Induced Maturation and Spawning of the Chinese Catfish Clarias fuscus     

Michael J. A.  Young Arlo W.  Fast Paul G.  Olin 《Journal of the World Aquaculture Society》1989,20(1):7-11

Chinese catfish ( Clarias fuscus ) were successfully spawned in Hawaii using human chorionic gonadotropin (HCG) at dosage rates of two and four international units (IU) per gram body weight. Fish not injected with HCG did not produce viable eggs. Successful spawns with HCG occurred between May and October. Hatch rates of up to 80% were obtained during June, July, and August for those fish given either a 2 or 4 IU per gram body weight injection of HCG. Fish spawned in either May or October yielded significantly higher hatch rates when injected with 4 rather than 2 IU per gram body weight. Fish held at elevated temperatures (28 to 30 C) prior to the normal spawning season developed significantly larger oocyte diameters, 60 days earlier than fish held under ambient temperature conditions (21.5 to 24 C). Photoperiod manipulation at ambient temperature conditions was associated with earlier oocyte maturation, but photoperiod effects were much less important than temperature.  相似文献   

The effects of a compressible plastic shoe - The Seattle shoe®- on the kinematics of the strides of galloping thoroughbred horses     

Patrick D. Wilson MS  DVM  Marc H. Ratzlaff DVM  PhD  Barrie D. Grant DVM  MS  Martha L. Hyde PhD  Olin K. Balch DVM  MS 《Journal of Equine Veterinary Science》1992,12(6):374-381

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Sex‐dependent responses of perch to changes in water clarity and temperature          下载免费PDF全文

Satu Estlander  Leena Nurminen  Tomáš Mrkvička  Mikko Olin  Martti Rask  Hannu Lehtonen 《Ecology of Freshwater Fish》2015,24(4):544-552

Rising temperatures and decreasing water transparency of lakes have strong wide ranging effects on fish. Fish responses to various changes in the environment are usually species‐dependent, but responses may also vary within species. In general, large individuals are considered to be more sensitive to environmental variation due to higher energy demand, than smaller individuals. Similarly, large individuals require more food to maintain bodily functions and are thus more sensitive to resource and food scarcity. These size‐specific responses to environmental gradients are also sex‐dependent in species that exhibit sexual size dimorphism (SSD). We studied in enclosures with short‐term experiments how rising temperatures and decreasing water transparency regulate the feeding rates of female and male European perch (Perca fluviatilis L.). To explore experimental results, we calculated perch SSD in nine lakes with varying environmental conditions using previously collected field data. The results of the experiments revealed that the combined effect of water transparency and temperature on the feeding rate of fish is gender‐dependent: feeding rate of females decreased more than that of males. The experimental results were also supported by field data that revealed a negative relation between water transparency and the magnitude of SSD in perch. Our results suggest that rising temperatures and decreasing water transparency may potentially decrease fish size in a sex‐dependent manner. As female size is one of the main demographic traits determining the reproductive success of a fish population, changing environments may have unexpected and far‐reaching consequences on fish population dynamics.  相似文献   

Migration strategies of brown trout (Salmo trutta) in a subarctic river system as revealed by stable isotope analysis     

Timo J. Ruokonen  Mikko Kiljunen  Jaakko Erkinaro  Panu Orell  Olli Sivonen  Eero Vestola  Roger I. Jones 《Ecology of Freshwater Fish》2019,28(1):53-61

We estimated the proportions of anadromous and freshwater‐resident brown trout (Salmo trutta) in different parts of the subarctic River Näätämöjoki/Neidenelva system (Finland and Norway) using carbon, nitrogen and hydrogen stable isotope analyses of archived scales as identifiers of migration strategy. Our results showed that carbon stable isotope values were the best predictor of migration strategy. Most individuals fell into two clearly distinct groups representing anadromous (47%) or freshwater‐resident (42%) individuals, but some fish had intermediate carbon values suggesting repeated movement between freshwater and the sea. The proportion of anadromous individuals decreased steadily with distance from the sea forming a spatial continuum in migration strategies which is probably maintained by the combination of several factors such as divergent availability of food resources, variable migration costs and genetic differences. These within‐catchment differences in migration strategies should be taken into account in fisheries management practices.  相似文献   

Colorado certified seed potato growers association     

W. H. Olin 《American Journal of Potato Research》1927,4(12):168-170

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A new world’s record potato yield     

W. H. Olin 《American Journal of Potato Research》1929,6(11):324-325

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A robust set of black walnut microsatellites for parentage and clonal identification     

Rodney L. Robichaud  Jeffrey C. Glaubitz  Olin E. Rhodes Jr.  Keith Woeste 《New Forests》2006,32(2):179-196

We describe the development of a robust and powerful suite of 12 microsatellite marker loci for use in genetic investigations of black walnut and related species. These 12 loci were chosen from a set of 17 candidate loci used to genotype 222 trees sampled from a 38-year-old black walnut progeny test. The 222 genotypes represent a sampling from the broad geographic distribution of the species. Analysis of the samples using the 12 loci revealed an average expected heterozygosity of 0.83, a combined probability of identity of 3×10⁻¹⁹, and a combined probability of exclusion for paternity analysis of >0.999. The 222 genotyped trees from the progeny test comprised 39 open-pollinated families, 29 of which (having at least five sampled progeny) were used to estimate the outcrossing rate for the progeny trial. The same 29 families were used to construct a Neighbor-Joining dendrogram based upon allele sharing between individuals. The multilocus estimate of the outcrossing rate was 100% (standard error of zero), higher than the 90% level found in previous studies at the embryo stage, suggesting that both artificial and natural selection against selfs may have occurred over the 38-year lifespan of the progeny trial. In the Neighbor-Joining dendrogram, the majority of the putative siblings grouped together in 21 out of the 29 families, showing that the microsatellites were able to discern most of the family structure in the dataset. Our results indicate that errors were sometimes committed during the establishment of the progeny test. This set of microsatellite loci clearly provides a powerful tool for future applications in black walnut.  相似文献   

Using airborne laser scanning data for detecting canopy gaps and their understory type in mature boreal forest     

Mikko Vehmas  Petteri Packalén  Matti Maltamo  Kalle Eerikäinen 《Annals of Forest Science》2011,68(4):825-835

• Introduction   

Canopy gap dynamics in old-growth boreal forests is a result of tree mortality caused by insects, diseases, or meteorological phenomena. Canopy gaps improve the possibilities of natural regeneration, and concentrations of decomposed deadwood are often found in these natural openings, which provide specific habitats for many deadwood-dependent species and organisms.  相似文献   

Hotspots in cold climate: Conservation value of woodland key habitats in boreal forests     

Jonna Timonen  Lena Gustafsson  Janne S. Kotiaho  Mikko Mönkkönen 《Biological conservation》2011,(8):2061-2067

The concept of Woodland Key Habitats (WKH, small-scaled presumed hotspots of biodiversity) has become an essential component of biodiversity conservation in Fennoscandian and Baltic forests. There have been debates over the importance of WKHs in relation to the conservation of biodiversity in production forests. We applied a systematic review protocol and meta-analysis to summarize knowledge on comparisons of biodiversity qualities, such as dead wood and species richness, between WKHs and production forests in relevant countries. We also summarized the knowledge on the impact of edge effects by comparing WKHs surrounded by production forests to WKHs surrounded by clear cuts. Studies had been conducted in Finland, Norway and Sweden. Based on our meta-analysis, WKHs seem to be relative hotspots for dead wood volume, diversity of dead wood, number of species and number of red-listed species. There were some differences also between countries in these biodiversity qualities. Only two studies compared WKHs surrounded by production forests and clear cuts, respectively. Hence, the capability of WKHs to maintain their original species composition and support species persistence over time remains to be addressed, as well as their role in relation to other conservation tools.  相似文献   

Cost-effective strategies to conserve boreal forest biodiversity and long-term landscape-level maintenance of habitats     

Mikko Mönkkönen  Pasi Reunanen  Janne S. Kotiaho  Artti Juutinen  Olli-Pekka Tikkanen  Jari Kouki 《European Journal of Forest Research》2011,130(5):717-727

Setting aside parcels of land is the main conservation strategy to reduce the rate of biodiversity loss worldwide. Because funding for biological conservation is limited, it is important to distinguish the most efficient ways to use it. Here, we assess implications of alternative measures to conserve biodiversity in managed boreal forest landscapes. We calculated four alternative spatio-temporal scenarios and compared these to the current management regime over 100-year time period. In the alternative scenarios, a fixed amount of funding was invested in (1) permanent large reserves (each tens of ha in size), (2) permanent small reserves (each a few ha in size), (3) temporary small reserves (based on 10-year contracts with private land owners), and (4) green-tree retention (small groups of trees retained on clear-cuts). To assess biodiversity implications, we used habitat suitability indices to calculate overall habitat availability for five groups of red-listed and habitat-specific species associated with decaying spruce logs. The possibilities for timber harvests did not differ among the scenarios, but biodiversity performance was different. The scenarios with permanent reserves tended to outperform other scenarios, suggesting that conservation policies based on permanent reserves are the most cost-efficient in the long term. Results, however, varied among time scales and species groups. In the short term, a strategy of investment in temporary small reserves was the most efficient. Habitat for species associated with old spruce dead-wood and preferring shade was rare throughout all simulations, and therefore, it is likely that these species cannot be sustained in managed forests. Species that live on fresh dead-wood and are associated with forest edges coped well in all scenarios suggesting that such species will persist in managed landscapes without additional conservation efforts. Explicit definition of conservation objectives and time frames for conservation action are thus prerequisites for successful conservation planning.  相似文献