Ch. I A discrepancy exists in the ancient sources between the record of Crassus' activities and assessments of his importance. Some possible reasons are considered. Ch. II Crassus' birth date is placed between late June -115 and very early 114. Absent from Rome between 81 and 82, Crassus entered the senate in about 81. He was praetor in 75 or 74, was prosecuted for incest in 73, and was therefore a privatus when given the command against Spartacus. His political position in the 70s is considered. Ch. III In 70 Crassus was concerned in the restoration of the tribunicia potestas, as he shows connections with several tribunes of the 70s. His breach with Pompey may concern the actions of the censors of 70. Crassus was interested in the reform of the courts, though probably friendly to Verres. Ch. IV Crassus may have been hostile to both Lucullus and Pompey in the early 60s, Cn.Piso prosecuted Manilius in 66/5, and was sent to Spain to facilitate a change of prosecutor. Catiline was involved against Manilius. Ch. V In 65 Crassus aimed to enfranchise the Transpadani in order to increase his power in the comitia. He was also concerned to annexe Egypt, frustrated by Catulus, he considered an alliance with Pompey, and began to cooperate with Caesar. Ch. VI Catiline's supposed Pompeian ties are unconvincing. Crassus supported. Catiline and Antonius. In 63 Cicero allied himself with the optimates, frustrated Crassus' tribunician programme, and tried to destroy his political credibility by virtually creating the Catilinarian "conspiracy". Ch. VII Pompey had hoped to return with his army. He then tried to ally himself with Cato, and dropped several former associates, one of whom, P.Clodius, was helped by Crassus. Crassus joined the optimates to ensure Pompey's frustration. The First Triumvirate ensued. Ch. VIII In April 59 Pompey and Caesar tried to drop Crassus, who managed, through his association with Clodius, to prevent this. The Vettius affair may have been genuine. The tribunician elections were held in October. Ch. IX Having failed to crush Pompey through Clodius, Crassus, with Caesar's help, forced him to a crisis from which he himself would emerge the strongest. Provincial commands were decided at Luca; the second consulship was not. Ch. X Most of the measures passed' in 55 were not politically significant. Crassus, more committed to the alliance, now incurred hostility. Though away in 54 he kept in touch, and may have been involved in the electoral scandal of that year. Ch. XI Crassus' style belied his great ambitions. The nature of his power necessitated an approach different from that of Pompey. His strategy for securing supreme power is considered. The political realignment that followed his death led inevitably to Civil War. Appendix A Crassus married the widow of a brother who died by 91. Publius, his elder son, married Scipio's daughter probably in 55. Marcus married Caecilia Metella in 70 or 69. Appendix B Plutarch's figure for Crassus' total wealth is too low. Pompey and Crassus were both very rich. Crassus had interests in the South of Italy, and derived his wealth from Spanish silver mines, housing, and slaves. Appendix C Cicero's Sixth Stoic Paradox may have existed before all six were published together in 46, Plutarch thought it a speech, and associated it with Crassus' trial for incest in 73.

The thick shelled river mussel belongs to a highly endangered group of organisms worldwide. A parasitic larval stage is included in the mussel's life cycle where its glochidia larvae attach to the gills of a host fish. The glochidia infection can affect the ability of fish populations to form schools, a behavior that is fundamental to the survival of many fish species. As the mussel is involved in conservation projects where the reintroduction of the glochidia larva is included, one should know more about how the parasite affects its host to be able to make well-founded decisions regarding possible reintroduction. In this study, a group of glochidia-infected minnows is compared to a control group where it was analyzed if the infected fish obtained a higher nearest neighbor distance (NND), a larger average school area (ASA) and a lower movement of the schools (MOS), two and four weeks after being infected. The minnows were infected in vitro where their schooling behavior was recorded with a video camera of which the footage material where analyzed. Collected data were analyzed with 2-way ANOVAS, where the results showed that there is a relationship between infection and changed schooling behavior with respect to the density and area of the fishes in general. NND and ASA increased in the infected group, but not in the non-infected group, at two and four weeks. If the goal through conservation measures is to restore the original balance of the parasite-host interactions of the thick shelled river mussel and the minnow, more research on how mussel parasites affect its fish hosts should be done. / Den tjockskaliga målarmusslan tillhör en starkt hotad organismgrupp över hela världen. Ett parasitiskt larvstadium ingår i musslans livscykel där dess glochidielarver fäster vid gälarna hos en värdfisk. Denna glochidieinfektion kan påverka fiskpopulationens förmåga att bilda stim, ett beteende som är grundläggande för många fiskarters överlevnad. Då musslan är med i bevarandeprojekt där återintroduktion av glochidielarven ingår bör kunskapen fördjupas gällande hur parasiten påverkar sin värd för att kunna ta välgrundade beslut inför eventuella åtgärder. I den här studien jämfördes glochidieinfekterade elritsor med en kontrollgrupp där det undersöks om de infekterade fiskarna får en högre nearest neighbour distance (NND), en större average school area (ASA) och en lägre movement of the schools (MOS) två och fyra veckor efter att de infekterats. Elritsorna infekteras in vitro där deras stimbeteende spelades in med en videokamera för att sedan bildanalyseras. Insamlade data analyserades med 2-vägs-ANOVOR, där resultaten visade att det finns samband mellan infektion och förändrat stimbeteende med avseende på fiskarnas täthet och area generellt. NND och ASA ökade hos de infekterade, men inte för de icke-infekterade under två och fyra veckor. Om målet genom bevarandeåtgärder är att återställa den ursprungliga balansen i parasit-värdinteraktionen för den tjockskaliga målarmusslan och elritsan, bör det undersökas vidare hur musselparasiter påverkar sina värdfiskar.

Mörrumsån har de förutsättningar som krävs för att Tjockskalig målarmussla (Unio crassus) skall kunna leva och föröka sig, men detta sker inte i samma utsträckning som tidigare. Ett samband mellan vattnets riktning söderut mot utloppet till Östersjön och minskad föryngring av Tjockskalig målarmusslas inventerade bestånd i Mörrumsån finns. Föryngringen uteblir samtidigt som man hittat fler döda musslor ju närmre åmynningen man kommer. Orsakerna till detta kan vara flera då denna mussla är beroende av specifika förhållanden under flera faser i sin utveckling och fortplantning. Ett av hoten är grumling av bottnar. Grumling kan bero på att sträckor utmed Mörrumsåns sluttningar och stränder beträds frekvent av besökare. Vegetation slits bort längs med stigar och vandringsleder vilket leder till erosion av stränder och sluttningar. Organiskt och oorganiskt material av olika storlekar följer med åns vatten i strömriktningen och sedimenterar. En grupp som oftast använder stränderna är sportfiskare och de sliter mer på vegetation och stränder i perioder då fisket är intensivt. En av de mer intensiva perioderna är vid premiären av laxfisket på våren. Under denna tid syns ett bibehållet slitage på vissa sträckor vid ån samt även utökat slitage i form av bredare stigar och även parallella stigar på andra sträckor. De platser som uppvisade att erosion ägde rum innan fiskepremiären hade eroderat mer vid utvärdering två veckor efter premiären. Man skulle kunna skydda vegetation genom att anlägga spänger längs med känsliga och utsatta stigar och stränder. Detta skulle dock inte förhindra den erosion som sker längs med stränder där sportfiskare kliver i och ur ån samt går längs med stranden under fiskeaktiviteten. Det är svårt att förutspå var en fiskare tänker stå och därför kan det inte uteslutas att en fiskare väljer att stå på någon annan plats än den som man byggt en spång på. Spångbygge kan kombineras med information om syftet och att det finns skyddsvärda starkt hotade arter som Tjockskalig målarmussla vilka utsätts för färre risker om man använder spänger, stigar och rekommenderade platser / Mörrumsån have the conditions required for the Thick-shelled river mussel (Unio crassus) to live and reproduce, but not to the same extent as before. There is a connection between the rivers direction towards the outlet to the Baltic sea and reduced regeneration of Unio crassus inventoried stocks in Mörrumsån. The number of dead mussels found in inventoried locations also shows this relationship, that the closer to the outlet you get more dead mussels are found and at the same time reduced regeneration. This could depend on several reasons since this mussel depends on specific conditions in several stages of development and reproduction. One of the reasons for the declining mussel stock is silting of the bottoms. Silt depends partly on visitor’s frequent use of tracks and trails along Mörrumsåns slopes and riversides. Along tracks and trails vegetation are damaged, this further on leads to erosion of riversides and hillsides. Organic and inorganic materials of different sizes erode with the water in the flow direction and sediment further down the stream. One group which uses the riversides more than others are anglers. This sport fishing activity are more intensely damaging the vegetation in the riparian zone during certain periods. One of these more intensive periods is around the premiere of salmon fishing in the spring. During this time there is a sustained wear to the sides of the river and even some extended wear in form of wider footpaths and also parallel paths on other routes. Some sites that showed that erosion took place before the premiere fishing has eroded even more during the evaluation period. There could be some protection to the vegetation by building footbridges along the vulnerable and exposed trails and riversides. This could prevent some erosion but not the ones that takes place along the riparian zones where anglers climb into and out of the river, or walks along the river during the fishing activity. It is difficult to predict were an angler will perform its activity. It can not be excluded that a angler choose to stand at any place other than the one you built a footbridge on. Footbridge constructions may be combined with information about the purpose and that there is endangered species such as Unio crassus worth protecting. And by using footbridges, recommended sites and tracks you expose some endangered species to fewer risks.

Im Jahr 2006 wurden insgesamt 767 Aale des Bodensee-Obersees auf den Befall mit dem Schwimmblasenwurm A. crassus und dessen Folgen untersucht. Zusätzlich wurden die Befallsdaten von weiteren 2.326 Aalen aus den Jahren 1988 bis 2005 und 2007 bis 2009 ausgewertet. Weiterhin wurden in den Jahren 2006 bis 2008 eine Anzahl von 383 Kaulbarschen und zahlreiche Copepoden auf den Befall mit dem Larvenstadium von A. crassus untersucht. Auf der Ebene der echten Zwischenwirte ließ sich A. crassus im Bodensee-Obersee im Freiwasserplankton nicht nachweisen. Jedoch konnten Copepoden der Gattung C. abyssorum experimentell mit A. crassus infiziert werden. Der Kaulbarsch ist für A. crassus der wichtigste Stapelwirt im Bodensee-Obersee. Die untersuchten Kaulbarsche waren zwischen 18,8% und 52,1% mit A. crassus infiziert, wobei die Infektion einen deutlichen Frühjahrespeak aufwies. Im Jahr 2006 lag die Prävalenz befallener Aale im Bodensee bei 55,6%, die durchschnittliche Befallsintensität lag bei 4,4 adulter Parasiten je Aal. Durch die Datenauswertung von insgesamt 3.425 Aalen konnte der Verlauf der Anguilli­coloidose im Zeitraum von 1989 bis 2009 rekonstruiert werden. Der Höhepunkt der Infektion lag demnach im Jahr 1993 mit einer durchschnittlichen Prävalenz des Erregers von 58,3% und einer durchschnittlichen Befallsintensität von 16,6. Seit 1996 werden die Schadwirkungen von A. crassus auf die Schwimmblase aufgezeichnet und wurden nun in dieser Arbeit ausgewertet. In diesem Zeitraum nahm die Anzahl der Aale mit schweren Schwimmblasenschäden deutlich zu. Im Jahr 2006 besaßen 89,9% der Aale eine Schwimmblase mit geringer bis sehr starker Schädigung. Bei den abwanderungswilligen Blankaalen besaßen insgesamt 10% eine Schwimmblase mit sehr starken Schäden. Es bestand eine positive Korrelation zwischen der Größe der Aale und der Ausprägung der Schwimmblasenschäden. Weiterhin wurde ein negativer Einfluss durch den Befall mit Larven von A. crassus auf das Milzgewicht beobachtet. Der Befall mit abgestorbenen Adulten war mit Anämie korreliert. Durch den kumulativen Effekt der Schwimmblasenschäden, die durch die Infektion mit A. crassus hervorgerufen werden, werden vor allen Dingen größere Aale im Bodensee-Obersee beeinträchtigt. Eine parasiteninduzierte Mortalität von A. crassus liegt jedoch nicht vor.

Im Jahr 2006 wurden insgesamt 767 Aale des Bodensee-Obersees auf den Befall mit dem Schwimmblasenwurm A. crassus und dessen Folgen untersucht. Zusätzlich wurden die Befallsdaten von weiteren 2.326 Aalen aus den Jahren 1988 bis 2005 und 2007 bis 2009 ausgewertet. Weiterhin wurden in den Jahren 2006 bis 2008 eine Anzahl von 383 Kaulbarschen und zahlreiche Copepoden auf den Befall mit dem Larvenstadium von A. crassus untersucht. Auf der Ebene der echten Zwischenwirte ließ sich A. crassus im Bodensee-Obersee im Freiwasserplankton nicht nachweisen. Jedoch konnten Copepoden der Gattung C. abyssorum experimentell mit A. crassus infiziert werden. Der Kaulbarsch ist für A. crassus der wichtigste Stapelwirt im Bodensee-Obersee. Die untersuchten Kaulbarsche waren zwischen 18,8% und 52,1% mit A. crassus infiziert, wobei die Infektion einen deutlichen Frühjahrespeak aufwies. Im Jahr 2006 lag die Prävalenz befallener Aale im Bodensee bei 55,6%, die durchschnittliche Befallsintensität lag bei 4,4 adulter Parasiten je Aal. Durch die Datenauswertung von insgesamt 3.425 Aalen konnte der Verlauf der Anguilli­coloidose im Zeitraum von 1989 bis 2009 rekonstruiert werden. Der Höhepunkt der Infektion lag demnach im Jahr 1993 mit einer durchschnittlichen Prävalenz des Erregers von 58,3% und einer durchschnittlichen Befallsintensität von 16,6. Seit 1996 werden die Schadwirkungen von A. crassus auf die Schwimmblase aufgezeichnet und wurden nun in dieser Arbeit ausgewertet. In diesem Zeitraum nahm die Anzahl der Aale mit schweren Schwimmblasenschäden deutlich zu. Im Jahr 2006 besaßen 89,9% der Aale eine Schwimmblase mit geringer bis sehr starker Schädigung. Bei den abwanderungswilligen Blankaalen besaßen insgesamt 10% eine Schwimmblase mit sehr starken Schäden. Es bestand eine positive Korrelation zwischen der Größe der Aale und der Ausprägung der Schwimmblasenschäden. Weiterhin wurde ein negativer Einfluss durch den Befall mit Larven von A. crassus auf das Milzgewicht beobachtet. Der Befall mit abgestorbenen Adulten war mit Anämie korreliert. Durch den kumulativen Effekt der Schwimmblasenschäden, die durch die Infektion mit A. crassus hervorgerufen werden, werden vor allen Dingen größere Aale im Bodensee-Obersee beeinträchtigt. Eine parasiteninduzierte Mortalität von A. crassus liegt jedoch nicht vor.

Unionoid mussels are globally threatened and their conservation requires species-specific knowledge on their ecology and parasite-host interaction. Unio crassus is one of Europe’s most threatened unionoid species and has a temporary obligate parasitic life stage (glochidia) on fish. A lack of suitable hosts is probably a major limitation for mussel recruitment, but host species composition, suitability and availability in time and space have yet to be fully explored. This thesis examines different aspects of the host fish species, including their composition, suitability and ecological importance, in relation to U. crassus, using both field and laboratory studies. The effects of mussel and host density on mussel reproductive potential were considered, as were aspects of evolutionary adaptations between mussels and fish and how climate change may affect their interaction. The results show that U. crassus is a host generalist, parasitizing a variety of fish species. Host suitability and density, which varied among fish species and rivers, affected the level of glochidia encapsulation, hence mussel reproductive potential, more so than the density of mussels taking part in reproduction. Ecologically important hosts included both highly suitable primary hosts, and less suitable hosts that were highly abundant. Whether or not U. crassus has specific adaptations to its hosts to enhance juvenile transformation remains unclear. No distinct pattern of local adaptation was found, nor was there an effect of host fish presence on the timing of glochidia release by adult mussels. Instead, temperature played a major role, with results suggesting that changes in spring water temperature regimes can cause temporal and spatial mismatches in the mussel-host interaction. This thesis indicates that investigations of local mussel-host interactions help in identifying mechanisms important for unionoid conservation management and prioritization. / Många sötvattenmusslor har en komplex livscykel där larverna (glochidier) under sin utveckling till frilevande musslor parasiterar på gälarna hos lämpliga värdfiskar. Flera av våra musslor, såsom den tjockskaliga målarmusslan (Unio crassus), är globalt hotade och för att kunna bevara och förvalta dessa arter på bästa sätt behöver vi lära oss mer om deras ekologi och samspelet mellan musslan och dess värdfiskar. Avsaknaden av värdfiskar innebär förmodligen en stor begränsning för rekryteringen av juvenila musslor, men det finns trots detta en begränsad kunskap om hur artsammansättningen i fisksamhället och dess tillgänglighet påverkar musselpopulationer.  Min avhandling undersöker olika aspekter av interaktioner mellan U. crassus och dess värdfiskar, som hur värdfisksamhällen och fiskarters värdlämplighet påverkar musslans reproduktionspotential. Jag har även studerat hur tätheter av olika fiskarter och vuxna musslor påverkar rekryteringen, eventuella evolutionära anpassningar samt om en förhöjd temperatur skulle kunna påverka interaktionen mellan U. crassus och dess värdfiskar. Resultaten visar att U. crassus är en generalist som parasiterar på en mängd olika fiskarter. Jag fann dock en stor variation i dominerande fiskarter och lämpliga värdar mellan olika åar, vilket påverkade reproduktionspotentialen hos musslorna mer än vad tätheten vuxna musslor som deltog i reproduktionen gjorde. Som ekologiskt viktiga värdar fanns således både särskilt lämpliga, primära värdarter, men också mindre lämpliga arter som förekom i höga tätheter. Ingen tydlig lokal anpassning kunde observeras, och fiskens närvaro påverkade inte tidpunkten för när de vuxna musslorna släppte sina glochidielarver. Däremot fann jag att temperaturen spelade en viktig roll för musslans reproduktion, där ökad temperatur föreslås ha negativa effekter på interaktionen mellan musslan och dess värdfiskar. Avhandlingen visar på vikten av att studera interaktioner mellan den tjockskaliga målarmusslan och dess värdar på lokal skala för att bättre kunna identifiera och prioritera viktiga naturvårdsåtgärder. / UnioCrassusforLIFE (European LIFE+ project: LIFE10 NAT/SE/000046)

The thick-shelled river mussel (Unio crassus) is a red listed species classified as Endangered (EN) and is also considered within the Habitats Directive. The distribution in Sweden is fragmented and it is mostly occurring in the south eastern parts. We investigated the presence of Unio crassus in a section of the stream Storån, Östergötland County, from Falerum to the inflow into Lake Åkervristen. The environmental parameters investigated were water depth, bottom substrate, shading, water velocity and the slope over the water surface. In this thesis I have focused mainly on water depth and shading, comparing sites with and without mussels. In addition, I used a multivariate PCA analysis to evaluate all parameters together. The water depth was significantly larger in habitats with mussels than in those without. Shading varied from 5 to 80 %, but there was no significant difference between habitats with and without mussels. There was no correlation between water depth and mussel density and not between shading and mussel density either. The multivariate PCA analysis showed that the habitats with and without mussels were different from with regard to the PC1 axis, which included water depth, bottom substrate and water velocity. Alone, the water depth is not enough to predict the presence of Unio crassus in the stream, and it is likely that more parameters need to be considered.  Previous work indicate that the more parameters and habitats that are investigated, the more confident results can be stated of which habitats Unio crassus prefer.

The thick shelled river mussel (Unio crassus) has a fragmented distribution in southern Sweden. It is a threatened and protected species. In both the Swedish red list and the IUCN Red List of Threatened Species Unio crassus is classified as Endangered (EN). Causes for this classification are for instance differentiated bottom substrate and deterioration in water quality. In this study, habitat preferences of Unio crassus were investigated to assist in future restoration work. The environmental parameters that were used to characterize the habitat in sites with or without Unio crassus were water depth, bottom substrate, water velocity, slope, and shading. In this thesis I focused in bottom substrate and water velocity. Sites with Unio crassus had finer bottom substrate and lower water velocity than sites without (t>2.54, p<0.05, t-test). Most of the sites with Unio crassus had a bottom substrate with a size <4 mm and a water velocity around 0.3-0.5 m/s. These two variables were correlated with each other. When the water velocity was higher, the bottom substrate was coarser. These results are in line with other studies, showing that if the bottom substrate is either too coarse or too fine, it could impact Unio crassus. Too coarse bottom substrate probably results in difficulty in burrowing and too fine most likely results in interfering with respiration and feeding. Earlier studies indicate that the water velocity can have a greater impact on unionids than bottom substrate. Because of the correlation between bottom substrate and water velocity it is not easy to disentangle the importance of each factor.

The thick shelled river mussel (Unio crassus) has a fragmented distribution in southern Sweden. It is a threatened and protected species. In both the Swedish red list and the IUCN Red List of Threatened Species Unio crassus is classified as Endangered (EN). Causes for this classification are for instance differentiated bottom substrate and deterioration in water quality. In this study, habitat preferences of Unio crassus were investigated to assist in future restoration work. The environmental parameters that were used to characterize the habitat in sites with or without Unio crassus were water depth, bottom substrate, water velocity, slope, and shading. In this thesis I focused in bottom substrate and water velocity. Sites with Unio crassus had finer bottom substrate and lower water velocity than sites without (t>2.54, p<0.05, t-test). Most of the sites with Unio crassus had a bottom substrate with a size <4 mm and a water velocity around 0.3-0.5 m/s. These two variables were correlated with each other. When the water velocity was higher, the bottom substrate was coarser. These results are in line with other studies, showing that if the bottom substrate is either too coarse or too fine, it could impact Unio crassus. Too coarse bottom substrate probably results in difficulty in burrowing and too fine most likely results in interfering with respiration and feeding. Earlier studies indicate that the water velocity can have a greater impact on unionids than bottom substrate. Because of the correlation between bottom substrate and water velocity it is not easy to disentangle the importance of each factor.

Presence of Triaenophorus crassus Forel in the flesh of lake whitefish (Coregonus clupeaformis (Mitchill)) and cisco (C. artedi Lesueur) can be an important economic problem for commercial coregonine fisheries. This study was initiated during the development of native fisheries in northern Quebec. Coregonine populations from 6 lakes of the Nottaway watershed were sampled to determine infection patterns of T. crassus in relation to age and size of fish, and to document interlake differences in prevalence and number of T. crassus. Interspecific and interlake differences in the infection dynamics of T. crassus were described in relation to capsule types, sizes and plerocercoid conditions. Infection dynamics were also investigated with age of fish. All coregonine populations were infected with T. crassus, and cisco more so than lake whitefish where the two species co-occurred. Prevalence and number of T. crassus were independent of fish age and size in most lake whitefish populations. Number of T. crassus increased with fish age and size in all cisco populations, but prevalence increased only in the populations from the largest lakes. Interlake differences in prevalence and number of T. crassus were detected for both coregonine species, and were related to feeding behaviour of the fish and lake biophysical characteristics. Heavy infections in one lake whitefish population were mainly associated with piscivory. Interspecific and interlake differences in the infection dynamics of T. crassus were also observed. Differences in the proportions of capsule types, sizes, and plerocercoid conditions suggest that population turnover of T. crassus in cisco is faster than in lake whitefish. In contrast to previous studies, plerocercoid condition was found to be independent of capsule size. Coregonine populations, which did not differ in prevalence and number of T. crassus, showed some differences in the proportions of capsule types, sizes and plerocercoid conditions, suggesting