Deep‐water cirripedes colonizing dead shells of the cephalopod Nautilus macromphalus from New Caledonian waters     

John BUCKERIDGE  Tom&#x; KOÍ  Jn SCHL GL  Adam TOMA&#x;OVÝCH  Martina KOOV VESELSK 《Integrative zoology》2019,14(6):561-575

Fossil cephalopods are frequently encrusted by epibionts; however, determining whether encrustation occurred prior to or post‐mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post‐mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta, with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post‐mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.  相似文献   

Distemper Studies in Ferrets—Part VI: VI. Attempted Control of a Distem per Epidemic in a Ferret Colony with Tissue Va ccines and with Anti-serum     

E. A. Watson  L. M. Heath  P. J. G. Plummer 《Canadian journal of veterinary research》1942,6(11):324-331

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Distemper Studies in Ferrets—Part II: II. Tissue Vaccines prepared from Viscerotropic Distemper Virus     

E. A. Watson  L. M. Heath 《Canadian journal of veterinary research》1942,6(6):176-181

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Distemper Studies in Ferrets—Part III: III. Tissue Vaccines Prepared from Neurotropic Distemper Virus     

L. M. Heath  E. A. Watson 《Canadian journal of veterinary research》1942,6(7):204-207

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铁路路堑边坡植被恢复调查研究     

于燕华  艾应伟  辜彬  左元彬  刘浩  陈黎萍 《北方园艺》2008,(8)

植被在边坡生态系统中有着非常重要的作用,具有涵养水源、保持水土的功能.选择四川省成昆铁路沿线不同坡向的土质路堑边坡和岩质路堑边坡,对边坡植物群落的植被类型及其结构特征、边坡植被恢复物种组成及其特征进行了调查研究.结果表明:铁路边坡自然定居物种共103种,隶属48科,全部植物中,常绿灌木2种,落叶灌木9种,藤本植物7种,1 a生草本20种,2 a或2 a以上草本植物49种;蕨类植物15种.群落物种的丰富度虽然较高,但是主要由草本植物构成,结构层次简单,应该适当的在边坡上栽植灌木或小乔木,形成坡面上乔、灌、草或草、灌相互映的群落景观.  相似文献   

Subacute symmetrical necrotising encephalopathy in young lambs     

Scholes SF  Higgins RJ  Holliman A  Watson PJ  Hutchinson JP  Daniel R 《The Veterinary record》2007,160(22):775

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The efficacy of repeated applications of the urease inhibitor N-(n-butyl) thiophosphoric triamide for improving the efficiency of urea fertilizer utilization on temperate grassland   总被引：1，自引：0，他引：1  

C. J. Watson  P. Poland†  M. B. D. Allen† 《Grass and Forage Science》1998,53(2):137-145

The effect of N-(n-butyl) thiophosphoric triamide (nBTPT)-amended urea on herbage dry-matter yield and nitrogen offtake by perennial ryegrass (Lolium perenne) was studied in fifteen grassland experiments at two sites in Northern Ireland between 1994 and 1996. The dry-matter yield and N offtake with applied urea was only significantly lower than that with applied calcium ammonium nitrate (CAN) on four occasions. On these occasions nBTPT increased the yield from the application of urea making it almost as effective as CAN. There was no evidence of any adverse effect on grass production with repeated applications of nBTPT-amended urea over a 3-year period and no indication that its efficacy to reduce NH₃, loss from ureatreated swards declined when used repeatedly on the same soil.  相似文献   

Ivermectin-resistant Cooperia in cattle   总被引：3，自引：0，他引：3  

Coles GC  Watson CL  Anziani OS 《The Veterinary record》2001,148(9):283-284

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Effects of antimicrobial peptides on growth,feed utilization,serum biochemical indices and disease resistance of juvenile shrimp,Litopenaeus vannamei     

Watson Ray Gyan  Qihui Yang  Beiping Tan  Shyam Shyh Jan  Li Jiang  Shuyan Chi  Xiaohui Dong  Hongyu Liu  Zhang Shuang 《Aquaculture Research》2020,51(3):1222-1231

This experiment was conducted to assess the effects of antimicrobial peptides at different levels (Diet 1 (0%), Diet 2 (0.1%), Diet 3 (0.2%), Diet 4 (0.4%), Diet 5 (0.6%) and Diet 6 (1%)), on growth, serum biochemical indices and antioxidant effect, feed utilization and disease resistance in Litopeneaus vannamei. There were four replicates in each group in the experiment (mean weight = 0.21 ± 0.00 g) and also fed with their respective diets for 8 weeks. Growth performance compared with the control group (0%) significantly increased at first and then decreased among treatment groups (p < .05) whereas the survival rate ranged from 78% to 96%. No significant differences were observed in terms of moisture, crude protein and ash content, but there was a significant increase in crude lipid (p < .05). In serum, acid phosphatase, alkaline phosphatase, polyphenol oxidase, triglyceride, glucose and total cholesterol changed as compared with 0%. Total antioxidant capacity, glutathione peroxidase, catalase, superoxide dismutase and malondialdehyde were also different from 0%. Disease resistance was increased in shrimp among treatment groups with 0.4% recording the lowest mortality percentage of 37% after the challenge test. The results from the present study suggested that supplementation of AMP at 0.4% in shrimp diet can improve growth performance, antioxidants activities and innate immune response of Pacific whiteleg shrimp.  相似文献   

Assessing the sublethal impacts of anthropogenic stressors on fish: An energy‐budget approach     

Joseph W. Watson  Kieran Hyder  Robin Boyd  Robert Thorpe  Marc Simon Weltersbach  Keno Ferter  Steven J. Cooke  Shovonlal Roy  Richard M. Sibly 《Fish and Fisheries》2020,21(5):1034-1045

Fish are increasingly exposed to anthropogenic stressors from human developments and activities such as agriculture, urbanization, pollution and fishing. Lethal impacts of these stressors have been studied but the potential sublethal impacts, such as behavioural changes or reduced growth and reproduction, have often been overlooked. Unlike mortality, sublethal impacts are broad and difficult to quantify experimentally. As a result, sublethal impacts are often ignored in regulatory frameworks and management decisions. Building on established fish bioenergetic models, we present a general method for using the population consequences of disturbance framework to investigate how stressors influence ecologically relevant life processes of fish. We partition impact into the initial energetic cost of attempts to escape from the stressor, followed by the energetic impacts of any injury or behavioural change, and their consequent effects on life processes. As a case study, we assess the sublethal effects of catch and release angling for the European sea bass (Dicentrachus labrax, Moronidae), a popular target species for recreational fishers. The energy budget model described is not intended to replace existing experimental approaches but does provide a simple way to account for sublethal impacts in assessment of the impact of recreational fisheries and aid development of robust management approaches. There is potential to apply our energy budget approach to investigate a broad range of stressors and cumulative impacts for many fish species while also using individual‐based models to estimate population‐level impacts.  相似文献