PhD Studentship - The Macroecology of globally-distributed deep-sea jellyfish.

A joint PhD studentship between The Natural History Museum, London and the University of Southampton.

Supervisors: Dr Cathy Lucas, Dr Sven Thatje (Ocean & Earth Science, UoS), Prof Beth Okamura (Life Sciences, NHM)

Project Start Date: October 2013. Interviews of short-listed candidates will be in June 2013.

Rationale: Macroecology provides a framework for understanding how local- and regional-scale processes interact, allowing us to understand how the biological and ecological traits of individual species influence large-scale patterns in diversity. Little is known about reproductive traits of deep-sea mesopelagic organisms and even less so on a macroecological scale. Jellyfish and related gelatinous zooplankton are conspicuous throughout the world’s oceans.

Aims: The overall aim is to investigate the population dynamics and reproductive traits of the deep-sea jellyfish, Periphylla and Atolla, on a macroecological scale. The specific objectives are to:
O1: Compile a global database of preserved specimens within the collection and any data from published/unpublished resources;
O2: Carry out a comprehensive taxonomic analysis of Periphylla and Atolla spp. in the world’s oceans using morphological and molecular methods, which will provide a framework for subsequent macroecological analyses;
O3: Analyse how reproductive traits are influenced by temperature and food;
O4: Determine whether changes in abundance and phenology have occurred over time.
The hypotheses to be tested in this project are: 1) macroecological patterns in reproduction of deep-sea coronate jellyfish broadly follow global patterns in temperature; 2) ecological plasticity in reproduction will be associated with environmental change.

Methodology: The project will make use of the unparalleled, but currently unexploited, historical resource of preserved specimens of coronate jellyfish archived in the IOS Discovery Collection housed at the NHM. Samples have been collected from throughout the world’s oceans, from a variety of depths and seasons since the early 1900s. The current Masters project has laid the foundation for this research, as the Discovery Collection database has been searched for jellyfish samples and several of the proposed analytical methods have been carried out very successfully. Individuals collected at specific locations will be identified using molecular (e.g. CO1, 16S & 28S rRNA) and morphological descriptors (e.g. coronal diameter, bell height, number of tentacles, pigmentation). Population structure will be described and reproductive traits such as size to maturity, breeding synchronicity, gonad index, gametogenesis, maximum oocyte size will be determined histologically. Samples may be supplemented by new material collected from the Norwegian fjords (UoS has established academic links with Bergen).

Expected outcomes: 1) A catalogue of Periphylla and Atolla specimens in the Discovery Collection; 2) Global maps of their spatial distribution; 3) Description of species using morphological and molecular methods; 4) In some locations, descriptions of annual patterns of relative abundance and population structure; 5) Comparison of life history and reproductive biology at different latitudes and food environments; 6) Analysis of potential long-term (~50-100 years) changes in population structure.

Innovations: Museum collections have never been used to assess large-scale and long-term trends in jellyfish populations. The project will be the most comprehensive macroecological study of a deep-sea jellyfish, making use of new DNA techniques that enable species to be identified using historical, formalin-preserved samples, as demonstrated with the Continuous Plankton Recorder survey.

TRAINING
At both UoS and the NHM, the student will acquire a range of generic (report writing, presentation skills, computing, Health & Safety) and analytical (microscopy, histology, molecular biological techniques, image analysis, statistical analysis) skills, some of which will be specific to the project (scyphozoan biology and molecular phylogenetic analysis, medusa morphometrics). The NHM and UoS both have postgraduate programmes that offer training in generic and transferable skills in line with the Roberts agenda. Thus the student will participate in skill development activities at the NHM or UoS as appropriate during residence periods with a view to maximise opportunities and avoid redundancy. The student will be encouraged and trained to present their research and results to the wider scientific community at national and international conferences, and to the public via public engagement activities.