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1.
Wilfried Klein Christian Reuter Wolfgang Bhme Steven F. Perry 《Organisms Diversity & Evolution》2005,5(1):47-57
Mesopneumonia of 28 and lungs of 44 species of scincomorph lizards are described, representing mesopneumonia in six of the seven scincomorph families and lungs of all seven families of this taxon. Except for gymnophthalmids and scincids, a family typical organization of mesopneumonia occurs. In cordylids, gerrhosaurids, xantusiids and lacertids the complete right ventral mesopneumonium (VMp) inserts cranially on the posterior vena cava and caudally on the dorsal surface of the right liver lobe. The left VMp is attached to the ventrolateral body wall in cordylids and lacertids; in gerrhosaurids the left VMp is short and inserts on the pericardium and the posterior vena cava; in xantusiids the left VMp is reduced and the lungs are fused cranially with the pericardium. In scincids the VMp of both sides vary in length and insert on the ventral mesentery, or may be lacking completely. The visceral topology of the gymnophthalmids Calyptommatus and Notobachia differs from the general scincomorph pattern, with the liver and stomach elongated and situated on the right and left side of the body cavity, respectively. The left and the right VMp extend over the entire length of the lungs and insert on the ventral mesentery. All lungs examined in the study are single-chambered and show no major structural variability of the inner surfaces, except in lacertids, some gerrhosaurids, Cordylus, and two genera of gymnophthalmids (Echinosaura and Neusticurus). In these groups, rows of dorsomedial niches are present.See also Electronic Supplement at: http://www.senckenberg.de/odes/05-06.htm 相似文献
2.
The femoral or cloacal region in lizards and amphisbaenians displays epidermal glands; these are commonly used for purposes of systematics. In spite of being recognized as semiochemical sources (Maderson [1986] Plenum Press, pp. 13–25), their precise role remains uncertain. The glands of lizards are assumed to be principally associated with reproduction and the demarcation of territory. Their function in amphisbaenians remains unknown. The histology of these glands has only been described for lizards. There are no ultrastructural studies of glands of either type. This study concentrates on the fine morphology of the pre-cloacal glands in Amphisbaena alba using routine histological and ultrastructural techniques. The pre-cloacal glands of amphisbaenians are, like those of lizards (Chiu and Maderson [1975] J. Morphol. 147:23–40), made up by a layer of germinative cells and various layers of polyhedral cells. The latter display three well-characterized stages of differentiation. Granules form and pass through two distinct stages. Thereafter, the granules fuse in the third stage. The glandular secretion is formed by cellular units that constitute the plug. Comparison of these morphological data with those available for lizards allows speculation about the function of the glands in amphisbaenians. © 1994 Wiley-Liss, Inc. 相似文献
3.
Shine R.; Olsson M. M.; LeMaster M. P.; Moore I. T.; Mason R. T. 《Behavioral ecology》2000,11(4):411-415
Male snakes possess paired reproductive systems (testes, efferentducts, hemipenes and associated components of the kidneys),with an independent set on either side of the body. Our studieson gartersnakes (Thamnophis sirtalis parietalis) reveal significantmorphological asymmetry in this system : testes, kidneys, andhemipenes on the right-hand-side of the body are larger thanthose on the left. Data from matings in the field, and in outdoor
enclosures, suggest that this asymmetry has implications forreproductive behavior and, possibly, reproductive success.Copulations using the right hemipenis produced a larger gelatinous"mating plug," and may thus more effectively delay rematingby the female. Although the overall usage of the two hemipenesin field matings averaged close to 50/50, hemipenis usage wasnot random. Males tended to alternate hemipenis use in successivematings, perhaps because of depletion of plug material. Also,male gartersnakes preferentially used their larger (right)hemipenis when mating at high body temperatures, perhaps becausethey are more able to make subtle postural adjustments (andthus, select the better system) under these conditions. 相似文献
4.
Convergent evolution and character correlation in burrowing reptiles: towards a resolution of squamate relationships 总被引:6,自引:1,他引:5
Michael S. Y. Lee 《Biological journal of the Linnean Society. Linnean Society of London》1998,65(4):369-453
The affinities of three problematic groups of elongate, burrowing reptiles (amphisbaenians, dibamids and snakes) are reassessed through a phylogenetic analysis of all the major groups of squamates, including the important fossil taxa Sineoamphisbaena, mosasauroids and Pachyrhachis; 230 phylogenetically informative osteological characters were evaluated in 22 taxa. Snakes (including Pachyrhachis) are anguimorphs, being related firstly to large marine mosasauroids, and secondly to monitor lizards (varanids). Scincids and cordylids are not related to lacertiforms as previously thought, but to anguimorphs. Amphisbaenians and dibamids are closely related, and Sineoamphisbaena is the sister group to this clade. The amphisbaenian-dibamid-Sineoamphisbaena clade, in turn, is related to gekkotans and xantusiids. When the fossil taxa are ignored, snakes, amphisbaenians and dibamids form an apparently well-corroborated clade nested within anguimorphs. However, nearly all of the characters supporting this arrangement are correlated with head-first burrowing (miniaturization, cranial consolidation, body elongation, limb reduction), and invariably co-occur in other tetrapods with similar habits. These characters are potentially very misleading because of their sheer number and because they largely represent reductions or losses. It takes very drastic downweighting of these linked characters to alter tree topology: if fossils are excluded from the analysis, a (probably spurious) clade consisting of elongate, fossorial taxa almost always results. These results underscore the importance of including all relevant taxa in phylogenetic analyses. Inferring squamate phylogeny depends critically on the inclusion of certain (fossil) taxa with combinations of character states that demonstrate convergent evolution of the elongate, fossorial ecomorph in amphisbaenians and dibamids, and in snakes. In the all-taxon analysis, the position of snakes within anguimorphs is more strongly-corroborated than the association of amphisbaenians and dibamids with gekkotans. When the critical fossil taxa are deleted, snakes ‘attract’ the amphisbaenian-dibamid clade on the basis of a suite of correlated characters. While snakes remain anchored in anguimorphs, the amphisbaenian-dibamid clade moves away from gekkotans to join them. Regardless of the varying positions of the three elongate burrowing taxa, the interrelationships between the remaining limbed squamates (‘lizards’) are constant; thus, the heterodox affinities of scincids, cordylids, and xantusiids identified in this analysis appear to be robust. Finally, the position of Pachyrhachis as a basal snake rather than (as recently suggested) a derived snake is supported on both phylogenetic and evolutionary grounds. 相似文献
5.
Diedrich Backhaus 《International Review of Hydrobiology》1976,61(4):471-516
Little research has been made on the litoral algal flora of unpolluted high mountain lakes and streams. Since the algal flora is often used to estimate the water quality, it is of great value to know more about the ecology of benthic forms living under extreme oligotrophic conditions. An investigation was made of the benthic and littoral microphytic vegetation of Esteragne torrent, and Lac de Port-Bielh in the High Pyrenees. Both waters combine a low calcium content with a consistently basic pH. A comparison of their flora with that of other lakes may help to deal with the problem of whether the algal flora is determined more by the calcium content or the pH. The algal flora of Esteragne torrent differs little from that of low-calcium streams of the central European highlands. In Lac de Porth-Bielh there is a distinct depth-zonation among the dominant algae. The dominant taxa at a depth of 0–0,5 metres are: Schizothrix lacustris f. lutescens, Sch. calcicola, Gloeocapsa tornensis, Pleurocapsa minor with Cyanostylon microcystoides and Hydrococcus cesatii particularly on the undersides of the stones; from 0,5 to 1,5 m: a massive growth of Nostoc zetterstedtii; from 2,5 to 4,5 m: Schizothrix funalis; from 7 m: Nitella flexilis. In addition the lake includes a number of rare and little known forms such as? Onkonema sp., of. Desmosiphon maculans, Lyngbya lachneri, Homeothrix sinensis, Chantransia chalybea v. profunda, Siphononema polonicum status chamaesiphonoides. Green algae were almost completely absent from the upper zones, in contrast to the usual findings. The littoral flora has a very distinctive character, and is not directly comparable with that usually found in lakes with either high or low calcium content. A certain resemblance to lakes with a high calcium content can be found only if all the forms present particularly with lower abundances are considered. The very strong development of lithophytes should be emphasized in contrast to their usually low density in lakes with low calcium content. The systematic section deals with systematic and taxonomic problems in a number of difficult forms. 相似文献
6.
The new genus Yushanograptus described in the present paper is a monotypic genuswith Yushanograptus separatus gen.et sp.nov.as the genotype which is represented by5 specimens securd by one of the writers(Han)in the summer of 1961 from the NingkuoShale at the locality near Lijiapeng of the Yushan district,northeastern Jiangxi(Kiangsi)Province(Field No.F61001).The marked features of the new genus are the two long and slender primary stipesand the Goniograptid type in branching.The young forms of this new graptolite bear astriking resemblance to the slender Didymograpti,such as Didymograptus gracilis T(?)rn-quist,D.cognatus Harris et Thomas etc.The same is the case in Zygograptus,particul-arly in Zygograptus irregularis Harris et Thomas.In the mode of branching of the 相似文献
7.
To investigate the affinities of snakes, amphisbaenians and dibamids, the phylogenetic relationships among the major lineages (families) of extinct and extant squamates are assessed through a combined analysis of 248 osteological, 133 soft anatomical, and 18 ecological traits. The osteological data set represents a revision of previous data, taking into account recent criticism; the ecological data set is new. In addition, potentially critical fossil taxa (polyglyphanodontids and macrocephalosaurs) are included for the first time. The osteological and soft anatomical data sets each place snakes within anguimorphs, with dibamids and amphisbaenians near gekkotans. The putative primitive fossil amphisbaenian Sineoamphisbaena groups with macrocephalosaurs and polyglyphanodontids, together the sister group to scleroglossans. All three data sets are congruent, and these results are reinforced by combined analyses. In these, as in the osteological analyses, snakes are nested within marine lizards. However, exclusion of fossil taxa from the osteological data set results in a ‘limbless clade’ consisting of snakes, amphisbaenians and dibamids, and introduces significant conflict between osteology and soft anatomy. Also, deletion tests and character weighting reveal that the signal in the reduced osteological data set is internally contradictory. These results increase confidence in the arrangement supported by the all-taxon osteological, the soft anatomical, and the combined data, and suggest that exclusion of fossils confounds the signal in the osteological data set. Finally, the morphological data support the nesting of snakes within marine lizards, and thus a marine origin of snakes. This result still holds when relationships between living forms are constrained to the topology suggested by molecular sequences: if marine lizards are allowed to ‘float’ within this molecular framework, they form the stem group to snakes, and do not group with varanids as previously suggested.See also Electronic Supplement at: http://www.senckenberg.de/odes/05-04.htm. 相似文献
8.
The relationship of the hemipenis to the cloaca in copula and sperm storage and transport in the female oviduct were studied in Anolis carolinensis using light and scanning electron microscopy. During copulation, the hemipenis does not penetrate beyond the cloaca, but the two apical openings of the bifurcate sulcus spermaticus appose the openings of the oviducts from the cloaca. Sperm enter the sperm storage tubules between 2 and 6 hr after insemination and small amounts of sperm reach the infundibulum 6 to 24 hr following mating. Sperm storage tubules are embedded in the wall of the utero-vaginal transition, and are formed by the folding and fusion of the oviducal epithelium. The importance of the hemipenile-cloacal relationship and the role of sperm storage in the life history of A. carolinensis are discussed. 相似文献
9.
Mateusz Tałanda 《Zoologica scripta》2016,45(1):1-8
Amphisbaenians are highly specialized limbless burrowing lizards of controversial relationships. Among fossil lizards, the Eocene (47 Ma) Cryptolacerta is allegedly closest to the amphisbaenian ancestor, but this is put in doubt in this study. Similarities between Cryptolacerta and amphisbaenians, such as limb reduction and expansion of the skull roof, may be a result of parallel evolution. Instead, the Late Cretaceous lizard Slavoia with well‐developed limbs and several plesiomorphic skull characters is proposed to be the oldest known stem amphisbaenian. This is supported by two different phylogenetic analyses and observations on numerous specimens together representing almost the whole skeleton. Among the unique features, that Slavoia shares with amphisbaenians, the most significant are vomers strongly underlapping palatines and pterygoid quadrate ramus tightly wrapping around posteromedial surface of quadrate. The anatomy of Slavoia suggests that the reinforcement of the snout in amphisbaenian evolution preceded the elongation of the postorbital part of the skull, and that of the body, as well as modification of the limbs. Reduction of its hindlimbs was more advanced than that of the forelimbs. The ancient geological age of the central Asiatic Slavoia suggests that diversification of the main North American amphisbaenian groups may have resulted from a faunal dispersals from Asia after the Late Cretaceous. 相似文献
10.
This study of the morphology, histology, histochemistry, and ultrastructure of the Harderian gland in Geckos (Squamata, Gekkota) revealed previously unreported variation. The gecko Harderian gland is unlike that of other squamates in that each cell of the secretory epithelium has both lipid and protein secretory granules. Lipid secretion has not been reported previously for the squamate Harderian gland. The structure of the protein granules resembles that described for a scincomorph lizard (Podarcis, Lacertidae). Differences between representatives of the subfamilies Gekkoninae and Diplodactylinae suggest possible phylogenetic constraints in the structure or function of Harderian glands within gekkotan lineages. The structural relationship between the Harderian gland and the lacrimal duct supports previous suggestions of a possible functional link between the Harderian gland and the vomeronasal organ. J Morphol 231:253–259, 1997. © 1997 Wiley-Liss, Inc. 相似文献
11.
Ehsan Sanaei Sylvain Charlat Jan Engelstädter 《Biological reviews of the Cambridge Philosophical Society》2021,96(2):433-453
Wolbachia is one of the most abundant endosymbionts on earth, with a wide distribution especially in arthropods. Effective maternal transmission and the induction of various phenotypes in their hosts are two key features of this bacterium. Here, we review our current understanding of another central aspect of Wolbachia's success: their ability to switch from one host species to another. We build on the proposal that Wolbachia host shifts occur in four main steps: (i) physical transfer to a new species; (ii) proliferation within that host; (iii) successful maternal transmission; and (iv) spread within the host species. Host shift can fail at each of these steps, and the likelihood of ultimate success is influenced by many factors. Some stem from traits of Wolbachia (different strains have different abilities for host switching), others on host features such as genetic resemblance (e.g. host shifting is likely to be easier between closely related species), ecological connections (the donor and recipient host need to interact), or the resident microbiota. Host shifts have enabled Wolbachia to reach its enormous current incidence and global distribution among arthropods in an epidemiological process shaped by loss and acquisition events across host species. The ability of Wolbachia to transfer between species also forms the basis of ongoing endeavours to control pests and disease vectors, following artificial introduction into uninfected hosts such as mosquitoes. Throughout, we emphasise the many knowledge gaps in our understanding of Wolbachia host shifts, and question the effectiveness of current methodology to detect these events. We conclude by discussing an apparent paradox: how can Wolbachia maintain its ability to undergo host shifts given that its biology seems dominated by vertical transmission? 相似文献
12.
R. A. Zinchenko A. A. Osetrova E. I. Sharonova G. I. El’chinova 《Russian Journal of Genetics》2012,48(3):329-335
The results of a genetic epidemiological study of hereditary deafness (HD) in ten raions (districts) of Kirov oblast (administrative
region), Russia, are presented. A total of 122 075 people have been examined. Segregation analysis of all families with diagnosed
HD has demonstrated a good fit to either the autosomal dominant (AD) or autosomal recessive (AR) mode of inheritance. The
total prevalence rates of AD and AR HDs, as well as the specific prevalence rates of nonsyndromic and syndromic forms of HD,
have been calculated for the population of ten raions. The HD prevalence rate in Kirov oblast has been found to be 1: 1043
people (1: 1453 and 1: 3699 for the nonsyndromic and syndromic forms, respectively). This value has been found to vary in
different raions, which is explained by differences in the genetic subdivision levels of the populations studied; the correlation
coefficient between the HD load and random inbreeding (F
ST) in district populations is r = 0.81 ± 0.22. The diversity of syndromic hearing disorders is described. 相似文献
13.
Moustafa M.A. Rizk Sobhy A.H. Temerak Farouk A. Abdel-Galil Dalia Y.A. Darwish 《Archives Of Phytopathology And Plant Protection》2013,46(14):1666-1674
Two forms of the insecticide (Spinosad®) are recommended by the Egyptian Ministry of Agriculture and Reclaimed Areas for the control of the fruit flies. One form is for partial spray on fruit trees and one form is for soil treatment. (a) Conserve 0.024% application: statistical analysis indicated that the toxicity regression line had a linear order with a coefficient of determination R2 = 0.779. The LC50 was determined by both mathematically and from the illustrated line as 95.17 ppm. Persistent regression line was of the first-order line with regression coefficient of ?16, simple correlation of 0.977 and coefficient of determination of 0.9552. The T50 was found to be 2.2 days. (b) Tracer 24% application: toxicity regression line has a linear order; the simple correlation was found to be 0.819; and the coefficient of determination (R2) was found to be 0.6712. The LC50 was determined by both mathematically and from the illustrated line as 15.5 ppm. Spinosad has a different mode of action from other pesticides and is most effective when applied in planned programmes with other insecticides of different mode of action. Moreover, users must avoid the use of same active ingredient or mode of action on consecutive generations of insect. However, repeated applications to control a single generation are acceptable. Thus, we strongly recommend applying Spinosad as a soil application to control the last generation of the summer season. 相似文献
14.
A recessive temperature dependent shooty mutant (tds) of Nicotiana tabacum L. (W38) is described. The mutant phenotype is expressed at low temperature (21 °C). Mutant characteristics include thick,
narrow leaves with abnormal mesophyll cells, short internodes, and near absence of apical dominance. Most plants remain vegetative
and the occasional flower has petaloid stamens. High temperature (30 °C) reverses the mutant phenotype, with formation of
normal leaves and restoration of apical dominance. However, many flowers still have petaloid stamens. Reciprocal grafting
and auxin-cytokinin interaction experiments do not suggest shifts in auxin-cytokinin balance. Overall, this mutant bears some
resemblance to transgenic tobacco overexpressing homeodomain genes from maize and Arabidopsis.
Received: 23 August 1996 / Accepted: 24 September 1996 相似文献
15.
Two new genera of giant ostracods Lacrimicypris n. gen. and Repandocypris n. gen. from Australia are described and eight new species:L. kumbar n. sp., R. austinensis n. sp., R. gleneagles n. sp., Mytilocypris coolcalalaya n. sp., Australocypris bennetti n. sp., A. beaumonti n. sp., A. mongerensis n. sp. and Caboncypris kondininensis n. sp. The number of known Australian genera and species of giant ostracods are now 6 and 21, respectively. Keys to genera and species are provided: all species can be distinguished using the hemipenis and male first leg. The usefulness of the bursa copulatrix as a species-level taxonomic character is highlighted. Most of the species described in this paper occur in salt lakes and existing ecological information on Western Australian species, as well as the distributions of all species, are summarized. Western Australia has a particularly rich halobiont fauna but current explanations relating richness of the halobiont fauna to the widespread occurrence of salt lakes appear incomplete. Australocypris bennetti is unusual in that it is frequently found at pH < 4. Its morphology differs slightly in acidic and alkaline waters. 相似文献
16.
17.
To obtain a clearer understanding of the evolutionary transition between short- and long-germ modes of embryogenesis in insects,
we studied the expression of two gap genes hunchback (hb) and Krüppel (Kr) as well as the pair-rule gene even-skipped (eve) in the dipteran Clogmia albipunctata (Nematocera, Psychodidae). This species has features of both short- and long-germ mode of embryogenesis. In Clogmia
hb expression deviates from that known in Drosophila in two main respects: (1) it shows an extended dorsal domain that is linked to the large serosa anlage, and (2) it shows
a terminal expression in the proctodeal region. These expression patterns are reminiscent of the hb expression pattern in the beetle Tribolium, which has a short germ mode of embryogenesis. Krüppel expression, on the other hand, was found to be rather similar to the Drosophila expression, both at early and late stages. eve expression starts with six stripes formed at blastoderm stage, while the seventh is only formed after the onset of gastrulation
and germband extension. Surprisingly, no segmental secondary Eve stripes could be observed in Clogmia although such segmental stripes are known from higher dipterans, beetles and hymenopterans. We therefore also studied another
nematoceran, Coboldia, to address this question and found that some segmental stripes form by intercalation as in Drosophila, although belatedly. Our results suggest that Clogmia embryogenesis, both with respect to morphological and molecular characteristics represents an intermediate between the long-germ
mode known from higher dipterans such as Drosophila, and the short-germ mode found in more ancestral insects.
Received: 24 August 1998 / Accepted: 29 October 1998 相似文献
18.
Summary The fine structure of Crystallolithus hyalinus (Gaarder and Markali), known to be the motile stage of Coccolithus pelagicus (Wallich) Schiller (Parke and Adams 1960), has been investigated for purposes of comparison with Chrysochromulina and Prymnesium, recently recognised as probably related to it. Anoptral contrast light microscopy of living cells and electron microscopy of thin sections and shadow-cast whole mounts show that there is a close resemblance to species of Chrysochromulina not only in cell structure but also in the details of haptonema structure and scale structure. The origin of the scales from internal vesicles has been traced as in other genera but the holococcoliths (crystalloliths) do not appear to arise in this way. The mode of origin of the crystalloliths is thus unknown, but it is suggested that they may be developed outside the cell from calcite secreted in solution into the appropriate cavity. Their constant position between a layer of scales and an outer enveloping skin is consistent with this and one unfamiliar cytoplasmic organelle, composed of peculiar thick-walled tubes within some large superficial vesicles, is described as perhaps involved in this process. Apart from these special features the resemblance to both Chrysochromulina and Prymnesium is sufficient to add considerable weight to Christensen's suggestion (Christensen 1962) that a new group should be defined to accommodate these genera. 相似文献
19.
Haruki Takahashi 《Mycoscience》2011,52(6):392-400
Two new species of Agaricales and a new Japanese record for Chaetocalathus fragilis from Ishigaki Island, a southwestern island of Japan, are fully described and illustrated: (1) Crinipellis (section Grisentinae) rhizomorphica sp. nov. produces brownish orange, fibrillose-squamulose basidiomata accompanied by white thread-like rhizomorphs on the
dead twig, olivaceous hairs in KOH, and oblong-ellipsoid, relatively long basidiospores; (2) Chaetocalathus (section Holocystis) fragilis is a new record for Japan, growing on the dead twig; (3) Psilocybe (section Cubensae) capitulata sp. nov. forms a furfuraceous-squamulose pileus, cyanescent flesh, a persistent, membranous annulus, capitulate pilocystidia,
and has a coprophilous habit on cow dung. 相似文献
20.
PER CHRISTIANSEN 《Biological journal of the Linnean Society. Linnean Society of London》2008,95(4):766-778
Evolutionary shape changes in skull and mandibular anatomy was analysed in 223 specimens of pantherine felids (Neofelis nebulosa, Panthera leo, Panthera onca, Panthera pardus, Panthera tigris, Panthera uncia) compared to a small‐felid outgroup, consisting of 86 specimens of nine different species, using digital surface morphometry on 25 (skull) and 17 (mandible) landmarks. Shape evolution in the pantherine species is complex and nonlinear, and involves both large‐scale and small‐scale shape changes. Shape changes frequently differ among the ingroup species, but the four large Panthera species (leo, onca, pardus, tigris) bear some resemblance to each other. The leopard and jaguar bear the closest resemblance to each other, and several shape changes are common to the lion and tiger, but have probably evolved convergently as a result of large size. The lion has undergone the largest and most numerous shape changes from a small‐felid outgroup. Certain shape changes in the skull and, in some respects, the mandible of the clouded leopard bear resemblance to those in the four large Panthera species. The snow leopard is often regarded as the most primitive of the extant Panthera, and skull and mandibular shape changes often diverge markedly from those observed in the other five ingroup taxa; its overall skull shape is rather similar to the small‐felid outgroup. This indicates that the shape changes in the clouded leopard are convergent with those of the four large Panthera species. Landmark integration showed no significant correlation with molecular phylogeny, chiefly owing to the snow leopard being placed among the four large Panthera species. A traditional phylogenetic topology with the snow leopard as the basal‐most species of Panthera yielded a weak but nonsignificant phylogenetic signal. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 766–778. 相似文献