The distribution of beetles in the Family Silphidae has not been well studied in Virginia.  The primary purpose of this study was to survey silphid beetles in a more systematic manner across different geographic regions of the state, with a special consideration for Nicrophorus species.  The seasonal abundance and diversity of silphid beetles in Montgomery County, Virginia, was also examined.  Baited pitfall traps were used to sample beetle distribution and abundance, and were placed in each of the five geographical regions of Virginia in the summers of 2007 and 2008.  Traps were placed approximately one kilometer apart and were checked daily over a five day period for each of three sampling periods.  A total of 4375 silphid beetles, consisting of 11 species in four genera, were collected in ten counties with beetles in the subfamily Silphinae being predominant.  Within the Nicrophorinae, Nicrophorus tomentosus and N. orbicollis were dominant in 2007; whereas in the summer of 2008, N. tomentosus and N. pustulatus were the most commonly collected.  Contingency analyses indicated that species abundance was associated with sampling period and geographic region.  Nicrophorus americanus was not collected during either summer of surveying and only three N. carolinus were trapped in Suffolk County in the summer of 2008.  For the Montgomery County survey, a total of 3276 beetles were found between the middle of April and the middle of October.  The prevalent species within Nicrophorinae was Nicrophorus tomentosus and within the Silphinae it was Necrophila americana.  Species abundance was associated with sampling period. / Master of Science in Life Sciences

Longline fishing is the most common elasmobranch capture method in the world, both for commercial fishing, and to a lesser extent for scientific surveys. The capture of an animal on a longline initiates a series of physiological responses designed to promote survivorship in the short term, but if unchecked, can cause reduced individual fitness and/or mortality in the long term. Given widespread declines in shark populations, an improved understanding of the physiological costs of longline capture is needed. The aim of this thesis was to investigate the physiological response of sharks to capture and restraint, to assess novel, non-invasive alternatives to scientific longline surveys, and to generate scientific insight into poorly understood elasmobranch populations in The Bahamas. The results presented herein suggest that some species of shark are able to recover from the physiological stress of capture despite the presence of persistent negative stimuli. Tonic immobility was assessed as a means of generating baseline blood chemistry data, but was found to be inappropriate given that it increases the magnitude of physiological perturbation in the short term. To avoid the stress of capture altogether, Baited Remote Underwater Video Surveys (BRUVS) were considered as a non-invasive alternative to capture based surveys, however, it was concluded that they lack the resolution necessary to answer fine scale demographic questions. For the Caribbean reef shark, longline surveys yielded high resolution data allowing the identification of fine scale spatiotemporal shifts in demographic population structure with minimal cost (mortality). Nevertheless, the ethics of using capture based surveys on sensitive species are questionable when alternative techniques are available. Deep water sharks caught on longline surveys exhibited high mortality rates, however, for these very poorly understood species moribund specimens have great scientific value which in some cases can offset the high ecological costs of the surveys. The results presented in this thesis highlight the on-going need for improved biological and ecological research into the majority of elasmobranch populations, particularly with regards to anthropogenic interactions such as capture. Given the tenuous conservation status of many species, the acquisition of applied, management focused data should remain the priority of elasmobranch scientists.

O presente trabalho objetivou inventariar borboletas frugívoras através de armadilhas atrativas, método para o qual não se tem registro do uso estandartizado no Rio Grande do Sul. Foram realizadas saídas a campo no Vale do Rio Maquine (29º35’S 50º16’W GR) RS, Brasil, de dezembro/2006 a abril/2007. Duas trilhas foram amostradas: mata em estágio intermediário de regeneração (MI) e mata preservada (MP). Foram calculados estimadores analíticos de riqueza, índices de diversidade, dominância e similaridade. Foram amostrados 684 indivíduos (N) em 34 espécies (S) (MI: S=27 e N=429 e MP: S=25 e N=255). Os estimadores de riqueza indicaram que 70-80% da fauna foi amostrada. Mais de 70% dos indivíduos pertencem a apenas cinco espécies, revelando a alta dominância. Hamadryas epinome (C. Felder & R. Felder, 1867) foi a espécie mais abundante, com dominância acentuada em MI. Mais de 50% das espécies foram compartilhadas. Índices de similaridade (Jaccard = 053 e Morisita = 0,85) indicam semelhança entre trilhas. Comparando os resultados com inventário realizado com rede entomológica, concomitantemente e nas mesmas áreas, obteve-se abundância e riqueza bastante superior em relação a guilda de frugívoras capturada com armadilhas, ressaltando a importância do uso de armadilhas para o real conhecimento desta guilda. Houve associação significativa entre método de captura e abundância das subfamílias (P < 0,001). Entre as quatro espécies mais abundantes, 21 a 59%, dos indivíduos foram recapturados pelo menos uma vez. Dados sobre longevidade foram surpreendentes, indicando sobrevivência além do esperado e conhecido para borboletas frugívoras neotropicais: por ex., H epinome, apresentou longevidade registrada de 128 e 129 dias (máximo registrável no período de estudo). Catoblepia amphirhoe (Hübner, [1825]), Penetes pamphanis Doubleday, [1849], Caligo brasiliensis (C. Felder, 1862), foram registros novos para Maquiné. Face o ineditismo dos dados, espera-se que o Presente estudo seja base para futuras pesquisas com esta guilda específica, da qual pouco Se conhece no Rio Grande do Sul. / Diversity of fruit-feeding butterflies (Lepidoptera: Nymphalidae) and evaluation of the use of baited traps associated to mark-recapture in Atlantic Forest environments, South Brazil. This work aimed to study fruit-feeding butterflies with baited traps, method for which there are no records of the standartized use in Rio Grande do Sul. Field work was carried out at the Maquiné Valley (29º 35’S 50º 16’W GR), RS, Brazil, from december/2006 to april/2007. Two transects were sampled: one along a forest at an intermediate stage of regeneration (M1) and another within a well preserved forest (MP). Richness analytical estimators, diversity, similarity and dominance indexes were calculated. As a whole, 684 individuals (N) in 34 species (S) were sampled (MI: S = 27 and N = 429 and MP: S = 25, N = 255). Species richness estimators indicated that 7040% of the fauna was sampled, Over 70% of individuals belonged to just five species, revealing a high dominance pattern. Satyrinae was the richest subfamily (S = 10) and the most abundant Biblidinae (N = 350). Hamadryas epinome (Felder & Felder, 1867) was the most abundant species, with marked dominance in MI. More than 50% of the species were shared among MI and MP. Jaccard (0,53) e Morisita (0,85) indexes corroborate the similarity between the sites. Comparing these results with those yielded by a survey conducted concomitantly at the same areas but using with butterfly nets, species richness and abundance was much higher for the fruit-feeding butterflies guild using baited traps. Thus, it is emphasized the importance of the use of traps for studying this guild. Also, there was a significant association between method of capture and abundance of subfamilies (P < 0.001). Among the four most abundant species, 21 to 59 % of individuals were recaptured at least once. Data on longevity was surprising, indicating survival beyond the expected and known for neotropical fruit-feeding butterflies: e.g., for two H. epinome it was registered 128 and 129 days between first and last capture (maximum recordable the period of study). Catoblepia amphirhoe (Hübner, [1 825]), Penetes pamphanis Doubleday, [1 849], Caligo brasiliensis (C. Felder, 1862), were new records for Maquiné. Given the novelty of the data here Presented, it is expected that this study shall encourage and support future research with this particular guild, for which so little is known in Rio Grande do Sul.

O presente trabalho objetivou inventariar borboletas frugívoras através de armadilhas atrativas, método para o qual não se tem registro do uso estandartizado no Rio Grande do Sul. Foram realizadas saídas a campo no Vale do Rio Maquine (29º35’S 50º16’W GR) RS, Brasil, de dezembro/2006 a abril/2007. Duas trilhas foram amostradas: mata em estágio intermediário de regeneração (MI) e mata preservada (MP). Foram calculados estimadores analíticos de riqueza, índices de diversidade, dominância e similaridade. Foram amostrados 684 indivíduos (N) em 34 espécies (S) (MI: S=27 e N=429 e MP: S=25 e N=255). Os estimadores de riqueza indicaram que 70-80% da fauna foi amostrada. Mais de 70% dos indivíduos pertencem a apenas cinco espécies, revelando a alta dominância. Hamadryas epinome (C. Felder & R. Felder, 1867) foi a espécie mais abundante, com dominância acentuada em MI. Mais de 50% das espécies foram compartilhadas. Índices de similaridade (Jaccard = 053 e Morisita = 0,85) indicam semelhança entre trilhas. Comparando os resultados com inventário realizado com rede entomológica, concomitantemente e nas mesmas áreas, obteve-se abundância e riqueza bastante superior em relação a guilda de frugívoras capturada com armadilhas, ressaltando a importância do uso de armadilhas para o real conhecimento desta guilda. Houve associação significativa entre método de captura e abundância das subfamílias (P < 0,001). Entre as quatro espécies mais abundantes, 21 a 59%, dos indivíduos foram recapturados pelo menos uma vez. Dados sobre longevidade foram surpreendentes, indicando sobrevivência além do esperado e conhecido para borboletas frugívoras neotropicais: por ex., H epinome, apresentou longevidade registrada de 128 e 129 dias (máximo registrável no período de estudo). Catoblepia amphirhoe (Hübner, [1825]), Penetes pamphanis Doubleday, [1849], Caligo brasiliensis (C. Felder, 1862), foram registros novos para Maquiné. Face o ineditismo dos dados, espera-se que o Presente estudo seja base para futuras pesquisas com esta guilda específica, da qual pouco Se conhece no Rio Grande do Sul. / Diversity of fruit-feeding butterflies (Lepidoptera: Nymphalidae) and evaluation of the use of baited traps associated to mark-recapture in Atlantic Forest environments, South Brazil. This work aimed to study fruit-feeding butterflies with baited traps, method for which there are no records of the standartized use in Rio Grande do Sul. Field work was carried out at the Maquiné Valley (29º 35’S 50º 16’W GR), RS, Brazil, from december/2006 to april/2007. Two transects were sampled: one along a forest at an intermediate stage of regeneration (M1) and another within a well preserved forest (MP). Richness analytical estimators, diversity, similarity and dominance indexes were calculated. As a whole, 684 individuals (N) in 34 species (S) were sampled (MI: S = 27 and N = 429 and MP: S = 25, N = 255). Species richness estimators indicated that 7040% of the fauna was sampled, Over 70% of individuals belonged to just five species, revealing a high dominance pattern. Satyrinae was the richest subfamily (S = 10) and the most abundant Biblidinae (N = 350). Hamadryas epinome (Felder & Felder, 1867) was the most abundant species, with marked dominance in MI. More than 50% of the species were shared among MI and MP. Jaccard (0,53) e Morisita (0,85) indexes corroborate the similarity between the sites. Comparing these results with those yielded by a survey conducted concomitantly at the same areas but using with butterfly nets, species richness and abundance was much higher for the fruit-feeding butterflies guild using baited traps. Thus, it is emphasized the importance of the use of traps for studying this guild. Also, there was a significant association between method of capture and abundance of subfamilies (P < 0.001). Among the four most abundant species, 21 to 59 % of individuals were recaptured at least once. Data on longevity was surprising, indicating survival beyond the expected and known for neotropical fruit-feeding butterflies: e.g., for two H. epinome it was registered 128 and 129 days between first and last capture (maximum recordable the period of study). Catoblepia amphirhoe (Hübner, [1 825]), Penetes pamphanis Doubleday, [1 849], Caligo brasiliensis (C. Felder, 1862), were new records for Maquiné. Given the novelty of the data here Presented, it is expected that this study shall encourage and support future research with this particular guild, for which so little is known in Rio Grande do Sul.

O presente trabalho objetivou inventariar borboletas frugívoras através de armadilhas atrativas, método para o qual não se tem registro do uso estandartizado no Rio Grande do Sul. Foram realizadas saídas a campo no Vale do Rio Maquine (29º35’S 50º16’W GR) RS, Brasil, de dezembro/2006 a abril/2007. Duas trilhas foram amostradas: mata em estágio intermediário de regeneração (MI) e mata preservada (MP). Foram calculados estimadores analíticos de riqueza, índices de diversidade, dominância e similaridade. Foram amostrados 684 indivíduos (N) em 34 espécies (S) (MI: S=27 e N=429 e MP: S=25 e N=255). Os estimadores de riqueza indicaram que 70-80% da fauna foi amostrada. Mais de 70% dos indivíduos pertencem a apenas cinco espécies, revelando a alta dominância. Hamadryas epinome (C. Felder & R. Felder, 1867) foi a espécie mais abundante, com dominância acentuada em MI. Mais de 50% das espécies foram compartilhadas. Índices de similaridade (Jaccard = 053 e Morisita = 0,85) indicam semelhança entre trilhas. Comparando os resultados com inventário realizado com rede entomológica, concomitantemente e nas mesmas áreas, obteve-se abundância e riqueza bastante superior em relação a guilda de frugívoras capturada com armadilhas, ressaltando a importância do uso de armadilhas para o real conhecimento desta guilda. Houve associação significativa entre método de captura e abundância das subfamílias (P < 0,001). Entre as quatro espécies mais abundantes, 21 a 59%, dos indivíduos foram recapturados pelo menos uma vez. Dados sobre longevidade foram surpreendentes, indicando sobrevivência além do esperado e conhecido para borboletas frugívoras neotropicais: por ex., H epinome, apresentou longevidade registrada de 128 e 129 dias (máximo registrável no período de estudo). Catoblepia amphirhoe (Hübner, [1825]), Penetes pamphanis Doubleday, [1849], Caligo brasiliensis (C. Felder, 1862), foram registros novos para Maquiné. Face o ineditismo dos dados, espera-se que o Presente estudo seja base para futuras pesquisas com esta guilda específica, da qual pouco Se conhece no Rio Grande do Sul. / Diversity of fruit-feeding butterflies (Lepidoptera: Nymphalidae) and evaluation of the use of baited traps associated to mark-recapture in Atlantic Forest environments, South Brazil. This work aimed to study fruit-feeding butterflies with baited traps, method for which there are no records of the standartized use in Rio Grande do Sul. Field work was carried out at the Maquiné Valley (29º 35’S 50º 16’W GR), RS, Brazil, from december/2006 to april/2007. Two transects were sampled: one along a forest at an intermediate stage of regeneration (M1) and another within a well preserved forest (MP). Richness analytical estimators, diversity, similarity and dominance indexes were calculated. As a whole, 684 individuals (N) in 34 species (S) were sampled (MI: S = 27 and N = 429 and MP: S = 25, N = 255). Species richness estimators indicated that 7040% of the fauna was sampled, Over 70% of individuals belonged to just five species, revealing a high dominance pattern. Satyrinae was the richest subfamily (S = 10) and the most abundant Biblidinae (N = 350). Hamadryas epinome (Felder & Felder, 1867) was the most abundant species, with marked dominance in MI. More than 50% of the species were shared among MI and MP. Jaccard (0,53) e Morisita (0,85) indexes corroborate the similarity between the sites. Comparing these results with those yielded by a survey conducted concomitantly at the same areas but using with butterfly nets, species richness and abundance was much higher for the fruit-feeding butterflies guild using baited traps. Thus, it is emphasized the importance of the use of traps for studying this guild. Also, there was a significant association between method of capture and abundance of subfamilies (P < 0.001). Among the four most abundant species, 21 to 59 % of individuals were recaptured at least once. Data on longevity was surprising, indicating survival beyond the expected and known for neotropical fruit-feeding butterflies: e.g., for two H. epinome it was registered 128 and 129 days between first and last capture (maximum recordable the period of study). Catoblepia amphirhoe (Hübner, [1 825]), Penetes pamphanis Doubleday, [1 849], Caligo brasiliensis (C. Felder, 1862), were new records for Maquiné. Given the novelty of the data here Presented, it is expected that this study shall encourage and support future research with this particular guild, for which so little is known in Rio Grande do Sul.

High-dose verbenone, verbenone plus nonhost volatiles (NHVs), and both semiochemicals in combination with aggregant-baited funnel traps were tested for stand- level protection against mountain pine beetle attack for two consecutive years (2004-2005) at three seral high elevation whitebark pine sites in the Greater Yellowstone Ecosystem. In 2004, two 0.25-hectare treatments comprised of 25 high-dose verbenone pouches or verbenone pouches combined with single baited funnel traps were tested in a push-pull strategy. In 2005, 25 high-dose verbenone and 25 NHV pouches, or verbenone and NHV in combination with baited funnel trap clusters were tested. In both years, treatments were compared to 0.25-hectare control plots with no semiochemicals or funnel traps. The proportion of trees attacked by mountain pine beetle in treated plots was significantly reduced, when compared to control plots, at only one site treated with verbenone in 2004, and at only one site in 2005. High-dose verbenone alone, verbenone and NHVs, and both semiochemicals combined with baited funnel traps in a push-pull strategy did not consistently reduce the proportion of mountain pine beetle attacked trees relative to control plots. No covariates tested, including stand density, beetle population size, or tree size were consistently significant in explaining proportion of trees attacked.

Precise and accurate species abundance and distribution data are important for making effective ecological conservation and management decisions. These data are often challenging to obtain, especially in marine environments where the logistical and technical difficulties of working underwater can limit the precision and accuracy of detection. The chosen survey methodology, along with the study design, will determine the extent to which species’ spatial or temporal variability in abundance and distribution may be investigated. Different observational methods may yield different results. I explore how the methodology used to collect sample measurements of fish abundance and diversity in marine environments can influence your understanding of the focal population and the effectiveness of spatial marine conservation measures. I compare inshore rockfish abundance and fish diversity estimates between paired towed video and baited video surveys and between dive and baited video surveys conducted on temperate rocky-reefs in the nearshore Northeast Pacific on the coast of British Columbia, Canada. I test if the baited video survey data yield equivalent insight to those data derived from the methods commonly used in shallow (dive surveys) and deeper waters (towed video surveys). Paired dive and baited video surveys took place inside and outside of spatial marine conservation areas designated for inshore rockfish called Rockfish Conservation Areas. I test whether the baited video data generate the same conclusions about Rockfish Conservation Area effectiveness as data derived from the dive surveys, and whether the Rockfish Conservation Areas have greater inshore rockfish abundance and fish diversity than paired locations outside the conservation areas. I find similar inshore rockfish abundance estimates between towed and baited video, but baited video surveys detect a greater number of unique species than the towed video surveys. The dive surveys detect greater inshore rockfish abundance and fish diversity than the baited video surveys, but the baited video data yield equivalent insight on Rockfish Conservation Area effectiveness to data derived from the dive surveys. I find little evidence that inshore rockfish recovery is influenced by Rockfish Conservation Area protection. When data were combined across all sites sampled, Rockfish Conservation Areas did not produce more inshore rockfish, bigger rockfish, or greater fish diversity than paired sites outside of Rockfish Conservation Areas, whether measured using a dive survey or a baited video survey. However, I did observe a positive effect of Rockfish Conservation Area protection for some of the individual Rockfish Conservation Areas surveyed that rated as having a high Conservation Score. This suggests certain Rockfish Conservation Areas may be effective conservation areas for inshore rockfish recovery. The differences I observe in inshore rockfish abundance and fish diversity between the paired surveys reveals the methodology used can influence species abundance and diversity estimates. Baited video surveys are a low cost and effort methodology that can be used to examine inshore rockfish abundance and fish diversity over rocky reefs from nearshore waters down to depths greater than 20 m, and to monitor the effectiveness of spatial marine conservation areas. / Graduate

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-01-05T11:14:19Z No. of bitstreams: 1 DissCSSF.pdf: 5294769 bytes, checksum: 0ab390d8f532ae94a15a76179151fb32 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-16T13:15:25Z (GMT) No. of bitstreams: 1 DissCSSF.pdf: 5294769 bytes, checksum: 0ab390d8f532ae94a15a76179151fb32 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-16T13:15:33Z (GMT) No. of bitstreams: 1 DissCSSF.pdf: 5294769 bytes, checksum: 0ab390d8f532ae94a15a76179151fb32 (MD5) / Made available in DSpace on 2017-01-16T13:15:40Z (GMT). No. of bitstreams: 1 DissCSSF.pdf: 5294769 bytes, checksum: 0ab390d8f532ae94a15a76179151fb32 (MD5) Previous issue date: 2016-09-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The teak wood is one of the most valuable in the world, creating interest among producers in its quality and great commercial value. In Brazil plantations are concentrated in the Midwest and North, and due to the increase in these exotic plantations, monitoring is necessary to learn about their insect diversity. In 2008 a program to monitor the quarantine pest Sinoxylon unidentatum (Coleoptera: Bostrichidae) in Tectona grandis was started in the state of Pará, Brazil, because of the proximity to the state of Mato Grosso, area of occurrence of this pest. The general objective of this research was to monitor S. unidentatum and other beetle borers in Canaã dos Carajás, Cumaru do Norte, Pau D’ Arco, Rio Maria, São Domingos do Araguaia and Ulianópolis. Our specific objectives were to determine the richness and diversity of Curculionidae (Scolytinae, Platypodinae) and Bostrichidae in these plantations, and to know if there was a seasonal variation for their most abundant species. Trappings were done biweekly with ethanol-baited flight intercept traps from June 2011 to April 2013, totaling 115 collections. We captured 10147 specimens of beetle borers, distributed in eight sub-tribes, and totaling 90 species. In Rio Maria we found the greatest diversity of beetles and in São Domingos do Araguaia the greatest richness. There was a predominance of Scolytinae of the sub-tribe Cryphalina, which probably develop in the understory or dry material above the soil. We trapped significantly more Bostrichidae and Hypothenemus during the dry season. Sinoxylon unidentatum, target species that started this research, was not detected. / A madeira de teca é uma das mais valiosas do mundo, despertando interesse entre os produtores pela sua qualidade e grande valorização comercial. No Brasil as plantações estão concentradas na região Centro-Oeste e Norte, e devido ao aumento destes plantios exóticos, o monitoramento faz-se necessário para o conhecimento da diversidade de insetos. No ano de 2008, iniciou-se um programa de fiscalização da praga quarentenária Sinoxylon unidentatum (Coleoptera: Bostrichidae) em plantios de Tectona grandis no estado do Pará, devido à proximidade com o estado de Mato Grosso, área de ocorrência desta praga. O objetivo geral desta pesquisa foi realizar o monitoramento de S. unidentatum e demais brocas capturadas nos municípios de Canaã dos Carajás, Cumaru do Norte, Pau D’ Arco, Rio Maria, São Domingos do Araguaia e Ulianópolis. Os objetivos específicos foram determinar a riqueza e diversidade, e verificar se há variação sazonal para as principais espécies de Curculionidae (Scolytinae, Platypodinae) e Bostrichidae em oito áreas experimentais no Pará. O experimento foi conduzido com armadilhas de intercepção de voo iscadas com etanol. As coletas foram realizadas a cada 15 dias, de junho de 2011 a abril de 2013, totalizando 115 coletas. Foram capturados 10147 espécimes de brocas, distribuídos em oito sub-tribos, totalizando 90 espécies. Em Rio Maria foi encontrada a maior diversidade de brocas e em São Domingos do Araguaia a maior riqueza. Houve predomínio de Scolytinae da sub-tribo Cryphalina, que se desenvolvem provavelmente no subbosque ou em material seco sobre o solo. Foram capturados significativamente mais Bostrichidae e Hypothenemus durante o período seco. Sinoxylon unidentatum, espécie alvo que iniciou esta pesquisa, não foi coletada.

Conservation of elasmobranch populations is often inhibited by a lack of data, particularly in understudied regions like the Red Sea. Survey efforts in this region have been infrequent and often highly localized. Establishing a broad baseline for elasmobranch diversity and abundance along the Saudi Arabian Red Sea coast could inform both conservation efforts and a nascent ecotourism industry. In this thesis, I describe a pilot study comparing biodiversity data from baited remote underwater video stations (BRUVS), unoccupied aerial vehicle surveys (UAVs), and eDNA sequencing at five islands in the Farasan Banks region of the Saudi Arabian Red Sea. Estimates of relative abundance were also compared between the BRUVS and UAVs. Each method identified species missed by the other two, but all three techniques exhibited clear habitat- and taxa-specific biases. I was able to identify key concerns for each approach that need to be addressed before large-scale implementation. If carefully planned and executed well, a full assessment of the Saudi Arabian coastline could establish a true baseline for shallow water elasmobranchs in the eastern Red Sea. Informing best conservation practices and identifying potential ecological attractions in accordance the environmental and economic goals of Saudi Arabia’s Vision 2030.

Despite very extensive studies related to molecular processes underlying memory formation, still little known about the potential differences in the brain biochemistry between &ldquo / good&rdquo / and &ldquo / poor&rdquo / learners belonging to a random population of young animals. In the present study, an attempt was taken to correlate the individual variation in short- and long-term spatial memory in three different lines of young, healthy rats: inbred Wistar (W), outcrossed Wistar/Spraque Dawley (W/S) and pigmented Long-Evans rats, with hippocampal levels of selected enzymes known as &ldquo / memory molecules&rdquo / including neuronal (n), endothelial (e) and inducible (i) NOS, CaMKII&alpha / , PKA and ChAT. Additionally, in order to indirectly estimate the activity of CaMKII&alpha / and PKA, hippocampal levels of their phosphorylated forms (pCaMKII&alpha / and pPKA) were assessed. Rats were classified as &ldquo / good&rdquo / and &ldquo / poor&rdquo / learners on the basis of their performance in a partially baited 12-arm radial maze. The hippocampal protein levels were measured using Western Blot technique. In addition to individual variation in animals&rsquo / learning capacity, strain-depended differences have also been observed. Deficient performance recorded in inbred W rats compared to outcrossed W/S rats, and &ldquo / poor&rdquo / learners from both rat groups had predominantly related to the higher frequency of reference memory errors. The results of biochemical assays showed strain-depended differences in the NOS expression. The overall NOS levels were significantly higher in outcrossed W/S rats compared to inbred W rats. In both rat lines, the rate of learning positively correlated with hippocampal levels of nNOS and negatively correlated with iNOS levels. Hippocampal eNOS levels correlated negatively with animals&rsquo / performance but only in the W rats. These results suggested that all 3 NOS isoforms are implemented in the learning process playing, however, different roles in neural signaling. Experiments carried out on Long-Evans rats did not reveal a significant difference in the basal hippocampal levels of the CaMKII&alpha / , however, the level of the pCaMKII&alpha / , was significantly higher in &ldquo / good&rdquo / learners. Also, hippocampal levels of both PKA and pPKA, as well as that of ChAT were significantly higher in &ldquo / good&rdquo / as compared to &ldquo / poor&rdquo / learners. Taken together, the latter findings indicate that low hippocampal expression of PKA and ChAT as well as low CaMKII&alpha / or PKA activation may cause learning deficits in random population of young rats, and thus, these enzymes can be considered target molecules when looking for cognitive enhancers to treat memory deficits in young subjects.