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1.
The ultrastructure of the sperm of the common bivalve species Mercenaria stimpsoni and Mactra chinensis from Peter the Great Bay is described. The sperm structure is typical for animals with external insemination. The sperm consists of a head, middle part, and flagellum. The sperm head of M. stimpsoni has a curved crescent form and includes the nucleus and acrosome; the head length is 9.8 μm. The acrosome is subdivided to the acrosome granule and the periacrosomal material. There are 4 mitochondria of about 0.8 μm in size in the middle part of the spermatozoon. The mitochondria surround the centriolar apparatus, which consists of proximal and distal centrioles located at a right angle. The axoneme originates from the distal centriole. The sperm of M. chinensis is barrel-shaped, with a head length of 3.2 μm. The acrosome is relatively larger, and its height is 1–1.2 μm. There are also 4 mitochondria 0.6–0.8 μm in the middle part of the spermatozoon. The sperm structure of the described species is typical of the families to which the mollusks belong, with insignificant variations.  相似文献   

2.
The larvae of Bittacidae, a cosmopolitan family in Mecoptera, have an interesting habit of spraying the body surface with soil through the anus after hatching, and each molts. The fine structure of Malpighian tubules, however, remains largely unknown in the larvae of Bittacidae to date. Here, we studied the ultrastructure of the larval Malpighian tubules in the hangingfly Terrobittacus implicatus (Huang & Hua) using scanning and transmission electron microscopy. The larvae of T. implicatus have six elongate Malpighian tubules at the junction of the midgut and hindgut. The tubule comprises a basal lamina, a single-layered epithelium, and a central lumen. The basal plasma membranes of the epithelial cells are conspicuously infolded and generate a labyrinth. The epithelium consists of two types of cells: large principal cells and scattered stellate cells. Mitochondria and cisterns of rough endoplasmic reticulum are numerous in the principal cells but are sparsely distributed in the stellate cells, indicating that the principal cells are active in transport. On the other hand, spherites are only abundant in the principal cells and are likely associated with the soil-spraying habit of the larvae.  相似文献   

3.
The larva, deutonymph, female, and male of a new water mite species, Georgella samaraensis, are described and illustrated. Larvae of Georgella are similar to larvae of the genus Hydryphantes, differing in the following characters: basal cheliceral segments have no longitudinal ribs, dorso-distal prominences of the pedipalpal tibia are undeveloped, and the excretory pore is partly surrounded by the anal sclerite. The larva known as G. koenikei (Münchberg, 1936) is erroneously treated as a larva of fresh-water Georgella (Hydrachnidia). The morphology of all the active developmental phases of Georgella strongly differs from that in mites of the genus Hydryphantes. Therefore, the generic status of Georgella should be restored.  相似文献   

4.
The larvae of Cinygmula malaisei (Ulmer, 1927) and Cinygmula unicolorata Tshernova, 1979 from the Russian Far East are described and illustrated. The larva of Cinygmula unicolorata is similar to those of Cinygmula putoranica Kluge, 1980 and Cinygmula uyka Gorovaya et Tiunova, 2013 but differs from the larva of C. uyka in the absence of gill filaments and from that of C. unicolorata in the shape of the first gill (tergalia). The upper outer margin of the first gill is rounded in the larva of C. unicolorata and almost straight in C. putoranica; the gills of C. unicolorata are matte and the trachea is poorly expressed, in contrast to the distinctly brown trachea of C. putoranica. The larvae of Cinygmula malaisei are similar to those of C. irina and C. autumnalis but differ from the latter in the presence of gill filaments. The larva of C. malaise differs from that of C. irina in the rounded outer margin of the first gill, the shape of gills VI and VII, and in the size of the leg segments.  相似文献   

5.
Larvae are described for the first time for three species of the genus Lixus (L. bifasciatus, L. rubicundus, and L. subulatus). The larvae dwell in stalks of herbaceous plants. The larvae differ in the structure of the endocarina and prelabium and the chaetotaxy of the head and epipharynx. Analysis of larvae of the new and already described species of this genus has shown that the larva of L. bifasciatus shares some characters with the larvae of L. astrachanicus, and L. rubicundus, and the larva of L. subulatus, with that of L. bescrensis.  相似文献   

6.
Red Sea’s goatfish (Mullidae), locally referred as ‘Sultan Ibrahim’, are a popular recreational fish that also supports neighboring commercial markets. The present study compares spermatogenesis, oogenesis and gonad structure, in two species of goatfish from Jeddah coast. The reproductive parameters including changes in gonado-somatic index (GSI),and spawning seasons were analyzed for Parupeneus heptacanthus (cinnabar goatfish) and Parupeneus cyclostomus (goldsaddle goatfish). P. heptacanthus spawn from February to June and P. cyclostomus spawning season begins from August to September. Remarkable difference in the egg size has been observed P. heptacanthus had the egg diameter (325.9 μm), while the smallest one is P. cyclostomus (209.6 μm) when compared to other species of Mullidae. P. heptacanthus was observed with largest flagellum length (8.7 ± 0.2 μm). The ultrastructure revealed some common features in both species like oval ova; further the ovarian follicular epithelium consists of two layers, an inner granulosa layer with zona radiata under them and an outer theca layer. Centrioles of both species consist of the typically arranged nine triplets (9 + 0) of microtubules. The external lay of zona radiata is thinner than internal one. Disparity in protein patterns of muscle and gonads were observed in the present study. There was also variation in the number of specific bands for each species in both protein soluble muscle and gonads. The histology results reported gonads to be typically gonochoristic and exhibited asynchronous development of oocytes in the ovary. The outcome of this study has yielded essential information of some of the imperative reproductive biology of P. heptacanthus and P. cyclostomus.  相似文献   

7.
8.
The scale insect Puto superbus (Putoidae) lives in mutualistic symbiotic association with bacteria. Molecular phylogenetic analyses have revealed that symbionts of P. superbus belong to the gammaproteobacterial genus Sodalis. In the adult females, symbionts occur both in the bacteriocytes constituting compact bacteriomes and in individual bacteriocytes, which are dispersed among ovarioles. The bacteriocytes also house a few small, rod-shaped Wolbachia bacteria in addition to the numerous large, elongated Sodalis-allied bacteria. The symbiotic microorganisms are transovarially transmitted from generation to generation. In adult females which have choriogenic oocytes in the ovarioles, the bacteriocytes gather around the basal part of the tropharium. Next, the entire bacteriocytes pass through the follicular epithelium surrounding the neck region of the ovariole and enter the space between oocyte and follicular epithelium (perivitelline space). In the perivitelline space, the bacteriocytes assemble extracellularly in the deep depression of the oolemma at the anterior pole of the oocyte, forming a “symbiont ball”.  相似文献   

9.
Previously unknown larvae of Trox ussuriensis Balthasar, T. koreanus Kim, T. zoufali Balthasar, and Glyptotrox ineptus (Balthasar) of the family Trogidae are described and illustrated. The larva of T. ussuriensis differs from that of T. sabulosus (Linnaeus) in the shape of setae on the abdominal tergite I and in the chaetotaxy of the head capsule. The larva of T. koreanus differs from those of T. zoufali and T. scaber (Linnaeus) in the chaetotaxy of the head capsule, clypeus, and labrum. The larva of T. zoufali is very similar to those of T. koreanus and T. scaber but differs in the chaetotaxy of the head capsule. The larva of Glyptotrox ineptus is similar to that of G. mandli (Balthasar) but differs in the chaetotaxy of the head capsule and in the presence of furrows on the frons. An original key to the known larvae of the family Trogidae of the fauna of the Russian Far East is given.  相似文献   

10.
11.
The current work prepared to describe the microscopic morphological appearance of the esophagus of the gilthead sea bream (Sparus aurata). The esophageal wall was organized into four tunica; mucosa, submucosa, muscularis and serosa. There are many goblets cells in the esophageal epithelium. The tunica muscularis is very thick and consisting of; an outer circular thick layer and an inner longitudinal layer of striated muscle. The presences of the many goblet cells help in the esophageal lubrication and protection. By the histochemical reactions with Alcian blue and PAS staining, the esopgaster secretory epithelium devoid from any goblet cells. There are many mucous droplets of the high electron density and the low electron density between surface epithelial cells within the goblet cells. The obtained results of the current investigation may help to understanding the physiology of the esophageal digestive functions in Sparus aurata.  相似文献   

12.
A previously unknown larva of Protaetia famelica is described and illustrated. The larva of P. famelica is similar to that of P. brevitarsis in the number of posterior epicranial setae and in the presence of anterior frontal setae but differs in the chaetotaxy of the head capsule, in the epipharynx structure, and in the number and position of spinules on the anal sternite. An original key to the known larvae of the genus Protaetia in the fauna of the Russian Far East is given.  相似文献   

13.
14.
Representatives of the subgenus Coptoformica build composite aboveground nests in much the same manner as red wood ants do. However, despite the superficial similarity, Coptoformica nests show a number of substantial differences that impact on the way in which ants use the nest. The aboveground part of a Formica (Coptoformica) exsecta nest consists of the temporary layer, the outer crust layer, the mound, and the intermediate layer. The material of all the layers includes soil and fragments of plants (picked up or excised), the relative proportion of the two components differing among the layers. The thick, soil-rich crust layer acts as armature and allows a variety of anthill shapes. The intermediate layer and the upper part of the mound harbor quite a few large chambers. Building material is often transferred from nest to nest. On the whole, F. exsecta nests are plastic and movable, which facilitates the activity of these ants in ecotone biotopes.  相似文献   

15.
A species of Isospora Schneider, 1881 (Protozoa: Apicomplexa: Eimeriidae) considered as new to science is described and characterised molecularly from the eastern white-throated spadebill Platyrinchus mystaceus Vieillot in the Parque Nacional do Itatiaia, southeastern Brazil. Isospora lopesi n. sp. has oöcysts that are subspheroidal to ovoidal, 18–24 × 18–22 (20.6 × 19.7) µm, with smooth, bilayered wall, c.1.5 μm thick. Micropyle and oöcyst residuum are absent, but one polar granule is present. Sporocysts are ellipsoidal, 12–16 × 8–11 (14.4 × 8.6) µm. The Stieda body is flattened to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, consisting of numerous spherules of different sizes. Sporozoites are vermiform with anterior and posterior refractile bodies and nucleus. Molecular analysis was conducted at the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This new isolate exhibited similarity greater than 98% with Isospora spp. isolates from spectacled warblers Sylvia conspicillata Temminck, 1820. This is the fourth isosporoid coccidian described from New World tyrannid birds, but is the first to have a complementary molecular characterisation.  相似文献   

16.
Two questions are of interest concerning the male reproductive system in Gordiida: (1) is the epithelium surrounding the testis continuous or discontinuous and (2) is the type of spermatozoon as described at the transmission electron-microscopical level for the two species of Gordius typical for all Gordiida? An examination of the South American species Pseudochordodes bedriagae has allowed us to add new information to this poorly studied phylum. Testicular tubes are large, filled with spermatozoa, and surrounded by a continuous epithelium. The epithelial cells that line the posterior testes occasionally overlap, and their cytoplasm is narrow and contains dense granules, abundant endoplasmic reticulum, and vesicles. The plasma membrane possesses microvilli with many filaments. This epithelium rests on a basement membrane. The spermatozoa in P. bedriagae resemble the known spermatozoa of two Gordius species but differ in presenting a uniform halo layer of less dense chromatin that surrounds the dense chromatin in the nucleus. The finding that a similar type of spermatozoa occurs in both genera (Pseudochordodes and Gordius) makes it likely that it is present in all other Gordiida and is therefore an autapomorphy of the Gordiida.  相似文献   

17.
Hypoaspis larvicolus (Acari: Laelapidae) (first report from Turkey) occurred together with Sancassania polyphyllae (Acari: Acaridae) on the larvae of the scarab beetle, Polyphylla fullo (Coleoptera: Scarabaeidae), that were feeding on the roots of strawberry in Aydin, Turkey. Laboratory studies were conducted to (1) observe whether H. larvicolus feeds and completes its life cycle on the various stages of S. polyphyllae or other astigmatid mites, such as Acarus siro, Carpoglyphus lactis and Tyrophagus putrescentiae (Acaridae), and to determine its population growth when feeding on these prey, and (2) to determine development periods, longevity and fecundity of H. larvicolus feeding on C. lactis. Hypoaspis larvicolus females did not feed on S. polyphyllae, but fed, developed and reproduced when A. siro, C. lactis or T. putrescentiae were provided as prey. Hypoaspis larvicolus is larviparous as well as oviparous. The female lays eggs or gives birth to larvae. If a female gives birth to a larva, it is attached under the female’s venter for 1–2 days, a phenomenon recorded for the first time in Hypoaspis; in fact, for the first time in mites. The results of the population growth experiments revealed that H. larvicolus feeding on C. lactis produced the highest number of eggs, juveniles and adults. The developmental periods of H. larvicolus feeding on C. lactis at life-cycle path I (larva to adult) and II (egg to adult) were 12.2?±?0.3 and 15.6?±?0.6 days (females) and 19.5?±?0.2 and 20.9?±?0.4 days (males), respectively. Longevity of females versus males of H. larvicolus was 120.6?±?7.2 versus 91.6?±?13.1 days (life cycle I) and 110.0?±?27.7 versus 118.3?±?10.9 days (life cycle II), respectively.  相似文献   

18.
Adaptation of Mycoplasma gallisepticum to unfavorable growth conditions results in altered morphological and physiological characteristics of the cells. M. gallisepticum populations in a complete nutrient medium contain pear-shaped vegetative cells ( d ~ 0.3 μm; l ~ 0.8 μm) with pronounced polar and cytoskeletonlike structures. Such mycoplasma cells are able to induce damage in a bacterial genome, causing an SOS response of the test strain (Escherichia coli PQ37). In a starvation medium, M. gallisepticum produces nanoforms, small coccoid cells (d ~ 0.15–0.2 μm) without either polar or cytoskeleton-like structures. Unlike vegetative cells, nanoforms do not induce genome damage. Alleviation of unfavorable growth conditions results in a reversion of nanoforms to vegetative cells.  相似文献   

19.
In vertebrates, early developing epidermis is a bilayered epithelium consisting of an outer periderm and the underlying basal epidermis. It eventually develops into a multi-layered epithelium. The mechanisms that control the architecture and homeostasis of early developing bilayered epidermis have remained poorly understood. Recently, we have shown that the function of Myosin Vb, an actin based molecular motor, is essential in peridermal cells for maintenance of plasma membrane homeostasis. Furthermore, our analyses of the goosepimples/myosin Vb mutant unravelled a direct link between plasma membrane homeostasis, cell size maintenance and tissue homeostasis in the developing epidermis. However, it remained unclear whether this link is specific to myosin Vb mutant or this is a general principle. Here we have identified two more genetic conditions, romeharsha mutant and clint1 knockdown, in which membrane homeostasis is perturbed, as evident by increased endocytosis and accumulation of lysosomes. As a consequence, peridermal cells exhibit smaller size and increased proliferation. We further show that decreasing endocytosis in romeharsha mutant and clint1 morphants rescues or mitigates the effect on cell size, cell proliferation and morphological phenotype. Our data confirms generality of the principle by reaffirming the causal link between plasma membrane homeostasis, cell size maintenance and tissue homeostasis.  相似文献   

20.
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