Search results for "Animal Science and Zoology"
showing 10 items of 2095 documents
Effects of Sulfamethoxazole on Fertilization and Embryo Development in the Arbacia lixula Sea Urchin
2022
To date, drugs released into the aquatic environment are a real problem, and among antibiotics, sulfamethoxazole is the one most widely found in wastewater; thus, the evaluation of its toxicity on marine organisms is very important. This study, for the first time, investigates the in vitro effects of 4 concentrations of sulfamethoxazole (0.05 mg/L, 0.5 mg/L, 5 mg/L, 50 mg/L) on the fertilization and development of the sea urchin Arbacia lixula. The gametes were exposed to drugs in three different stages: simultaneously with, prior to, and post-fertilization. The results show a significant reduction in the percentage of fertilized oocytes at the highest drug concentrations. Moreover, an incr…
Demographic characterization and genetic variability of the Girgentana goat breed by the analysis of genealogical data
2004
The aim of this paper is to present an overview of the actual Sicilian Girgentana population structure by the analysis ofgenealogical data. Statistics show that in 1983 the population consisted of 30,000 Girgentana goats; ten years lateralmost 98% of the entire Girgentana population disappeared. The remaining population consists of 461 individuals (134males and 327 females), with 368 living animals. The effective population size is 380 individuals. The inbreeding rate pergeneration was equal to 0.13%. The average estimated inbreeding level within the living male population was equal to0.8% (0-15%); and the average inbreeding level within the living female population was equal to 0.7% (0-31%…
Review of studies of polymorphic blood systems in the Aymara indigenous population from Bolivia, Peru, and Chile.
1995
A review was made of all studies available from the literature referring to polymorphic blood systems of South American Aymara Indians. 33 original papers published up to 1990 covering a period of 45 years were summarized. Aymara samples were considered from a total of 55 localities in Bolivia, Peru, and Chile. Gene frequencies were tabulated for 21 polymorphic genetic systems comprising blood groups (AB0, MNSs, P, Rh, Lu, K, Le, Fy, Jk, Di), erythrocyte enzyme groups (AcP, 6PGD, PGM1, AK, ADA, EsD), and plasma protein groups (Hp, Tf, Gc, Gm, Km). Weighted average and range over all Aymara samples were computed for each blood system and compared with corresponding mean value and range in So…
Individual consistency and sex differences in migration strategies of Scopoli’s shearwaters Calonectris diomedea despite year differences
2014
Abstract Recently-developed capabilities for tracking the movements of individual birds over the course of a year or longer has provided increasing evidence for consistent individual differences in migration schedules and destinations. This raises questions about the relative importance of individual consistency versus flexibility in the evolution of migration strategies, and has implications for the ability of populations to respond to climatic change. Using geolocators, we tracked the migrations of Scopoli’s shearwaters Calonectris diomedea breeding in Linosa (Italy) across three years, and analysed timing and spatial aspects of their movements. Birds showed remarkable variation in their …
Segregation and co-occurrence of larval cestodes in freshwater fishes in the Bothnian Bay, Finland
1992
SUMMARYTwo autogenic (Triaenophorus crassus and T. nodulosus) and four allogenic (Diphyllobothrium latum, D. dendriticum, D. ditremum and Schistocephalus solidus) larval cestode species were found in 13 out of 31 fish species studied from the Bothnian Bay, NE Baltic. Gasterosteus aculeatus was the most heavily infected fish with 4 larval cestode species; for two of them (D. ditremum and S. solidus) the three-spined stickleback was found to be the required fish intermediate host. Among allogenic cestode species, those restricted to different definitive host species segregated their larval population in relation to the fish host, while, for example, D. ditremum and S. solidus, both maturing i…
Sex-Specific Habitat Selection in an Edge Habitat Specialist, the Western Barbastelle Bat
2011
The niche variation hypothesis suggests that a population's ability to react to varying environmental conditions depend on the behavioural variability of its members. However, most studies on bats, including the work on the habitat use of the western barbastelle bat, Barbastella barbastellus, have not considered sex-specific and individual variability. We studied the habitat use of 12 female and five male western barbastelle bats within their home ranges with respect to available habitat types by applying kernel methods and Euclidean distances. Our results indicate individual habitat preferences within and among sexes of this species. Females preferred deciduous forest and linear elements w…
Survival Rates of Young MagpiesPica picain a Mountain Population of Eastern Spain
2007
Abstract. The aim of this study was to estimate the survival of young Magpies between fledging and the next breeding season and to identify some of the factors affecting it. A total of 50 nestlings were colour-ringed in two breeding seasons in the valley of the Pitarque River (Teruel, E Spain), and were monitored weekly until May of the following year. 59 nestlings were also colour-ringed in two nearby localities (4–5 km) to detect possible dispersal to and from our study area. Mark-recapture analyses were used to estimate weekly survival, which was assumed to be constant for periods of four weeks in order to reduce the number of parameters. Models with the effect of time, age class, season…
Molecular phylogeny of treecreepers (Certhia) detects hidden diversity†
2006
We sequenced a part of the mitochondrial cytochrome-b gene from the seven treecreeper species, including 18 subspecies, to reconstruct the phylogeny of the genus Certhia. Species status of all seven species could be affirmed. Certhia discolor, C. himalayana, C. nipalensis, and C. tianquanensis, the species with relatively small distribution ranges in southeast Asia and simple territorial song, are found at the base of all phylogenetic trees, although without good support. A comparatively recent sister species of C. tianquanensis is C. nipalensis, replacing C. discolor as closest relative. Certhia familiaris, C. brachydactyla and C. americana form a derived set of species (again only weak su…
Harnessing productivity potential and rehabilitation of degraded sodic lands through Jatropha based intercropping systems
2016
Abstract This paper evaluates an intercropping model with J atropha curcas L. (JCL) as an alternative crop on degraded sodic land in north India. Monoculture of JCL has not proven economically viable in India in view of its poor yield; therefore, intercrops in between JCL plantations were tried to optimize land use efficiency. The results revealed that the planting of JCL at 3 × 3 m spacing with inter-cultivation of sweet basil–matricaria (SB-M) cropping system for four years was more economically viable than planting at 3 × 2 m spacing and the other rotations tested in the study. Improvements in soil properties in terms of soil pH, EC and organic carbon were found with the SB-M cropping sy…
Competition for breeding sites and site-dependent population regulation in a highly colonial seabird, the common guillemot Uria aalge
2004
Summary 1. The hypothesis of site-dependent population regulation predicts that birds utilize available nesting sites in a pre-emptive (ideal despotic) manner, leading to density dependence in heterogeneous habitats as poorer sites are used at higher population densities. At small population sizes adaptive site choice protects populations against fluctuations (the buffer effect). 2. Common guillemots Uria aalge (Pontoppidan) breed at high density on sea-cliffs. The population breeding on the Isle of May, Scotland increased by 60% between 1981 and 2000. A good nest-site is a prerequisite for successful breeding and there is much competition for the best sites. Throughout this period, site us…