las capturas fueron realizadas utilizando trampas de caída ubicadas a lo largo de una transecta de 1800 m de longitud desde noviembre 2000 hasta diciembre 2001. La mayor riqueza y abundancia fueron registradas en el Orden Prostigmata con 18 géneros en ocho familias, mientras que en el Orden Mesostigmata se encontraron 11 géneros incluidos en seis familias. Del total de ácaros Prostigmata (2085), Eupodidae estuvo representada por los géneros Eupodes y Linopodes, que explicaron el 69,6% de la abundancia en la hojarasca. Para los Mesostigmata (398 individuos), Laelapidae fue la más abundante (40,7%) y de mayor riqueza con cuatro géneros encontrados, de los cuales Hypoaspis y Cosmolaelaps resultaron los más abundantes 28,6% y 8%, respectivamente. Se requiere más investigación para incluir a los Cryptostigmata y completar la información sobre la diversidad de la acarofauna del estrato suelo-hojarasca del Parque Universitario.