Ontogenia do sistema sensorial de pacu Piaractus mesopotamicus (Holmberg, 1887) (Characidae: Serrasalmidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ontogenia do trato digestório e desenvolvimento gonadal de Betta splendens: aspectos morfológicos

Pós-graduação em Aquicultura - FCAV

Desenvolvimento inicial de jatuarana, Brycon amazonicus (Teleostei, Characidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variação diária e caracterização morfológica das larvas de peixes do complexo estuarino do Rio Amazonas - PA

A grande importância dos recursos pesqueiros para a Amazônia, aliada à necessidade de ampliar os conhecimentos básicos sobre identificação das larvas de peixes (coletadas em ambiente natural), justifica o desenvolvimento deste trabalho, que tem como objetivo expandir as informações sobre o ictioplâncton, relacionando as com as tendências de variação diária e entre marés, do complexo estuarino do rio Amazonas – PA. As coletas foram realizadas durante o período diurno e noturno, no segundo semestre de 2007, pelo Projeto PIATAM mar II, sob ponto fixo na subárea 1 (estuário do rio Paracauari) e na subárea 2 (baía do Guajará) nas marés de sizígia e quadratura, em arrastos horizontais na sub-superfície da coluna d‟água com rede de plâncton cônico-cilíndrica e malha de 300μm. As amostras foram acondicionadas em recipientes contendo formalina a 4%. Os fatores hidrológicos foram obtidos in situ pelo Grupo de Oceanografia Química do Museu Paraense Emilio Goeldi. As amostras foram triadas e identificadas por meio de características morfológicas, morfométricas e merísticas, baseando-se na técnica de sequência regressiva de desenvolvimento e em bibliografias especializadas. As principais estruturas e características das fases iniciais dos peixes foram descritas e ilustradas, facilitando assim futuros estudos ictioplanctônicos para região. A temperatura superficial da água, potencial hidrogeniônico e oxigênio dissolvido não apresentaram diferenças significativas nas áreas estudadas. Os valores de salinidade não apresentaram diferença significativa entre as estações de coleta e marés, registrando apenas variação horizontal com aumento gradativo em direção à foz com valores máximos (12) e mínimos (0) para as subárea 1 e subárea 2, respectivamente. As maiores densidades de ovos foram registradas na subárea 1, em relação à subárea 2, com as maiores densidades para o período diurno (163,29 ovos/100m³) na subárea 1 e noturno (19,70 ovos/100m³) na subárea 2. As larvas foram distribuídas em 22 taxa representados por 13 famílias e 21 espécies, sendo os taxa dominantes: P. flavipinnis (46,29%), R. amazonica (19,75%), Engraulidae (10,70%), P. squamosissimus (7,55%), A. lineatus (5,19%), O. saurus (3,30%) e Gobiosoma sp. (2,15%), com elevada participação relativa dos Clupeiformes (76,75%). Quanto aos estágios de desenvolvimento, foi observada maior abundância de larvas em pré-flexão nas subáreas 1 e 2, sendo o estágio larval vitelino e pós-flexão os menos representativos. O período noturno apresentou as maiores densidade de larvas e número de taxa, evidenciando uma possível migração nictemeral do ictioplâncton. Apenas M. furnieri apresentou abundância significativamente maior nas amostras diurnas. A grande maioria dos taxa não apresentaram diferenças significativas entre as abundâncias diurnas e noturnas. Logo, a densidade de larvas e o número de taxa diferem entre o período diurno e noturno e entre maré. Portanto, as características morfológicas descritas no presente trabalho permitem uma adequada identificação das larvas, ampliando o conhecimento biológico das espécies estuarinas do litoral paraense, uma vez que as informações sobre larvas de peixes ainda são escassas, fazendo-se necessária uma intensificação nas pesquisas. Além disso, a compreensão da ecologia dos organismos, sobre tudo daqueles que apresentam seu ciclo de vida associado aos estuários, e as variações no transporte das larvas entre os períodos do dia e da noite e entre as marés são questões fundamentais para aprimorar o manejo e a conservação destes recursos renováveis.

Influência da idade e de induções hormonais consecutivas no desempenho reprodutivo do pacu, Piaractus mesopotamicus

Pós-graduação em Aquicultura - FCAV

Efeito da temperatura de incubação e de criação sobre o tecido adiposo e desempenho de frangos de corte

Pós-graduação em Zootecnia - FCAV

Hatching, survival and deformities of piracanjuba (Brycon orbignyanus) embryos subjected to different cooling protocols

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Moments of induced spawning and embryonic development of Brycon amazonicus (Teleostei, Characidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Developmental aspects of early pregnancy in mares

In mares, the embryo migrates to the uterus between days 5 and 6 postovulation beginning its mobility through all uterine segments, which is essential for the maternal recognition of pregnancy. During the mobility phase, the embryonic vesicle shows a linear growth rate until its fixation between days 15 and 17, when the orientation phenomenon occurs. From fixation to day 28 of pregnancy, the embryonic growth is less evident (plateau) by cross-section ultrasound examination. After this period the linear growth rate is reestablished until day 46. This plateau is attributed to the increased uterine tone that compresses the vesicle and to volume expansion, making it difficult to detect the conceptus growth only by the cross-section diameter. Around day 20, the embryo proper is visualized as an echogenic spot in the ventral aspect of the vesicle. Additionally, development of allantoic sac, embryonic heartbeat, yolk sac regression and posterior umbilical cord formation also can be visualized from days 20 to 40. An intimate interaction between uterus and conceptus is essential for the normal pregnancy development. Color-and spectral-Doppler ultrasonography can be useful for the evaluation of this interface. A gradual increase on uterine vascularity during the early pregnancy and transient changes in endometrial vascularity accompanying the vesicle location during the mobility phase have been described. Around day 38 of gestation, the formation of the endometrial cups begins and, consequently, the synthesis of the equine chorionic gonadotropin (eCG) induces the formation and development of supplementary corpora lutea, which are important to secrete progesterone and to maintain pregnancy until around day 120.

Bacillus subtilis na qualidade dos pintinhos ao nascer, desempenho e características intestinais dos frangos

Pós-graduação em Zootecnia - FCAV

State of the art on animal embryonic chimeras

Embryonic chimerism is generally used in basic research and in vivo diagnosis of undifferentiated embryonic stem cells (ESC), mostly using mice embryos, although there have been reports in the literature on using rat, rabbit, sheep, chicken, primate, bovine, goat and pig embryos. Several techniques can currently be used to produce chimeric embryos, including microinjection, co-culture with ESC, fusion and aggregation. Although microinjection is the most commonly used method in mice, the mere aggregation of embryos with ESC may result in viable chimeras and be as efficient as microinjection. In mice, this chimerism technique has been shown to have the advantage of aggregating embryos in different stages of development with different ploidy, in addition to using ESC in the tetraploid complementation assay. Compared to other techniques for producing chimeras, the aggregation technique is a cheaper, faster and easier methodology to be performed. Moreover, aggregation can be simplified by chemically removing the zona pellucida with pronase or acidic Tyrode’s solution and be enhanced by using the Well of the Well culture system in combination with adhesion molecules, such as phytohemagglutinin. The most commonly used stages for chimerism by aggregation are those that precede the full compaction of the morula. In these stages, embryos have low-tension adherent junctions at the tangential point between two blastomeres. During the embryonic development of mice, the inner cell mass differentiates into epiblast and hypoblast. These layers will originate the fetal tissues and a portion of the extraembryonic tissues (yolk sac, allantois and amnion), whereas the trophectoderm (TE) gives rise to the chorion. A functional TE is essential for the complex molecular communications that occur between the embryo and the uterus. Embryos produced by somatic cell nuclear transfer, such as commercial cattle clones or endangered species, are subject to large fetal and neonatal losses. Hence embryo complementation with heterologous TE could be of assistance to decrease these losses and might as well assist development of high-value embryos in other approaches.

Early development of Betta splendens under stereomicroscopy and scanning electron microscopy

Betta splendens is a very important ornamental species. The current paper describes the embryonic and larval development of B. splendens under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of B. splendens are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0-2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2-3 hpIC and the early gastrula phase was observed at 3-4 hpIC with 20% epiboly, which was finalized after 13-18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23-25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 +/- 0.2 degrees C. The newly hatched larvae measured 2.47 +/- 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of B. splendens and provides relevant information for its reproduction, rearing and biology.

Morphological and morphometric aspects of early life stages of piabanha Brycon gouldingi (Characidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Incubation temperature manipulation during fetal development reduces adiposity of broiler hatchlings

Broilers are known as an efficient source of lean meat. Genetic selection resulted in broiler strains with large body size and fast growth, but a concomitant increase in fat deposition also occurred. Other than reducing nutrient intake, there is a lack of alternative methods to control body fat composition of broilers. The present study assessed whether incubation temperature (machine temperatures: 36ºC, 37.5ºC, and 39ºC; eggshell temperatures: 37.4 ± 0.08°C, 37.8 ± 0.15ºC, and 38.8 ± 0.33°C, respectively.) from d 13 affects broiler hatchling fat deposition. We analyzed adipocyte hypertrophy and proliferation in 3 body regions; weight and chemical composition of yolk-free chicks and yolk sacs; and serum lipid profile. Increased incubation temperature reduced abdominal and cervical adipocyte size. Independently of temperature, cervical adipocytes were smaller and showed higher proliferation than adipocytes in the abdominal and thigh regions. Smaller cervical adipocytes were observed in birds from eggs incubated at 36ºC and 39ºC. With regard to weight and composition of chicks, ash content as a percentage of dry matter was the only variable affected by temperature; it was higher in chicks from eggs incubated at 36ºC than at 39ºC and showed no significant difference between chicks incubated at 39ºC and 37.5ºC. Absolute and relative weights of yolk sacs were higher from eggs incubated at 39ºC than at 36ºC, and these two treatments did not differ from the 37.5ºC control. Absolute measures of yolk sac lipids, moisture, dry matter, and crude protein content were lower in chicks from eggs incubated at 36ºC, and no significant differences were found for these variables between chicks from eggs incubated at 37.5ºC and 39ºC. Hatchlings from eggs incubated at 36°C had significantly higher cholesterol levels than chicks incubated at the other 2 temperatures, but no additional effects on blood lipids were detected. Incubation temperature manipulation during fetal development altered cervical and abdominal adipocyte size in broiler hatchlings and could become a tool in hatcheries to manipulate chick quality, although further studies are needed to evaluate its long-term effects.

Desenvolvimento inicial e densidade de estocagem de larvas de Aracu-riscado, Leporinus agassizii (Characiformes: Anostomidae)

Pós-graduação em Aquicultura - FCAV