Made available in DSpace on 2017-07-10T17:47:51Z (GMT). No. of bitstreams: 1 Anelise_Carradore_Lutz.pdf: 653471 bytes, checksum: 13b467a27a78c3b2a37a5189e6c50cfe (MD5) Previous issue date: 2013-02-28 / The catfish (Rhamdia branneri) is a native fish endemic to the Iguaçu River that has potential to grow due to their husbandry characteristics, due to this the present work aims to describe its initial development, with a view to commercial exploitation and management for conservation species. The study was conducted at the Experimental Station of Ichthyological Studies in Plant Ney Braga, reservoir Segredo, between January and February 2012. Spawnings were conducted, collected and analyzed 438 eggs, 394 individuals in the larval stage-yolk, 35 in pre-flexion, flexion 15 in, 13 in post-flexion and 1 juvenile. The eggs are yellow, non-adhesive and spherical, have a double membrane, diameter 1.13 mm, the perivitelline space has an average size of 0.21 mm during this period, there were four steps: initial cleavage, early embryo, and embryo free tail end. The larvae hatch after 26:00 hours at a temperature of 23.3 ° C, with mean standard length of 2.60 mm, are slightly pigmented and have a large yolk sac, being poorly developed. The complete absorption of the yolk sac occurs with 5.52 mm and exogenous feeding began with 39:00 hours, and can observe the presence of food in the digestive tract. It can be concluded that the characteristics of eggs, embryonic and larval development are essential for an understanding of the biology of R. branneri. Furthermore, the data constitute an information base for intensive species, and is considered of commercial interest and high potential for fish farming / O jundiá (Rhamdia branneri) é um peixe nativo endêmico do rio Iguaçu que tem potencial para cultivo devido às suas características zootécnicas, devido a isto o presente trabalho tem como objetivo descrever seu desenvolvimento inicial, com vistas ao aproveitamento comercial e manejo para a conservação da espécie. O estudo foi realizado na Estação Experimental de Estudos Ictiológicos, na Usina de Ney Braga, reservatório de Segredo, no período entre janeiro e fevereiro de 2012. Foram realizadas desovas, coletados e analisados 438 ovos, 394 indivíduos no estágio larval-vitelino, 35 em pré-flexão, 15 em flexão, 13 em pós-flexão e 1 juvenil. Os ovos são amarelos, não adesivos e esféricos, apresentam membrana dupla, diâmetro médio de 1,13 mm, o espaço perivitelino tem tamanho médio de 0,21 mm, durante este período, observaram-se quatro etapas: clivagem inicial, embrião inicial, cauda livre e embrião final. As larvas eclodem após 26:00 horas, à uma temperatura de 23,3°C, com comprimento padrão médio de 2,60 mm, são pouco pigmentadas e possuem um saco vitelino grande, sendo pouco desenvolvidas. A completa absorção do saco vitelino ocorre com 5,52 mm e a alimentação exógena iniciou com 39:00 horas, sendo possível observar a presença do alimento no trato digestório. Pode-se concluir que às características de ovos, desenvolvimento embrionário e larval são essenciais para uma melhor compreensão da biologia do R. branneri. Além disso, os dados obtidos constituem uma base de informações para a criação intensiva da espécie, sendo que é considerada de interesse comercial e com alto potencial para a piscicultura

Acidentes com peixes peçonhentos são muito freqüentes na região costeira do Brasil. Os bagres marinhos são os peixes peçonhentos que causam o maior número de acidentes no Brasil, especialmente no litoral sudeste, onde o bagre amarelo Cathorops spixii (Ariidae) é o mais abundante. O acidente é caracterizados por lesão dolorosa, edema intenso e ocasionalmente alguns sintomas sistêmicos. Embora estes sejam muito comuns, apenas nesta década, iniciaram-se os estudos sobre as ações dos venenos. Sendo assim, este trabalho objetivou caracterizar as principais atividades tóxicas (edema, nocicepção, hemorragia, necrose, proteólise, alterações na permeabilidade vascular e na microcirculação) induzidas pelos venenos do muco e do ferrão de C. spixii em modelo murino (Swiss, 20-22g); bem como caracterizar algumas de suas propriedades bioquímicas. Os venenos do muco e do ferrão e a mistura (muco+ferrão) foram testados. Nos ensaios de nocicepção e edema, os venenos(3; 10; 30 ou 60μg / 30μl PBS estéril) foram injetados na pata dos camundongos; para os testes de hemorragia e necrose, 50; 150 ou 300μg / 50μl PBS estéril foram injetados no dorso dos camundongos. Para a proteólise utilizou-se 3; 10; 30 ou 60μg sobre um substrato de caseína. Para a permeabilidade vascular, 10; 30 ou 60μg foram injetados via i.p. Enquanto que as alterações na microcirculação utilizouse 30μg. Ambos os venenos induziram nocicepção a partir de 3μg. Edema foi considerado significativo quando acima de 30% do controle. Todas as doses, para ambos os venenos foram capaz de induzi-lo, com pico após 2h da injeção e permanecendo por até 24h. Hemorragia e necrose não foram induzidas, mesmo após a injeção de altas doses. A permeabilidade vascular foi observada após 2h com todas as doses e venenos testados. As alterações na microcirculação foram observadas para ambos os venenos. Com 30μg observou-se o aumento do rolling de leucócitos (após10 min), extase sanguínea (após 30min, apenas no caso do muco) e contração miofibrilar (após40min). SDS-PAGE (12%) mostrou um perfil eletroforético bastante complexo, com proteínas majoritárias, acima de 97 kDa, com aproximadamente 97 kDa, entre 45 e 60 kDa e entre 20 e 30 kDa, no caso do veneno do muco. E na faixa dos 33 e acima dos 66 kDa no caso do veneno do ferrão. Diferenças são observadas entre as condições redutora e não redutora principalmente nos grupos acima de 97 kDa. A cromatografia em gel filtração não foi eficiente em separar os componentes protéicos de ambos os venenos, porém, evidencia diferenças entre os perfis. O veneno do muco contém proteínas com PI próximo a 5,0. E o ferrão deve ser composto de proteínas primordialmente aniônicas. Estes resultados mostram as importantes ações tóxicas induzidas pelos venenos do bagre marinho C. spixii, além de aspectos bioquímicos, que podem ser úteis no acompanhamento da evolução clínica e tratamento dos acidentados. / Accidents with venomous fishes are very frequent in costal waters of Brazil. Marine catfishes are the venomous fishes that cause the greatest number of accidents in Brazil, specially in southeast littoral, where the yellow-catfish Cathorops spixii (Ariidae) is the most abundant. The accidente is characterized for painful injury, intense edema and some eventul systemic symptoms; ande even these accidents are very commom,only in this decade, studies about its venoms had started. So this work intend to caracterize the main toxic activities (edema, nociception, hemorrhage, necrosis, proteolysis, alterations is vascular permeability and in microcirculation) induced by mucus and sting venom of C. spixii inmurine model (Swiss, 20-22g); besides it\'s biochemical characterization. Mucus, sting and mixture (mucus+sting) venoms were tested. In nociceptive and edematogenic assays venoms (3; 10; 30 or 60μg / 30μl sterile PBS) were injected in mice paw, whereas in hemorrhagic and necrosis assays, venoms (50; 150 or 300μg / 50μl sterile PBS) were injected in mice back. To proteolytic assay, 10; 30 or 60μg were utilized over a casein substrate. To vascular permeability assay 10; 30 or 60μg were injected by i.p. way. Whereas on microcirculation alterations 30μg were aplied over exposed cremaster muscle. All venoms induced nociception with 3 μg or more. Edema was considered significant when over 30% of control group and was induced by all venoms, too, with bottom after 2h, and continuing until 24h. Hemorrhage and necrosis weren\'t observed even so high doses were injected. Alterations on micocirculation were observed for bath venoms. 30μg increased leukocyte rolling (after 10min), blod flow stopped (after 30min, but only with mucus venom), and caused contraction on miofibres (after 40min). SDS-PAGE (12%) showed a complex pattern with several bands allover the gel. Skin and Sting venoms share some identical bands but there are important differences. Mucus venom majority bands are found between 20-30 kDa, 45-60 kDa and over 97 kDa. Sting venom major ones are between 33 kDa and 55-60 kDa. Gel- Filtration (Sephadex) showed 4 (Mucus venom) and 5 peaks (Sting venom). In this differential peak, there are molecules with high molecular weight. These results show that both venoms are able to induce important toxic activities induced by mucus and sting venoms of C. spixii. Besides, biochemical aspects that can be usefull to understand envenonming and propose better treatment.

Estudou-se o sistema porta hepático do bagre africano Clarias gariepinus Burchell, 1822, sob o ponto de vista da anatomia macroscópica e microscópica, utilizando-se várias técnicas anatômicas, que envolveram anestesia, injeção de substâncias recomendadas ao estudo do sistema vascular (látex, nanquim, cloreto de polivinil e substância radiopaca), dissecação, corrosão ou radiografia, conforme a exigência de cada técnica, como meio de compreensão da anatomia vascular do fígado deste peixe. Foram utilizados 16 exemplares do sexo feminino, com comprimento total entre 45 e 53,5 centímetros e massa corpórea entre 575 e 1068 gramas. Para a execução dessas técnicas, os peixes foram devidamente anestesiados com benzocaína, garantindo a narcose profunda e evitando qualquer tipo de sofrimento a eles. Os resultados obtidos com essas técnicas mostram que o fígado de Clarias gariepinus ocupa a cavidade abdominal cranial e apresenta uma lobação bem definida, sendo constituído por dois grandes lobos, denominados direito e esquerdo, conectados cranialmente por uma ponte dorsal à transição entre o esôfago e o estômago. O lobo esquerdo apresenta-se ligeiramente maior que o contralateral. Em suas extremidades caudais, os lobos esquerdo e direito formam um ápice pontiagudo, de formato triangular, que continua tenuemente através de um istmo eminentemente vascular que liga esses ápices a dois outros lobos, chamados acessórios direito e esquerdo, bem menores que os demais, e que ficam seqüestrados em um recesso peritoneal, lateral à cavidade abdominal. Os resultados indicam ainda que o sistema porta hepático de Clarias gariepinus está representado por duas veias portas principais denominadas direita e esquerda, levemente assimétricas em diâmetro, que drenam o sangue das vísceras abdominais (baço, estômago, vesícula biliar, intestino e gônadas) através dos tributários viscerais desse sistema. Ainda, devido a uma situação peculiar dos lobos acessórios, definem-se mais duas veias portas secundárias ligadas às principais e designadas igualmente por acessórias, uma esquerda e outra direita. Ambas as vv. portas principais se ramificam, atingindo o hilo da face visceral, enquanto que as vv. acessórias penetram por uma região restrita do lobo. Através de ramos interlobares, ambas as vv. portas principais se anastomosam no parênquima hepático. A v. porta esquerda, com discreto aumento de diâmetro, forma-se pela terminação da v. intestinal, concomitante à desembocadura da v. gastrointestinal e da v. porta acessória esquerda. A v. porta direita se define pela terminação da v. intestinal cranial, simultaneamente à chegada da v. porta acessória ipsilateral, drenando sangue do intestino médio, estômago e vesícula biliar. Nessa espécie, também estão caracterizados dois sítios de comunicação entre o sistema porta hepático e o sistema porta renal através de anastomoses em cada v. porta. Sob as condições em que o trabalho foi desenvolvido e considerando-se a metodologia proposta e a análise dos resultados, conclui-se que todos os métodos foram adequados ao estudo do aparelho circulatório de Clarias gariepinus, sendo recomendados para experimentos futuros sobre o mesmo assunto em outras espécies piscícolas; porém, dentre as três metodologias utilizadas para análises macroscópicas, a injeção de cloreto de polivinil seguida de corrosão das peças e subseqüente obtenção de moldes vasculares mostrou-se mais eficiente na marcação e identificação dos vasos que compõem o sistema porta hepático deste peixe. Conclui-se também que, devido à presença dos lobos acessórios, a lobação hepática é peculiar nesta espécie, em virtude da posição ocupada por estes lobos, assim como a circulação porta, em função das duas veias porta acessórias, e ainda a anastomose entre as duas veias porta principais, característica que deve ser considerada em trabalhos que envolvam cirurgia hepática no bagre africano / The hepatic portal system of the African catfish Clarias gariepinus Burchell, 1822, was studied considering the macroscopic and microscopic anatomy, by means of several anatomic techniques, including anesthesia, injection of substances recommended to the study of the vascular system (latex, Indian ink, polyvinyl chloride and radiopaque substance), dissection, corrosion or radiography, according to the requirement of each technique, as a way of understanding the hepatic circulatory pathway in the African catfish. Sixteen female specimen were used, being the entire length between 45 and 53.5 centimeters and the corporal mass between 575 and 1068 grams. To perform these techniques, the fishes were adequately anesthetized with benzocaine, assuring the deep narcosis and preventing them from any suffering. The results obtained through such techniques show that the liver of Clarias gariepinus occupies the cranial abdominal cavity and shows a clear lobation, the liver consisting of two large lobes, called right and left, cranially connected by a bridge dorsal to the transition between the esophagus and the stomach. The left lobe is slightly larger than the contralateral lobe. At their caudal ends, the left and the right lobes form a sharp triangle-like apex that tenuously passes through a strip eminently vascular that links these apexes with two other lobes, called right and left accessories, much smaller than the others, these lobes being wrapped in a peritoneal recess, situated at the side of the abdominal cavity. The results still show that the hepatic portal system of Clarias gariepinus is represented by two main portal veins named right and left, slightly asymmetric in diameter, that empty the blood out of the abdominal viscera (spleen, stomach, gall bladder, intestine and gonads) through the visceral tributaries of this system. Furthermore, due to a peculiar situation of the accessory lobes, two other secondary portal veins were defined; they are connected to the main veins and are equally called right and left accessories. Both the main portal veins branch, reaching the hilum of the visceral face, whereas the accessory veins go into a restricted region of the lobe. Through interlobar branches, both the main portal veins anastomose in the hepatic parenchyma. The left portal vein, with a slight increase in diameter, is formed by the terminatio of the intestinal vein, accompanying the discharge of the gastrointestinal vein and the accessory left portal vein. The right portal vein is defined by the terminatio of the cranial intestinal vein, simultaneously with the accessory ipsilateral portal vein, emptying the blood out of the medial intestine, stomach and gall bladder. In this species it is also possible to distinguish two connecting sites between the hepatic portal system and the renal portal system by means of anastomoses in each portal vein. Under the conditions in which the experiment was carried out and considering the methodology suggested and the analysis of the results, it is concluded that all the methods were suitable for the study of the circulatory system of Clarias gariepinus, being recommended for future tests on the same subject in other fish species; however, among the three methodologies used in the macroscopic analyses, the injection of polyvinyl chloride followed by the corrosion of pieces and subsequent getting of vascular moulds was believed to be more efficient at the marking and identification of the vessels that compose the hepatic portal system of this fish. It was also concluded that, due to the presence of the accessory lobes, the hepatic lobation is peculiar in this species because of the position occupied by these lobes, as well as the portal circulation, caused by the two accessory portal veins, in addition to the anastomose between the two main portal veins, a characteristic that must be thought of in studies of hepatic surgery in the African catfish

M.Sc. / The Lesotho Highlands Water Project (LHWP) is bound to adversely affect the ecology of the Orange River system and in particular the highland tributaries. The Senqunyane River (a tributary of the Orange River) would be no exception. Water extraction by means of the proposed Mohale Dam (Phase 1B of LHWP) is expected to alter the downstream habitat of the Senqunyane River, which is alarming as the rare rock catfish (Austroglanis sclateri) occur in these waters. Another concern is the lack of knowledge on the riverine ecology as no research has been conducted in the Senqunyane River downstream from the proposed Mohale Dam wall. In order to gain baseline information on the aquatic habitat, distribution and composition of the fish community as well as habitat parameters of the rock catfish , four surveys (from Spring 1994 to Summer 1996) were conducted in the Senqunyane River, major tributaries and in the Senqu River. This information is needed for future monitoring of downstream alterations to the riverine ecosystem and to determine the habitat preference of A. sclateri. Water quality variables were generally in accordance with the guidelines of Kempster, Hattingh & Van Vliet (1980) and the Department of Water Affairs and Forestry (1993), but excessive levels of un-ionized ammonia and phosphates were recorded at antropogenically disturbed areas. Two distinctly different fish communities were respectively found upstream and downstream from the Semongkoaneng Waterfall as this waterfall serves as a migration barrier. The upstream community consists entirely of Psemlobarbus quathlantbae (Maloti minnow), while the downstream community consists of Barb us amens (Smallmouth yellowfish). Labe() capensis (Orange River mudfish). Austraglanis .cclateri (rock catfish) and Oncorhunchus An ecological investigation of the aquatic vertebrates below the proposed Mohale Darn Wall in the Senqunyane River, Lesotho, with emphasis on the rock catfish (Austroglanis sclateri) al1111111Hry mykiss (Rainbow trout). B. aeneus has the highest-representation within this community while 0. mykiss has the lowest representation. Low numbers of the latter species is probably related to the temperature regime and bottom siltation and therefore the Senqunyane River can be regarded as of a marginal area for the occurrence of trout. A. sclateri also has a low representation within the community which is probably a result of its specific habitat requirements as apposed to 13. aeneus and L. capensis which utilize a wider variety of habitat types. Distinctly different habitat preferences were observed for different A. sclateri lifestages. Recruits preferred backwater pools, juveniles preferred suckles and adults preferred runs. It is clear that juveniles and adults prefer strong current velocities and would probably not do well in conditions of reduced flow. A. sclateri could therefore be regarded as an indicator species in the context of instream flow requirements for the Senqunyane River below the proposed Mohale Dam wall.

Aquaculture is playing an important role in the development of fisheries in Vietnam, a role which has accelerated since 2000. Sustainability in aquaculture is receiving increasing attention, and this issue is not only the concern of government, but also stakeholders participating in the value chain. Therefore, this study aims to identify sustainability issues of farmed seafood by assessing the main sustainability issues raising concern. The Global Value Chain framework described by Gereffi et al. (2005) is applied for this study to explore the business relationships in supply chain and the perceptions of sustainability concerned by the value chain actors. A combination of qualitative and quantitative methods was used to collect data. An assessment of four species cultured on the Mekong Delta, the countries farmed seafood ‘hub’, found a clear distinction between species cultured with a local domestic market orientation (Giant Freshwater Prawn Macrobrachium rosenbergii; and Tilapia Oreochromis niloticus) and the two key export commodities - Striped catfish (Pangasianodon hypophthalmus) and Penaeid shrimp (Penaeus monodon & Litopenaeus vannamei). These orientations were based on a range of factors including the development of effective seed supplies and the cultural value of marketing in the live format. This study, conducted in ten provinces in the Mekong Delta from 2009 to 2013 had a focus on understanding the export-orientated commodities, striped catfish and shrimp through collection of baseline information on the value chain of farmed seafood, focusing on the farming sector, the actors and institutions involved and beneficiaries. Sustainability issues and perceptions of experts (top-down) and primary stakeholders (bottom-up) opinions were assessed through participatory workshops. Shrimp and striped catfish production are mainly farmed for export, with 83% and 95% of its production, respectively, leaving the country mainly after processing. Currently, mainly families operate small-/medium-scale farms; while large-farms are integrated within seafood processors. Production efficiency of large-farms tends to be better than small-/medium farms. Many striped catfish and shrimp farms are likely to reach several standard criteria such as economic feed conversion ratio (eFCR), stocking density, no banned chemical/drug and wild-seed use, and land property rights; however, there were still many standard criteria that existing farms could not meet such as effluent management, farm registration, fishmeal control, farm hygiene and record-keeping requirement. Hence, current farming practices, especially small-/medium farms have a long way to go to meet emergent international food standards. Recently, many small-/medium catfish farms faced problems with low fish prices, so they have had to cease catfish farming activities and temporarily stop farming; while some larger farms also had to temporarily stop farming. Therefore, fish price has tended to be a main driving force for catfish farm changes. In the shrimp industry, there were technical changes occurring in the high intensity level of shrimp farms (HiLI); whereas, the remaining shrimp farms had fewer changes in farm management. Most HiLI shrimp farms were affected by AHPNS disease, which was a main factor driving their farm changes. Many perceptions of sustainability were identified by stakeholder groups, however seven sustainability issues had a high level of agreement among stakeholders including input cost, capital & credit costs, unstable markets, government regulation & policy, disease, seed quality, water quality and water availability factors. Hatcheries, farmers and manager groups were more concerned about environmental issues; while for the input suppliers and processors, economics was the main issue. Farmers and processors were two main actors that played an important role in the production process of the value chain. Small-/medium farms dominated the number of farms overall and still played an important role in primary production. However, small-scale farms were considered as more vulnerable actors in the value chain, and they faced more difficulties in meeting increasing requirements on food quality/safety. To maintain the position in the value chain, the solutions could be horizontal and vertical coordination. Thus policy makers will need to find ways to include them in the planning processes. To reach sustainability will require the efforts of direct stakeholders, the role of the state agencies is essential in negotiation and diplomacy to create partnerships with the seafood importing countries. However, efforts to develop sustainable production become impossible without participation from importers, retailers and consumers.

Knowledge of Wels Catfish (Silurus glanis) at its northernmost distribution area is limited on even basic behavioral characteristics, such as habitat preferences and activity patterns. It has thus proven difficult to aid the species in any predictable way. In a telemetry study on Wels Catfish, I examined habitat preferences, activity patters and site fidelity of ten adult individualsat their most northern range. Fish were surgically equipped with acoustic transmitters, frequently recording the position of each individual in a small Swedish lake. Wels Catfishpreferred deeper areas than randomly expected during the entire year, except for late spring and early summer. This indicates that spawning took place at shallow, vegetated areas in May-June 2019. Fish were highly active during summer, utilizing the entire lake. Behavior shifted during winter as fish became bottom dwelling with minimal activity, small home ranges and likelyminimal feeding. Wels Catfish had a nocturnal activity pattern during the entire year, but especially during summer. Fish preferred shallower areas during night than during day, indicating that deeper areas were used for resting and shallower areas for foraging. Lastly, home ranges were much larger than expected during summer, implying that S. glanis might be less territorial in small lakes than previously believed. In summary, conservation efforts should focus on protecting and restoring shallow areas with lots of vegetation and food items, adjacent to deep areas with underwater structures. These areas are important for the survival of S. glanisas they fulfill requirements for feeding, reproduction, resting, and hibernation.

Black Carp (Mylopharyngodon piceus) is an invasive fish species native to Asia that has become increasingly abundant within the Mississippi River Basin during the past decade. Originally introduced to control snails that are an intermediate host for trematode parasites of fishes in aquaculture ponds, Black Carp are now present in several rivers in the U.S. and represent a potential threat to threatened and endangered mussel populations. Black Carp have historically been classified as molluscivores; however, a recent study that examined gut contents of Black Carp collected from the Mississippi River Basin indicated that Black Carp are opportunistic consumers that prey upon a wide variety of invertebrates and are flexible in their feeding modes. Despite the potential for Black Carp to compete with native riverine fish species for invertebrate prey, only one published study has compared Black Carp trophic position with that of native fishes in a small portion of the Black Carp’s invaded range. Therefore, the objectives of this study were to assess trophic overlap between Black Carp and two fish species native to the Mississippi River Basin using isotopic niche analysis and gut contents analysis. Dorsal muscle tissue samples were collected from Black Carp, Freshwater Drum (Aplodinotus grunniens), and Blue Catfish (Ictalurus furcatus) and analyzed for δ13C and δ15N to assess each species’ isotopic niche. Freshwater Drum and Blue Catfish gut contents were also removed and analyzed and compared to published Black Carp stomach contents data. Gut contents analysis indicated differences in diet composition between Black Carp and the two native fish species. Chironomidae had the highest frequency of occurrence (67%) and percent of taxa by number (47%) for Freshwater Drum. Trichoptera had the highest frequency of occurrence (58%) and percent of taxa by number (30%) for Blue Catfish, and Gastropoda had the highest frequency of occurrence (16.5%) of any specific prey taxa for Black Carp. Black Carp showed low isotopic niche overlap (≤47%) with both native species when muscle tissue δ13C and δ15N data from all fish collection locations were combined and when assessment of isotopic niches was restricted to the subset of locations where all three species were collected. Isotopic niche overlap was also low (10-48%) between Black Carp and both native species when isotopic niches were compared at individual collection locations. Intraspecific isotopic niche overlap among fish collection locations was highly variable (0-69%) within each of the three species, highlighting the need to assess interspecific isotopic niche overlap by collection location. Broad isotopic niches exhibited by Black Carp in the Mississippi River and tributaries are indicative of substantial trophic diversity among individuals and use of multiple basal energy sources, consistent with a recently published study which found that Black Carp diet composition differed among individuals and that Black Carp consumed a variety of invertebrates, including non-benthic taxa.

A Catfish Management Database (CMD) was developed to analyze data from large commercial catfish farms. The CMD was developed so that data collected by the farm could be used for management of the farm and for identifying some of the risk factors associated with important bacteria diseases. This database was designed to 1) to incorporate production data already being recorded for generating reports for use at weekly managerial meetings focused on feeding rates, feed conversion ratios, mortalities and harvesting events 2) be easily used by a catfish farmer to collect management data in order to analyze production efficiency through a series of farmer defined management reports and 3) provide the farm with easy access to management reports. Additional customized reports can be generated as requested by the farm management. The next objective of this research was to determine pond level risk factors associated with columnaris disease and Enteric Septicemia of Catfish related mortalities. The data from the CMD was used to produce two publications detailing the analysis of the data and production of a univariate and multivariate models of pond level risk factors associated with both diseases. These studies showed some commonly recorded production variables were associated with either columnaris and/or ESC associated mortalities and if monitored could help identify “at risk” ponds prior to disease outbreaks. A study was then conducted to examine the cost associated with mortality on Mississippi commercial catfish farms. The mortalities examined included ponds that had mortalities from columnaris disease, ESC and then any ponds that had mortalities from either. The cost of each disease was determined along with other factors such as pond age, feed conversion ratio and feed cost that influence the profitability of a commercial catfish farm.

Drepanocephalus auritus is a digenetic trematode parasitizing the double-crested cormorant, a piscivorous waterbird often found feeding on catfish aquaculture ponds in Mississippi. The aquatic snail Planorbella trivolvis was the only known intermediate host in Mississippi until a new snail host, Biomphalaria havanensis, was discovered releasing cercariae belonging to North and South American D. auritus haplotypes. In addition, previous work has reported D. auritus metacercariae begin to resolve in channel catfish 7-21 days post-infection. As a result, a 2-year study was undertaken to elucidate the life cycle of D. auritus and identify if channel catfish can serve as a true intermediate host. In year 1, the role of the channel catfish as a true intermediate host was established, as gravid adults were recovered from double-crested cormorants fed parasitized fish. In year 2, each step of the life cycle was completed, and developmental timelines for each life stage were established.

Edam and Cheddar whey were thermized (T) for different time periods (5–30 min) at 70 degrees Celsius, vacuum evaporated, and spray dried to obtain whey powders (WP). Native and thermized WP were evaluated for antioxidative properties. Edam and Cheddar WP significantly reduced thiobarbituric acid-reactive substances (TBARS) and peroxide value (PV) in ferric-catalyzed soybean oil emulsions. Thermization significantly improved antioxidative properties of WP with 5T, 10T, and 15T treatments showing better protective effects compared to 20T and 30T treatments. Based on these results, native (0T) and thermized (5T, 10T, and 15T) Edam and Cheddar WP coatings, with and without enzymatically hydrolyzed casein (CH), were used to reduce oxidative degradation and moisture loss of cubed beef steak and pork loin. Thermized treatments significantly reduced TBARS and PV in both types of meat, with CH containing treatments showing enhanced antioxidative properties. Protein oxidation as reflected by carbonyl formation and a decrease in sulfhydryls was also reduced by thermization. Treated and native WP coatings significantly reduced moisture loss of meat samples. Cubed beef steak treated with Cheddar WP coatings were evaluated for microbiological quality and basic sensory attributes. Although not statistically significant, 5T, 10T, and 10TCH treatments numerically showed potential for microbial reduction up to 4 days of storage. Sensory evaluation showed significant protection of key sensory attributes by treatments throughout the storage period when compared to controls with the 5 min thermization showing the best effect on lowering offlavor development based on sensory scores. The effect of pH and glucomannan (GM) on antioxidative properties of thermized (5T) Cheddar WP coatings applied to catfish fillets was also investigated. Coatings at pH 7.0, 7.5, and 8.0 (with GM) showed markedly greater protection against oxidative degradation compared to coatings without GM, as reflected by TBARS values and PV after 7 days of storage. Carbonyl formation and oxidation of sulfhydryl groups were also significantly reduced by coatings containing GM. Cheddar WP-based edible coatings (pH 7.0–8.0) with GM markedly reduced lipid oxidation and protein oxidation of fresh catfish fillets.