Metodologia di editing immagini per analisi dati morfometrici dei primi stadi di sviluppo di Engraulis encrasicolus (Linnaeus, 1758)

Tra le più importanti risorse alieutiche di molte regioni del Mar Mediterraneo vi sonole acciughe (Engraulisencrasicolus, Linnaeus, 1758), piccoli pesci pelagici appartenenti alle famiglie degli Engraulidae. Dati IREPA del 2009, hanno di fatto reso noto che in Italia, la pesca di E. encrasicolusha rappresentano in media il 26% circa del pescato totale. Questa specie viene continuamente monitorata e grazie a tali programmi è stato evidenziato che vi sono delle fluttuazioni inter-annuali molto pronunciate (Cergoleet al., 2002; Cingolani, 2004), le cui cause possono essere molteplici, da fattori antropicicome l’elevato sforzo di pesca a fattori naturali (Borjia et al., 1996). Va però posta molta attenzione sulle dinamiche biologiche ed ambientali che influiscono sulla sopravvivenza dei primi stadi di vita di questa specie, che ricadendo sul successivo reclutamento, possono essere una delle cause fondamentali delle contrazioni e degli incrementi annuali dello stock adulto (Thikonova et al., 2000; James et al., 2003; Cuttitta et al., 2003, 2006).Lo studio delle fasi ittioplanctoniche e delle sue relazioni con l’ambiente e gli altri organismi, risulta quindi di primaria importanza nell’ambito delle conoscenze necessarie per il corretto sfruttamento delle risorse alieutiche.

Estrutura e dinâmica de populações de Hydrochoerus hydrochaeris (Linnaeus, 1766) (Rodentia) em duas áreas urbanas no norte do Paraná, Brasil

This study aimed to evaluate the population ecology of Hydrochoerus hydrochaeris (Linnaeus, 1766) in two urban areas in the north of Paraná, an open and other protected by assessing the effects of these two different types of environments on the structure and dynamics of the population and its implications for conservation of the species. The monitoring of the populations were performed monthly between June 2014 and March 2015 in Jaboti Lake Park (Apucarana / PR) and Conservation Unit Parque Arthur Thomas (Londrina / PR). To conduct the survey population data was used the methodology of total census (direct counting of individuals).They were evaluated ecological parameters of the populations of capybaras, such as ecological density, abundance, age distribution and birth rate, as well as performed the analysis of the landscape. It was applied to analysis of variance (ANOVA) to test the differences between the averages of the abundance of each age group per year of observation, as well as the differences between the average ecological density over the years of observation. The standard relationship between the use of classes and land use in the landscape and the ecological parameters of the capybara populations was evaluated by Principal Component Analysis (PCA). The trend of variation of average abundance over time to Thomas Arthur Park revealed abrupt decrease of the population in a short period of time (2014 16 ± 9, 14 ± 1 and 2015 7±1) as well as ecological density in 2015 (0.05 ind./ha). On the other hand, the Jaboti Lake Park, showed an increase in absolute abundance, with marked recovery of the population in the same period (2014 38±8,30 and 2015 45±1,73) and coming up with an ecological density in 2015 (2 ind ./ha). The birth rate found Lake Park Jaboti was superior to Arthur Thomas Park, which had a negative rate between 2012 and 2015. The use and land cover analysis showed significant differences from the point of view of the relative contribution of landscape elements in the spatial heterogeneity. Arthur Thomas Park shows areas of dense vegetation and urban areas relatively higher than those observed in Jaboti Lake Park that revealed relatively higher proportions of the areas of agriculture / field and exposed soil. Thus, the present study revealed that the local population structure is directly related to the spatial characteristics of both studied landscapes, as can be seen by the greater abundance and density seen in Jaboti Lake Park compared to Arthur Thomas Park in recent years of study.

Processing traits of European catfish (Silurus glanis Linnaeus, 1758) from outdoor flow-through and indoor recycling aquaculture units

The quality of fish cultured using recycling units may differ from that of fish from outdoor farming units due to a range of deviating environmental determinants. This applies not only to flesh quality but also to morphological (processing) traits. This study evaluates processing yields of sibling fish cultured in two different farming units: (i) an outdoor pond aquaculture system with a flow-through regime (24.6 ± 0.2°C), and (ii) indoor tanks using a recirculation aquaculture system (RAS; 26.0 ± 1.0°C). Clear differences were observed in the most important processing traits, i.e. skinned trunk and fillet yields, which were both significantly higher (P < 0.01) in RAS fish due to significantly smaller (P < 0.05) head weight in fish of the flow-through system. Skin represented a significantly higher (P < 0.01) proportion of total weight in both RAS males and females. The most obvious difference was in the deposited fat weight, which was significantly higher (P < 0.01) in RAS fish. Visceral fat deposits were significantly higher (P < 0.01) in females and ventral and dorsal fat deposits higher (P > 0.05) in males.

Fertilization strategies for Sea Bass Dicentrarchus labrax (Linnaeus, 1758): effects of pre-incubation and duration of egg receptivity in seawater

Studying gamete biology can provide important information about a species fertilization strategy as well as their reproductive ecology. Currently, there is a lack of knowledge about how long sea bass Dicentrarchus labrax eggs can remain viable after being activated in seawater. The objectives of this study were to understand the effects of pre-incubation of fresh and overripe sea bass eggs in seawater and to determine the duration of egg receptivity. Pooled eggs (fresh and overripe) from four females were pre-incubated in seawater for 0 min (control), 0.5 min, 1 min, 3 min, 10 min and 30 min and then fertilized by pooled sperm from four males. The fresh eggs had a higher fertilization success than overripe eggs. Our results revealed a significant effect of pre-incubation time for both the fresh (P < 0.01) and overripe eggs (P < 0.01). Fertilization success of eggs significantly declined for both these treatments after 3 min of pre-incubation, which clearly indicates that sea bass eggs are able to be fertilized by sperm for up to 3 min after release into seawater. This study has particular importance for understanding fertilization strategies, reproductive potential, as well as reproductive ecology of sea bass.

Changes in catches and biological characteristics of Nile tilapia (Oreochromis niloticus Linnaeus) in Lake Wamala (Uganda) under changing climatic conditions

There have been changes in catches and biological characteristics of the Nile Tilapia, Oreochromis niloticus (Linnaeus) in Lake Wamala (Uganda) since its introduction and establishment, but the factors which have contributed to these changes are not adequately understood. This study examined changes in catches and biological characteristics of Nile tilapia in relation to changes in temperature, rainfall and lake depth to provide an understanding of the role of changing climatic conditions. There was an increase in minimum, maximum and average temperature since 1980, but only minimum (0.021ºCyr-1) and average (0.018ºCyr-1) showed a significant trend (p < 0.05). Rainfall increased by 8.25 mmyr-1 since 1950 and accounted for 79.5% of the water input into the lake while evaporation accounted for 86.2% of the water loss from the lake. The lake depth was above 4 m during the years rainfall was above normal average of 1180 mm, except during the period 2011-2014. The contribution of Nile tilapia to total catch and CPUE changed with rainfall and lake depth up to 2000, after which they decreased despite increase in rainfall. There was a strong positive correlation between lake depth and average total length of Nile tilapia (r = 0.991, p < 0.001) and length at 50% maturity (r = 0.726, p < 0.001). The length-weight allometry between high and low lake depths was significantly different [t (6) = 3.225, p < 0.05], with Nile tilapia being heavier (for a given length) at high lake depth than at low lake depth. Fecundity of Nile tilapia was higher and egg diameter lower than what is reported in literature. Nile tilapia shifted from algal dominated diet during the wet season to include more insects during the dry season. The study showed that the catches and biological characteristics of Nile tilapia change with climate and hydrological factors and these need to be considered in management of the fisheries of Lake Wamala.

Engraulis encrasicolus (Linnaeus, 1758): technical report about extraction and recognition of the digestive tract contents in early stages of the life cycle

The study of ichthyio-plankton stages and its relations with the environment and other organisms is therefore crucial for a correct use of fishery resources. In this context, the extraction and the analysis of the content of the digestive tract, is a key method for the identification of the diet in early larval stages, the determination of the resources they rely on and possibly a comparison with the diet of other species. Additionally this approach could be useful in determination on occurrence of species competition. This technique is preceded by the analysis of morphometric data (Blackith & Reyment, 1971; Marcus, 1990), that is the acquisition of quantitative variables measured from the morphology of the object of study. They are linear distances, count, angles and ratios. The subsequent application of multivariate statistical methods, aims to quantify the changes in morphological measures between and within groups, relating them to the type and size of prey and evaluate if some changes appear in food choices along the larvae growth.

Utilização da macroalga Ulva lactuca linnaeus na redução de nutrientes (NH4+,NO3- e PO4-2) provenientes da carcinicultura

Dentre as macroalgas capazes de absorver altas concentrações de N e P dissolvidos na água, destaca-se a Chlorophyta Ulva lactuca, bastante adaptável e resistente às adversidades ambientais, como grandes variações de temperatura, salinidade, matéria orgânica e metais pesados. Trata-se também de uma espécie bastante comum nas áreas intertidais do litoral norte-riograndense. Devido a suas características ecológicas, fisiológicas e nutricionais, foi avaliado nesse estudo, o seu potencial como biofiltro na redução de NH4+, NO3- e PO4-2, tanto em condições controladas como também em um viveiro de camarão. No experimento laboratorial, foram utilizados quatro aquários de vidro de 30 x 20 x 20cm com 10L de água, sendo três aquários experimentais contendo 20g de U. lactuca e um controle. O acréscimo de biomassa foi de 2,92g (22,92 ± 6,29g; p < 0,05) em relação ao inóculo inicial de 20g, sob temperatura (28,50 ± 0,58ºC), salinidade (35,00 ± 0,00 ), pH (8,26 ± 0,02) e luz constante (250 μmol.m2s-1). O crescimento positivo (1,78 ± 4,38%dia-1; p < 0,05), juntamente com a alta eficiência de absorção de amônio (83%; p < 0,001), nitrato (83%; p < 0,001) e ortofosfato (53%; p < 0,001), demonstrou que, nessas condições, a Ulva lactuca absorveu os nutrientes e aumentou sua biomassa. Já no experimento de campo, realizado na fazenda TECNARÃO, situada no município de Arez/RN (06° 11 40 Latitude Sul, e 35º 09 37 Longitude Oeste), foram utilizadas três gaiolas de PVC, posicionadas a 12cm da superfície da água, cada uma com dimensões de aproximadamente 59 x 59 x 15cm, onde foram colocadas 200g de U. lactuca. O ganho de biomassa de 3g (203,00 ± 41,02g; p < 0,001) foi muito semelhante às condições controladas, demonstrando a adaptabilidade da espécie em condições ambientais variáveis, onde, apesar da temperatura pouco variável (27,45 ± 0,64ºC), houve progressiva diminuição de salinidade (25 - 15 ), devido ao período de fortes chuvas (34,70 ± 23,78mm). Somado a isso, foram observados vários fatores biológicos interferindo no viveiro, como a presença de epífitas, organismos endofíticos, fouling e a herbivoria por parte dos próprios camarões. Houve aumento nas concentrações de NH4+ (4,36 ± 1,69 μmol.L-1), NO3- (0,17 ± 0,25μmol.L-1) e PO4-2 (0,41 ± 0,13μmol.L-1), coincidindo com o crescimento da espécie até a terceira semana. Todos os parâmetros ambientais analisados, assim como a biomassa e a Taxa de Crescimento Relativo (TCR), obtidos no campo, apresentaram variações altamente significativas (p < 0,001). As correlações observadas entre biomasa e NH4+ (r = 0,82; p < 0,001) e entre biomassa e PO4-2 (r = 0,87; p < 0,001), indicam que esta espécie é capaz de ter um crescimento satisfatório nas condições eutróficas de um viveiro de camarão, sendo possível seu uso como biofiltro.

Survey of parasitic infection of Sander lucioperca (Linnaeus, 1758) and Silurus glanis (Linnaeus, 1758) in Aras reservoir with emphasizes of monogenean parasites

The parasites fauna of 491 specimens of Sander lucioperca, Linnaeus 1758 (246 specimens) and catfish, Silurus glanis, Linnaeus 1758 (245 specimens) in different size from Aras Reservoir situated in North —west of the Iran was investigated. During 2006-2007 Totally 16 parasite species were recorded. The most various parasites was found in catfish (10 species) while the lowest number was recorded in Sander lucioperca (6 species). Among them, however three genera of protozoa (Trichodina, Vorticella, Ichthyophthirius), two genera of Monogenea (Gyrodactylus, Silurodiscoides), Digenea, Cestoda, Nematoda, Acanthocephala and Annelida one species each (Diplostomum, Protocephalus, Eustrongylides, Neoechinorhynchus, Pisicola) and two crustacean genera (Argulus and Lernea) recorded and we can come to conclusion in comparison with the earlier data the actual parasite fauna of two hosts has been greatly improved. According to the present study the prevalence, mean abundance and mean intensity of parasites species of both hosts were highly influenced by seasons of the year. Some species found, however show a tendency to be more abundant ides Trichodina sp., Ichthyophthirius multifiliis, Silurodiscoides vistolensis, Protocephalus osculatus respectively. Most parasites species live in gills and skin, where is highly sensitive to some pathogens parasites species (Trichodina, Vorticella, Ichthyophthirius, Pisicola geometra, Argulus foliaceus; Lernea) and While some are specialist (Silurodiscoides vistolensis and Silurodiscoides siluri) other more or less generalist (ichthyophthirius).

Effect of diet on phosphine toxicity, rate of development and reproduction of the rice weevil Sitophilus oryzae (Linnaeus)

One of the loci responsible for strong phosphine resistance encodes dihydrolipoamide dehydrogenase (DLD). The strong co-incidence of enzyme complexes that contain DLD, and enzymes that require thiamine as a cofactor, motivated us to test whether the thiamine deficiency of polished white rice could influence the efficacy of phosphine fumigation against insect pests of stored grain. Three strains of Sitophilus oryzae (susceptible, weak and strong resistance) were cultured on white rice (thiamine deficient), brown rice or whole wheat. As thiamine is an essential nutrient, we firstly evaluated the effect of white rice on developmental rate and fecundity and found that both were detrimentally affected by this diet. The mean time to reach adult stage for the three strains ranged from 40 to 43 days on brown rice and 50–52 days on white rice. The mean number of offspring for the three strains ranged from 7.7 to 10.3 per female over a three day period on brown rice and 2.1 to 2.6 on white rice. Growth and reproduction on wheat was similar to that on brown rice except that the strongly resistant strain showed a tendency toward reduced fecundity on wheat. The susceptible strain exhibited a modest increase in tolerance to phosphine on white rice as expected if thiamine deficiency could mimic the effect of the dld resistance mutation at the rph2 locus. The strongly resistant strain did not respond to thiamine deficiency, but this was expected as these insects are already strongly resistant. We failed, however, to observe the expected synergistic increase in resistance due to combining thiamine deficiency with the weakly resistant strain. The lack of interaction between thiamine content of the diet and the resistance genotype in determining the phosphine resistance phenotype suggests that the mode of inhibition of the complexes is a critical determinant of resistance.

Fissura placentária de gatas SRD, Felis catus - Linnaeus, 1758: aspectos macro e microscópicos

Nossa pesquisa consiste no estudo esquemático macroscópico na placenta de gatos e a sua caracterização como tipo, placenta zonária, que 62,5% dos casos apresenta uma fissura na área distal do funículo umbilical. Esse é formado por uma área justa fetal, área justa placentária e área média, encontrando achados histológicos de 2 artérias, uma veia, 2 pedículos vitelínicos e 2 pedículos alantoidianos. Na fissura, encontramos um epitélio alantoidiano cobrindo esta área em 10% dos casos e, em 90% dos achados foram encontrados um trofoblasto diminuído comparado com outras áreas placentárias fora da fissura. Portanto, a placenta felina, com sua relação materno fetal mostra uma placenta zonária incompleta, diferente do ocorrido nos outros carnívoros.

Utilização de glúten de trigo na alimentação de dourada, Sparus aurata (Linnaeus, 1758)

A incorporação de fontes proteicas alternativas à farinha de peixe na alimentação de espécies piscícolas tem sido objecto de variados estudos no âmbito da nutrição animal. Neste contexto realizou-se o presente trabalho, cujo objectivo foi determinar o nível de substituição ideal de farinha de peixe por glúten de trigo na alimentação de dourada. Foram realizados dois ensaios, um de crescimento e um de digestibilidade. O ensaio de crescimento efectuou-se para determinar qual o nível máximo de substituição sem que os animais apresentassem diferenças significativas em termos de taxa de crescimento. O ensaio de digestibilidade teve como principal objectivo determinar qual das dietas testadas proporcionaria melhores valores de utilização digestiva por parte dos animais. Tendo em conta os resultados dos ensaios e as condições experimentais em que se realizaram, verificou-se que a substituição até 40% não afecta significativamente o desempenho zootécnico das douradas. ABSTRACT; The incorporation of alternative protein sources in fish diets has been the aim of many scientific experiments in animal nutrition. ln this study, the main objective was to evaluate the ideal level of wheat gluten incorporation in substitution of fishmeal in diets for gilthead sea bream (Sparus aurata L). To reach this objective, two experiments were carried out, in which growth and digestibility were studied. The aim of the growth experiment was to evaluate the maximum level of fish meal substitution by wheat gluten (20%, 40%, 60% and 80%), without affecting significantly the animals growth rate. The digestibility experiment took place to evaluate which animals presented better food utilization with the tested diets (20%, 40%, 60% and 80%). Observing the results of these two experiments, it was concluded that the substitution until 40% did not affect significantly the performance of the fishes.

Lysossomal membrane stability of the brown mussel Perna perna (Linnaeus) (Mollusca, Bivalvia) exposed to the anionic surfactant Linear Alkylbenzene Sulphonate (LAS).

The effects of the Linear Alkylbenzene Sulphonate (LAS) were evaluated on the mussel Perna perna (Linnaeus, 1758), using a cellular level biomarker. The Neutral Red Retention Time (NRRT) assay was used to estimate effects at cellular levels. Significant effects were observed for the NRRT assay, even in low concentrations. The effects at cellular level were progressive, suggesting that the organisms are not capable to recover of such increasing effects. Additionally, the results show that the levels of LAS observed for Brazilian coastal waters may chronically affect the biota.

Digestibilidad aparente por medio de la implementación de óxido de cromo (Cr2O3) como marcador nutricional en la especie jaguar (pantheraonca, linnaeus, 1758) en condiciones de cautiverio

Tesis (Zootecnista). -- Universidad de La Salle. Facultad de Ciencias Agropecuarias. Programa de Zootecnia, 2014

Population structure and sexual maturity of the calico box crab Hepatus epheliticus Linnaeus (Brachyura, Hepatidae) from Yucatan Peninsula, Mexico

The calico box crab Hepatus epheliticus is an abundant species from shallow and continental shelf waters of the Atlantic coast of USA and Mexico. Information about population structure and sexual maturity is absent, even though this crab is caught to be used as bait for the octopus fishery in the Campeche Bank, Mexico. In order to achieve such information, a total of 768 individuals were collected from January to March 2010 through baited traps installed in the Yucatan Peninsula, Mexico. Our results showed that sex ratio is biased towards more males than females (1:0.55), contradicting to that reported in other brachyuran crabs. The absence of ovigerous females suggests that they did not enter into the traps during embryogenesis. Males reached a larger maximum size than females (64.0 +/- 6.15 and 58.4 +/- 5.60 mm carapace width, respectively). The general scheme of growth being positive allometric throughout ontogeny of both sexes. Males presented a transition phase from juveniles to adult corresponding to the puberty moult. The estimation of the onset of functional sexual maturity revealed a steady situation for the population, with 21.5 and 13.8% of males and females, respectively, morphologically immature at the time of catch. This study constitutes the first report on population structure and sexual maturity in a population of the calico box crab H. epheliticus.