Книги з теми "Algal feeding"

Nearly three decades ago, biologists discovered that planktotrophic larvae of sea urchins can alter the size of their ciliated feeding structures in response to the concentration of food (i.e., unicellular algae). In the years since, this response has become one of the best-studied examples of phenotypic plasticity in marine organisms. Researchers have found that this form of plasticity occurs widely among different types of feeding larvae in several phyla, and involves energetic trade-offs with a suite of correlated life history characters. Furthermore, investigators have recently started to unravel the genetic and molecular mechanisms underlying this plasticity. We review the literature on feeding-structure plasticity in marine invertebrate larvae. We highlight the diversity of species and variety of experimental designs and statistical methodologies, summarize research findings to draw more general conclusions, and target promising directions for future research.

Symbiotic algae are a crucial source of fuel for the reef, via corals and others, but how is the food and energy from the corals transferred to other parts of the ecosystem to support the huge abundance and diversity seen there? ‘Microbial and planktonic engines of the reef’ describes the filter feeding—extracting particles from the water—of the large proportion of reef animals. These particles consist of plankton, microbes, bacteria, viruses, and zooplankton. Sponges also display microbial symbiotic connections with algae and cyanobacteria that is a key component of material and energy transfer. The productivity from seaweeds on which numerous species of herbivorous fish and sea urchins graze is also important.

The aim of the study was to determine the effect of feed additives (algae, soybean, and sunflower oil) used in the rabbit feed on: growth indices and slaughter traits, pH, colour, texture, chemical composition, fatty acid profile and oxidative stability (TBARS) of the meat as well as FTO and FABP4 genes expression in the meat’s intramuscular fat (m. longissimus lumborum), depending on the age and sex. The experimental material consisted of Termond White rabbits (n = 160, 80 females and 80 males). Animals were weaned on the 35th day of life, and housed in metal cages arranged in batteries (4 rabbits of the same sex in a cage). From weaning to 12 or 18 weeks of age, the rabbits were fed pellets ad libitum. Animals in the control group (C) received non-supplemented pellets throughout the experiment. In the other groups, the pellet contained 1% algae (A), 3% sunflower oil (OS), and 3% soybean oil(SO).The experimental diets were formulated to have similar protein and energy content. Diets were balanced by lowering the proportion of other feed components. The total share of all components remained at 100%. The results indicate that 3% vegetable oils (soybean or sunflower) supplementation of diets for growing rabbits leads to an increase of body weight and improvement of some of the slaughter traits, while 1% addition of algae to the feed causes deterioration of body weight and slaughter traits. The effect of oil additive depends on the animals’ age. Supplementation of the rabbits’ diet with algae (1%) or sunflower and soybean oils (3%) led to an increase in the dressing percentage of rabbits slaughtered at 18 weeks of age (approx. 3%), but had no effect on the dressing percentage of rabbits slaughtered at 12 weeks of age. Feeding pellets with either 3% vegetable oils or 1% algae additive to the rabbits did not significantly change the chemical composition of the meat. Protein content increased and intramuscular fat content decreased with age, while ash and water content were similar. The feed additives significantly differentiated meat acidity without deteriorating meat quality. Diet modification has not affected negatively meat colour. 24 h after the slaughter, the colour of rabbit meat was similar across the studied feeding groups. Correlation between diet and rabbits’ age was found. Meat texture (hardness, springiness and chewiness) of all rabbit groups slaughtered at 12 weeks of age was similar, and the shear for cewas greater in rabbits fed pellets with algae and soybean oil. At 18 weeks of age, rabbit meat from experimental groups had lower hardness and chewiness, compared to meat of the animals from the control group. Meat shear force was higher in the control group, and from algae-supplemented group. The correlation between diet and age was also found. The use of 3% vegetable oils or 1% algae as feed additives significantly reduced meat oxidative stability. Soybean or sunflower oil (3%) usedas feed additives favourably modified the fatty acid composition of intramuscular fat. Polyunsaturated fatty acids (PUFA) content was increased, including linoleic acid, and PUFA/MUFA ratio was improved. The content of these acids decreased with age. The use of algae (1%) as a feed additive resulted in positive effect on the increase of n-3 fatty acid content (EPA and DHA) in meat intramuscular fat. Algae supplementation improved pro-health properties of meat, with low n-6/n-3 acid ratio (2.5), indicating that diet modification may affect the fatty acid composition of rabbit meat. The influence of diet and age on FTO and FABP4 gene expression in meat intramuscular fat (m. longissimus lumborum) was found. FTO and FABP4 gene expression increased with age and was the highest in the group of rabbits with 1% algae supplementation in the diet. The effect of rabbits’ gender on growth, slaughter traits, meat quality and gene expression in rabbits was not observed. In conclusion, the use of natural feed additives, such as sunflower, soybean oil or algae, can improve the nutritional value of rabbit meat, without changing its chemical or physical properties, and therefore the meat can serve as functional food, with properties beneficial to human health. The results obtained in this study also indicate that the expression of FTO and FABP4 genes in rabbit muscles is regulated by dietary factors and age, which, in addition to cognitive significance, has practical implications for improving technological and dietary quality of rabbit meat.

Relationship between functioning ecosystem services and human wellbeing has been established as a bridge connecting nature and society. It has also become central pillar of sustainability science and dictates the paradigms of sustainable development. But, conceptual frameworks that systematically integrates the important roles played by natural ecological chemicals by establishing empirical links between the nature and ecology not only varies, but lacks clear support. The value of ecological chemicals as ecosystem derived natural products warrants explicit acknowledgement, only then trade-offs between services and prioritization of policy can be realised. In the last 20 years, important roles played by the ecological chemicals in Bornean terrestrial and marine ecosystems were investigated and reported. Terrestrial plants produce Volatile Organic Chemicals (VOCs) and structurally interesting secondary metabolites that facilitate their ecological processes that are aimed to establish communication such as defence, attraction, deterrent and territorial marking. Some of the most commonly utilized herbs and plants of traditional medicine importance showed very interesting chemical constituents, that justify their traditional utilization for human wellbeing. The role of VOCs that originated from animal diet and emitted through decomposition of faeces, was traced back to their important role as attractants of insects, particularly dung beetles that facilitates the remineralization of faeces and returns C and N to soil as to replenish global C and N-sink. Marine flora and fauna are perhaps the most vivid producers of structurally interesting secondary metabolites with more than one ecological functions. Halogenated secondary metabolites produced by red algae Laurencia are unique in their structural design and exhibited multiple biological potentials. Similarly, soft corals in the Sulu-Sulawesi Coral Triangle produced a huge diversity of terpenoids and functions as feeding deterrents of these soft bodied invertebrates. Ecological chemicals obtained from the Bornean biodiversity also exhibited a wide array of medically important biological activities such as anti-microbial, anti-inflammation, anti-anticancer and serves an important array of lead pharmaceuticals. Some of these compounds are very potent and have been patented as lead-pharmaceutical candidates from Bornean natural products. Hence, ecological chemicals are important natural products that regulate ecological processes that ensures ecological balance in tropical ecosystems. Humans who are the custodians of natural ecosystem, stand to benefit directly and indirectly when we practice sustainable utilization and regulation of our natural resources.