Postgraduate Seminar Speakers 3rd August 2017

S P E A K E R   1

How are inbreds successful?

Waldir M. Berbel-Filho 

 

Genetic diversity is considered a key factor to fitness and survival on ever-changing environments.  As a consequence, inbreeding is thought to be as an evolutionary dead end. However, several examples of inbred organisms (i.e. asexual/clonal lineages, invasive species, and bottlenecked populations) have been reported to successfully cope with a wide range of environmental pressures. If genetic diversity is a requirement to adaptability, how are inbreds successful?

S P E A K E R   2

Biogeography of protists with different forms of acquired phototrophy in the global oceans

Suzana G Leles

There is increasing awareness that many marine protists are mixotrophs, i.e., combine autotrophy and heterotrophy in a single cell. The most praised mixotrophs conform to ‘plants that eats’, but many others are ‘animals that photosynthesize’ through acquired phototrophy. Acquired phototrophy among protists takes place within a gradient from species with lower to species with higher control over the acquired machinery; therefore, differences in their distribution in time and space may be expected. A global analysis of marine protists with different forms of acquired phototrophy revealed that they are ubiquitous in the oceans, with different groups dominating in different regions. This study provides basis to validate future modelling studies addressing mixotrophy within pelagic marine food-webs.

S P E A K E R   3

Understanding the autecology of local Porphyra populations as a knowledge baseline for successful cultivation

Jessica Knoop

Red algae of the genus Porphyra are facing increasing harvesting pressure by a growing number of small-scale companies in Wales. The successful cultivation would not only conserve local stocks but also enhance product yield and quality. As different Porphyra populations seem to need a series of environmental conditions for the completion of the life cycle, understanding the population dynamics throughout the year could help in finding these specific conditions. Therefore, the autecology of two Porphyra populations (Langland, Freshwater West) was studied in South Wales over a year in a permanent area (30x30m). Porphyra reproduction status, density (individuals·m^-2), cover (%), maximum length as well as environmental parameters (pH, water temperature, salinity) were monitored. Reproduction was observed throughout the year with peaks from late autumn to late spring. Rising temperature and day length resulted in decreased abundance and fertility. Released spores in laboratory conditions always germinated into the filamentous conchocelis stage. Individuals were largest in late spring. The observed strong seasonal variation of Porphyra in South Wales could help in finding the right temperature and photoperiod combinations needed for the successful completion of the life cycle.