East Pacific Rise Cruise 2001 - Another Holiday at Sea

FWF research project P13762 BIO

Projects

The Search for Babies

The Search for Symbionts

Collaboration with C.M. Cavanaugh

Quantitative Meiobenthos Collections

Collaboration with B. Govenar & C. R. Fisher

Collaboration with scientists and crew

Work and Fun

11/26/2002 - 12/22/2002

Chief Scientist: C.R. Fisher (The Pennsylvannia State University, PA, USA)

Austrian participants

Monika Bright

Andrea Nussbaumer

Julia Zekely

 

Research Vessel Atlantis

Deep Submergence Vehicle Alvin

     

Again we were invited to continue our research at the hydrothermal vents of the East Pacific Rise 9°N. We would like to thank C. R. Fisher and C. M. Cavanaugh for their support.

More information about the Submergence Vehicle Alvin, the Research Vessel Atlantis and all cruises is provided on the WHOI webpages.

The Search for Babies

In order to find tiny tubeworms, we deployed 5 Vestimentiferan artifical settlement divices (VASD) in December, 2001 (cruise 2001). 3 of them were successfully recovered after 11 months. Animals settled on and inhabiting the traps were identified and preserved, and their numbers were counted.

           

                                                 Deployment 2001                                                                                  Recovery 2002

A house for tubeworms Riftia pachyptila, Tevnia jerichonana, Oasisia alvinae (Vestimentifera, Siboglinidae): Two of the VASDs, one deployed on a basalt that had been cleared off tubeworms last year and another one close to a small tubeworm clump, were inhabited by 15 viz. 30 tubeworms. Their size ranged from 210 μm (settled larva) to 3 cm. The larger individuals were identified as belonging to Riftia pachyptila, Tevnia jerichonana, and Oasisia alvinae. Currently, we investigate the timeframe and mode of symbiont uptake and the development of the trophosome.

         

                                                       Babytrap                                                                                                   Babies

A house for worm molluscs

(Helicoradomenia ssp. : Solenogastres, Mollusca)

Surprisingly, one of the VASDs, deployed in vicintiy to a large tubeworm clump but without elevated temperature, prooved ideal for at least two species of Helicoradomenia. A total of 96 individuals were found. Preliminary studies onboard suggest that there are bacteria covering the surface of the animals. Currently, we investigate the possibility of whether or not a symbiosis is present.

          

                      Helicoradomenia acrodema (Scheltema, 2001)                                                Helicoradodemia sp.

                                                             SEM picture of Helicoradodemia sp. showing bacterial symbionts

The Search for Symbionts

Collaboration with Prof. C. M. Cavanaugh

We collected 3 males and 3 females of Riftia pachyptila and fixed gonads and gonoducts in order to search for the symbiont in the reproductive organs. In order to prevent contamination of gonoduct content with trophosome, we tied off the gonoduct carefully with a thread posterior to the gonopore and further backwards before separating it from the posterior and anterior parts of the gonoduct.

Dissection of adult Riftia pachyptila

Quantitative Meiobenthos Collections

Collaboration with B. Govenar & C. R. Fisher

Using the 'bushmaster' quantiative collection device, two tubeworm aggregations each at TICA and Riftia Field, 5 mussel collections at Mussel Field, and one tubeworm, mussel aggregation at Biovent were collected. While the macrobenthos is part of Breea Govenar doctoral thesis (The PennState University), the meiobenthos will be investigated in our lab.

        

                                                        Bushmaster                                                                                        Meiofauna

Collaboration with scientists and crew - Work and Fun

Science party

       

                                                          All together                                                                                      Sunset

Awaiting Alvin

First dive - new & exciting

     

                                                 Back on board (Julia)                                                                        Warm welcome

Cold shower

Happy scientists

        

                                                      Evidence cups                                                                   Monika at work - like always!