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1.
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.
Both scanning electron and light microscopy were used to examine the epidermal structure of scales taken from several ontogenetic stages of Xenosaurus grandis and Shinisaurus crocodilurus. In addition, scales from all xenosaurid species were examined by scanning electron microscopy to determine scale surface variation among genera, species, and subspecies. A varied and phylogenetically informative morphology characterizes the scale surfaces of xenosaurid lizards. Scale surface morphology is conservative among the species and subspecies of Xenosaurus, but is more variable between the two xenosaurid genera. Their scale surfaces are characterized by folds in the oberhautchen, beta, mesos, and alpha epidermal layers, forming polygonal ridges of a type previously described for the Iguania. The three species of Xenosaurus possess lenticular scale organs, whereas Shinisaurus has scale organs with spikes (bristles). The spikes of Shinisaurus are formed by the beta and oberhautchen layers, with the alpha layer forming a dome-shaped cap over a dermal papilla. Shinisaurus crocodilurus exhibits a dramatic ontogenetic change in scale surface morphology, that is here reported for the first time in any lizard. © 1993 Wiley-Liss, Inc.  相似文献   

3.
The distribution of the adrenaline and noradrenaline chromaffin cells in the adrenal glands of 10 members of the family Cordylidae have been examined. In the genus Gerrhosaurus, all the catecholamine cells lie on the surface of the adrenal gland, forming a continuous envelope of one or two layers of cells that mainly contain noradrenaline (NA). In the genus Platysaurus, the chromaffin envelope is intermittent. There are relatively large tracts of interspersed interrenal tissue containing some adrenaline cells (A). Islets of chromaffin cells are scattered between these interrenal tracts. In the genus Pseudocordylus and the genus Cordylus, the superficial chromaffin cells tend to gather into a multilayered dorsal mass, containing mainly NA cells. Inside the interrenal parenchyma, there are always numerous chromaffin islets, containing mainly A cells.  相似文献   

4.
Generation glands are holocrine epidermal glands occurring on the ventral aspect of the thigh of cordylid lizards. In most species these glands seemingly start to differentiate with the onset of sexual maturity, but macroscopic signs of generation gland activity were noted in neonates of the large-scaled girdled lizard, Cordylus macropholis. The glands of neonatal, subadult, and adult individuals were examined microscopically using standard histological techniques. The glands of the five neonatal specimens examined, including both males and females, all had the same basic structure and displayed two layers of mature glandular material. In subadult and adult specimens, the number of layers varied from seven to nine. The structure of the generation glands of C. macropholis is similar to that of the few other Cordylus species that have been described to date. They are of the protruding kind with multiple mature glandular generations. Juveniles of an additional 12 cordylid species have been examined for the presence of active generation glands. Active glands were found to be present in neonates of C. tasmani and C. tropidosternum, both of which are, like C. macropholis, terrestrial species. In C. cordylus and C. coeruleopunctatus, active generation glands are absent in neonates, but differentiate soon after birth. In other cordylid species, generation glands apparently differentiate only with the onset of sexual maturity. J. Morphol. 235:177–182, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

5.
There is a high incidence of melanism among the cordylid lizards of Africa and it was suggested that melanism has a thermoregulatory function in these species. One prediction of the thermal melanism hypothesis would be that melanistic cordylid species would be restricted to cool environments. The aim of our study was to determine the climatic conditions with which melanistic cordylids are currently associated. Distributional data for the eight melanistic cordylid taxa occurring at the south-western tip of Africa were obtained from the CapeNature State of Biodiversity database. Using GIS and principal component analyses, the climatic variables best describing the geographical distribution of melanistic cordylids were investigated. We found that several melanistic cordylid populations show a distinct association with a high incidence of fog and cloud cover, underscoring the thermal melanism hypothesis. Several other populations, however, do not show such an association. We conclude that some species, such as Pseudocordylus capensis , have a morphology that provides them with great flexibility in habitat use, allowing them to overcome the constraints of melanism in warm environments. The available information suggests that melanism in cordylids evolved during the Miocene in response to the development of the cold Benguela Current along the west coast of Africa. We also conclude that viviparity, a sit-and-wait foraging strategy and a rock-dwelling lifestyle would have preadapted cordylids for survival in cool conditions brought about by the development of the cold Benguela Current. These conditions would have been unfavourable for oviparous, active-foraging lizards. The co-occurrence of melanistic lizards and melanistic molluscs at the Landdroskop locality casts some doubt on improved heating rates as the only explanation for melanism in cordylids, because molluscs are not heliothermic baskers.  相似文献   

6.
Chameleons (Chamaeleonidae) feature many adaptations to their arboreal lifestyle, including zygodactylous feet, a prehensile tail, and epidermal microstructures. In arboreal tree chameleons, the substrate‐contacting site of the feet and tail is covered by microscopic hair‐like structures (setae) of 6–20 µm length. Their friction enhancing function has been shown in recent studies. Leaf chameleons and one representative of the tree chameleons (Chamaeleo namaquensis) secondarily have become ground‐dwelling. Because leaf chameleons are paraphyletic, one could expect that in the three leaf chameleon genera Brookesia, Rhampholeon, and Rieppeleon and the tree chameleon Ch. namaquensis, epidermis has adapted independently to terrestrial locomotion. Using scanning electron microscopy, we investigated the substrate‐contacting surfaces of the feet (subdigital) of 17 leaf chameleon species and five tree chameleon species that have not yet been examined. Additionally, surfaces not involved in locomotion, the flanks (dorsolateral), and scale interstices, were examined. Although the subdigital microstructures in leaf chameleons are more diverse than in tree chameleons, we found some features across the genera. The subdigital microornamentation of Rhampholeon spinosus consists of long thin setae and spines, comparable to those of tree chameleons. All other Rhampholeon species have spines or short but broad setae. Rh. spectrum had tooth‐like structures instead of setae. Subdigital scales of Brookesia have either thorns or conical scale‐tops in the center and feature honeycomb microstructures. In Rieppeleon, subdigital scales have a thorn. Scale surfaces are covered by honeycombs and short hair‐like structures (spines). As subdigital scales with a thorn in the center and honeycomb microstructures were also found in the terrestrial tree chameleon Ch. namaquensis, one can assume that this geometry is a convergent adaptation to terrestrial locomotion. Despite the great number of genus‐specific traits, the convergent evolution of honey‐comb structures in Brookesia, Rieppeleon, and Ch. namaquensis and the high variability of spines and setae in Rhampholeon suggests a rapid adaptation of subdigital microornamentation in Chamaeleonidae. J. Morphol. 276:167–184, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   

7.
The micro‐morphology of nutlets in 30 taxa (28 species and 2 varieties) of Microula Benth. (Boraginaceae) was surveyed by light and scanning electron microscopy. A principal coordinate‐based ordination analysis (PCO) (8 morphological and 14 micro‐morphological characters) was applied to explore whether taxa clustered according to the current sectional taxonomy. The nutlet epidermis showed three major features: trichomes, papillae and lamellae. Two basic trichome types could be identified: branched and unbranched. Stellate trichomes (STT) and stipitate stellate trichomes (SST) can be considered as two subtypes of branched trichomes based on shape and branching location. Three kinds of unbranched trichomes were recognized by their shapes: slender trichomes (SLT), spear‐like trichomes (SPT) and conical trichomes (CT). Four types of papillae were revealed in this genus: central apiculate papillae (CAP), debris‐covered convex papillae (DCP), rugous papillae (RP) and tabular papillae (TP). The lamellae was classified in five types: glossy lamellae (GL), thread‐like lamellae (TL), rugous lamellae (RL), interrupted lamellae (IL) and debris‐covered lamellae (DCL). The variation in the nature of surface sculpturing, nutlet shape and size, dorsal aperture shape, and attachment scar positions proved useful diagnostic characters. Taxa belonging to the same section generally clustered together in the PCO analysis. A key based on the morphology and micro‐morphology of nutlets is provided to distinguish the sections of Microula. The presence of SLT, STT, DCP and DCL is consistent with the macro‐morphological classification and provides additional evidence for the subgeneric delimitations. The SST, SLT, CAP, DCP, RP, DCL, GL and RL are useful in discriminating species in Microula. Additionally, the distribution of some trichomes, papillae and lamellae types is correlated with the altitudinal distribution of the species.  相似文献   

8.
To elucidate the functional significance of the three distinct types of generation glands that have been identified among cordylid lizards, we mapped gland type to the terminal taxa in the most recent phylogenetic tree for the Cordylidae. We used the phylogenetic programme Mesquite and applied the principle of parsimony to infer character states for the ancestral nodes in the tree. For those species where information on gland type was not available from the literature, we conducted a histological investigation of generation gland morphology, using standard histological techniques. We included two species of the sister family Gerrhosauridae in the analysis to serve as outgroups. In both Gerrhosaurus typicus and G. flavigularis, scales immediately anterior to the femoral pores displayed glandular activity, but differed from generation glands of cordylids in the absence of mature glandular generations. Among the cordylids investigated, we identified a fourth type of generation gland in Pseudocordylus subviridis, P. spinosus, and in the two Hemicordylus species, one where the glands consistently comprise of two mature glandular generations. In H. capensis, both single‐ and two‐layer type glands are present. Our reconstruction of ancestral character states suggests a minimum of six transformations from one gland type to another during the evolutionary history of the family. The reconstruction furthermore suggests that the single‐layer type gland reappeared at least once (in Hemicordylus) in the Cordylinae after having been lost. The reconstruction also unequivocally shows that the pit‐like multiple‐layer type gland evolved directly from the single‐layer type and not from the protruding multiple‐layer type. The two‐layer type gland appears to be an intermediary condition between the multiple‐layer and single‐layer types. The evolutionary transformation of generation gland type appears to be linked to changes in lifestyle and associated changes in degree of territoriality and the need for chemical communication. J. Morphol. 275:456–464, 2014. © 2013 Wiley Periodicals, Inc.  相似文献   

9.
10.
The ultrastructure of Pyramimonas pseudoparkeae sp. nov., a member of the class Prasinophyceae occurring in tidal pools along the east, south and west coast of South Africa, is described. The cell surface is covered by three distinctive body scales whilst the flagellar surfaces possess four types of scales. The structure of these scales is described. P. pseudoparkeae resembles Pyramimonas parkeae Norris and Pearson but differs in the structure of the type 2 body scale. The symmetry and ultrastructure of the cell are described with special attention given to the flagellar apparatus. Preliminary information on the life cycle of this species is presented. This new species is compared with other closely related members of the genus Pyramimonas.  相似文献   

11.
Abstract: The fossil record of the callianassid genus Glypturus (Decapoda, Axiidea) is re‐evaluated. Our systematic revision, both of extant and fossil taxa, is based on major cheliped morphology only, thus providing an important impetus for palaeontological studies. Both spination and tuberculation of chelipeds are herein considered of great taxonomic importance. Presence of spines on the upper margins of the merus and propodus and the lower margin of the carpus are significant for generic assignment, whereas the extent of tuberculation on lateral surfaces of the propodus is important for assignment at the species level. Altogether, four extant and six exclusively fossil species of Glypturus are recognized. Several extinct callianassid taxa are now transferred to the genus, namely Callianassa berryi, Callianassa fraasi, Callianassa munieri, Callianassa pugnax and Callianassaspinosa; Callianassa pseudofraasi is considered a junior synonym of C. fraasi. Based on a comparison of ecological preferences of extant representatives, the presence of Glypturus in the fossil record is considered to be linked with tropical to subtropical, nearshore carbonate environments of normal salinity. We argue that Glypturus is of Tethyan origin, with a stratigraphical range going as far back as the Eocene. Since then, the genus migrated both westwards and eastwards, establishing present‐day communities in the western Atlantic and Indo‐West Pacific which both comprise several distinct species. In the presumed area of origin, the genus does no longer occur today. The exlusively fossil (middle Eocene) genus Eoglypturus from Italy is considered closely related to Glypturus and is thus assigned to the subfamily Callichirinae as well.  相似文献   

12.
Cathaya Chun et Kuang is a monotypic genus and one of the gymnosperms endemic to China. We investigated Cathaya argyrophylla with both light and scanning electron microscopy to study the external and internal surfaces of leaf cuticle, leaf blade, petiole, shoot apex, young stem, bark, wood, young and old roots, and mycorrhizae. It is shown that Cathaya has unique characteristics as well as common features of the Pinaceae, there being a difference between Cathaya and Pinus and the rest of the family. So far as the vegetative organs are concerned, the genus is most closely related to Pseudotsuga and Larix. Data derived from the study of structures of vegetative organs of Cathaya are very different from those of reproductive organs, indicating the complexity of the problem of systematics and evolution in these plants. However, the present study supports the view that Cathaya should not be included in the genus Pseudotsuga as a new species.  相似文献   

13.
The gymnophthalmid lizard R iolama inopinata sp. nov. is described from the summit of Murisipán‐tepui, Bolívar State, Venezuela. The new species is characterized by its small size, slender body, short neck, chestnut brown dorsum with two conspicuous orange‐brown dorsolateral stripes, 30 or 31 mid‐dorsal scales, and 18 or 19 ventral scales in transverse rows, 28 scales around midbody, seven supralabials, five or six infralabials, subdigital lamellae divided in small granular scales, ten or 11 small femoral pores in males, dorsal surface of tongue covered with oblique chevron‐shaped plicae interrupted by a small midsection of imbricate scale‐like papillae, and a small weakly bilobed hemipenis having the sulcus spermaticus flanked by an extensive nude area on each side, and the asulcate and lateral faces of the organ with short series of small roughly equidistant, feebly developed flounces, each bearing a single medial hook‐shaped spine. Molecular phylogenetic analyses based on one nuclear and two mitochondrial DNA genes confirm the allocation of the new species to the genus Riolama, but do not support the assignation of Riolama to the subfamily Cercosaurinae as previously suggested based on overall morphological similarities, nor to any other known subfamily of the Gymnophthalmidae. Therefore, a new subfamily, the Riolaminae, is proposed to accommodate the genus. © 2015 The Linnean Society of London  相似文献   

14.
A new species ofNeosartorya, N. sublevispora (anam.Aspergillus sublevisporus), is described and photographed. The species is characterized by non-ostiolate ascomata covered loosely with a pale yellowish hyphal envelope, lenticular ascospores with two low equatorial crests, and subglobose to ellipsoidal, microtuberculate conidia. The ornamentation of ascospores, which is composed of two closely appreassed crests and small even-sized echines on their convex surfaces, particularly serves to distinguish this species from other recognized species. A revised key to all accepted species of the genus is provided.  相似文献   

15.
B. Becker  B. Marin  M. Melkonian 《Protoplasma》1994,181(1-4):233-244
Summary The cell body and flagellar surfaces of certain green flagellates are covered by non-mineralized scales. Scale structure has been widely used in the systematics of this group of algae commonly known as the Prasinophyceae. The special importance of the flagellar hairs as a taxonomic marker is discussed. We summarize current knowledge about the structure and chemical composition of these scales with emphasis on thecate flagellates. Scales consist mainly of acidic polysaccharides involving unusual 2-keto sugar acids. Glycoproteins as minor components are mainly involved in mediating scale subunit and scale-membrane interactions and species specific glycosylation patterns exist. In thecate prasinophytes the elaboration of 3-deoxy-manno-2-octulosonic acid and galacturonic acid side chains presumably favours a complex of thecal scales with calcium ions and thus extracellular coalescence of the scales to a rigid cell wall. Scales are formed within the Golgi apparatus (GA) and especially in thecate prasinophytes scale formation (i.e., during flagellar regeneration) represents an excellent model system for GA function. Movement of developing scales through the GA requires cisternal progression. Biogenesis of scales involves mainly polysaccharide synthesis, whereas about 50% of the scale-associated glycoproteins are added from a pre-existing pool. Possible functions of prasinophyte scales are briefly discussed.Abbreviations Dha 3-deoxy-lyxo-2-heptulosaric acid - DSA Datura stramonium agglutinin - ER endoplasmic reticulum - GA Golgi apparatus - GNA Galanthus nivalis agglutinin - Kdo 3-deoxy-manno-2-octulosonic acid - MeKdo 3-deoxy-5-O-methyl-manno-2-octulosonic acid - SDS-PAGE sodium dodecyl sulphate polyacrylamide gel electrophoresis  相似文献   

16.
The Araceae include both taxa with rewarding and deceptive trap pollination systems. Here we report on a genus in which rewarding and imprisonment of the pollinators co‐occur. We studied the pollination of four species of Colocasia in Southwest China and investigated the morpho‐anatomical adaptations of the spathe related to the attraction and capture of pollinators. All four species were pollinated by drosophilid flies of the genus Colocasiomyia. The flies are temporally arrested within the inflorescence and departure is only possible after pollen release. Trapping of the flies is accomplished by the closure of the spathe during anthesis. Moreover, in two species the spathe is covered with papillate epidermal cells known to form slippery surfaces in deceptive traps of Araceae. However, in Colocasia the papillae proved not slippery for the flies. The morpho‐anatomical properties of the spathe epidermis indicate that it is an elaborate osmophore and serves for the emission of odours only. Despite its similarity to deceptive traps of other aroids, Colocasia and Colocasiomyia have a close symbiotic relationship, as the attracted flies use the inflorescence as a site for mating and breeding. The trap mechanism has presumably evolved independently in Colocasia and is supposed to facilitate more efficient pollen export.  相似文献   

17.
Male pyralid moths in the subfamily of Phycitinae are known to possess composite scale brush structures associated with the 8th abdominal sternite, but the histology and the structural morphology of these organs have not been adequately explored. As such, the phylogenetic utility of these structures is unknown. We examine the pre-genitalic abdominal histology of male Dioryctria reniculelloides (Pyralidae: Phycitinae) associated with the composite scale brushes, as well as structural morphology within the genus Dioryctria and two closely related genera. The composite scale brushes are composed of fused scales. The musculature associated with the base of sternum 8 shows considerable modification compared to previously described Lepidoptera. Complex glandular tissue was also found associated with the scale brush structures, suggesting secretory function. Phylogenetic utility of ultrastructure and gross morphology was examined for major Dioryctria species groups. Many characters were homoplasious, but several supported the monophyly of the genus, as well as some internal relationships. In conclusion, the combination of ultrastructural, gross morphological and histological characters can be a rich source of information for elucidating a range of evolutionary relationships within the subfamily.  相似文献   

18.
19.
In further consideration of the lizard ear, the fine structure of the cochlea has been investigated and related to auditory sensitivity in members of the family Cordylidae. The ear of this group of lizards is unusual in that a tectorial membrane is present only in a modified and seemingly vestigial form, and this membrane makes no connections with the auditory hair cells. These cells are provided instead with a series of sallets, small bodies extending in a single row through the dorsal and middle regions of the cochlea, where they rest upon the tips of the ciliary tufts and evidently bring about a stimulation of the hair cells because of their inertia. At the ventral end of the cochlea this line of sallets ends, and here is a single, relatively enormous structure, the culmen papillae, that serves a similar purpose for a large group of hair cells. Consideration is given to the manner of stimulation of the auditory sense cells in these species in relation to others with the usual arrangements involving connections between the ciliary tufts and a tectorial membrane. Included also is a study of a species of Gerrhosaurus, which some have included in the cordylid family and others have placed in a family of its own. The cochlear structure in this species is similar to that of the cordylids in many respects but differs in the ventral region, where instead of the culmen there is a heavy tectorial plate, similarly covering a large number of hair cells but connected to a tectorial membrane. The functioning of these ears is assessed in terms of the cochlear potentials, and is found to vary with species from better than average to excellent in comparison with other lizards investigated. The structural differentiation also is of fairly high degree, and hence it appears that ears without tectorial connections, or with such connections only in a limited region of the cochlea, can perform in a highly serviceable manner.  相似文献   

20.

The catshark genus Holohalaelurus Fowler is currently represented by five species distributed off the southern and eastern parts of the African coast. Very few parasitological records exist for any of these five species, representing a significant knowledge gap. We report the first monogenean species from the bathydemersal species Holohalaelurus regani (Gilchrist): a new species of Microbothriidae Price, 1936, Leptomicrobothrium holohalaelure n. sp. from the dorsal skin surface, and a new species of Hexabothriidae Price, 1942 representing a new genus, Scyliorhinocotyle narvaezae n. gen., n. sp., from the gill lamellae. Both monogenean records represent the first for any member of the catshark genus Holohalaelurus. Previously we focused on the identification of monogenean taxa of emerging veterinary importance for public aquaria. We now begin a focused effort to document a generally unexplored monogenean biodiversity from diverse marine habitats off South Africa.

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