Tackling the Ctenophores

The modern ctenophore Mertensia ovum (NOAA photograph)

For the past decade or so, my colleagues and I have been working to make sense of the fossils we are collecting from the William Lake site in central Manitoba (some research downloads can be found here, while a description of the fieldwork is here). Many of these specimens are difficult to interpret, as they represent groups that are poorly known elsewhere in the fossil record. We find ourselves doing endless photography and microscopic study, and we carry out a lot of literature research.

We also endeavour to examine comparative material whenever we can. Living and working in Winnipeg it can be difficult to carry out first-hand examination of modern marine organisms, since we are located almost as far from the ocean as you can get in North America! As a result, when I travel I try to visit collections elsewhere.

Fragmented specimens of the modern ctenophore Pleurobrachia sp., in a petri dish

The fossils that have risen to the top of my “research heap” are odd little structures that show considerable evidence of being preserved ctenophores, or comb jellies. We have been working to image and document these, and have reached the stage where we need to finalize our interpretation of the various features so that a paper can be written.

I have acquired preserved modern comb jellies and carried out simple experiments to see what happens to them when they are desiccated on and in fine lime mud. The results were intriguing and consistent with the interpretation of our fossils, but we still need to look at specimens showing some of the diversity of modern ctenophores, and at some examples that are better preserved than those could be acquired through commercial channels (the broken ones above were received from a scientific supply house).

Anderson House, a former mansion converted into residence and dining hall by the Huntsman, is glimpsed through the evening fog

This quest has brought me, this week, to the Huntsman Marine Science Centre in St. Andrews, New Brunswick. The Huntsman maintains the Atlantic Reference Centre (ARC), which curates preserved examples of Canadian Atlantic marine life. The large collections include many groups, and I will be examining numerous examples of ctenophores and other “jellyfish.” I am also delighted to be returning to an institution where I spent some of the pleasantest weeks of my life, taking an undergraduate marine biology course, and I really don’t mind that St. Andrews is one of the prettiest towns in Canada!

I start on the collections tomorrow, and I hope to find things that make this visit worthy of a blog update …

© Graham Young, 2013