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21.
Berthella canariensis is described from Canary Islands. Themantle is smooth and its ground colour is grey, with black andopaque white spots scattered regularly all over the dorsal surface.White spots are less abundant than black ones. The posterior halfof the mantle has areas of with a paler ground colour that are variablein size. Berthella canariensis has several features that distinguishit from other described members of Berthella. It had a broadradula with numerous teeth per half-row. However, other aspectsof its anatomy, such as the absence of a medial buccal glandand the presence of a tuberculate gill, distinguish it fromother species with a broad radula. As the present species has two features found in some speciesof Pleurobranchus and several new higher taxa have been describedrecently, Willan's (1987) phylogenetic hypothesis was re-analysed.This analysis largely supports the hypothesis presented by Willan. The sister-group relationship of B. Canariensis with B. californiais supported by two synapomorphies. The relationship of thesetwo species to other species of Berthella is poorly resolvedin the present analysis and requires additional study of allmembers of the genus. Similarly, questions of the monophylyof Bathyberthella, Polictenidia, Parabathyberthella, Tomthompsoniaand Berthella require the consideration of additional speciesand comparison with other member of Berthella and Berthellina. Despite the need for further study, the mohophyly of the cladecontaining Bathyberthella, Polictenidia, Parabathyberthellais well supported. Similarly, numerous synapomorphic featuresconfirm the monophyly of the clade containing Bathyberthella,Polictenidia, Parabathyberthella, Tomthompsonia, Berthellinaand Berthella, and its sister-group relationship with the Pleurobranchus. The present study reveals that the Notaspidea have three distinctconfigurations of triaulic reproductive systems, not previouslydifferentiated. (Received 19 January 1998; accepted 15 November 1999)  相似文献   
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ABSTRACT. We report the characterization of cell-associated and extracellular peptidases of Bodo sp., a free-living flagellate of the Bodonidae family, order Kinetoplastida, which is considered ancestral to the trypanosomatids. This bodonid isolate is phylogenetically related to Bodo caudatus and Bodo curvifilus . The proteolytic activity profiles of Bodo sp. were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis containing co-polymerized gelatin, casein, hemoglobin, or bovine serum albumin as substrates. The enzymatic complex degraded gelatin better in acidic pH, and under these conditions four proteolytic bands (120, 100, 90, and 75 kDa) were detected in the cellular or extracellular extracts. Two peptidases (250 and 200 kDa) were exclusively detected with the substrate casein. All these enzymes belong to the serine peptidase class, based on inhibition by aprotinin and phenylmethylsulfonyl fluoride. This is the first biochemical characterization of peptidases in a free-living Bodo sp., potentially providing insight into the physiology of these protozoa and the evolutionary importance of peptidases to the order Kinetoplastida as some of these enzymes are important virulence factors in pathogenic trypanosomatids.  相似文献   
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The correct identity of three chromodorid nudibranch species,Chromodoris clenchi, C. neona and C. binza is established onthe basis of material from the Caribbean Sea. These three speciesare compared with C. britoi, from the northeastern Atlanticand the Mediterranean Sea. All four species have a colour patternof cream with red (or yellow) lines and blue spots. (Received 30 March 1993; accepted 20 November 1993)  相似文献   
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Morphogenetic events during division, physiological reorganization, and postraumatical regeneration, the last being induced both chemically and microsurgically, were studied by light microscopy on protargol-impregnated specimens of the hypotrichous ciliate, Laurentiella acuminata. Parakinetal stomatogenesis, from transverse cirrus-1 during division and reorganization, changes during regeneration to a parakinetal one which characterizes more primitive members of Hypotrichida in the S. O. Stichotrichina, but solely when the AZM is damaged. These morphogenetic events a) confirm the previous inclusion of L. acuminata among the Oxytrichidae on the basis of its morphological characters and indicate that it is a primitive species of this family related with the Stichotrichina through genera Pleurotricha and Paraurostyla; b) suggest a synthetic model that explains both the positioning and timing of cortical morphogenesis in the cell cycle. The key point of this model is the attribution to the AZM of a repressive capacity on the stomatogenic area, the last one being positioned according to the system of gradients of morphogenetic activity proposed by Jerka-Dziadosz to explain location of primordia in urostylids. This repression is manifested not as a gradient, as indicated by De Terra, but as a long-term repression limited to a certain distance. Simultaneous repression and stimulation occurring in a growing cortex with the AZM remaining constant in size could explain the critical ratio, buccal cortex/somatic cortex, at which stomatogenesis is triggered as indicated by De Terra.  相似文献   
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Six valid species of the nudibranch genus Dendrodons Ehrenberg,1831 inhabit the Atlantic Ocean, including the Mediterraneanand Caribbean Seas. Dendrodons lumbata (Cuvier, 1804), Dendrodonsgrandiflora (Rapp, 1827), Dendrodons nigra (Stimpson, 1855)(immigrant from the Red Sea), Dendrodons krebsu (Mörch,1863), Dendrodoru senegalensis Bouchet, 1975 and Dendrodonswarta Marcus & Gallagher, 1976. Additional data about thebiology and geographical distribution of these species are presented.New evidence suggests that other species assigned to the genusDendrodons, Dendrodons racemosa Pruvot-Fol, 1951 and Dendrodonsminima Pruvot-Fol, 1951, must be included in the genus DoriopsillaBergh, 1880. Three new species of Dendrodoris are describedfrom the Northeastern Atlantic and West Africa;Dendrodons angolensis,Dendrodoris guineana and Dendrodons herytra. The variable external morphology makes species recognition difficult.Instead, the diagnostic characters utilised to separate speciesare the shape of the male cirrus hooks, the structure of thereproductive system and features of the egg-mass. (Received 25 April 1995; accepted 1 August 1995)  相似文献   
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