The mitotic chromosomes of the lampreyMordacia mordax (agnatha: Petromyzonidae)

Résumé L'étude des chromosomes somatiques de la lamproie de l'hémisphère sud,Mordacia mordax (Richardson), montre que l'équipement chromosomique diploïde de cette espèce est composé de 76 chromosomes très petits. La plupart des chromosomes sont métacentrique ou bien submétacentrique. Ces chromosomes sont différents en nombre de ceux décrits pour les lamproies de l'hémisphère nord.     

Somatic chromosomes of the flat-headed bats (Tylonycteris spp)

Zusammenfassung Zwei sympatrische, nahverwandte Fledermausarten,Tylonycteris pachypus (Temminck) undT. robustula Thomas, besitzen 46 beziehungsweise 32 Chromosomen, was offenbar den Robertson'schen Translokationen zuzuschreiben ist.     

Somatic chromosomes of the common palm civet,Paradoxurus hermaphroditus (Viverridae — carnivora)

Zusammenfassung Paradoxurus hermaphroditus Männchen habenXY Geschlechtschromosomen, im Unterschied zu den ungewöhnlichenXO Männchen vonHerpestes auropunctatus. Beide Species gehören zu der Familie Viverridae der Ordnung Carnivora und demonstrieren die Robertsonsche Chromosomen-Evolution in Zahl und Struktur.     

Somatic chromosomes of Indian burrowing toad,Uperodon globulosum (Gunther) (Anura; Amphibia)

Summary Somatic chromosome complements of the Indian burrowing toad,Uperodon globulosum, have been described for the first time. The 2n number is 26 (NF=52) in both the sexes. No heteromorphism in relation to sex chromosome pair has been recorded. Deviations from 2n number (2n=10–28) have been noticed in the cells of different specimens. The result has been compared withU. systoma.Acknowledgment. Sincere thanks are due to Prof. P. K. Ghosh, Hooghly Mohsin College and to Dr A. K. Roy of the same college for encouragement. Thanks are due to Mr Bipul Kumar Das for his help during collection of specimen.     

The chromosomes of the southern hemispheric lamprey,Geotria australis Gray

Summary Approximately 180 small and mainly acrocentric chromosomes are present inGeotria australis (Geotriidae) from the southern hemisphere. This is closer to the situation found in northern hemispheric species (Petromyzonidae) than in other southern hemispheric lampreys (Mordaciidae).We wish to express our gratitude to Mr R. W. Hilliard and Mr D. J. Bird for technical help. Financial assistance was provided by the Australian Research Grants Committee.     

The mitotic chromosomes of the lamprey,Petromyzon marinus L.

Résumé L'étude des chromosomes somatiques de la lamproie,Petromyzon marinus L. a montré que l'équipment chromosomique diploïde de cette espèce est composé de 168 chromosomes très petits, dont queleues-uns des plus grands sont métacentriques. Le chiffre semble représenter le plus grand nombre de chromosomes trouvé dans une espèce de Vertébré. On a comparé les chromosomes de P.marinus avec ceux des autres espèces de lamproies.

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Holder of a Science Research Council Fellowship.     

Somatic chromosomes of black-headed oriole,Oriolus xanthornus (Linn.): A probable case of translocation heterozygosity

Summary 2n=80. There are 7 pairs of macrochromosomes in the male karyotype. In 2 females, besides the sex chromosomes, chromosome 3 and the largest microchromosome are unpaired and there is an additional large unpaired macrochromosome. This aberrant karyotype is best interpreted in terms of a reciprocal translocation heterozygosity, in all likelihood, at the population level.Acknowledgment. We thank Prof. U.S. Srivastava, Zoology Department, Allahabad University, for providing facilities. Financial assistance from CSIR, India in the form of a Senior Research Fellowship to one of us (H.A.A.) is thankfully acknowledged.     

The chromosomes ofCalamoichthys calabaricus (Pisces,Polypteriformes)

Riassunto È stato descritto il cariotipo di un Polypteriforme,Calamoichthys calabaricus, Smith. Il numero diploide, 2n=26, le dimensioni dei cromosomi e la stessa morfologia del cariotipo mettono in evidenza le affinità filetiche intercorrenti tra Polypteriformi e Dipnoi e la linea evolutiva tetrapoda, diversificandoli, al contrario, dagli altri primitivi Attinopterigi, Holostei e Chondrostei.     

Centromere nature of the chromosomes ofRanatra (Heteroptera)

Zusammenfassung Histologisch-cytologische Untersuchungen zeigen, dass die Chromosomen vonRanatra monozentrisch sind. Der Befund steht im Gegensatz zu Ergebnissen anderer Autoren an andern Heteroptera-Arten, die polyzentrische Chromosomen haben. Die Natur des Centromers ist also bei verschiedenen Arten der Heteropteren verschieden.     

The chromosomes ofPasseromyia heterochaeta Villeneuve (Muscidae: Diptera)

Summary The 2 n=10 complement ofPasseromyia heterochaeta Villeneuve consists of 4 pairs of metacentric chromosomes and 1 pair of dots. The evolutionary implications of 2 n=10 in the tribe Phaoniini (Fam. Muscidae) are discussed.Acknowledgments. Thank are due to Dr Adrian C. Pont of British Museum (Natural Histoty), London for identifying our speciens through the courtesy of Dr Rokuro Kano, Dean Faculty of Medicine, Tokyo Medical and Dental University Tokyo, Japan. We also thank Dr U.S. Srivastava, Professor and Head, Dept. of Zoology, Univ. of Allahabad for providing the necessary laboratory faclities.     

New contribution to the study of chromosomes of the European Cryptocephalinae (Coleoptera,Chrysomelidae)

Summary The chromosomes of three species ofPachybrachis and nine ofCryptocephalus chrysomelids were analyzed. The male meiotic bivalent formula ofP. azureus Suffr.,P. catalonicus Burl. andP. petitpierrei Daccordi is 7^II+Xy_r.Cryptocephalus sexmaculatus Ol. andC. vittula Suffr. have 13^II+Xy_p,C. bipunctatus L. 14^II+Xy_r,C. ochroleucus Steph. andC. ocellatus Drap. 14^II+Xy_p,C. crassus 01. 15^II+Xy_r,C. sulphureus 01. 15^II+Xy_p, the same number as inC. fulvus Goeze with 2n=32 chromosomes, whileC. primarius Har. has 19^II+Xy_p. The modal chromosome number inCryptocephalus is 2n=30 (about 60% of spp.), and most species are characterized their small chromosomes. The low variation found in the karyotypes of Cryptocephalinae along with their possible interrelationships with allied chrysomelid subfamilies are also discussed.     

Meiotic chromosomes in the male slender loris,Loris tardigradus lydekkarianus (Cabrera)

Zusammenfassung Die diploide Chromosomenzahl beiLoris tardigradus lydekkarianus beträgt 62, und der Karyotyp besteht sowohl aus akro- wie aus metazentrischen Chromosomen. Beobachtungen über die meiotischen Chromosomen des Männchens ergeben, dass sich die Chiasmaformation zwischenX undY befindet.     

A high number of chromosomes in the hillstream cyprinid,Tor putitora (Pisces)

Summary The karyotype of a cyprinid fish occurring in India,Tor putitora is described. The diploid complement comprises 100 chromosomes. The modal number in this family being 2n=50,T. putitora appears to be another case of tetraploidy.The author is highly indebted to Prof. G.K. Manna, and Prof. A.K. Bose, Department of Zoology, University of Kalyani, for encouragement and laboratory facilities. Sincere thanks are due to Dr Raj Tilak, ZSI, Government of India, for identification of the specimens. Financial aid from the University of Kalyani is gratefully acknowledged.     

The chromosomes of two species of the genusOryzomys (rodentia-cricetidae)

Resumen Oryzomys es un género altamente politípico y primitivo que ocupa un área geográfica que se extiende por todo el continente Sudamericano y el sur de Norteamérica. De este género se describen los cromosomas de dos especies pertenecientes al subgéneroOryzomys. O. albigularis (posiblementeO. a. camcolus) (2N=66) yO. delicatus (2N=60) cuyos cromosomas son fundamentalmente del tipo acrocéntrico o subtelocéntrico con algunos pares matacéntricos o submetacéntricos.