Genus

About: Genus is a research topic. Over the lifetime, 68921 publications have been published within this topic receiving 590966 citations. The topic is also known as: monospecies genus & genus (zoology).

Evolution and symbiosis in the genus chlorella and related algae

Abstract: Chlorella or Chiarella-like algae are found as intracellular symbionts in several invertebrate phyla, including the Protozoa (both Sarcodina and Ciliata), Porifera, Platyhelminthes, and Coelenterata. (See review of Droop, 1963 for additional details.) The evolutionary history of these associations is of interest because the algal symbionts from these diverse hosts seem closely related to one another and to freeliving strains of the genus Chlorella. To what degree have the symbiotic algae become adapted to their intracellular mode of existence, and how specific is the association between particular host species and potential symbionts? Comparisons of symbiotic algae from diverse hosts and freeliving algae with respect to their infectivity into particular host species, and with respect to the characteristics of the symbiotic association which they form, ought to provide at least a partial answer to these questions. The symbiotic association of the ciliated protozoan Paramecium bursaria with Chlorella is especially suited for such studies. The protozoan host can be rid of its naturally occurring intracellular symbionts, and the resulting aposymbiotic strains are readily cultured. Moreover, many of the symbiotic algal strains can be cultured axenically. The host reinfects easily with its own or other symbiotic algae (Siegel, 1960; Karakashian, 1963) and is small and unicellular, which simplifies the quantification of the infectivity of the algae. We have recently examined the affinity

Description of Ceratodus: A Genus of Ganoid Fishes, Recently Discovered in Rivers of Queensland, Australia

Abstract: After some introductory remarks the author proceeds to give a description of the external characters which appear to indicate the existence of two species, viz. Ceratodus forsteri, with fewer and larger, and Ceratodus miolepis with smaller and more numerous scales.

Phylogenetic relationships of vespertilionid genera (Mammalia: Chiroptera) as revealed by karyological analysis

Abstract: Banded karyotypes of 50 species belonging to 23 genera were analyzed. The diploid chromosome numbers ranged from 26 to 50. For karyotypic comparison we used a 44 chromosomes karyotype, consisting of 4 metacentric and 17 acrocentric autosomes, as “basic karyotype”. Almost all of its 25 autosomal arms could be identified in each individual karyotype. In 8 chromosomes, i. e. 1/2, 7, 11, 12, 13, 15, 23 and X, small inversions were detected. As a result, each of the chromosomes mentioned occurs in two states which differ slightly in their banding patterns. These were used as character states in the cladistic analysis together with other chromosomal rearrangements. The implications drawn from the cladogram obtained are: The Miniopterinae clearly belong to the Vespertilionidae but are the first to branch off from the common stem. The tribe Myotini should be raised to the rank of a subfamily. Within the largest subfamily Vespertilioninae, one autapomorphic chromosomal character was found for each of the tribes Vespertilionini and Pipistrellini. In addition, both tribes are distinguished from the other Vespertilioninae tribes by two synapomorphic features. These results allow for the first time an unequivocal classification of the systematically difficult “pipistrelloid” species. The species of the genus Pipistrellus (sensu Hill and Harrison 1987) are spread over the Pipistrelllni and Vespertilionini. We therefore suggest the splitting of this heterogenous genus into at least four genera. Only the members of the previous subgenus Pipistrellus constitute the genus Pipistrellus and belong to the Pipistrellini. The previous subgenera Hypsugo, Vespadelus and Falsistrellus, given generic rank in some recent studies, belong to the tribe Vespertilionini and are not closely related to Pipistrellus. For the genera Eptesicus and Hesperoptenus, which belong neither to the Vespertilionini nor to the Pipistrellini, the tribe Eptesicini was established. The phylogenetic relations of this tribe and the status of the presumably polyphyletic tribe “Nycticeiini” could not be solved.

A Monograph of the Lichen Genus Pseudoparmelia Lynge (Parmeliaceae)

Abstract: Hale, Mason E., J r . A Alonograpli of the Lichen Genus Pse~idopai~melia Lynge (Parmeliaceae). Smi fhsonian Contl-ibzitions to Botany, number 31, 62 pages, 18 figures, 197(i.--A ~vorld monograph ot“ the genus Pseiidopai-melia is presented. The re are 76 species, most occurring in dry subtemperate to tropical areas and especially concentrated in the arid scrub lands of South Africa, Australia, and Brazil. T h e genus is characterized 13) a n unusually high number of species with di1,aricatic acid and related orcinol depsitles. T h e following new species are described: P. callicliroa KnrokaMa, P. concornitnns Hale, P. conlabiosa Hale, P. dahlii Hale, P. ncoquintal-ia Hale, P. siibarnbigzia Hale, P. .subamplexa Hale, and P. ixnczolnnu Hale. T h e following new combinations are made: P. L‘OV rugati-im (Kurokawa and Filson) Hale, P. c x o m n t a (Zahlbruckner) Hale, P. geilachci (Zahlbruckner) Hale, P. papillo.sa (Lynge ex Gyelnik) Hale, P. Totlrigiiesiana (Hue) H:ile, P. scliistncca (Kurokawa arid Filson) Hale, P. scotop l iy l la (Kurokawa) Hale, and P. spodochroa (Kui-okaxva and Filson) Hale. OFFICIAL l’IBL.ICATIO\ 1)Ai I: is hantlstampetl i n a lilnitetl tiutiihcr of initi;tl copies and is recorded in rhc Institution’s annual report. Snzitiisoizicin l’cnr. SLKIFS co\ ER D E S I G ~ : Leaf clearing from thc Katsnra trce Cei .c id iphy l lu in jnfmnicuin Siebold and Zuccarini. Library of Congress Cataloging in Publication Da ta Hale, hlason E. .4 monograph of the lichen genus Pseudopar??~c lk~ Llnge (Parmeliaceae) (Smithsonian Contributions to botany ; no. 31) 15ibliography: p . Includes index Supt. of Docs. no.: SI 1.29:31 I . Pseudoparmclia. I . Title. 11. Series: Sn1itl1sonian Institution. Smithsonian contributions to botzGi) , no. 31. Q K l S 2 7 4 7 no. 31 [Qh585.P2] 381’.08s [389’.1] 73-619375

New Psychodids from the Cretaceous Ambers of Lebanon and France, with a Discussion of Eophlebotomus connectens Cockerell, 1920 (Diptera, Psychodidae)

Abstract: Two new psychodid flies, Eophlebotomus gezei sp. nov. and E. carentonensis sp. nov., are described from Lebanese and French Lower Cretaceous ambers. They are considered here to form part of the same genus as the Upper Cretaceous Burmese amber, Eophlebotomus connectens Cockerell, 1920. These discoveries allow the description of the antenna and male genitalia of this enigmatic genus. Although the new species of Eophlebotomus share numerous characters with the Phlebotominae, especially the male genital structures, we retain this genus in the stem-group of the Sycoracinae and Trichomyiinae.