Gastric emptying of Sprattus sprattus and Arenicola spp. (gastric lavage) and formulated pellets (X-Ray studies) was investigated in a range of sizes of whiting, Merlangius merlangus fed different meal sizes at different temperatures. Emptying of indigestible solids, barium sulphate spheroids and ballotini were also studied. Additionally stomach contents of whiting sampled from Red Wharf Bay, Eastern Anglesey, UK. were analysed to determine diet composition, diel feeding periodicity and feeding strategy of whiting. Daily and total annual intake of main prey taxa, sprat, sandeel and crab, were estimated. Finally feeding behaviour of whiting in captivity was monitored. With respect to the studies conducted under laboratory conditions, it was found that gastric emptying is best described by a linear function. The results indicated significant changes in gastric emptying rates with both prey type and size. The seasonal change in temperature did not yield a significant change in gastric emptying rate. Increase in diet surface area also did not alter the gastric emptying rate significantly. The results have also shown that in continuously- feeding whiting gastric emptying is affected by the second meal such that the arrival of the second meal is accompanied by rapid emptying of a small fraction of the first meal. Despite difficulties encountered with individual variation among whiting of similar size held under similar conditions, gastric emptying times (GET) for both natural food and formulated pellets can be adequately predicted by the equations: GET = 126.47 W -0.111 g 0.26 e -0.068T for the natural food, GET = 6.6 e -0.09T + 2.48 W0.566 e -0.044T for the formulated pellets; where W is the fish weight (g), S is the meal size (g) and T is the temperature (°C) suggesting that a similar meal size of formulated pellet is emptied faster than natural food, Sprattus sprattus. This was interpreted as evidence that natural diets may reflect a combination of 2 factors (a) the relative size of stimulation to the stomach (% distension) and (b) the existence of protective, fibrous skin which resists digestion. Barium sulphate spheroids of diameter 1 mm (ca 20 per g food) and ballotini of diameter 0.029- 0.049 mm (60-100 per 1.58g) were selectively retained by the whiting stomach, suggesting that these indigestible materials can not be used in gastric emptying studies in whiting. Under laboratory conditions with continuous food availability, medium size whiting (155.25±27.98 g) consumed 5.29 g sprat corresponding to 3.41 %bw (approximately 3 sprat, 1.88g each) at 14 °C. The return of appetite after a single meal was found to follow the gastric emptying curve closely. However if food is not offered directly, but made available through demand feeding, the whiting feed rhythmically (every 21 hours), under these conditions it was estimated that feeding activity returns when the stomach is 40 % full. It wa§ found that, in the wild, whiting prefer fish (Sprattus sprattus and Ammodytes spp. ) and crustaceans and only turn to the polychaetes as a third option, even when they are readily available, when preferred food is scarce. The availability of prey was found to be the main criterion in whiting feeding strategy. In March fish were dominant for most whiting, in August and September/October however, Liocarcinus spp. and Corystes cassivelaunus were the main prey items found in whiting stomach reflecting the availability of these prey species. A highly correlated relationship was found between predator (whiting) and prey (sandeel) length, however this was not noticed for sprat; whiting prey on sprat regardless of its length. An increase in feeding intensity was observed in the morning (August), in the evening (September/October), or at both times, crepuscular feeding pattern, (March). However, when feeding behaviour was investigated under laboratory conditions it was found that whiting is mainly a day time feeder with a slight increase in the morning and in the evening, but some feeding also occurs at night. Additionally a strong tendency was found for crustaceans to be found in fish captured during the daylight hours and fish at night in August and September/October. A linear model to estimate food consumption from the field samples was developed. F= (S2-S1) + 1.5 K T, where S2 and SI are average stomach contents at time tI and t2, K is the gastric emptying rate (gh-1) and T is temperature (°C). The average recruited whiting stock in the area of approximately 150 km2 in Red Wharf Bay was estimated to be 129,000 with a total biomass of 22 tonnes. It was estimated that young whiting (groups 0+ to 3+ years) in Red Wharf Bay eat between 1.29 and 6.57 g day-1 in February. By August, when temperature has maximised, these values increase by approximately 70-80 %. Daily intake of sprat, sandeel and crab was estimated to be 0.41,0.14 and 0.14 g for the 0+ group. This was increased to 0.70,0.80 and 0.94 g by the age of 4. On a daily basis the long-term average of the amount of sprat, sandeel and crab consumed were estimated to be 820, 370 and 520 g/km2/day respectively. Total food consumption per year by the recruited whiting stock in the area studied however was 44.8 tonnes of sprat (approximately 11.5 million sprats), 20 tonnes of sandeel and 28.5 tonnes of crab. These figures were compared with the available data from the North Sea as well as from other parts of the Irish Sea and it was concluded that whiting in the Irish Sea eat more than they do in the North Sea.

Chrysaora fuscescens is a cnidarian scyphomedusa that occurs in the northern California Current. In this upwelling system, medusae are seasonally abundant, and individuals can ingest 10-60% of the standing stock of vulnerable zooplankton taxa per day. Yet little is known about this medusa's feeding ecology. Using laboratory pseudokreisels, C. fuscescens feeding rates and behavior were quantified in the presence of a controlled flow field. C. fuscescens collected aboard research cruises were dissected, and prey items were counted in order to calculate feeding rates and prey selectivity. In the lab, C. fuscescens feeding rates were not affected by shear flow, and medusa maintained position by swimming counter-current. Field work demonstrates high feeding rates and positive prey selection for nonmotile taxa. For the first time, high clearance rates of ichthyoplankton have been documented. An understanding of jellyfish behavior can help explain jellyfish distributions and trophic impacts in a productive upwelling system.

OBJETIVOS: Descrever as taxas de início de aleitamento materno em gêmeos; investigar o efeito do aconselhamento pré-natal nas taxas de aleitamento materno total e exclusivo em gêmeos e identificar os fatores associados ao desmame e os fatores citados por mães de gêmeos como motivo para a interrupção da amamentação, durante os primeiros seis meses de vida dos lactentes. MÉTODOS: Estudo prospectivo em que cento e setenta e uma grávidas de gêmeos foram randomizadas para grupo aconselhamento pré-natal ou grupo controle. Dados de aleitamento materno foram coletados por entrevistas pessoais presenciais em três diferentes momentos após o parto: 30 a 40 dias (Período 1), 90 dias (Período 2) e 180 dias (Período 3). RESULTADOS: A análise foi composta por 68 grávidas de gêmeos no grupo aconselhamento pré-natal e 60, no grupo controle. Cento e vinte e três mães de gêmeos iniciaram amamentação (96,1%). Não houve diferença significativa nas taxas de aleitamento materno total entre o grupo aconselhamento pré-natal e grupo controle nos tempos analisados: Período 1 [razão de chances (RC) 1,87, intervalo de confiança (IC) de 95% 0,71 - 4,95], Período 2 [RC 1,50, IC 95% (0,72 - 3,10)], Período 3 [RC 1,06, IC 95% (0,51 - 2,19)]. Não foi observada também diferença nas taxas de aleitamento materno exclusivo entre os grupos: Período 1 [razão de chances (RC) 0,76, intervalo de confiança (IC) de 95% 0,28 - 2,11], Período 2 [RC 1,59, IC 95% (0,36 - 6,87)], Período 3 [RC 0,83, (IC 95% 0,10 - 6,45)]. Ao considerar-se a correlação entre gêmeos de mesma mãe, também não houve diferença entre as razões dos riscos (RR) para desmame no grupo aconselhamento pré-natal e GC até 180 dias de vida dos lactentes, RR 2,091 (IC 95% 0,27 - 15,77). A análise da associação dos fatores (maternos, obstétricos, neonatais e relacionados ao processo de amamentação) com o desmame em gêmeos durante os primeiros 180 dias de vida, avaliados pela metodologia das análises de sobrevivência, evidenciou maior risco de parada da amamentação nas participantes com: modo de amamentação não-exclusivo (p = 0,004, modelo de regressão de riscos proporcionais de Cox); ausência de ajuda durante o período de lactação (p = 0,001); dificuldade para amamentar (p = 0,003); duração da amamentação prévia menor do que 12 meses (p = 0,001); e peso do nascimento do recémnascido inferior a 2.300g (p < 0,001). Os fatores mais citados por mães de gêmeos como motivo para desmame, nos três períodos analisados, foram oferta inadequada de leite materno, comportamento dos lactentes e retorno ao emprego/ trabalho. CONCLUSÕES: Em gêmeos, o aconselhamento pré-natal não aumentou significativamente as taxas de aleitamento materno. Foram identificados os principais fatores associados ao desmame em lactentes gêmeos nos primeiros 180 dias de vida. Esse conhecimento pode ajudar a melhorar as estratégias para aumentar as taxas de aleitamento materno em gêmeos / OBJECTIVES: To describe the rates of initiation of breastfeeding in twins; to evaluate the effect of antenatal counseling on the rates of any and exclusive breastfeeding in twins; and to identify the factors associated with weaning and the factors cited by mothers of twins as a reason for breastfeeding cessation during the first six months of twin infants\' age. METHODS: A prospective trial in which one hundred and seventy-one women pregnant with twins were randomized into the prenatal counseling group or control group. Breastfeeding data were collected through personal interviews at three different times after birth: 30-40 days (Time 1), 90 days (Time 2) and 180 days (Time 3). RESULTS: The analysis comprised 68 women pregnant with twins in the prenatal counseling group and 60 in the control group. One hundred and twenty-three mothers of twins initiated breastfeeding (96.1%). There was no significant difference in the any breastfeeding rates between prenatal counseling group and control group in the analyzed times: Time 1 [odds ratio (OR) 1.87, 95% confidence intervals (CI) 0.71 - 4.95], Time 2 [OR 1.50, 95% CI (0.72 - 3.10)], Time 3 [OR 1.06, 95% CI (0.51 - 2.19)]. There was also no difference in the exclusive breastfeeding rates among the groups: Time 1 [OR 0.76, 95% CI (0.28 - 2.11)], Time 2 [OR 1.59, 95% CI (0.36 - 6.87)], Time 3 [OR 0.83, 95% CI (0.10 - 6.45)]. When considering the correlation between twins of the same mother, no difference was found between prenatal counseling group and control group, once the hazard ratio (HR) for weaning was 2,091 [95% CI (0.27 - 15.77)]. The analysis of the association of factors (maternal, obstetric, neonatal and related to the breastfeeding process) with weaning in twins during the first 180 days of life, evaluated by survival analysis methodologies, demonstrated a higher risk of breastfeeding cessation in the participants with: non-exclusive breastfeeding mode (p = 0.004, Cox proportional hazards regression model); absence of help during the lactation period (p = 0.001); difficulty in breastfeeding (p = 0.003); duration of previous breastfeeding less than 12 months (p = 0.001); and birth weight of the newborn of less than 2300g (p < 0.001). The main reasons for weaning cited by mothers of twins were insufficient breast milk supply, infant\'s behavior and returning to work. CONCLUSIONS: In twins, prenatal counseling did not significantly increase breastfeeding rates. The main factors associated with weaning in twin infants during the first 180 days of life were identified. This knowledge can help improve strategies to increase breastfeeding rates in twins

OBJETIVOS: Descrever as taxas de início de aleitamento materno em gêmeos; investigar o efeito do aconselhamento pré-natal nas taxas de aleitamento materno total e exclusivo em gêmeos e identificar os fatores associados ao desmame e os fatores citados por mães de gêmeos como motivo para a interrupção da amamentação, durante os primeiros seis meses de vida dos lactentes. MÉTODOS: Estudo prospectivo em que cento e setenta e uma grávidas de gêmeos foram randomizadas para grupo aconselhamento pré-natal ou grupo controle. Dados de aleitamento materno foram coletados por entrevistas pessoais presenciais em três diferentes momentos após o parto: 30 a 40 dias (Período 1), 90 dias (Período 2) e 180 dias (Período 3). RESULTADOS: A análise foi composta por 68 grávidas de gêmeos no grupo aconselhamento pré-natal e 60, no grupo controle. Cento e vinte e três mães de gêmeos iniciaram amamentação (96,1%). Não houve diferença significativa nas taxas de aleitamento materno total entre o grupo aconselhamento pré-natal e grupo controle nos tempos analisados: Período 1 [razão de chances (RC) 1,87, intervalo de confiança (IC) de 95% 0,71 - 4,95], Período 2 [RC 1,50, IC 95% (0,72 - 3,10)], Período 3 [RC 1,06, IC 95% (0,51 - 2,19)]. Não foi observada também diferença nas taxas de aleitamento materno exclusivo entre os grupos: Período 1 [razão de chances (RC) 0,76, intervalo de confiança (IC) de 95% 0,28 - 2,11], Período 2 [RC 1,59, IC 95% (0,36 - 6,87)], Período 3 [RC 0,83, (IC 95% 0,10 - 6,45)]. Ao considerar-se a correlação entre gêmeos de mesma mãe, também não houve diferença entre as razões dos riscos (RR) para desmame no grupo aconselhamento pré-natal e GC até 180 dias de vida dos lactentes, RR 2,091 (IC 95% 0,27 - 15,77). A análise da associação dos fatores (maternos, obstétricos, neonatais e relacionados ao processo de amamentação) com o desmame em gêmeos durante os primeiros 180 dias de vida, avaliados pela metodologia das análises de sobrevivência, evidenciou maior risco de parada da amamentação nas participantes com: modo de amamentação não-exclusivo (p = 0,004, modelo de regressão de riscos proporcionais de Cox); ausência de ajuda durante o período de lactação (p = 0,001); dificuldade para amamentar (p = 0,003); duração da amamentação prévia menor do que 12 meses (p = 0,001); e peso do nascimento do recémnascido inferior a 2.300g (p < 0,001). Os fatores mais citados por mães de gêmeos como motivo para desmame, nos três períodos analisados, foram oferta inadequada de leite materno, comportamento dos lactentes e retorno ao emprego/ trabalho. CONCLUSÕES: Em gêmeos, o aconselhamento pré-natal não aumentou significativamente as taxas de aleitamento materno. Foram identificados os principais fatores associados ao desmame em lactentes gêmeos nos primeiros 180 dias de vida. Esse conhecimento pode ajudar a melhorar as estratégias para aumentar as taxas de aleitamento materno em gêmeos / OBJECTIVES: To describe the rates of initiation of breastfeeding in twins; to evaluate the effect of antenatal counseling on the rates of any and exclusive breastfeeding in twins; and to identify the factors associated with weaning and the factors cited by mothers of twins as a reason for breastfeeding cessation during the first six months of twin infants\' age. METHODS: A prospective trial in which one hundred and seventy-one women pregnant with twins were randomized into the prenatal counseling group or control group. Breastfeeding data were collected through personal interviews at three different times after birth: 30-40 days (Time 1), 90 days (Time 2) and 180 days (Time 3). RESULTS: The analysis comprised 68 women pregnant with twins in the prenatal counseling group and 60 in the control group. One hundred and twenty-three mothers of twins initiated breastfeeding (96.1%). There was no significant difference in the any breastfeeding rates between prenatal counseling group and control group in the analyzed times: Time 1 [odds ratio (OR) 1.87, 95% confidence intervals (CI) 0.71 - 4.95], Time 2 [OR 1.50, 95% CI (0.72 - 3.10)], Time 3 [OR 1.06, 95% CI (0.51 - 2.19)]. There was also no difference in the exclusive breastfeeding rates among the groups: Time 1 [OR 0.76, 95% CI (0.28 - 2.11)], Time 2 [OR 1.59, 95% CI (0.36 - 6.87)], Time 3 [OR 0.83, 95% CI (0.10 - 6.45)]. When considering the correlation between twins of the same mother, no difference was found between prenatal counseling group and control group, once the hazard ratio (HR) for weaning was 2,091 [95% CI (0.27 - 15.77)]. The analysis of the association of factors (maternal, obstetric, neonatal and related to the breastfeeding process) with weaning in twins during the first 180 days of life, evaluated by survival analysis methodologies, demonstrated a higher risk of breastfeeding cessation in the participants with: non-exclusive breastfeeding mode (p = 0.004, Cox proportional hazards regression model); absence of help during the lactation period (p = 0.001); difficulty in breastfeeding (p = 0.003); duration of previous breastfeeding less than 12 months (p = 0.001); and birth weight of the newborn of less than 2300g (p < 0.001). The main reasons for weaning cited by mothers of twins were insufficient breast milk supply, infant\'s behavior and returning to work. CONCLUSIONS: In twins, prenatal counseling did not significantly increase breastfeeding rates. The main factors associated with weaning in twin infants during the first 180 days of life were identified. This knowledge can help improve strategies to increase breastfeeding rates in twins