Plains viscacha were established in the laboratory to Spanish by Llanos & Crespo (), and some details of reproduction were given. Llanos, A. and J. Crespo. Ecología de la vizcacha (Lagostomus maximus maximus Blainv.) en el nordeste de la provincia de Entre Ríos. Rev. Llanos, A. C. and J. A. Crespo. Ecología de la vizcacha (Lagostomus maximus maximus Blainv.) en el nordeste de la Provincia de Entre Ríos. Revista de.

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The pigmented cells were counted in pregnant and nonpregnant viscachas. Field and laboratory design Duringfive samplings were carried out in four 1O-km2 areas, represen- tative of the four above defined habitats.

In the present study, the histochemical and ultrastructural results demonstrate the presence of melanin in the female viscacha pineal gland. Neither tracks or faeces of vizcachas were found in the rocky elevations, even in those with vizcacheras at their foot. Briefly, animals were anesthetized with ketamine chlorhydrate In relation with this hypothesis, we suggest that vizcachas tend to display a higher selectivity in circumstances in which preferred species are more available; this could be interpreted as food quality becoming a less limiting resource.

A light and electron microscopic study of the pineal gland of the viscacha Lagostomus maximus maximus Journal of Pineal Research. Vizcacha’s diet in La Payunia, within the most arid and elevated region of its distribution, showed a similar variety since half of the plant species present in the field were included.

Different letters indicate significant differences. Spectrochimica Acta Part A: On the mosaic-like design of La Payunia, plains availability could be a limiting factor for vizcachas.


Epididymis of viscacha Lagostomus maximus maximus: Support Center Support Center. The accuracy and biases of the microhistological method have been documented Vavra and Holechek ; Holechek et al.

In our laboratory, the morphology of the viscacha retinal melanosomes has been described [ 44 ]. The presence of pigment has been demonstrated in different nervous structures such as those of retina, substantia nigraand locus coeruleus.

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Materials and Crezpo 2. Melanin plays critical functions most easily appreciated in furred mammals. The gestation period lasts approximately days, and it ends in spring when the mother and offsprings have greater probabilities of survival [ 26 ]. Faecal samples composed by 10 fresh pellets were collected from 10 vizcacheras selected on each sampling area.

The pineal pigment was histochemically identified as melanin. Nevertheless, high abundances of vizcacheras were obtained in Zaino and Guadalosos, where plains occupied a high and low surface proportion, res- pectively.

In sections stained with H-E credpo PTAH, the pigmented cells were ovoid or rounded in shape, and they appeared light to dark brown in colour. In Huayquerfas Coloradas plains, vicacha were the only category showing a significant difference between availability and diet. To analyze pituitary PRL immunoreactivity, 3 slides with 3 adenohypophyseal sections per slide corresponding to rostral end, medial, and caudal end regions were tested 5 animals per experimental group.

Omission of the primary antibody did not reveal any staining in all examined sections.

Sections were counterstained with hematoxylin for morphological orientation, dehydrated, and mounted. The ultrastructural features of the pineal pigment granules were also analyzed.

The immunoexpression of PRL increased in mid- and term pregnant groups, exhibiting in the latter the highest reactivity, especially in those lactotropic cells closest to the capillaries. The hydrogen peroxide treatment was also carried out. This hypothesis is reinforced by vizcachas using Hyaiis with avoidance, which gizcacha among the less crewpo and the most available shrub in plains. Presence of melanin in the cat pineal gland.


Our analysis of LHR expression in the ovary of vizcachas revealed an active transcription level at midpregnancy and in response to the LH surge. These tests were competitive radioimmunoassays for in vitro use.

Eaten plant cresop Availability in: During gestation, particularly from midpregnancy, we detected a significant accumulation of pituitary PRL that reached its maximum at term pregnancy. Masson-Fontana silver method, counterstained with nuclear fast red.

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Lactating female group LCT was established by selecting those nonpregnant animals whose mammary glands exhibited the histological features already described for this period [ 2938 ] Table 1.

The biology of Hystricomorph rodents. This variety might be a conse- quence of food scarcity and unpredictability in the arid zones, rather than dietary gene- ralism. Revista Chilena de Historia Natural, Di Giorgio et al. Immunohistochemical scoring was determined using a 4-point scale: Proportions of Poa and Panicum were significantly higher in diet than in availa- bility.

Over forty years ago, Barbara Weir described particular aspects of the reproductive biology of female vizcachas that highlight this species among the majority of mammals [ 2526 ].