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61 results on '"Malacarne, Giorgio"'

53. Diet of Dinocras cephalotesand Perla marginata(Plecoptera: Perlidae) in an Apennine stream (northwestern Italy)

Author

Bo, Tiziano, Fenoglio, Stefano, and Malacarne, Giorgio

Abstract

AbstractThe feeding habits of nymphs of Perla marginata(Panzer) and Dinocras cephalotes(Curtis) were investigated in the Rio Orbarina (northwestern Italy). These species are among the largest European carnivorous freshwater invertebrates and they play an important role in the trophic structure of small, fishless Apennine streams. We examined the gut contents of 60 P. marginataand 60 D. cephalotesnymphs to characterize the diets and evaluate possible feeding differences between the species. In both of these predaceous stoneflies, the diet included vegetable detritus, mainly in the smaller instars. Both species showed trophic preferences, since only a few taxa constituted most of the ingested prey items, independently of their availability in the substratum. Interestingly, there were no clear differences in prey selection between nymphs of the two species.

Published
2007
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54. Prolactin and sexual behaviour in the crested newt (Triturus cristatus carnifex Laur

Author

Cristina Giacoma, Camillo Vellano, Valdo Mazzi, and Malacarne Giorgio

Subjects
Male, endocrine system, medicine.medical_specialty, animal structures, Hypophysectomy, Time Factors, medicine.medical_treatment, media_common.quotation_subject, Transplantation, Autologous, Courtship, chemistry.chemical_compound, Sexual Behavior, Animal, Endocrinology, Internal medicine, medicine, Ergocryptine, Animals, Ergolines, media_common, biology, Courtship display, biology.organism_classification, Triturus, Prolactin, chemistry, Pituitary Gland, Spermatophore, Animal Science and Zoology, Female, hormones, hormone substitutes, and hormone antagonists, Hormone
Abstract

In an attempt to elucidate the possible prolactin involvement in sexual behaviour in the male crested newt, we have devised three experimental approaches: (1) hypophysectomy followed by replacement therapy with prolactin; (2) ectopic pituitary autograft; and (3) treatment with ergocryptine. After hypophysectomy (1), the percent time spent in courtship falls rapidly and is restored partially only by exogenous prolactin. In the short-term ectopic pituitary autograft (2), the enhanced release of endogenous prolactin triggered by the operation exerts a stimulatory effect on sexual behaviour. Courtship behaviour declines in the subsequent days. In long-term operated animals, spermatophore deposition is suppressed and concurrent testes regression takes place. After ergocryptine treatment (3), the percent of time spent in courtship decreases and is restored partially by exogenous prolactin. Hence prolactin appears to control sexual behavior in the crested newt, although other hormones seem to be involved in this mechanism. The occurrence of a synergism between prolactin and gonadal hormones in sustaining sexual behaviour in the crested newt is suggested. The action of prolactin on peripheral organs also is discussed.

Published
1982

61. Effects of beta-carotene on adult immune condition and antibacterial activity in the eggs of the Grey Partridge, Perdix perdix.

Author

Cucco M, Guasco B, Malacarne G, and Ottonelli R

Subjects
Animals, Dietary Supplements, Egg Yolk chemistry, Female, Lipids analysis, Male, Muramidase metabolism, Organ Size, Anti-Bacterial Agents metabolism, Galliformes immunology, Galliformes microbiology, Immunity drug effects, Ovum drug effects, Ovum microbiology, beta Carotene pharmacology
Abstract

Carotenoids are important dietary constituents in birds. Their functions are numerous and complex, and breeding females are potentially faced with an optimal allocation of these resources between themselves and offspring. We conducted a dietary experiment (low and high supply of beta-carotene) to examine the effect of beta-carotene on health and immune response of 64 reproducing pairs of Grey Partridge (Perdix perdix L.) and on the quality of their eggs, as revealed by the measurement of biochemical components in yolk and albumen, the egg hatching rate and chick survival. We found a beneficial effect of beta-carotene on the erythrosedimentation rate and immune response of females (PHA reaction), while the diet did not significantly affect these variables in males. In both sexes, the plasma level of carotenoids was not related to the quantity of beta-carotene supplied. A higher quantity of beta-carotene in the diet did not induce a variation of egg nutrients (proteins and lipids), nor an increase of yolk beta-carotene concentration. We detected a higher concentration of lysozyme, an enzyme with antibacterial activity, in the albumen of eggs laid by females with a high supply of beta-carotene. These eggs showed higher hatching rates. The present study indicates that although carotenoid supplementation does not influence blood and yolk carotenoid levels, it results in better immune conditions of females, eventually translated into increased antibacterial activity of the eggs. The broad range of beneficial effects of carotenoids is discussed.

Published
2007
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