This thesis examines the relationship between insect life history and behavioural decisions and underlying cellular biochemistry, with particular focus on bethylid parasitoid wasps in the genus Goniozus. This comprises the first major body of work attempting to draw links between the underlying metabolome of an organism and its behaviour. This thesis further optimised the first known example of a combined LC-MS and NMR metabolomic approach capable of analysing extremely low biomass samples (<1 mg), a vital requirement when studying the behaviour of individual organisms. Part 1 of this thesis details the optimisation and validation of this metabolomic approach, whilst also examining the effects of aging on the metabolome of adult Goniozus wasps. Part 2 applies this approach to examine the effects of diet, host species and host aging on Goniozus wasp behaviour and biochemistry. Comparisons of the metabolomes of starved and honey fed wasps indicate that G. legneri is capable of utilising a carbohydrate rich diet as an energy source. Aged honey fed wasps possessed higher levels of large storage lipids, such as tri- and diacylglycerides, than starved wasps of the same age. Metabolomic analysis also detected a legacy effect on the metabolome of G. legneri associated with differences in the species of host each wasp was reared on. A similar legacy effect was confirmed when examining the metabolomes of wasps reared on artificially aged hosts. Whilst Goniozus wasp oviposition behaviour was altered by the species of host presented, no links between changes in a wasp’s metabolome and its resulting contest behaviour were found. Part 3 of this thesis examines the morphological, behavioural and chemical mimicry of another wasp, the hyperparasitoid Gelis agilis. G. agilis demonstrated an enhanced predation avoidance rate compared with control species, similar to that of the black garden ant Lasius niger. Agitation of G. agilis also resulted in the chemical emission of a known ant alarm pheromone.

A study of the secondary metabolism of two nudibranchs and one soft coral has led to the isolation of eighteen new and two known secondary metabolites. The structures of all compounds were determined by a combination of the interpretation of spectral data, chemical degradations and interconversions, and single crystal x-ray diffraction analysis. The British Columbian dorid nudibranch Diaulula sandiegensis yielded two new steroidal metabolites, diaulusterols A (41) and B (42). The 25-(3-hydroxybutanoate) residue of diaulusterol A (41) and the 2α,3α-diol array of both 41 and 42 are not commonly encountered in naturally occurring steroids. Both metabolites exhibited considerable antibacterial and antifungal activity. Steroid 41 exhibited fish antifeedant activity. The relative concentration of 4.1 and 42 in the skin extracts of D. sandiegensis appears to be related to the animals' seasonal abundance. Extracts of the British Columbian soft coral Gersemia rubiformis yielded a series of ten diterpenes possessing cembrane (170-175), pseudopterane (167-169) and gersolane (176) carbon skeletons. The structure of an eleventh diterpene remains unresolved. In addition, the structure of a degraded diterpene possessing a 13-membered ring (177) is tentatively proposed. G. rubiformis represents the first example of a soft coral to yield pseudopterane diterpenes. The organism is the first to contain cembrane, pseudopterane and gersolane metabolites, a fact which has biogenetic implications. Two new sesquiterpenes were also isolated. Tochuinyl acetate (165) and dihydrotochuinyl acetate (166) represent the first examples of cuparane sesquiterpenes to be isolated from a soft coral. A biogenesis is proposed. Metabolite 166 exhibited fish antifeedant activity. Investigations of Gersemia rubiformis collected in Newfoundland waters revealed that the secondary metabolism differed from west coast specimens. The isolation of the new unstable sesquiterpene (+)-β-cubebene-3-acetate (178) resulted. Skin extracts of the dendronotoid nudibranch Toquina tetraquetra were examined in an attempt to correlate its feeding dependency and lack of predation to the presence of allomones. Metabolites 165, 166, 170, 179 and the new butanoate diterpene 180 could be traced to the coelenterates which make up the animal's diet. Tochuinyl acetate (165), dihydrotochuinyl acetate (166) and rubifolide (170) were previously found in extracts of Gersemia rubiformis. Ptilosarcenone (179) has been reported as one of the major metabolites of the sea pen Ptilosarcus gurneyi²¹³. The exact origin of a sixth metabolite, pukalide (63), remains unknown. It is proposed that Tochuina tetraquetra selectively sequesters dietary metabolites for defensive purposes. / Science, Faculty of / Chemistry, Department of / Graduate

Marine organisms show potential as sources for novel, biologically and pharmacologically active, secondary metabolites. Examination of three nudibranch and one bryozoan species for biologically active metabolites has led to the isolation and structural elucidation of nine new and two known secondary metabolites. The structures of all the compounds were determined by using a combination of spectral analysis, chemical interconversion, synthesis, and single-crystal X-ray diffraction analysis. The British Columbian dorid nudibranch Acanthodoris nanaimoensis yielded three new sesquiterpenoids. The structures of nanaimoal (61) , acanthodoral (64) , and isoacanthodoral (65) represent novel sesquiterpenoid carbon skeletons. The natural mixture of aldehydes 61, 64, and 65 exhibited antibacterial and antifungal activity. From Aldisa cooperi, two ∆⁴-3-ketosteroidal acids 23 and 24, and glycerol ether 25 were isolated. Acid 23 showed feeding deterrent activity against fish. The dendronotid nudibranch Meli be leonina gave 2,6-dimethy1-5-heptenal 53 and 2,6-dimethyl-5-heptenoic acid 54. The aldehyde 53 was responsible for the "grapefruit like" odour of the nudibranch. The bryozoan Phidolopora pacifica was examined in an attempt to correlate the absence of surface fouling, in the field, with the presence of biologically active secondary metabolites. The purine alkaloids 179 and 180, which contain the rare naturally occurring nitro functionality, were responsible for much of the antifungal and antialgal activity of the crude extracts. Three nitrophenols 181, 189, and 209 were also isolated from P. pacifica. Nitrophenol 181 had been previously shown to inhibit chloroplast development both in green plants and in the unicellular algae Euglena sp. / Science, Faculty of / Chemistry, Department of / Graduate

Kantzoner längst vattendrag i skogen är en komplex och artrik miljö som är av stor vikt för flertalet arter. Ett stort hot mot kantzoner är skogsindustrin och främst kalavverkning som kan ha en negativ effekt på hela ekosystem. Det finns idag ingen lag som kräver att kantzoner längst vattendrag bevaras med det rekommenderas. En kalavverkning kan minska tillförsel av nedfall som terrestra invertebrater till vattendraget med så mycket som en tredjedel, även om en kantzon på 30 meter bevaras. Tillförsel av terrestra invertebrater till vattendragen är av stor vikt då det kan utgöra upp till 50% av energiintaget hos fisk. Frånvaro av terrestra invertebrater skulle kunna leda till en ökad biomassa av perifyton och en minskad tillväxt hos fisk. För att undersöka om kantzonernas bredd längst vattendrag i skogen påverkar nedfallet av invertebrater till vattendraget genomförs en fältstudie. 17 lokaler har besökts i studien där fällor placerats ut på två ställen längst en 100 meters sträcka. Fällornas innehåll sorterades sedan till ordning. Krontäckningen kontrollerades även på varje lokal och vegetationen inventerades. Regressionsanalys, HCA, PCA och korrelationsanalys utfördes. Efter analys indikerade resultatet på att det är vegetationens sammansättning som är den viktigaste faktorn. Lokaler med mycket örter och bar jord hade en större förekomst av individer och ordningar. Detta kan bero på att ett kalhygge släpper in mer ljus och värme. Avverkade områden kan ha högre näringsvärde vilket kan gynna flertalet arter. Lokalerna som besöktes i studien var förhållandevis ung produktionsskog vilket kan även ha spelat in då dessa skogar har en relativt låg biodiversitet. Vid planering och konstruktion av kantzoner längst skogliga vattendrag bör det prioriteras att skapa kantzoner av god ekologisk status. / Riparian forests is a complex and species-rich environment that is of great importance for many species. A big threat to the riparian forests is the forest industry and mainly clear-cut felling, which can have a negative effect on entire ecosystems. There is currently no law that requires that buffer zones along forest streams be preserved, it is however recommended. A clear cut can reduce the input of to the stream by as much as a third, even if a buffer zone of 30 meters is preserved. The input of terrestrial invertebrates to streams is of great importance as it can account for up to 50% of the energy intake of fish. An absence of terrestrial invertebrates could lead to increased periphyton biomass and reduced growth in fish. A field study was performed to investigate if the buffer width effects the input of terrestrial invertebrates. 17 sites were visited where traps were placed at two placed along a 100 stretch. The content of the traps was then sorted into order. The canopy cover was controlled, and the vegetation was inventoried. Regression analysis, HCA, PCA and correlation analysis was performed. After analysis, the results indicated that it is the composition of the vegetation that is the most important factor. Sites with a lot of herbs and bare soil had a greater presence of individuals and orders. This may be because clear cuts let in mor e light and heat, they can also have a higher nutritional value which can benefit several species. The sites visited in the study were relatively young production forest which also may have played a role as these forests have a relatively low biodiversity. When planning and constructing buffer zones along forest streams, it should be prioritized to creating buffer zones of good ecological status.

The overall objective of this study was to identify trends of sediment nutrients and benthic macro-invertebrates in recreational fishing ponds. The Ekman dredge and the Yabby pump, also were compared for benthic macro-invertebrate sampling effectiveness. Large ranges in the coefficient of variation for Pw (52 – 123.9), C:N (13.4 – 124), density (61.5 – 98.5), and diversity (67 – 142) indicated significant spatial variability within and among ponds. Invertebrate familial diversity was the only variable that did not show any significant temporal variation (H = 4.31, P = 0.230). Results from the gear comparison indicated no differences between the Ekman dredge and Yabby pump (3 pulls); however, showed the Ekman dredge was more effective than the Yabby pump (12 pulls) (Z = -1.796, P = 0.073) indicating potential gear saturation. Although these data supported no discernable patterns between sediment nutrients and macro-invertebrates, it provided an opportunity to detail an operational framework for future studies.

No description available.

Nickel (Ni) is a metal that is anthropogenically enriched in aquatic settings. It has been reported as having three main modes of toxicity in freshwater animals (ionoregulatory disturbance, respiratory impairment, and the generation of oxidative damage), but there is little understanding of Ni toxicity in marine and estuarine environments. The mechanism(s) of Ni uptake and toxicity were investigated using three model species (adult green shore crab, Carcinus maenas; adult Atlantic killifish, Fundulus heteroclitus; early life-stages of the New Zealand sea urchin Evechinus chloroticus). In crabs, sea water protected against Ni accumulation and toxicity. In more dilute salinities, however, all three modes of Ni toxicity were identified at a sub-lethal level, with effects noted at Ni exposure levels as low as 8.2 µg/L, the US EPA environmental regulatory limit. In killifish, similar protective effects of SW were observed, however this species was much more resilient to Ni toxicity, with only minor changes in ionoregulation and oxidative stress noted, and no evidence of respiratory toxicity. Sea urchin larvae were found to be the most sensitive marine organisms to Ni toxicity yet reported, with a 96 h median effect concentration of 14.1 µg/L measured. Toxicity in this species was related to Ni impairment of calcium influx, consistent with proposed mechanisms of uptake observed in the other two models. Overall, the elevated ion levels associated with salinity were shown to be protective, suggesting a role for water chemistry in modifying Ni accumulation. However, physiology, which varies between species, developmental stages, and as a function of environmental salinity, also influenced organism sensitivity to Ni. These data contribute novel information regarding the relationships between water chemistry, Ni accumulation, and Ni toxicity, and as such, will be integral in the future development of predictive modelling tools for protecting marine and estuarine animals against environmental Ni. / Thesis / Doctor of Science (PhD)

No description available.

No description available.

Stream ecosystems are influenced by the surrounding landscape, and agriculture within their catchments has changed many characteristics of streams. Agriculture has been a prominent land use activity in the southern Appalachian Mountains of the eastern United States for over 500 years. However, recent socioeconomic changes in the region have caused many farmers to abandon agriculture leading to widespread reforestation of historical farmland. I investigated the influence of agriculture on the physical, chemical, and biological structure and ecosystem processes of streams in the southern Appalachians. In addition, I studied streams in watersheds previously agricultural but currently reforested to determine how historic agriculture generates long-term effects on streams. Stream draining agricultural catchments (i.e., agricultural streams) had higher temperatures, light inputs, nutrients, and suspended sediments than forested streams and contained smaller substrate, dominated by sand and silt. Temperature and light regimes recovered in streams of reforested catchments, but the other aspects of stream physicochemistry remained elevated or changed due to historical agriculture. I expected biological community structure and ecosystem processes to reflect these altered conditions in streams with current and historical agriculture. Higher chlorophyll, lower macroinvertebrate biodiversity, fewer shredder-detritivore invertebrates, and more pollution-tolerant organisms characterized agricultural streams compared to forested streams, but each of these biological features was similar in long-term forested streams and streams with reforested catchments but with agricultural histories. Agricultural streams had higher rates of gross primary production (GPP) and GPP to respiration (P/R) ratios than forested streams, indicating that agriculture enhances autotrophic metabolism in streams. Agriculture did not have a significant effect on wood breakdown or microbial biofilm development on wood substrates. Together, these data suggest that agriculture causes many different changes in stream physical and chemical properties and that many of these properties do not recover following reforestation of catchments over the past 50 years. However, biological community structure and ecosystem processes appear to respond to physical aspects of streams that do recover from historic agriculture including light, temperature, and organic matter supply and type. / Ph. D.