Cladorhizid sponges from hydrothermal vents and cold seeps in the NE Atlantic Ocean

• Main Author: Thomassen, Jon Hestetun
• Format: Master Thesis
• Language: English
• Published: The University of Bergen 2009
• Subjects: Cladorhizidae; 759906; VDP::Matematikk og Naturvitenskap: 400::Basale biofag: 470; Arctic; Folmer; North Atlantic
• Online Access: http://hdl.handle.net/1956/3934

Sponges are known to frequently contain a great number of symbiotic organisms. Symbiosis is also a characteristic trait of vent and seep animals worldwide. Sponges in the deep sea family Cladorhizidae, otherwise also known for their surprising ability to capture invertebrate prey, are among the most common sponges found in proximity to vents, and in one reported case methanotrophic symbiotic bacteria have been described in a cladorhizid species at a mud volcano. The phylogenetic relationships within the Cladorhizidae and between the cladorhizids and sister families are uncertain. New species of Cladorhizidae are still discovered, even in comparatively well studied areas such as the North Atlantic, and their affinity to vent systems make them likely candidates for harboring methanotrophic symbionts. The 2006-2009 R/V G.O. Sars" cruises to methane rich habitats in the Norwegian and Arctic Seas have yielded a number of cladorhizid specimens. This thesis contains a taxonomic inventory of these specimens using traditional morphological methods, and the results of sequencing the Folmer COI, and ITS partitions of the identified species. Lastly, the pmoA partition of the gene coding for particulate methane monooxygenase in known methanotrophic bacteria, was sequenced as a method to determine the presence of any methanotrophic symbionts from the specimens sampled. Morphological results showed that the R/V G.O. Sars" material contained six Asbestopluma and three Cladorhiza species. With the exception of two species affiliated to A. lycopodium, all were previously described species from the North Atlantic and Arctic. Though obtaining sequences proved challenging due to contamination from other organisms, cloning allowed the separation of cladorhizid and contaminant sequences, and it proved possible to get COI and ITS sequences from nearly all morphologically identified species. ITS sequences proved too divergent for phylogenetic analysis; however Folmer COI sequences had a level of resolution applicable both to place the ...