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The species composition and recruitment of apogonids in the coastal waters off southwestern Taiwan were investigated, in order to understand their spatiotemporal variation and the biology of the dominant species, Apogon fasciatus. From June 2000 to August 2005, samples were collected by a beam trawl, operating at seven stations, including Jiading, Zouying, Jhongjhou, Linyuan, Dapeng, Linbian and Fangliao. In total, 33 cruises with 411 nets were included. A total of 4,540 specimens of Apogonidae were collected, belonging to 2 genus and 15 species. There were 6 species, including Apogon fraenatus, Apogon moluccensis, Apogon nigripinnis, Apogon nigrifasciatus, Apogon notatus and Apogon semilineatus, which were first recorded in the sandy or muddy habitats. The number of species was highest at Fangliao (11 species) and lowest at Dapeng and Jiading (5 spp.). Abundance and biomass were highest at Zouying (15.3 ind./net ) and Jhongjhou (60.0 g/net), respectively, whereas, the lowest abundance and biomass were both at Jiading (2.1 ind./net; 11.1 g/net). The most abundant species was Apogon fasciatus (86.6%), which also was the dominant species at each station, following by Apogon pleuron (4.5%), Apogon striatus (2.7%), Archamia bleekeri (2.7%) and Apogon niger (1.2%), comprising 97.7% of the apogonids. Although A. fasciatus and A. pleuron resemble similarly in shape and decorative pattern, the length-weight relationships are significantly different (ANOCA, p<0.001). The former is BW = 1.7 ¡Ñ (10^-6)(TL^3.488), the later is 3.4¡Ñ(10^-6)(TL^3.312) . The parameters, K, L¡Û, t0, of von Bertalanffy growth function of A. fasciatus were 1.88 yr^-1, 105.5 mm TL and -0.04. Showing that A. fasciatus growths much quicker before Age 1 than thereafter. The minimum size of mature female A. fasciatus was found 46.39 mm TL, and the size at maturity (L50) is estimated 75.39 mm TL, approximately 7 month-old. The frequency distribution of egg diameter indicated it is a multiple spawner. In May and October which were transit period between dry and rainy seasons, the abundance of A. fasciatus was normally higher than rest months reflecting the annual recruitment of this species. The GSI variation showed that the major breeding season was form on March to September. However, the small A. fasciatus (< 30 mm TL, about 1 month-old) were found throughout the year that implied A. fasciatus may reproduce annually. Moreover, coastal southward waters of Linyuan was the mainly habitat of A. fasciatus in southwestern coastal waters off Taiwan.

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Predatory gastropods (Neogastropoda) feed with a proboscis (elongate snout) and complex foregut. The presence of developmental modules (semi-autonomous components) in foregut development may have facilitated emergence of predatory feeding. In species with indirect development (feeding larval stage) physical and temporal separation of developing foregut modules (dorsal=larval esophagus; ventral=juvenile feeding structures) allows larval feeding and rapid switch to carnivory. However, previous studies on neogastropods with direct development (no feeding larval stage) did not identify foregut developmental modules. Thus, I investigated foregut development in two predatory, direct developing neogastropods: Nucella lamellosa and N. ostrina (Muricoidea), using histological sectioning, 3D reconstructions, TEM, and SEM. In both species, I showed evidence for dissociable dorsal and ventral foregut developmental modules. In N. lamellosa, the two modules were physically separate, although they were not separate in N. ostrina. My results reconcile differences in previous descriptions of foregut development between neogastropods with indirect and direct development. / Graduate

Individual-level life-history strategies are the rails that guide population dynamics. Due to the difficulty of conducting long-term, individual-based studies, current management practices often focus on estimating and controlling demographic rates with little consideration for the individual-level responses that guide them. This approach cannot account for important factors such as age-specific responses to changes in population density or long-term impacts of conspecific density and resource limitation. As such, population-level approaches may fail to predict age structure or the rate of population growth. Recent studies of mammals and birds have shown that short-term changes in factors such as population density can have lasting impacts on vital rates of individuals. These results highlight the importance of long-term individual-based analyses in understanding population dynamics. However, very few researchers have thus far been able to isolate and study interacting effects of density and resources on life histories apart from processes such as predation, interspecific competition, and management of anthropogenic disturbance. The feral horses (Equus ferus caballus) of Sable Island, Nova Scotia, Canada, exist in a natural though simplified system without predation, human interference, or interspecific competition (they are the island’s only terrestrial mammal, numbering approximately 500 individuals). Here I determined the roles of local conspecific density and an interacting resource gradient in guiding the reproduction and survival of adult female Sable Island horses (2008–2012). I used body condition (estimates of subcutaneous fat) as an indication of resource allocation towards the often conflicting purposes of reproduction and maintenance. Reproduction was best predicted by body condition (reproducing females were in relatively poorer condition) but there was also evidence of density-dependence in reproductive success. Survival was predicted by and positively related to body condition. Survival was also predicted by an interaction between conspecific density and location on the island consistent with expectations of a known east-west resource gradient that occurs on Sable Island (in available water and forage). Greater variability in fitness estimates in resource-poor, eastern Sable Island suggests that regions of low density and resources may be high risk/high reward habitats. Such habitats may be disproportionately avoided by young animals and exploited by senescent animals. All feral horses are descended from domesticated animals and recent work has found evidence of artificially selected life-history traits in unmanaged populations of domestic mammals like cattle, sheep, and horses (e.g., reproducing even at high densities and earlier in life than expected). I therefore attempted to determine if effects of artificial selection existed in the Sable Island population by examining age-based contributions to population growth and the relationship between reproduction (foaling) and female mortality. Perhaps due to the population’s long history of low management (>250 years), I failed to find any strong evidence of artificially selected life-history traits in Sable Island horses. That is, life history trade-offs in survival and reproduction in Sable Island horses were more similar to wild species of large herbivores inhabiting natural environments, than other populations of feral ungulates. My research suggests a rarely documented but fascinating instance of reversal of artificial selection by natural selection for a domesticated species like the horse.

This dissertation provides a comprehensive and systematic examination of anthropoid primate milk composition and its relationship to a species' evolutionary history, ecological context, and life history strategy. Milk samples from 14 species of anthropoid primate (Alouatta paliatta, Callithrix jacchus, Cebus apella, Gorilla beringei beringei, Gorilla gorilla gorilla, Hylobates lar, Leontopithecus rosalia, Macaca mulatta, Macaca sinica, Pan paniscus, Pan troglodytes, Pongo pygmaeus, Saimiri boliviensis boliviensis, and Symphalangus syndactylus) were analyzed for proximate composition (fat, protein, lactose, dry matter, and minerals) and milk fatty acid composition. The objectives of this study were identification of primitive features in anthropoid milks, shared-derived features of anthropoid families or superfamilies, and unique-derived features of species, including Homo sapiens.Results did not support the null hypothesis of a generalized anthropoid milk composition. Variation among anthropoids in milk fatty acid profiles and proximate milk composition was influenced by phylogeny and the life history strategy of the species, as well as the diet and environment (captive or wild living) of the mother.Maternal diet had a direct influence on fatty acid profiles and created distinct groupings of wild and captive living individuals. Phylogenetic patterns were identified within captive and wild groups, particularly a distinction between milk fatty acid profiles of hominoids (including humans) and monkeys.Significant variation in proximate milk composition was identified at the level of the superfamily. Cercopithecoid milk was highest in mean fat, dry matter, the proportion of energy from fat, and total gross energy. Ceboid milk was highest in mean protein and the proportion of energy from protein. Hominoid milks were lowest in mean fat, protein, dry matter, the proportion of energy from fat, and total gross energy.Hominoid milk also was lowest in the degree of plasticity in milk composition. Milk of captive living monkeys was higher than milk of wild living monkeys in mean fat, percent energy from fat, and total gross energy. Milk fat and energy also were highly variable within captive living monkeys. In contrast, fat and total gross energy were not significantly different between captive and wild living hominoids and were less variabile among captive living hominoids as compared to monkeys. The lack of variability and the relatively low energy values in hominoid milk suggest that it may be buffered against environmental fluctations. Larger body size and a longer duration of lactation may permit hominoids, including humans, to decouple maternal condition from milk energy and instead relying on energy storage.

Phenotypic plasticity, the ability of a genotype to express different phenotypes in different environments, allows organisms to cope with variation in resources and invade novel environments. Biologists have long been fascinated with the costs and tradeoffs that generate and maintain variation in plasticity, such as possible increases in brain size and delays in reproduction associated with the evolution of learning. However, the costs of plasticity vary: many studies have failed to find costs of plasticity, the degree of costs often vary with the system or environments considered, and many costs of plasticity are variable even within the lifetime of an individual. This research adopts a developmental perspective to predict the degree and incidence of costs of plasticity, using host learning in butterflies as a case study. Learning, a mechanism of plasticity that develops through a trial-and-error sampling process, should result in developmental costs and allocation of energy towards development (at the expense of reproduction). Furthermore, costs of learning should be less pronounced in environments for which organisms have innate biases and for learned traits underlain by short-term memory, relative to long-term memory (which requires more developmental re-structuring). This research found support for all three predictions across three levels of costs: behavioral costs, tissue costs, and fecundity trade-offs. Butterflies exhibited genetic variation in their ability to learn to recognize different colored hosts. Genotypes with higher proxies for long-term memory emerged with relatively larger neural investment and smaller reproductive investment. In contrast to these costs of long-term learning, proxies of short-term learning were only correlated with increased exploration of a range of possible resources (types of non-hosts) early in the host-learning process. Family-level costs of plasticity emerged from the ability to learn to locate a red host, for which butterflies do not have an innate bias. Costs of learning were also induced by learning itself: following exposure to novel (red) host environments, individual butterflies, regardless of genetic background, increased exploratory behavior, increased neural investment, and re-allocated energy away from reproduction towards other functions (e.g., flight). Considering developmental mechanisms helps to predict how costs will influence the evolution of learning and plasticity.

Climatic variation is an important driver of avian life history and population dynamics. Climate change models predict increased variability for many regions and to predict the effects on species, we need to examine how their life history characteristics influence their response to climate. I studied how environmental conditions influenced the ecology of white-tailed (Lagopus leucura) and rock ptarmigan (L. mutus) in tundra habitats of the southern Yukon Territory. Although sympatric in the study area, breeding territories were generally segregated, with white-tailed ptarmigan selecting steep, rocky slopes at higher elevations and rock ptarmigan preferring lower elevation sedge meadows. For both species, cold spring temperatures delayed the onset of breeding, resulting in smaller clutch sizes and fewer hatched young per female. However, delayed breeding led to a stronger reduction in these rates for rock ptarmigan, suggesting a lower resilience to extend reproductive effort in colder years. White-tailed ptarmigan were also more likely to re-nest following failure and had higher daily nest survival, both of which contributed to greater annual productivity compared to rock ptarmigan. Annual adult survival showed the opposite pattern to productivity as rock ptarmigan survival was 24 percent higher than white-tailed ptarmigan. This finding suggested a reproduction-survival trade-off exists for the two species, which may be driven by differing susceptibility to environmental factors in the region. Life history theory predicts that if the likelihood of future breeding opportunities is low, individuals should increase current reproductive effort, which may explain why white-tailed ptarmigan have longer breeding seasons and higher reproductive effort under unfavourable climatic conditions. Population models showed that growth rates (λ)were approximately stable for rock ptarmigan (λ=1.01), but declining for white-tailed ptarmigan (λ=0.96). Simulations showed that warmer spring temperatures over the next few decades would elevate λ by ~0.05 for both species, but the extent of increase in λ may be reduced with more variable spring conditions. Population growth will also depend on how changing winter conditions influence survival for each species. Model simulations suggest that if juvenile and adult survival are positively correlated, rock ptarmigan would be more resilient to severe years that simultaneously depress reproduction and survival.

Years of habitat loss, hatchery production and water regulation in the Puntledge River have potentially compromised diversity in coho salmon. Diversity was interpreted from age and early rearing history of mature coho that returned to spawn in 2009 (n=28). Life history groups were interpreted through a visual analysis of the micro-chemistry profiles in the otoliths. There were 2 age classes and 9 life history groups detected. Group differences in Sr:Ca, Ba:Ca and Mn:Ca were significant (p<0.0001) between groups with >2 members (n=6). Cluster analysis using Sr:Ca and Ba:Ca resulted in similar groups. Sr:Ca profiles indicate different rearing habitats, coho that reared in both freshwater and the estuary, and a Jack that reared entirely in the estuary. Results support the need for further studies on the extent of diversity in Puntledge coho, and management actions that identify, restore and protect important rearing habitats.

No description available.