The limnological investigation of any body of water is undertaken in order to secure more accurate information concerning the factors which play an important role in fish production or sanitation. This study shows the qualitative and quantitative planktonic algae in Lake Dallas, for the year 1937-38.

Marine protected areas (MPAs) have received much attention recently as an innovative approach to restoring and protecting valued ocean resources. The acceptability of MPAs in the U.S. will depend, to a large extent, on society's perceptions regarding the relevant costs and benefits of such areas. In order to incorporate social impact information into marine resource management decisions, it is necessary to study the values, beliefs and attitudes of affected stakeholders. The cognitive hierarchy model provides a theoretical framework for understanding relationships among these cognitions. According to this model, value orientations and beliefs can directly influence attitudes toward a particular attitude object. This study utilized the cognitive hierarchy model to investigate relationships among saltwater anglers' value orientations, beliefs and attitudes connected with MPAs. The moderating effects of recreation specialization and MPA knowledge on these relationships were also explored. Data were collected using a mail survey sent to a representative sample of private boat saltwater anglers in the Northeast United States. Attitudes were measured for four types of hypothetical MPAs ranging from least to most restrictive on saltwater anglers. Three value orientations (biocentric/anthropocentric, general marine resource values, and open access/ocean zoning) and three higher order beliefs (health of the oceans, impact of recreational fishing, and long-term effect of recreational catch reductions on fishing quality) were measured. Ocean zoning/open access value orientation and beliefs about the ocean's health were the best predictors of MPA attitudes. As hypothesized, anglers with ocean zoning value orientations hold more favorable attitudes towards marine protected areas than do anglers with open access value orientations. Similarly, anglers who believe that the oceans are in poor health hold more favorable attitudes towards marine protected areas than do anglers who believe the oceans are relatively healthy. Recreation specialization and MPA knowledge were not found to have a moderating effect for most cognitive relationships tested. However, for highly specialized anglers, the variable measuring beliefs about the impact of recreational fishing on the marine environment was significantly correlated with attitudes towards the MPA alternative allowing only “catch and release” recreational fishing. Implications of these results for marine resource policy and management are discussed.

The role of autotrophic production in different coastal habitats in the production of fish in estuaries is an important consideration in coastal management and conservation. In the estuarine waters of the Australian east coast, many economically important fish species occur over mudflats lacking conspicuous vegetation. I used stable isotope analysis to examine where such fish ultimately derived their nutrition, in the subtropical waters of southern Moreton Bay, Queensland, Australia. I first tested traditional processing methodologies of autotroph samples, in this case of mangrove leaves, and examined variability in mangrove isotope values at different spatial scales. Mangrove leaves processed using time-consuming grinding showed no significant difference in isotope values than coarsely broken leaf fragments. Isotope values of green leaves were not meaningfully different from yellow or brown leaves that would normally be the leaves that actually dropped on to the sediment. Future analyses therefore can use green leaves, since they are more abundant and therefore more easily collected, and can simply be processed as whole leaf fragments rather than being ground to a powder. Carbon and nitrogen isotope values varied at several spatial scales. The proportion of variability partitioned at different scales varied depending on the species of mangrove and element (C or N) analysed. To properly represent a geographic area, isotope analysis should be done on leaves collected at different locations and, especially, from different trees within locations. The autotrophic source(s) supporting food webs leading to fish production on mudflats might be either in situ microphytobenthos or material transported from adjacent habitats dominated by macrophytes. I tested the importance of these sources by measuring ?13C values of 22 fish species and six autotroph taxa (microphytobenthos on mudflats, and seagrass, seagrass epiphytic algae, mangroves, saltmarsh succulents and saltmarsh grass in adjacent habitats) in Moreton Bay. I calculated the distribution of feasible contributions of each autotroph to fishes. All fish ?13C values lay in the enriched half of the range for autotrophs. For over 90% of fishes, the top three contributing autotrophs were seagrass, epiphytes and saltmarsh grass, with median estimates of approximately 60-90% from these sources combined. Seagrass was typically ranked as the main contributor based on medians, while epiphytic algae stood out based on 75th percentile contributions. The other three sources, including MPB, were ranked in the top three contributors for only a single fish. Organic matter from seagrass meadows is clearly important at the base of food webs for fish on adjacent unvegetated mudflats, either through outwelling of particular organic matter or via a series of predator-prey interactions (trophic relay). Modelling results indicate that saltmarsh grass (Sporobolus) also had high contributions for many fish species, but this is probably a spurious result, reflecting the similarity in isotope values of this autotroph to seagrass. Carbon from adjacent habitats and not in situ microphytobenthos dominates the nutrition for this suite of 22 fishes caught over mudflats. The ultimate autotrophic sources supporting production of three commercially important fish species from Moreton Bay were re-examined by further analysing carbon and nitrogen stable isotope data. Mean isotope values over the whole estuary for fish and autotroph sources were again modelled to indicate feasible combinations of sources. Variability in isotope values among nine locations (separated by 3-10 km) was then used as a further test of the likelihood that sources were involved in fish nutrition. A positive spatial correlation between isotope values of a fish species and an autotroph indicates a substantial contribution from the autotroph. Spatial correlations were tested with a newly developed randomisation procedure using differences between fish and autotroph values at each location, based on carbon and nitrogen isotopes combined in two-dimensional space. Both whole estuary modelling and spatial analysis showed that seagrass, epiphytic algae and particulate organic matter in the water column, potentially including phytoplankton, are likely contributors to bream (Acanthopagrus australis) nutrition. However, spatial analysis also showed that mangroves were involved (up to 33% contribution), despite a very low contribution based on whole estuary modelling. Spatial analysis for sand whiting (Sillago ciliata) demonstrated the importance of two sources, mangroves and microalgae on the mudflats, considered unimportant based on whole estuary modelling. No spatial correlations were found between winter whiting (Sillago maculata) and autotrophs, either because fish moved among locations or relied on different autotrophs at different locations. Spatial correlations between consumer and source isotope values provide a useful analytical tool for identifying the role of autotrophs in foodwebs, and were used here to demonstrate that organic matter from adjacent habitats, and in some cases also in situ production of microalgae, were important to fish over mudflats. Whilst recognising that production from several habitats is implicated in the nutrition of fishes over mudflats in Moreton Bay, clearly the major source is from seagrass meadows. Organic matter deriving from seagrass itself and/or algae epiphytic on seagrass is the most important source at the base of fisheries food webs in Moreton Bay. The importance of seagrass and its epiphytic algae to production of fisheries species in Moreton Bay reinforces the need to conserve and protect seagrass meadows from adverse anthropogenic influences.

Upwelling, atmospheric nitrogen (N2) fixation by cyanobacteria, and freshwater inputs from the Mississippi River system have been shown to stimulate new production by alleviating nitrogen (N) limitation in the northern Gulf of Mexico (GoM). Stable carbon (delta13C) and nitrogen (delta15N) isotopes were used to investigate whether these sources are utilized differentially by coastal and marine pelagic food webs. Particulate organic matter (POM), Trichodesmium, and zooplankton were collected from the Mississippi River plume and Loop Current (LC) which were detected using remote sensing data. Stable isotope values were used to separate coastal and marine water masses and environmental data (salinity, nutrient and pigment concentrations) allowed me to relate variability to the degree of freshwater influence. Published food web data from these two environments were then assessed to establish whether isotopic baseline shifts observed in our data occur at an ecosystem level. Isotope values of the POM and zooplankton were found to be significantly different between coastal and marine water masses. This was not the case for Trichodesmium whose isotope values were not significantly different between the two water masses. We found that marine water masses (sal > 35) exhibited silicate concentrations, cyanobacterial pigments and DIN: P that suggest an increased abundance of diazotrophs. In contrast, coastal water masses (sal < 35) exhibited increased diatom pigments and molar C:N indicating terrestrial sources fuel phytoplankton production. When published food web data were compared, we found producer and consumer delta15N values were enriched in the coastal compared to the marine environments. This work suggests that differences in delta15N values within my data set and published data reflect a shift in the use of biologically available N where higher trophic levels are sustained by diazotrophic activity in marine environments versus those supported by terrestrial sources in coastal ones. Food webs that have been constructed without considering Trichodesmium as a significant source of organic matter in the GoM should be reconsidered. By re-evaluating published data, this research gives insight into the early life ecology of larval fishes and works to help answer questions about the structure and function of pelagic food webs.

The observation was carried out in twenty fishponds in the surrounding of Vodňany and seven fisponds in the surrounding of Třeboň. The aim of the work was to evaluete the quality and quantity of the zooplankton depending on fish production. The samples were obtained and the observations were realized during the 4 years in Vodňany fishponds area and during the 2 years in Třeboň fishponds area. At first the samples were collected and data about the observed localities were organized. These data should explain changes in the aquatic ecosystems of these fishponds areas during the last decades.

Submitted by biblioteca unifenas (biblioteca@unifenas.br) on 2017-08-30T13:16:05Z No. of bitstreams: 1 Grenei Alves de Jesus dissertação.pdf: 560677 bytes, checksum: b388ca79e03c073423728ad41787d1ae (MD5) / Made available in DSpace on 2017-08-30T13:16:05Z (GMT). No. of bitstreams: 1 Grenei Alves de Jesus dissertação.pdf: 560677 bytes, checksum: b388ca79e03c073423728ad41787d1ae (MD5) Previous issue date: 2017-03-21 / Tilapia farming grows significantly throughout the national territory, mainly due to the market acceptance of tilapia fillet and the productive characteristics of this species. Although the productive chain of tilapia has shown great development in the last years, some obstacles are still persistent, like the high mortality rates and slow growth after allocation of the fingerlings or juveniles in the net tanks. The aim of this study was to evaluate the zootechnical characteristics of Nile tilapia (Oreochromis niloticus) fingerlings submitted to supplementation with crude green propolis. The animals were purchased at the commercial property Aquaminas, located in the city of São João da Mata, MG. Propolis was extracted from colonies of Apis mellifera bees, settled in an apiary in the Municipality of Cabo Verde, in the South of Minas Gerais, belonging to the Apiário Sol-Exportadora de Apiculas Company. A completely randomized design was used, with three treatments and three replications, with subdivision of plots. The experiment consisted of two phases. In the first phase, 1800 animals were used, masculinized, with an average weight of 1.5 ± 0.5g, distributed in six boxes of 500 liters, with aeration and constant water flow. In the second phase the plots were subdivided into 12 subplots and taken to net tanks. These tanks were randomly distributed in a conventional masonry tank (20 x 5 x 1 m) under ambient growing conditions. The water temperature, pH and dissolved oxygen were measured daily. Every two days the amount of total ammonia and nitrite were analyzed. The diets were elaborated with increased commercial diets with three levels of propolis concentrations (0, 1 and 2%). The rations used in the diet of the first phase were slurried and pelleted (1.8 mm), with 56% and 42% crude protein, respectively. In the next phase, to prepare the diet, pelleted ration with granulometry of 3 millimeters and 42% crude protein was used. Fish were fed four times daily in amounts of 10% of live weight. At the end of the experiment the following performance parameters were evaluated: standard length, total length, final weight, weight gain, apparent feed conversion and biomass. Fish consuming the feed supplemented with 1 and 2% crude green propolis showed higher growth. In view of the obtained data we conclude that the crude green propolis had efficacy as a growth promoter for Nile tilapia fingerlings. / A tilapicultura cresce de forma expressiva em todo o território nacional, devido principalmente à aceitação do mercado ao filé de tilápia e às características produtivas desta espécie. Embora a cadeia produtiva da tilápia tenha mostrado grande desenvolvimento nos últimos anos, alguns entraves ainda são persistentes, como as altas taxas de mortalidade e o crescimento lento após a alocação dos alevinos ou juvenis nos tanques-redes. Portanto, é necessário pesquisa que avalie alternativa para melhorar esses índices. Objetivou-se neste trabalho avaliar as características zootécnicas de alevinos de tilápia do Nilo (Oreochromis niloticus) submetidos à suplementação com própolis bruta verde. Os animais foram adquiridos da propriedade comercial Aquaminas, situada na cidade de São João da Mata, MG. A própolis foi extraída de colônias de abelhas Apis mellifera, instaladas em um apiário no Município de Cabo Verde, no Sul de Minas Gerais pertencente à Empresa Apiário Sol-Exportadora de Produtos Apícolas. Foi utilizado um delineamento inteiramente casualizado, com três tratamentos e três repetições, com subdivisão de parcelas. O experimento contitui-se de duas fases. Na primeira fase, foram utilizados 1800 animais, masculinizados, com peso médio de 1,5 ± 0,5g, distribuídos em seis caixas de 500 litros, com aeração e fluxo de água constante. Na segunda fase, as parcelas foram subdividas em 12 subparcelas e levadas para tanques-rede. Esses tanques foram distribuídos aleatoriamente em um tanque convencional de alvenaria (20 x 5 x 1 m) em condições ambientais de cultivo. A temperatura da água, o pH e oxigênio dissolvido foram aferidos diariamente. A cada dois dia foi analisada a quantidade de amônia total e de nitrito. As dietas foram elaboradas com rações comerciais incrementadas com três níveis de concentrações de própolis (0; 1 e 2%). As rações utilizadas na dieta da primeira fase foram na forma farelada e peletizada (1,8 mm), com 56% e 42% de proteína bruta, respectivamente. Na fase seguinte, para compor a dieta, utilizou-se ração peletizada com granulometria de 3 milímetros e com 42% de proteína bruta. Os peixes foram alimentados quatro vezes por dia em quantidades de 10% do peso vivo. Ao fim do experimento, avaliaram-se os seguintes parâmetros de desempenho: comprimento padrão; comprimento total; peso final; ganho de peso; conversão alimentar aparente e biomassa. Peixes que consumiram a ração suplementada com 1 e 2% de própolis bruta verde mostraram maior crescimento (p<0,05). Diante dos dados obtidos, conclui-se que a própolis bruta verde teve eficácia como promotora de crescimento para alevinos de tilápia do Nilo.

The morphology and physiology of crustacean cardiovascular systems has long been regarded as poorly organized and loosely controlled, systems serving only as a conduit to carry hemolymph. Current investigations of cardiovascular systems of decapod Crustacea have revealed an organization that is more complex than previously thought. The purpose of this research is to extend the study of crustacean cardiovascular physiology by investigating the hemodynamics of the freshwater crayfish, Procambarus clarkii, and the lobster, Homarus americanus. Crayfish and lobster were exposed to a P$\sb{\rm O\sb2}$ of 150 mmHg (control) followed by P$\sb{\rm O\sb2}$s of 25, 40, 75 and 115 mmHg O$\sb2$. Arterial hemolymph velocities were measured (Pulsed Doppler system) in the major arteries of crayfish and lobster. Hemolymph pressures were measured throughout the circulatory system of the crayfish. The cardiovascular response of hypoxic crayfish to injection of hyperoxic water into the branchial chamber was monitored to determine the location of O$\sb2$ receptors. Heart frequency in both species decreased as water P$\sb{\rm O\sb2}$ was lowered. Cardiac output was maintained in the crayfish due to an increase in stroke volume. Hemolymph flow increased to the anterior aorta only. Hemolymph pressures and ventilatory frequency increased down to a P$\sb{\rm O\sb2}$ of 50 mmHg O$\sb2$; below this all parameters declined. Cardiac output and stroke volume in the lobster were maintained down to a P$\sb{\rm O\sb2}$ of 75 mmHg O$\sb2$; at lower P$\sb{\rm O\sb2}$s cardiac output declined as a result of the hypoxia induced bradycardia. Hemolymph flow increased in the lateral arteries and ventral thoracic artery. Hypoxic crayfish showed a rapid increase in cardiovascular parameters (2.5 second) with a long lag in the respiratory response (75 seconds) to injection of hyperoxic water into their branchial chamber. Injection of hyperoxic water into animals that had defined gill sets removed indicates the presence of O$\sb2$-sensitive chemoreceptors in the posterior region of the branchial chamber. The redistribution of cardiac output in crayfish and lobster results in a maintenance of hemolymph flow to the anterior regions of the animals. The maintenance of cardiac output with hypoxia may not be solely related to maintaining M$\sb{\rm O\sb2}$, but may play a role in maintaining oxygen delivery to nervous tissue. The response to a declining water P$\sb{\rm O\sb2}$ is mediated by O$\sb2$ receptors associated with the posterior gills.

The neuroanatomical distribution and the physiological role of the biogenic amine octopamine was investigated in the prosomal central nervous system (CNS) of the horseshoe crab, Limulus polyphemus. Perfusion of octopamine onto the isolated CNS elicited the rhythmic feeding motor pattern in the entocoxal motor nerves which innervate the feeding musculature. The specific effects of octopamine on the CNS and the pharmacology of its action are described. The stimulation of the feeding motor program at concentrations comparable to that of octopamine by the octopamine agonists NC-5, NC-7, and NC-13, the diterpene adenylate cyclase activator forskolin and the cyclic AMP analogue, 8-bromo cyclic AMP indicated that octopamine's effects may be mediated by a second messenger. The putative octopamine antagonists tested were ineffective or weakly blocked the effects of octopamine. The distribution and localization of octopamine in the prosomal CNS was determined by light and electron microscopic immunocytochemistry. Sixteen discrete clusters of octopamine-like immunoreactive (Oct-LIR) neurons were found in the circumesophageal ring (CER) of fused thoracic ganglia. The distribution of these immunoreactive cells are described. The immunoreactive somata are 40 to 100 $\mu$m in size and are found in clusters of 12-24 cells. There is extensive distribution of Oct-LIR nerve fibers in Limulus; the wide distribution of Oct-LIR provides an anatomical basis for the several effects of octopamine in Limulus. The subcellular localization of octopamine in Oct-LIR terminals in the CER was determined by postembedding immunoelectron microscopy with a 5 nm immunogold label. Labelled terminals are morphologically unique; they contain large, dense-core granules of a distinct shape, typically cylindrical with an indentation or depression in one end. These large granules are typically 100-150 nm in diameter and 150-400 nm in length. The dense labelling of these unusual granules with the gold particles indicates that octopamine is sequestered in or associated with these granules.

No description available.

No description available.