Transmissions- und rasterelektronen-mikroskopische Untersuchung an den Sinnesknospen der Tentakeln von Myxine glutinosa L. (Cyclostomata)

Sensory buds of different sizes have been found in the epidermis from the barbels of Myxine glutinosa. The electron microscopic investigations reveal their composition as one type of receptor cells and two types of supporting cells. The receptor cells have apical stereocilia with filamentous internal structure and there are microvilli on the supporting cells. The cytoplasma of the receptor cells contain fibrils and fibril bundles. The sensory buds are innervated by a nerve plexus below the basal lamina with nerve endings between the basal cells, which lie below the sensory buds. A comparison with sensory buds in some other vertebrates is drawn.     

Phylogeny and classification of Corylophidae (Coleoptera: Cucujoidea) with descriptions of new genera and larvae

Abstract Phylogenetic relationships within the family Corylophidae were investigated. Twenty ingroup taxa and six outgroups were included in a cladistic analysis, based on 48 characters derived from adult and larval morphology. Phylogenetic analysis confirms that Corylophidae are monophyletic within the superfamily Cucujoidea and may be subdivided into two subfamilies: the Australian Periptycinae and the cosmopolitan Corylophinae containing 10 tribes: Foadiini trib.n. , Cleidostethini, Aenigmaticini, Parmulini, Sericoderini, Peltinodini, Orthoperini, Corylophini, Teplinini and Rypobiini. All currently recognized family‐group taxa are thoroughly diagnosed, and keys to their identification based on adults and larvae are provided. Two new genera and three species are described: Weirus gen.n ., containing only W. tozer sp . n . (Australia: Queensland), and Stanus gen.n. , with the two species S. bowesteadi sp.n . (New Zealand) and S. tasmanicus sp.n. (Tasmania). The larvae of Pakalukodes bimaculatus?lipiński et al. from Queensland and of Stanus bowesteadi sp.n. from New Zealand are described and illustrated for the first time.     

The ultrastructure of the Crustoidea and the evolution of graptolite skeletal tissues

The Crustoidea are important in discussions of graptolite origins, because they represent a morphoecological type intermediate between the Rhabdopleurida and the Dendroidea. TEM and SEM studies of their rhabdosomes provide new data on the structural variation displayed by the graptolite periderm. Since the crustoid fusellar fabric does not differ markedly from the fuseller fabric of other graptolites and is dissimilar to that of pterobranchs, it is supposed that the fundamental graptolite fibril pattern was attained at the crustoid stage of graptolite evolution. The crustoid cortex is made of paracortex (the multiple deposition of sheets separated by an intersheet material in the form of condensed meshwork of fibrous material) and of pseudocortex (the accumulation of sheets and intersheet material devoid of fibrous character). The presence of sporadically genuine cortex is noted. Presumably the mechanisms of cortical fibrilogenesis were attained at the crustoid stage, but only in an incipient and incomplete form. Modes of periderm corticization arc discussed. Sheets, common elements in secondary deposits of pterobranchs and graptolites, arc compared, but some problems still remain unclear. ?Crustoidea, Pterobranchia, phytogeny, ultrastructure, cortex, morphogenesis, homology.     

Actiniscus canadensis n. sp., A. pentasterias Ehrenberg v. arcticus n. var., Pseudoactiniscus apentasterias n. gen., n. sp., Marine Relicts in Canadian Arctic Lakes

SYNOPSIS. The family Actiniscaceae Kützing, 1845, (generally placed in the dinoflagellates) includes species derived from Actiniscus pentasterias Schütt, some of which became lacustrine relicts. A. pentasterias v. arcticus. living in Arctic and Altantic waters, differs from the Mediterranean species in having a greater number of siliceous skeletons (pentasters). Advanced atrophy of pentasters in lacustrine A. canadensis , and absence of such structures in Pseudoactiniscus apentasterias , probably results from decreased salinity and an undetermined ecologic factor. Morphogenesis and physiologic transformation of past euryhaline Actiniscaceae into contemporary limnobionts began, presumably, during the prelimnic phase of Great Bear Lake and Keyhole Lake. Arctic Actiniscus which exist under subzero temperatures and endure 10-month-long winters, appear to satisfy their energy requirements by heterotrophy and frequent phagocytosis. Survival of lacustrine Actiniscus species in both Arctic lakes seems possible because of lack of competition from co-existing phytoplankton organisms which can endure extreme dystrophic conditions.     

Landscape‐scale redistribution of a highly mobile threatened species,Pteropus conspicillatus (Chiroptera,Pteropodidae), in response to Tropical Cyclone Larry

Abstract Severe category 4 Tropical Cyclone Larry, which crossed north‐east Queensland on 20 March 2006, provided a unique opportunity to examine the short‐term impacts of a major disturbance event on the population of a highly mobile threatened species, Pteropus conspicillatus. As we had recorded, the species’ population distribution in colonial roosts (camps) across the region each month for almost 2 years prior to Cyclone Larry, we continued monthly surveying of P. conspicillatus camp‐sites for a year post‐cyclone. Here we report on how P. conspicillatus responded and redistributed immediately after the cyclone, and over the subsequent year. Post‐cyclone, P. conspicillatus typically roosted in smaller camps than pre‐cyclone, suggesting that these animals had largely dispersed to locate available blossoms and fruit. For 6 months after Cyclone Larry, up to 90% of the pre‐cyclone P. conspicillatus population (ca. 250 000) was unaccounted for across the region. Information provided by the general public assisted us in locating six small camps of P. conspicillatus at ‘new’ locations, but contributed little to increase our overall population estimate for the species at this time. After November 2006, the number of P. conspicillatus built up at located camp‐sites until a post‐cyclone peak of 209 000 at the end of the study in March 2007, comparable with the population estimates in March 2005 and 2006. There is no evidence that the cyclone caused significant direct mortality among P. conspicillatus, although there may yet be longer‐term and indirect effects on population size. We suggest that redistribution by P. conspicillatus makes sense ecologically in the face of major habitat disturbance and short‐ to long‐term food resource limitation, and is not unlike the response of other Australian mainland Pteropus species to seasonal changes in food availability.     

Morphologie und Morphogenese des Bodenciliaten Oxytricha granulifera sp.n. (CiIiophora, Oxytrichidae)

Oxytricha granulifera sp.n. differs from other members of the genus by its subpellicular granules and the strongly shortened dorsal kinety 4. The overall pattern of the morphogenetic events is similar to that known from other Oxytrichidae. However, the oral primordium evolves de novo between the left marginal cirral row and the postoral cirri. The six anlagen of the frontoventral cirri are of different origin. Two anlagen of the proter evolve from parental frontal cirri, two from the opisthe, and one includes basal bodies of the proter and opisthe. Two anlagen of the opisthe evolve from the oral primordium, and three primordia originate from the postoral cirri. Frontal cirrus 1 evolves from the paroral membrane in the proter, and from the oral primordium and the anlagen of the frontoventral cirri in the opisthe. The genus Oxytricha can be subdivided into several groups with regard to the origin of its oral primordium and the development of the frontoventral cirri. The morphogenesis of the dorsal kineties in the Hypotrichida is reviewed. Seven different modes of origin are distinguished. We conclude that morphogenetic features cannot be used in the classification of the Hypotrichida at the generic level, because we have too little information to decide whether special morphogenetic features are important at the generic or species level.