7. Sponge project II:

Evolutionary and ecological success of sponges - the world's simplest animals

2.6 mio. DKR. granted by Danmarks Frie Forskningsråd (Independent Research Fund Denmark) to Hans Ulrik Riisgård, together with Jonathan Brewer (SDU) and Peter Funch (AaU) for 2 years (2018-2020).

Abstract: Sponges were present more than 600 million years ago and have ever since been important components in aquatic ecosystems. They are sessile and pump huge amounts of water through their bodies from which they filter out food particles. Most likely they share basic characteristics with more advanced filter-feeders that all possess protection and cleaning mechanisms to overcome particle-overloading. The goal of the project is to understand the mechanisms ensuring maintenance of the sponge filter-pump by providing a basic understanding of the origin and purpose of contractile behaviour of sponges. Understanding of the ecophysiology of sponges and comparison with other filter-feeders, such as the blue mussel that reduces its respiration rate to overcome starvation during winter months, may shed light on the evolutionary and ecological success of sponges - the world's simplest multicellular animals.

6. Sponge project I:

Early evolution of multicellular sponges - a bioenergetic and bio-fluid mechanical approach for understanding evolutionary adaptation to animal filter-feeding in the sea

 Grant from VILLUM FONDEN: 6.4 mio. DKR (for 4 years: 2015-2019)

 Hans Ulrik Riisgård, Don Canfield, Niels T. Eriksen, Peter Funch, Poul Scheel Larsen, Jens H. Walther, Knud Erik Meyer, Tom Fenchel, Claus Nielsen, Ana Riesgo, Gert Wörheide

Abstract: Sponges are one of the earliest evolved, and simplest, groups of animals. They are multicellular but lack the typical organization of other animals with e.g. anterior-posterior polarity and nerves. Sponges are sessile animals with water-pumping choanocyte chambers. They share a number of characteristics with other filter-feeding animals. However, they also share characteristics with choanoflagellates, a group of filter feeding flagellates believed to be the sister group to all animals including sponges; they are not ancestral as such, but share a common ancestor. In this project we will study the bioenergetics and bio-fluid mechanical properties of free-living choanoflagellates, colonial choanoflagellates and sponges. Our goal is to investigate, elucidate and quantify the major differences in functional biology of unicellular choanoflagellates and multicellular sponges in order to identify the evolutionary steps that enabled the development of multicellular sponges in which the entire body is specialized for filter-feeding, and to therefore understand a critical step in the history of animal evolution. The project is focused on comparative morphology combined with experimentally measured bioenergetic parameters, including filtration, respiration, particle capture efficiency, food ingestion and excretion in sponges and choanoflagellates. Bio-fluid mechanical studies will also play a central role in the project where we will track particle motion and flow fields around free-swimming choanoflagellates, colonies of choanoflagellates, and the internal water flows through sponge canals and filters. We will also explore the mixing created by exhalant jet-currents from the sessile sponge colonies. Observations will lead to detailed biophysical models explaining the flow patterns and dynamics of food capture in all of the studied organisms. Finally, we want to explore the origin and evolution of a multicellular water-pumping sponge from a phylogenetic point of view.

5. Water processing and bio-mechanical characterization of filter-feeding jellyfish:

This project is supported by a personal frame-grant (336,960 DKR) to Professor Hans Ulrik Riisgård from the Danish Council for Independent Research | Natural Sciences, DFF-4002-00494, (Det Frie Forskningsråd/Natur og Univers, sagsnummer 4002-00494) in the period 1 July 2014 to 30 June 2017). The project focuses on several basic problems, among these the following questions: What is the energetic cost of jellyfish water processing (swimming and filter feeding), and to what degree is viscosity (i.e. pure physics) rather than biological mechanisms controlling the effects of temperature? The suggested studies on swimming, feeding and other bio-mechanical activities in jellyfish are designed to answer these questions of fundamental importance for understanding the impact of jellyfish in the sea with expected future creasing temperatures. See full application on this link.

4. MarBioShell:

A network supported by the Danish Agency for Science Technology and Innovation in the period 1 January 2008 to 31 December 2012. Besides of coordinating the research activities among the participants, the MarBioShell network intends to support a broader communication to and between national and international companies, research teams and public authorities. As scientific leader of the project I am responsible for coordination and internal communication within the network. See homepage



3. BioFlow:

BioFlow (Flume facility co-operation network for biological benthic boundary layer research).

Bioflow is an EU funded co-operative network for biological flumes. The network comprises 17 institutes all with biological flume facilities, and wasofficially started in December 2001. One of the activities within BioFlow is the organisation of 4 workshops on topics of common interest.



EUROpean GELatinous zooplankton: Mechanisms behind jellyfish blooms and their ecological and socio-economic effects (EUROGEL).

A research project supported by the European Commission


The problem

Jellyplankton outbreaks (massive occurrences of medusae and other gelatinous planktonic organisms) are an increasing threat for some key economic activities in coastal areas, such as fisheries, aquaculture and recreation.


Project objectives

- Identify and quantify key factors regulating the abundance and succession of jellyplankton species in European waters

- Better understand the role of jellyplankton in marine ecosystems

- Develop models able to forecast the likelihood of jellyplankton outbreaks

- Estimate the socio-economic effects of jellyplankton outbreaks in European coastal areas.


1. Biological Oceanography:

International Study Programme in Biological Oceanography - supported for 3 first years by EU Interreg IIIA.

The University of Southern Denmark and the University of Kiel, Germany, have developed a new joint study programme in Biological Oceanography with support from EU Interreg IIIA. The study is offering an interdisciplinary combination of lectures, seminars, practicals and field courses covering all aspects of biological oceanography. A close collaboration between the two Universities in a joint study programme in Biological Oceanography provides the best training of university students in biological oceanography within the region and an excellent opportunity to establish an international network.


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