World Congress of Malacology Antwerp ... - Unitas Malacologica

independently, some successfully intruding into the body tissue, others moving along the body
surface. Similar to the situation in Microhedyle remanei (Marcus, 1953) mature sperm of P.
milaschewitchii shows a midpiece surrounded by one single glycogen helix. The extremely elongated
and keeled sperm nuclei are discussed to be an adaptation to the mode of hypodermal insemination,
easing the sperm to intrude into the epidermis and move through the body tissue in a corkscrew-like
manner.
Molluscs in human impacted habitats - summary of present records in the Czech Republic
Jurickova, Lucie
Department of Zoology, Charles University, Vinicna 7, Prague 2, 128 44 Czech
Republic,
Email: lucie.jurickova@seznam.cz
The composition of molluscan assemblages of several human impacted habitats in the Czech
Republic is presented: castle ruins, after the Second World War ruined villages, old quarries, big
cities, motorway verges and fields. Malacocoenoses of nearly 500 localities were compared using
published and unpublished mostly author’s data. Individual habitats represent various succession
stages. Higher proportion of invasive species occurs in the molluscan assemblages of fields (almost
70% localities) and big cities (25 % localities), in other type of habitats it is under 10%. The number
of localities with synanthropic species was surprisingly lowest in motorway verges and old quarries,
and highest in field and cities again. All ruined villages, and nearly all castle ruins host
anthropophobic species, and approximately 50 % of these localities host strong antropophobic
molluscs. The number of localities inhabited by these species decrease from quarries, cities, and
motorways to fields. The most slugs occur in fields, and no slugs live in the motorway verges. The
habitats of early succession stages (motorway verges, fields) host more invasive, catholic, and
synanthropic species. By contrast, the habitats of the later succession stages (ruined villages, and
castle ruins especially) represent refuges for antropophobic species in the surrounding human
impacted landscape. In a region of long human impact history, like Central Europe, long-term
coexistence of humans with nature led to development of specific molluscan assemblages adapted to
different habitat types.
Importance of Cretaceous methane-seep associations in Japan for deciphering the evolution of
chemosynthesis-based communities
Kaim, Andrzej 1 ; Jenkins, Robert G. 2 ; Hikida, Yoshinori 3 ; Tanabe, Kazushige 2
1. Department of Earth and Planetary Science, University of Tokyo, Hongo 7-3-1, Tokyo 113-8654,
Japan and Instytut Paleobiologii PAN, ul. Twarda 51/55 00-818 Warszawa, Poland,
Email: kaim@twarda.pan.pl
2. Department of Earth and Planetary Science, University of Tokyo, Hongo 7-3-1, Tokyo 113-8654,
Japan,
Email: robert@eps.s.u-tokyo.ac.jp; tanabe@eps.s.u-tokyo.ac.jp
3. Nakagawa Museum of Natural History, Hokkaido 068−0835, Japan,
Email: nmhikida@coral.ocn.ne.jp
Since long time Japan remains in active margin zone and starting from Cretaceous sources wellpreserved
material from the chemosynthesis-based associations represented by numerous gastropods,
bivalves, decapods, and vestimentiferan tube worms. Studied material suggests that some modern
distribution of animals in the chemosynthesis based communities might be strictly connected to their
place of entering such community and its further local evolution. The Cretaceous methane seeps in
Japan reveal some striking similarities to their recent counterparts. Acmaeid limpets Serradonta,
which is apparently, still endemic for Japan also in Cretaceous lived on vestimentiferan tubes.
Another acmaeid Bathyacmaea is also found in the Cretaceous seeps. This is the only known
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