247
providing over 40 h of high definition video transects, 39
biological samples and in situ records of environmental
parameters. Nine species demosponges and four of hexactinellids were morphologically identified and molecularly
characterized at the mitochondrial COI gene. Eleven species, all from different families, are potentially new to science. One intriguing potentially new demosponge is a
carnivorous Cladorhizidae, while another presents a unique,
sensational, kebab-like branching shape and might belong
to a new genus of Phellodermidae. One gigantic branched
hexactinellid could be a member of a new genus of Farreidae.
Morphological results for both potentially new genera are
supported by genetics. Other potentially new glass sponges
include a species of Vitrollula, a genus only previously
observed in Japan, and a species of Tretodictyum with a
coral-like arborescent body. These results encourage our
team to further investigate the mysterious sponge biodiversity of the Galapagos seamounts, with the aim to characterize sponge communities and assess their value in order to
improve seamount conservation and sustainable
management.
15.2.6 Influence of an External Magnetic Field
on a Planktonic Foraminifer
Charlotte Eich
1,2*
, Nina Keul
1
, Stefanie Ismar
2
1
Christian-Albrechts-Universität
–
Institut
für
Geowissenschaften, Ludewig-Meyn Straße 10,
24118 Kiel, Germany
2
Experimental Ecology – Food Webs, GEOMAR
Helmholtz Institute for Ocean Research Kiel, Düsternbrooker
Weg 20, 24105 Kiel
*corresponding author: eich.charlotte@gmx.de
Keywords: Globigerinoides ruber, Gametogenesis,
External triggers, Lunar cycle, Spinose planktonic
foraminifera
Many planktonic species, as, for example, foraminifera,
conduct a simultaneous gametogenesis, which seems to be
coupled to the lunar cycle. The change of the Earth’s magnetic field during the lunar cycle, especially around full
moon, has been suggested as one potential external trigger.
We experimentally tested, whether an external magnetic field
of the strength of the Earth’s magnetic field (50 μT) triggers
gametogenesis in the planktonic foraminifera Globigerinoides
ruber by quantifying the survival and gametogenesis rates
and assessing floating behaviour. All experiments were conducted during a cruise (MSM58, Reykjavík (Iceland) to
Ponta Delgarda (Azores)) aboard the Maria S. Merian.
Understanding the trigger behind simultaneous gamete
release in G. ruber might be a useful model for understanding other big spawning events of planktonic species and help
us to further understand both the physiology and ecology of
planktonic foraminifera.
15.2.7 Applications of Stereo-Camera Systems
in Marine Conservation
Nils T. Willenbrink
1*
, Barbara Horta E. Costa
1
1
Centre of marine sciences (CCMAR), University of the
Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
*corresponding author: n.willenbrink@hotmail.de
Keywords:
Stereo-cameras,
Sampling
methods,
Ichthyofauna, Marine reserve
The utilization of underwater cameras has brought numerous advantages into the field of marine biology. In situ
recordings are non-extractive in comparison to fisheries
methods and less demanding on personal and logistics than
scuba methods. Technological advances considerably
enhanced video and information quality but almost always at
high material cost. We present a low-cost stereo-camera
dropdown system that outperforms single-camera setups by
obtaining precise measurements through the principle of triangulation. Tested in a coastal marine reserve in SW Portugal,
this system enables scientists to assess the areas performance
in protecting ichthyofauna. We will discuss possibilities and
drawbacks of the method and how modifications can be
made depending on research interest and budget.
15.2.8 Feeding Plants to Predators: Lupin
as a Feed Supplement for the European Sea Bass
(Dicentrarchus labrax)
Enno Fricke
1*
, Reinhard Saborowski
1
, Monika Weiß
1
,
Christina Hörterer
1
, Sinem Zeytin
1
, Matthew James Slater
1
1
Alfred Wegener Institute, Helmholtz Centre for Polar
and Marine Research, Am Handelshafen 12, 27570
Bremerhaven, Germany
*corresponding author: cef@hotmail.de
Keywords: Feed supplements, Plant protein, Digestibility,
Enzymes, Growth
Lupin presents a promising alternative protein source for
aquaculture diets, particularly for locally sourced or GMOfree use feeding high value finfish species. In the current
study a feeding trial with juvenile European sea bass
(Dicentrarchus labrax, initial weight ca. 15 g) was conducted
to evaluate two experimental diets containing 50% dry matter untreated and enzymatically fermented dehulled lupin
meal (Lupinus angustifolius). Weight gain of D. labrax fed
the lupin based diets was about 20% lower than those fed a
fishmeal control diet. Fish fed the untreated lupin meal diet
showed a significantly reduced condition factor, whereas fish
feeding on the fermented lupin meal diet had a significantly
lower hepatosomatic index, both compared to the fishmeal
control. Apparent digestibility coefficients of dry matter and
carbon differed significantly between all diets with untreated
lupin meal exhibiting the lowest, fermented lupin meal intermediate and the fish meal diet the highest values. The highest
protein digestibility coefficients were measured in the ferAppendices
providing over 40 h of high definition video transects, 39
biological samples and in situ records of environmental
parameters. Nine species demosponges and four of hexactinellids were morphologically identified and molecularly
characterized at the mitochondrial COI gene. Eleven species, all from different families, are potentially new to science. One intriguing potentially new demosponge is a
carnivorous Cladorhizidae, while another presents a unique,
sensational, kebab-like branching shape and might belong
to a new genus of Phellodermidae. One gigantic branched
hexactinellid could be a member of a new genus of Farreidae.
Morphological results for both potentially new genera are
supported by genetics. Other potentially new glass sponges
include a species of Vitrollula, a genus only previously
observed in Japan, and a species of Tretodictyum with a
coral-like arborescent body. These results encourage our
team to further investigate the mysterious sponge biodiversity of the Galapagos seamounts, with the aim to characterize sponge communities and assess their value in order to
improve seamount conservation and sustainable
management.
15.2.6 Influence of an External Magnetic Field
on a Planktonic Foraminifer
Charlotte Eich
1,2*
, Nina Keul
1
, Stefanie Ismar
2
1
Christian-Albrechts-Universität
–
Institut
für
Geowissenschaften, Ludewig-Meyn Straße 10,
24118 Kiel, Germany
2
Experimental Ecology – Food Webs, GEOMAR
Helmholtz Institute for Ocean Research Kiel, Düsternbrooker
Weg 20, 24105 Kiel
*corresponding author: eich.charlotte@gmx.de
Keywords: Globigerinoides ruber, Gametogenesis,
External triggers, Lunar cycle, Spinose planktonic
foraminifera
Many planktonic species, as, for example, foraminifera,
conduct a simultaneous gametogenesis, which seems to be
coupled to the lunar cycle. The change of the Earth’s magnetic field during the lunar cycle, especially around full
moon, has been suggested as one potential external trigger.
We experimentally tested, whether an external magnetic field
of the strength of the Earth’s magnetic field (50 μT) triggers
gametogenesis in the planktonic foraminifera Globigerinoides
ruber by quantifying the survival and gametogenesis rates
and assessing floating behaviour. All experiments were conducted during a cruise (MSM58, Reykjavík (Iceland) to
Ponta Delgarda (Azores)) aboard the Maria S. Merian.
Understanding the trigger behind simultaneous gamete
release in G. ruber might be a useful model for understanding other big spawning events of planktonic species and help
us to further understand both the physiology and ecology of
planktonic foraminifera.
15.2.7 Applications of Stereo-Camera Systems
in Marine Conservation
Nils T. Willenbrink
1*
, Barbara Horta E. Costa
1
1
Centre of marine sciences (CCMAR), University of the
Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
*corresponding author: n.willenbrink@hotmail.de
Keywords:
Stereo-cameras,
Sampling
methods,
Ichthyofauna, Marine reserve
The utilization of underwater cameras has brought numerous advantages into the field of marine biology. In situ
recordings are non-extractive in comparison to fisheries
methods and less demanding on personal and logistics than
scuba methods. Technological advances considerably
enhanced video and information quality but almost always at
high material cost. We present a low-cost stereo-camera
dropdown system that outperforms single-camera setups by
obtaining precise measurements through the principle of triangulation. Tested in a coastal marine reserve in SW Portugal,
this system enables scientists to assess the areas performance
in protecting ichthyofauna. We will discuss possibilities and
drawbacks of the method and how modifications can be
made depending on research interest and budget.
15.2.8 Feeding Plants to Predators: Lupin
as a Feed Supplement for the European Sea Bass
(Dicentrarchus labrax)
Enno Fricke
1*
, Reinhard Saborowski
1
, Monika Weiß
1
,
Christina Hörterer
1
, Sinem Zeytin
1
, Matthew James Slater
1
1
Alfred Wegener Institute, Helmholtz Centre for Polar
and Marine Research, Am Handelshafen 12, 27570
Bremerhaven, Germany
*corresponding author: cef@hotmail.de
Keywords: Feed supplements, Plant protein, Digestibility,
Enzymes, Growth
Lupin presents a promising alternative protein source for
aquaculture diets, particularly for locally sourced or GMOfree use feeding high value finfish species. In the current
study a feeding trial with juvenile European sea bass
(Dicentrarchus labrax, initial weight ca. 15 g) was conducted
to evaluate two experimental diets containing 50% dry matter untreated and enzymatically fermented dehulled lupin
meal (Lupinus angustifolius). Weight gain of D. labrax fed
the lupin based diets was about 20% lower than those fed a
fishmeal control diet. Fish fed the untreated lupin meal diet
showed a significantly reduced condition factor, whereas fish
feeding on the fermented lupin meal diet had a significantly
lower hepatosomatic index, both compared to the fishmeal
control. Apparent digestibility coefficients of dry matter and
carbon differed significantly between all diets with untreated
lupin meal exhibiting the lowest, fermented lupin meal intermediate and the fish meal diet the highest values. The highest
protein digestibility coefficients were measured in the ferAppendices