Morfologia e topografia do fígado e pâncreas de emas Rhea americana

As emas são aves ratitas nativas do continente sul americano, são consideradas aves primitivas do ponto de vista filogenético que constituem um grupo altamente especializado. Este estudo buscou caracterizar macro e microscopicamente o fígado e pâncreas de emas. O material foi coletado no Centro de Multiplicação de Animais Silvestres (CEMAS), na cidade de Mossoró-RN, Brasil, (Registro IBAMA n° 14.78912). Utilizaram-se 20 animais jovens com idade entre dois e seis meses independente do sexo. Em emas, o fígado se relacionava cranialmente com o ápice do coração, dorsalmente com os pulmões, esôfago e o proventrículo gástrico, caudalmente, com o ventrículo gástrico, o baço, o duodeno e parte do jejuno. Apresentava coloração vermelha escura e possuía apenas dois lobos, sendo o direito ligeiramente menor que o esquerdo. Histologicamente, era revestido por uma cápsula de tecido conjuntivo delgada e cada lóbulo hepático pôde ser identificado pela presença evidente de veias centrais, com muitos sinusoides comunicando-se com elas. O pâncreas, ventralmente, apresentava-se como uma fita fina, formado por um lobo dorsal e um lobo ventral. Longitudinalmente o pâncreas em emas localiza-se no mesentério dorsal desde o fígado até a flexura cranial do duodeno, mantendo-se preso às alças duodenais por ligamentos. Histologicamente, era composto por uma cápsula delgada de tecido conjuntivo denso, com discretos lóbulos separados por tecido conjuntivo capsular, compostos por estruturas tubuloalveolares e ductos. O fígado e pâncreas de emas apresentam padrão morfológico similar ao descrito para aves domésticas.

Habitat alteration and community-level effects of an invasive ecosystem engineer: a case study along the coast of NSW, Australia

We investigated the effects of the habitat-modifying green algae Caulerpa taxifolia on meiobenthic communities along the coast of New South Wales, Australia. Samples were taken from unvegetated sediments, sediments underneath the native seagrass Zostera capricorni, and sediments invaded by C. taxifolia at 3 sites along the coast. Meiofaunal responses to invasion varied in type and magnitude depending on the site, ranging from a slight increase to a substantial reduction in meiofauna and nematode abundances and diversity. The multivariate structure of meiofauna communities and nematode assemblages, in particular, differed significantly in sediments invaded by C. taxifolia when compared to native habitats, but the magnitude of this dissimilarity differed between the sites. These differential responses of meiofauna to C. taxifolia were explained by different sediment redox potentials. Sediments with low redox potential showed significantly lower fauna abundances, lower numbers of meiofaunal taxa and nematode species and more distinct assemblages. The response of meiofauna to C. taxifolia also depended on spatial scale. Whereas significant loss of benthic biodiversity was observed locally at one of the sites, at the larger scale C. taxifolia promoted an overall increase in nematode species richness by favouring species that were absent from the native environments. Finally, we suggest there might be some time-lags associated with the impacts of C. taxifolia and point to the importance of considering the time since invasion when evaluating the impact of invasive species.

Nitrate reduces the negative effect of UV radiation on photosynthesis and pigmentation in Gracilaria tenuistipitata (Rhodophyta): the photoprotection role of mycosporine-like amino acids

Photoprotection of the agarophyte red alga Gracilaria tenuistipitata against ultraviolet radiation (UVR) was investigated in algae submitted for 1 week to photosynthetically active radiation (PAR, 260 mu mol photons m(-2) s(-1)) or PAR + UVR (UV-A, 8.13 W m(-2) and UV-B, 0.42 W m(-2)) under different nitrogen concentrations: 0, 0.1, and 0.5 mM of NO3-. Photosynthetic pigments decreased during the time of the experiment mainly under low nitrogen supply and UVR. Incubation under high nitrogen supply (0.5 mM) sustained the photosynthetic levels over time. In contrast, mycosporine-like amino acids (MAAs) increased up to eightfold in the presence of UVR and 0.5 mM NO3-. Under PAR + UVR, maximal quantum yield was positively correlated to MAA abundance, whereas under PAR no correlation was found. The photosynthetic yield of algae cultivated during seven days under PAR + UVR was less affected by a 30-min exposure of high UVR (16 W m(-2)) and fully recovered after transferring to low PAR irradiances, whereas algae kept under PAR were more affected by UV exposure and no full recovery was observed. Growth rates decreased after three days in the presence of UVR and under low nitrate supply. However, these rates were similar when compared with treatments of PAR and PAR + UVR after seven days, with the exception of samples in 0 mM NO3-, indicating that the acclimation after one week's exposure is related to nitrate supply. In conclusion, the lowest negative effect of UVR on photosynthesis and growth rate in high N-supply-grown algae could be explained by the stimulation of photoprotection mechanisms, such as accumulation of MAAs. Photostimulation of MAA accumulation by UVR under high N supply was observed in G. tenuistipitata even after 20 years in culture without the induction of this photomorphogenic light signal.

Molluscicidal activity of some marine substances against the snail Biomphalaria glabrata (Mollusca, Planorbidae)

Freshwater snails of the genus Biomphalaria play a major role as intermediate hosts of Schistosoma mansoni, the etiologic agent of schistosomiasis. While Biomphalaria spp. control by molluscicides is one of the main strategies to reduce the snail population in infected areas, there are few effective molluscicides commercially available. Natural products may be considered as potentially useful and safe molluscicides. We have evaluated the molluscicidal activity of 12 extracts from ten marine organisms on adult and embryonic stages of Biomphalaria glabrata. Only extracts of the red algae Liagora farinosa and of the sponge Amphimedon viridis presented molluscicidal activity. Lethal concentration (LC)(50) values obtained were 120 mu g/mL for L. farinosa CH2Cl2 extract (apolar fraction) and 20 mu g/mL for A. viridis extract and halitoxin. The polar alga fraction and halitoxin had no effect on B. glabrata embryos. The algae apolar fraction was active on B. glabrata in all embryonic development stages, with LC50 values for blastulae at 42 mu g/mL, gastrulae at 124 mu g/mL, trochophore at 180 mu g/mL, and veliger at 222 mu g/mL. This is the first report of extracts from marine organisms which presented molluscicidal activity.

Os fatores de riscos alimentares para câncer colorretal relacionado ao consumo de carnes

Uma das estratégias metodológicas para realizar a prática baseada em evidências é a revisão integrativa, que neste estudo teve como objetivo buscar e sintetizar as evidências disponíveis na literatura científica sobre os fatores de riscos alimentares para o câncer colorretal relacionado ao consumo de carnes. As bases de dados LILACS, MEDLINE, CINAHL e COCHRANE Library foram consultadas e os estudos pertinentes ao consumo de carnes somaram seis. As metanálises demonstraram que a ingestão de carne vermelha está relacionada com o aumento do risco para câncer colorretal em 28% a 35%, enquanto a carne processada está associada ao risco elevado de 20% a 49%. As evidências apontam a carne vermelha, a carne processada e o total de carne consumida como fatores de risco para o desenvolvimento de pólipos e câncer colorretal. Não foi identificado estudo que indicasse a ingestão de frango e peixe como fatores de risco.

Preferencia de alimento del erizo cachero "Arbacia lixula" (Echinodermata: Arbacidae) ante una dieta basada en dos macroalgas.

Se estudió la preferencia de alimento del erizo cachero (Arbacia lixula) al administrarle una dieta basada en dos macroalgas (Ulva sp. y Cystoceira humilis). Los erizos muestran una tendencia clara a consumir mayor cantidad del alga verde frente al alga parda.ABSTRACT The food preferences of the black sea urchin (Arbacia lixula) was studied giving it a diet based on two macroalgae (Ulva sp. and Cystoceira humilis). The sea urchins showed a clear tendency to consume a higher quantity of green algae against brown algae.

Análisis espacio-temporal de las praderas de Cymodocea nodosa (Ucria) Ascherson en la isla de Gran Canaria

Máster Oficial en Gestión Costera

Variación en la producción de tinta de las liebres de mar Aplysia dactylomela en función de la alimentación

[ES] Se describe la variación en la producción de tinta (medida en absorbancia) en función de la composición de la dieta de la liebre de mar Aplysia dactylomela. Se observa que la absorbancia de la tinta expulsada como respuesta defensiva en aplysias que se alimentan del alga roja Hydropuntia cornea es mayor que en aquéllas que se alimentan del alga verde Ulva rigida.

Bioindicadores funcionales en macroalgas del litoral canario : evaluación de la vulnerabilidad y aclimatación al estrés ambiental

Programa de doctorado de Acuicultura: producción controlada de animales acuáticos.

Acto celebrado en la sala de grado de la Facultad de Ciencias del Mar de la Universidad de Las Palmas de Gran Canaria, el 28 de junio de 2013, actuando como Presidenta María Candelaria Gil Rodríguez (Universidad de La Laguna), Secretaria Ascensión Viera Rodríguez (Universidad de Las Palmas de Gran Canaria), vocales, José María Gorostiaga Garay (Universidad del País Vasco), Juan Luis Gómez Pinchetti (Universidad de Las Palmas de Gran Canaria) y Nathalie Korbee Peinado (Universidad de Málaga)