ABSTRACT. Daily food intake by the herbivorous parrotfish Sparisoma v~nde, as well as assimdation efficiencies of algal food, protein and energy, were quantified through a combination of laboratory feeding tnals and field observations. The intake of algal ash-free dry wt (AFDW) per bite increases hnearly with fish wet wt (FWW, g) and algal biomass (mg AFDW cm-2), and is further determined by the skeletal density of the limestone substrate. Low-density substrates yield higher amounts of AFDW per bite than do high-density substrates. The percentage of the total food intake that is derived from endolithic and crustose coralline algae increases with the size of the flsh, and can be 9 0 % depending on the biomass of epilithic algae. The daily pattern of foraging activity is positively correlated with diurnal changes in food quality, while seasonal daylength variations result in 13 % variation in total daily bites taken. Daily number of bites of S. viride in the field decreases wlth fish size, and is further dependent on life phase and foraging depth. In experiments, fish attained an assimilation efficiency of ca 20% from a natural diet of low algal biomass and high-density dead coral substrates that predominates in the shallow reef. Assimilation efficiency was ca 70 % from a diet of high algal biomass and lowdensity substrates that predominates on the deeper reef parts. In spite of lower daily foraging effort, territorial fish, living in deeper parts of the reef, ingest and assimilate higher amounts of AFDW, protein and energy per day than non-territorial fish foraging on the shallow reef. The difference is caused by increased availability of high-yield food and substrate types inside territories compared to the situation on the shallow reef. Daily assimilated energy (kJ d-') is 0.85 X FWW'.~'~ for fish foraging in the shallow reef zone, and 1.22 X FWW0854 for S. viride foraging inside territories on the deeper reef.

ObjectivesSexual inequality starts in utero. The contribution of biological sex to the developmental origins of health and disease is increasingly recognized. The aim of this study was to assess and interpret sexual dimorphisms for three major adverse pregnancy outcomes which affect the health of the neonate, child and potentially adult.MethodsRetrospective population-based study of 574,358 South Australian singleton live births during 1981–2011. The incidence of three major adverse pregnancy outcomes [preterm birth (PTB), pregnancy induced hypertensive disorders (PIHD) and gestational diabetes mellitus (GDM)] in relation to fetal sex was compared according to traditional and fetus-at-risk (FAR) approaches.ResultsThe traditional approach showed male predominance for PTB [20–24 weeks: Relative Risk (RR) M/F 1.351, 95%-CI 1.274–1.445], spontaneous PTB [25–29 weeks: RR M/F 1.118, 95%-CI 1.044–1.197%], GDM [RR M/F 1.042, 95%-CI 1.011–1.074], overall PIHD [RR M/F 1.053, 95%-CI 1.034–1.072] and PIHD with term birth [RR M/F 1.074, 95%-CI 1.044–1.105]. The FAR approach showed that males were at increased risk for PTB [20–24 weeks: RR M/F 1.273, 95%-CI 1.087–1.490], for spontaneous PTB [25–29 weeks: RR M/F 1.269, 95%-CI 1.143–1.410] and PIHD with term birth [RR M/F 1.074, 95%-CI 1.044–1.105%]. The traditional approach demonstrated female predominance for iatrogenic PTB [25–29 weeks: RR M/F 0.857, 95%-CI 0.780–0.941] and PIHD associated with PTB [25–29 weeks: RR M/F 0.686, 95%-CI 0.581–0.811]. The FAR approach showed that females were at increased risk for PIHD with PTB [25–29 weeks: RR M/F 0.779, 95%-CI 0.648–0.937].ConclusionsThis study confirms the presence of sexual dimorphisms and presents a coherent framework based on two analytical approaches to assess and interpret the sexual dimorphisms for major adverse pregnancy outcomes. The mechanisms by which these occur remain elusive, but sex differences in placental gene expression and function are likely to play a key role. Further research on sex differences in placental function and maternal adaptation to pregnancy is required to delineate the causal molecular mechanisms in sex-specific pregnancy outcome. Identifying these mechanisms may inform fetal sex specific tailored antenatal and neonatal care.

BackgroundPregnant women are at increased susceptibility to vitamin D deficiency. Hence, there is continuing interest in determining how vitamin D influences pregnancy health. We aimed to compare vitamin D status in two distinct populations of pregnant women in Australia and New Zealand and to investigate the relationship between vitamin D status and pregnancy outcome. This included evaluating possible effect measure modifications according to fetal sex.MethodsSerum 25-hydroxy vitamin D (25(OH)D) was measured at 15 ± 1 weeks’ gestation in 2800 women from Adelaide and Auckland who participated in the multi-centre, prospective cohort SCreening fOr Pregnancy Endpoints (SCOPE) study.ResultsMean serum 25(OH)D in all women was 68.1 ± 27.1 nmol/L and 28% (n = 772) were considered vitamin D deficient (< 50 nmol/L). Serum 25(OH)D was lower in the women recruited in Adelaide when compared to the women recruited in Auckland and remained lower after adjusting for covariates including maternal body mass index and socioeconomic index (Adelaide: 58.4 ± 50.3 vs. Auckland: 70.2 ± 54.5 nmol/L, P < 0.001). A 53% decreased risk for gestational diabetes mellitus (GDM) was observed with high (> 81 nmol/L) “standardised” vitamin D status when compared to moderate-high (63–81 nmol/L, aRR, 0.47; 95% CI: 0.23, 0.96). Marginal sex-specific differences occurred between vitamin D status and GDM: women carrying a female fetus had a 56% decreased risk for GDM in those with low-moderate levels of standardised vitamin D (44–63 nmol/L) compared to moderate-high levels (aRR: 0.44; 95% CI: 0.20, 0.97), whilst in women carrying a male fetus, a 55% decreased risk of GDM was found with high standardised vitamin D when compared to moderately-high vitamin D, but this was not statistically significant (aRR: 0.45; 95% CI: 0.15, 1.38).ConclusionsHigh serum 25(OH)D at 15 ± 1 weeks’ gestation was shown to be protective against the development of GDM. A possible association between fetal sex, vitamin D status and GDM provides further questions and encourages continual research and discussion into the role of vitamin D in pregnancy, particularly in vitamin D replete populations.Electronic supplementary materialThe online version of this article (10.1186/s12884-018-1887-x) contains supplementary material, which is available to authorized users.