Neue integrative Ansätze für das Sammeln, Bearbeiten und Beschreiben skelettloser Hexacorallia am Beispiel chilenischer Seeanemonen

Actiniaria, Corallimorpharia, Zoanthidae and Ceriantharia belong to
the most neglected marine taxa. Habitats that were difficult to
access in the past, complicated and doubtful methods for
identification, the lack of summarizing literature and the lack of
specialists led soft-bodied hexacorals into a dramatic and
increasing under-representation in both biodiversity assessments
and in ecological studies. The taxonomic state of knowledge for
this group is far behind this of other taxa of comparable
importance. This global description of the situation is especially
valid for the South East Pacific. Therefore important aspects of
systematic work with soft-bodied hexacorals have been addressed in
the presented dissertation and exemplified by Chilean sea anemones.
The results have been presented in specialist journals and at
relevant meetings. To fill existing gaps and to alleviate
difficulties, traditional procedures have been combined with modern
methods. The applied techniques were tested for their
expenditure/benefit ratio. On this base a novel, efficient approach
for systematic studies of soft-bodied hexacorals was elaborated.
With this approach one of the most common shallow-water sea
anemones of north and central Chile, which spread out remarkably
during the last decades, was described as Anemonia alicemartinae.
The two most common shallow-water sea anemone species of the south
east Pacific, Phymactis papillosa and Phymanthea pluvia, were
re-described and fundamentally revised. The four south-hemispheric
genera Isoulactis, Isocradactis, Saccactis and Oulactis, which
exhibit extraordinary morphology, were revised and put together in
the genus Oulactis. The deep-water genus Actinostola was revised
and the species Actinostola chilensis was re-described.
Traditionally used characteristics to distinguish species of the
genus Actinostola were critically tested and new, alternative
features were proposed. The discovery of a colonial sea anemone
disproved the common idea of Actiniaria as a purely solitary group.
The phenomenon of coloniality in sea anemones was described in
detail and phylogenetic consequences were discussed. Some
biomechanical and evolutionary-ecological hypotheses, which were
used to explain the absence of colonial sea anemones, were
questioned by this discovery. The reproductive strategies of the
addressed Chilean sea anemone species were summarized and
appearance, habitat, bathymetric distribution and reproductive mode
were compared. Existing hypotheses about links between these
parameters were tested and discussed. A hypothesis on spreading
tendencies of some Chilean sea anemone species was elaborated. The
effects on populations of other invertebrates, especially on those
of economic importance, were discussed on the basis of some
examples. The distribution of Chilean species and their relation to
the South West Atlantic and the Antarctic fauna was analysed and
the discovered zoogeographic patterns were discussed. The problems
with identification and taxonomy of soft-bodied hexacorals were
summarized, analysed and discussed. A working protocol was proposed
as a new standard. An illustrated identification guide, which
includes all known species, was made for the better known
Mediterranean soft-bodied hexacorals. The crisis in systematics of
soft-bodied hexacorals may be overcome by consequent ap-plication
of modern methods and the close cooperation of taxonomists,
ecologists and mo-lecular biologists. New funding programs and a
growing interest within the younger genera-tion give cause for the
hope that soft-bodied hexacorals might receive the attention
merited by their ecological importance in marine benthic
communities.