4. Jahrestagung von NOBIS Austria 2. - 3. Dezember 2010

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Endoparasitic bivalves in Philippine palaeopneustid sea urchins (Echinoidea: Spatangoida) Kroh, A. 1 , Mandic, O. 1 , Ziegler, A. 2 & Miskelly, A. 3 1 Naturhistorisches Museum Wien, Geologie & Paläontologie, Burgring 7, 1010 Wien, Austria; E-mail: andreas.kroh@nhm-wien.ac.at, oleg.mandic@nhm-wien.ac.at 2 Institut für Immungenetik, Charité-Universitätsmedizin Berlin, Thielallee 73, 14195 Berlin, Germany; E-mail: alexander.ziegler@charite.de 3 9 Kirkwood Ave, Blackheath, NSW, Australia; E-mail: seaurchins1@optusnet.com.au Recently, a large number of Philippine upper shelf sea urchins (Echinodermata: Echinoidea) became available, presumably due to shifting of local fishing activity from over-exploited shallow water habitats to deeper areas. The use of tangle nets and bottom fishing accounts for a huge number of by-catch, including echinoids. The faunal spectrum recovered from these fishing nets is rather selective, consisting mainly of large and epifaunal species, while burrowing or small species are underrepresented. Among the echinoids recovered, members of the genus Plesiozonus (Irregularia: Spatangoida) are especially large, often exceeding 120 mm test length and are thus commonly collected by the fishermen. Previously, Plesiozonus species were known by very few specimens only. Consequently, little is known on their biology, ecology, and physiology. While cleaning specimens of Plesiozonus hirsutus, we discovered double-valved bivalves in their rectum. Our first assumption, namely that these animals were simply swallowed by the deposit-feeding sea urchins proved to be unlikely: in every specimen with preserved intestine, a single articulated bivalve was located close to the periproct and contained mummified tissue. This strongly suggested that the bivalves were actually living inside the intestine of the sea urchins, rather than having been accidentally swallowed during feeding. Considering the size of the bivalves, which approaches or exceeds that of the respective echinoid peristome, the latter possibility seems even less likely. The bivalves are characterized by an extremely thin shell as well as a reduced hinge region and represent yet unknown galeomatid or montacutid species. Both taxa are known to live in association with echinoderm hosts, mainly holothurians. From sea cucumbers, the minute endoparasite Entovalva mirabilis has been reported. In echinoids, endoparasitic bivalves have not yet been described, although three galeomatid species are known to live externally attached to the periproct of the spatangoid Brissus latecarinatus. We hypothesize that it is probably only a small evolutionary step from such a life style to an endoparasitic one. Especially so, as Entovalva has been observed to actively force its way back into the intestine of its holothurian host when artificially removed. _____________________________________________________________________________ 28 Ber. Inst. Erdwiss. K.-F.-Univ. Graz, Band 15, 2010; ISSN 1608-8166
Population genetics and phylogeography of Cylindrus obtusus (Gastropoda: Pulmonata: Helicidae) an endemic of the Austrian Alps Kruckenhauser, L., Haring E., Däubl, B. Cadahia, L., Zopp, L. & Sattmann, H. Museum of Natural History Vienna, Burgring 7, A-1010 Vienna, Austria E-mail: luise.kruckenhauser@nhm-wien.ac.at Cylindrus obtusus (Helicidae) is a hermaphroditic land snail, endemic in the Austrian Alps, which is restricted to high elevations (1600 to 2500 m asl) and limestone. As a specialist of high alpine rocky habitats, C. obtusus has a quite patchy distribution area which may become even further reduced in the future due to global warming. Previous investigations revealed geographic differences in the genital apparatus: All specimens from the more western populations had one stylophore and two equally developed mucus glands more than twice the length of the stylophore. In contrast, in individuals from the eastern margin of the species distribution one or two mucus glands were found and the size ratio between stylophore and mucus gland(s) was highly variable. To find out whether these anatomical differences reflect a genetic differentiation, which might be an indication for distinct glacial refugia, we investigated a 650 bp fragment of the COI sequence (200 individuals) and 9 microsatellite loci (500 individuals from 29 populations) from samples covering the whole distribution range of the species. The COI sequences showed a geographic differentiation between eastern, central and western populations. However, genetic distances are small (max. 1.7 %). The microsatellite analysis reveals a high differentiation between the populations implying restriction of gene flow. The highest genetic variability was found in the central populations. Remarkable nearly all individuals from the eastern populations, which are variable in their genital morphology, are homozygous in all microsatellite loci (although different alleles were found within populations). The most plausible explanation for this finding is an altered mode of reproduction. Further investigations shall elucidate whether this lack of heterozygotes is caused by selfing and if so, why it occurs at such a high frequency. _____________________________________________________________________________ Ber. Inst. Erdwiss. K.-F.-Univ. Graz, Band 15, 2010; ISSN 1608-8166 29
Page 1 and 2: 4. Jahrestagung von NOBIS Austria 2
Page 3 and 4: Systematics - applied? Donnerstag -
Page 5 and 6: 13:50 - 14:10 J. Walochnik & H. Asp
Page 7 and 8: Astonishing Diversity of Somatic Ci
Page 9 and 10: Long-distance travels with short-li
Page 11 and 12: How and why to achieve more objecti
Page 13 and 14: Protists as bioindicators for soil
Page 15 and 16: Crypitc diversity in European Genti
Page 17 and 18: Determination of the prevalence of
Page 19 and 20: The roots of sea-turtle fouling bar
Page 21 and 22: Integrative taxonomy: Combining che
Page 23 and 24: Morphological distinctness despite
Page 25 and 26: The eastern wolf: truths and myths
Page 27: WoRMS and the World Echinoidea Data
Page 31 and 32: Microscopic and molecular analyses
Page 33 and 34: Lichen diversity of Armenia Mayrhof
Page 35 and 36: Species evolution in lichen symbios
Page 37 and 38: Quantifying evolution - paleolake m
Page 39 and 40: Oil gland chemistry as a source of
Page 41 and 42: The endosymbiont Wolbachia in fruit
Page 43 and 44: Clypeasteroid echinoids of the Indi
Page 45 and 46: What are conodonts? Suttner, T.J. 1
Page 47 and 48: Is Babesia still Babesia? Walochnik
Page 49 and 50: Sabine Agatha - Universität Salzbu
Page 51: Günther Raspotnig - Karl-Franzens-

4. Jahrestagung von NOBIS Austria 2. - 3. Dezember 2010

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