enriched diets and the growth, development and survival of litoria moorei (anura) tadpoles reared in captivity at low density

Increasing numbers of amphibian species require conservation breeding programs for their survival.A major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.Aquatic tadpoles of the West Australian frog Litoria moorei were kept at low density(1 tadpole per 1.95 litres water) in aquaria at 25℃.Fed on a staple diet of boiled lettuce and leaf litter,group of diets were supplemented with either control,Wardley Premium Spirulina Discs,Sera~(TM) GVG-mix tropical fish food,or a combination of Wardley Premium Spirulina discs and Sera~(TM) GVG-mix fish food.There was a relatively high loss(i.e.,found dead,euthanized due to scoliosis,or not found) of tadpoles fed with the lettuce/leaf litter alone,but this was increased significantly when supplemented with Wardley Premium Spirulina discs,either alone or with Sera~(TM) GVG-mix fish food,and Sera~(TM) GVG fish food alone.However,the survived tadpoles fed on the three supplements were all heavier after three weeks and at metamorphosis than those fed with lettuce/leaf litter alone,and reached metamorphosis quicker.It is concluded that any benefit of the food supplements in terms of increasing the rate of growth and development of the tadpoles is outweighed by greater mortality.There is now a need for the efficient rearing of tadpoles,many from novel species that need complex habitats.Further studies of diet are required due to the current conservation crisis of amphibians.

Complementary effect of zoo compost with mineral nitrogen fertilisation increases wheat yield and nutrition in a low-nutrient soil

Excess nitrogen(N) fertiliser use in agriculture is associated with water pollution and greenhouse gas emissions.While practices and programs to reduce N fertiliser application continue to be developed,inefficient fertiliser use persists.Practices that reduce mineral N fertiliser application are needed in a sustainable agricultural ecosystem to control leaching and gaseous losses for environmental management.This study evaluated whether fully or partially replacing mineral N fertiliser with zoo compost(Perth Zoo) could be a good mitigation strategy to reduce mineral N fertiliser application without affecting wheat yield and nutrition.To achieve this,a glasshouse experiment was conducted to assess the complementary effect of zoo compost and mineral N fertiliser on wheat yield and nutrition in a sandy soil of southwestern Australia.Additionally,a chlorophyll meter was used to determine whether there was a correlation between chlorophyll content and soil mineral N content,grain N uptake,and grain protein content at the tillering(42 d after sowing(DAS)) and heading(63 DAS) growth stages.The standard practice for N application for this soil type in this area,100 kg ha^(-1),was used with a soil bulk density of 1.3 g cm^(-3) to calculate the amount of mineral N(urea,46% N) and Perth Zoo compost(ZC)(0.69% N) for each treatment.Treatments comprised a control(no nutrients added,T1),mineral N only(100 kg N ha^(-1),T2),ZC only(100 kg N ha^(-1),T7),and combinations of mineral N and ZC at different rates(mineral N at 100 kg N ha^(-1)+ ZC at 25 kg N ha^(-1)(T3),mineral N at 75 kg N ha^(-1)+ ZC at 25 kg N ha^(-1)(T4),mineral N at 75 kg N ha^(-1)+ ZC at 50 kg N ha^(-1)(T5),and mineral N at 50 kg N ha^(-1)+ ZC at 50 kg N ha^(-1)(T6)).The T6 treatment significantly increased grain yield(by 26%) relative to the T2 treatment.However,the T7 treatment did not affect grain yield when compared to the T2 treatment.All treatments with mineral N and ZC in combination significantly improved the 1 000-grain weight compared to the T2 treatment.Chlorophyll content was better correlated with soil mineral N content(r = 0.61),grain N uptake(r = 0.62),and grain protein content(r = 0.80) at heading(63 DAS) than at tillering(42 DAS).While ZC alone could not serve as an alternative to mineral N fertiliser,its complementary use could reduce the mineral N fertiliser requirement by up to 50% for wheat without compromising grain yield,which needs to be verified in the field.Chlorophyll content could be used to predict soil mineral N at the heading stage,and further studies are warranted to verify its accuracy in the field.Overall,the application of ZC as part of integrated nutrient management improved crop yield with reduced N fertiliser application.