摘要:

The home-ranges and activities of the fox were studied by radiotelemetry in a high alpine valley of the Gran Paradiso National Park (Aosta, Italy). The patterns of food dispersion and availability, combined with those of human disturbance, are the shaping pressure on the fox's use of its range in a peculiar way. Foxes seem to prefer an intermediate belt between the valley floor and the high pasture as denning and resting areas where they return every day: this pattern seems the optimal strategy to have access to the food resources of both low and high altitude habitats.

ISSN:0373-4137    

DOI:10.1080/11250008409439466

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A statistical evaluation of skull and horn measurements comparing sexually mature male Abruzzo and Pyrenean chamois,Rupicapra rupicapra ornataandR. rupicapra pyrenaica, has shown that these taxa differ significantly in the length of the frontomaxillary fontanelle, the frontal length of the horns, their height and anteroposterior and transverse basal diameters. In particular, the fontanelle length discriminates the two taxa very clearly. Thus, the sub-specific separation ofornatafrompyrenaicaappears to be fully justified morphometrically, in spite of their close general resemblance.

ISSN:0373-4137    

DOI:10.1080/11250008409439467

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In the pyloric mucosa ofScyliorhinus stellarisat least eight cell types can be identified, showing well-differentiated ultrastructural features, especially in the secretory granules. With semithin/ultrathin techniques only some of these cells are easily demonstrable. Type I and Type II cells can be considered as enterochromaffin (EC) cells since both are positive to argentaffin reaction, but the ultrastructural features of the granules are quite dissimilar. Type III cells could not be found in the semithin sections but the aspect of the granules is like that in the intestinal EC cells. Type IV cells contain round vesicular granules with an eccentric, highly osmiophilic core in which the number and size of the granules can vary from cell to cell. This cell type is positive to the Grimelius silver reaction and may be equivalent to the gastrin storing or gastrin-cholecystokinin storing cell. Type V cells contain round granules with a clear halo showing a weakly positive Grimelius silver reaction. Histochemically this cell type resembles the pancreatic A cell but the granule size is slightly different. Type VI cells are characterized by argyrophilic and non-argentaffin granules, round or rod-shaped. Type VII and Type VIII cells show similarities with two pancreatic cell types. The Type VII may be a D cell. All pyloric endocrine cells except cell Type III are of Fujita's “open” type.

ISSN:0373-4137    

DOI:10.1080/11250008409439468

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In the digestive tube of 200 specimens of aquatic arthropods belonging to orders of the Classes of Crustacea and Insects and taken from two different biotopes (Lake Trasimene and the River Tiber) the following species of eugregarines were isolated (those marked with an asterisk are now reported for Italy for the first time):Rotundula gammariGoodrich (*);Eliterocystis ephemeraeFranzius (*);Actinocephalus sieboldiKölliker (*);Pileocephalus nemourae(Foerster, 1938) Stein (*);Stylocystissp. (*);Asterophora tiaroidesBaudoin,Asterophorasp.,Ancyrophorasp. 2 Baudoin;Sphaerocystissp. (*).

ISSN:0373-4137    

DOI:10.1080/11250008409439469

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

InR. tigerinaovaries and fat bodies undergo annual cyclical changes. The fat bodies, well developed between September-March, begin to reduce in size from April onwards reaching a nadir in July-August. The decline in fat body size is correlated with the vitellogenic growth of oocytes and subsequent breeding. Bilateral fat body excision (fatectomy) in the first week of April retarded the vitellogenic growth of oocytes and therefore the mean size of the largest oocytes was significantly lower than in the sham operated controls (p<0.001) after 30 days as the incorporation of yolk was less. In the controls the vitellogenesis was complete. The gonadosomatic index and the mean weights of ovaries and oviducts did not change following fatectomy. These findings suggest that the fat bodies in the frog have a supporting role in the vitellogenic processes.

ISSN:0373-4137    

DOI:10.1080/11250008409439470

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The new speciesTetranchyroderma esarabdophorumis characterized by having two pairs of cephalic tentacles and three pairs of dorsolateral rod-like processes.T. esarabdophorumis close toT. enallosaand more so toT. antennatum, which has also been found in the Mediterranean.

ISSN:0373-4137    

DOI:10.1080/11250008409439471

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

We studied the tubificid communities of the lower reaches of two Veneto rivers: the Adige and the Brenta.

ISSN:0373-4137    

DOI:10.1080/11250008409439472

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Concentrations of plasma corticosterone were increased in 6–8 week old chickens after a 48 h fast. When allowed to feedad libitumthe concentration declined to the prefasting level within 30 min. A similar decline in the corticosterone level was also observed when fasted birds were refed 1, 5, 15 or 30 g of diet although the duration of suppression was directly related to the amount of food consumed. Adrenocortical suppression was also induced by glucose administration and by force feeding synthetic diets of differing energy content. The causal effect of nutritional stimuli on adrenocortical suppression was shown by the duration of suppression being related to dietary energy content.

ISSN:0373-4137    

DOI:10.1080/11250008409439473

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

To investigate the infantile signals of laboratory mice a simple and effective method using pups dead from freezing and virgin females has yielded the following conclusions. 1) Dead pups can elicit from a distance the adult to look for them. 2) Younger pups are preferred to older ones for signals that do not need the living condition. 3) The absence of fur gives rise to a preference. 4) Fetuses can elicit some parental response, but pups are more effective.

ISSN:0373-4137    

DOI:10.1080/11250008409439474

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Each of 98 virgin female albino mice was presented for the first and only time with a 10-day old pup that had been randomly selected, shaven or unshaven, and killed by freezing. From analyzing the principal parental activities, it emerged that the shaven pup more than its unshaven litter-mate stimulated retrieving and nest-building. The greater infantile effectiveness was clearly linked to the lack of fur. The behaviour of the females seemed to evince uncertainty, consistent with the hypothesis that the shaven pup releases not only signals proper to its age but also a signal of younger age.

ISSN:0373-4137    

DOI:10.1080/11250008409439475

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor