Assisted reproduction in Hong Kong: Status in the 1990s

Information on assisted reproduction in Hong Kong for the period from January 1992 to December 1993 was collected from the three centres that offer assisted reproduction. Altogether, 912 treatment cycles of in vitro fertilisation and embryo transfer, 158 treatment cycles of gamete intrafallopian transfer, and 87 cycles of zygote intrafallopian transfer were initiated during this period. The delivery rates per cycle started were 8.4% for in vitro fertilisation, 29.1% for gamete intrafallopian transfer, and 13.8% for zygote intrafallopian transfer. During the same period, 233 cycles of replacement of frozen thawed embryos were completed with a delivery rate of 11.2% per cycle. Pregnancies were also achieved using oocyte donation and micromanipulation techniques.published_or_final_versio

Latent effects of larval food limitation on filtration rate, carbon assimilation and growth in juvenile gastropod Crepidula onyx

In this study we examined the latent effects of larval food limitation on the performance of juvenile Crepidula onyx under both laboratory and field conditions, and the possible mechanisms through which these latent effects were mediated. Larvae were reared at either high or low food concentrations before they were induced to metamorphose. Feeding larvae at a low food concentration reduced the size, total organic content and energy reserves of newly metamorphosed juveniles. Juvenile growth (measured as increases in shell length and total organic carbon content) and survival were then followed for 3 to 17 d. Under both laboratory and field conditions, we found that growth was compromised for the juveniles that developed from larvae fed at the low food concentration. However, feeding larvae at the low food concentration reduced juvenile survival only under laboratory conditions, not in the field. Thus, juvenile habitat conditions seem to have altered the latent effects of larval food limitation on juvenile survival. Our results also suggest that the filtration rate of juveniles developed from larvae fed at the low food concentration was significantly reduced. Follow-up experiments showed that the larval food concentration did not affect carbon assimilation efficiency of juveniles, and that the latent effects of limited larval food conditions did not simply reflect the consequence of reduced energy reserves or size at metamorphosis. Poor food-collecting performance of juveniles was at least partially responsible for the observed latent effects of larval food limitation on juvenile growth. © Inter-Research 2007.link_to_subscribed_fulltex