A report from a Swedish-British expedition to the Marine Biological Association

At the end of March colleagues from The Maritime Museum and Aquarium in Gothenburg (Arne Nygren), Tjärnö Marine Laboratory, Gothenburg University (Fredrik Pleijel), and the National Museum Wales (Andy Mackie and Katie Mortimer-Jones), arrived at the laboratory of the Marine Biological Association in Plymouth for a one-week trip to collect marine bristleworms. The MBA is an ideal place for marine biologists with our interests to visit. The lab is well suited for our purposes and a very rich marine fauna can be found only a 15 minute boat trip away.            

Monday was spent on the laboratory's research vessel RV Sepia sampling several localities and hunting for polychaete worms of different kinds. Back in the lab the material was either sieved or left standing in buckets with sea water. This latter method is very gentle on soft bodied animals like bristleworms as many worms crawl out of the material themselves, and can be either picked with soft forceps or sucked up with a pipette from inside the bucket. The picked out worms were then studied under the microscope, photographed alive, and preserved for further studies, such as DNA-analysis. With the help of DNA we have discovered that new and undescribed species can still be found, even in well surveyed areas such as the Plymouth Sound. Sampling these hitherto unknown and undescribed species was one of the main goals of our expedition.

To summarize, we are very pleased with our stay and hope that you enjoy the sheer beauty of these marine animals as much as we do. Below you will see some of our findings as they present themselves under the macrolens, these specimens are between one and two cm in length. Many thanks to the friendly staff at MBA, with special thanks to our hosts John Bishop and Aisling Smith, and to Sepia skipper Roger Pawley and Seagoing Research Technician Sophie Banham.

Amblyosyllis formosa - a fantastic animal with very long antennae and dorsal cirri, that may curl up and stretch out, used for tactile purposes.

Eupolymnia nebulosa - one can really appreciate the name nebulosa when looking at live animals. Eupolymnia nebulosa was formerly thought to have a distribution from northern Norway to the Mediterranean but molecular data has shown that what was thought of as one species actually contains several species that have more restricted distributions. This is the real one! The species was described from southwest England by Col. Montagu almost 200 years ago.

Dorvillea rubrovittata - one of our favourite animals; we found a specimen in
perfect condition.

An undescribed species of the genus Eumida - one of the hitherto unknown species that will soon be described and given a scientific name.

Pterocirrus macroceros - yet another example of a species that has turned out to consist of several species with a similar morphology.

Eulalia tripunctata - it is not difficult to understand where it got it species name from.

A species of Notophyllum that is referred to as Notophyllum foliosum in fauna reports from the area, but molecular as well as morphological data have shown that it is not. The true Notophyllum foliosum has a more northern distribution, nearest confirmed record is from Scandinavian waters. The real Notophyllum foliosum is characterized by white spots on the dorsum which the species of Notophyllum found in southern England lack.

Myrianida pinnigera - a very decorative species, with a short row of developing stolons in an early stage (start of row indicated with arrow). The stolons will, when mature, have developed eyes, antennae and long thin swimming chaetae, and will be packed with either sperm or eggs depending on their sex. The stolons will break off from the main individual and swim to the surface and mate with the opposite sex. After spawning the female stolons survive for a few weeks caring for their young, in a ventral egg sac, until they have developed into small larvae.

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Apr 4, 2017 By guba