28.02.2013 (Thursday). The trawl
of today was quite unusual. The station was the deepest so far : 770m, so we
were expecting (and hoping) to find some different kinds of animals than the
usual. When the trawl was brought back above the working deck, everyone was
surprised to see an enormous amount of mud in the net. The deck has never been
so dirty. At first we cannot see anything, so it´s always a surprise to wash
some of this mud and see if there´s something in it. There was a lot of
organism hidden in there: seestars, a lot of ophiurids, sponges … and
amphipods. Not so much (or most probably we couldn´t find them so easily in the
mud) but really interesting ones. We found some Eusirus giganteus of an unusual coloration. I did my master thesis
on the pseudocryptic diversity inside this genus, so this interested me a lot.
We found out during my thesis that the species of Eusirus can most probably be distinguished with the coloration,
along with other less visible morphological characters. There was a species in the complex giganteus of a bright red coloration
that we called the “red dragon”. At first, I thought the specimens we found
today belonged to this species, but the coloration is still different, the body
is grayish with blood red appendices. It´s another piece of the Eusirus problem, and raises even more
the interest in continuing the study of the genus.
In the
evening, I dissect the first serie of specimens of interest for my Phd thesis,
in order to begin the DNA extractions. I withdraw one or two pleopods and put
them in absolute alcohol. At the end, the work with the stereomicroscope begins
to get very hard, as the sea is getting rougher and rougher. We make sure that
everything is fixed and attached with ropes, because the night will be quite
agitated, with a wind of force 9. Indeed, we are woken up around 4 am by a
violent bump that makes everything fall on the ground in the cabin. I sleep
real bad, I´m probably not used anymore to such movements but I fortunately don´t feel any
seasickness.
(Marie)
28.02.2013 (Thursday). Oh, its already the last day of February.
Time is running like a meteor on the planet Antarctica... In the morning, same
weather than yestrerday evening: foggy. The wave are moderate but are supposed
to increase seriously later today. We are at our second sampling area in the
Bransfield Strait. We will again do three or four stations here at various
depths and at bottom topologies for estimating the influence of these
parameters on the structure of the benthic communities. Today we will have our
deepest station so far: about 770 m depth. The net comes full with a huge load
of brown pasty mud. It does not smell. We find a lot of Eusirus of the complex giganteus.
Most of them belong to the chromotype 'gray back/crimson legs', not yet found
during this cruise. Truly giant amphipods reaching 100 mm with a vibrant
colouration.
In the coming days we will probably have a second trap operation. So
we need more ballast (piece of rail of 50 kg). They have rermained in a container
in the hold. The second officer Felix Lauber told me that there is a problem.
The main door of that container has been soldered. The other door can only be
slightly open and only a narrow-chested man can go inside. This will be
difficult but normally it will be possible.
In the evening, the strength of the waves increases considerably. We
have to fix everything in our lab (and the dredge outside). Waves hit the
window of our lab. During the night, I hear in my sleep that the telephone and
the bin of our cabin fel down and are rolling from one corner to the other.
Marc, who sleep below me, put them in security in a safe corner.
(Cédric)
Eusirus complex giganteus, chromotype gray back / crimson legs.
This is the tip of the spine of a cidaroid sea urchin. There are tiny bivalve molluscs and holothurians (the pink sausage) living specifically on them.
Detail of the same.
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