ILIAC ARTERIES IN SHREWS (SORICIDAE, INSECTIVORA, MAMMALIA) - MORPHOLOGY, FUNCTION AND PHYLOGENY

The arrangement and variations of the vessels supplied by the internal and the external iliac arteries in four European soricids are studied . Forty-six shrews captured in the field, belonging to the subfamilies Crocidurinae (Crocidura russula : 11 males, 14 females) and Soricinae (Sorex araneus: 4 males, 8 females; S. coronatus: 3 males, 2 females; S. minutus : 2 males, 2 females), were analysed by injection of colou red latex solution through the left ventricle of the heart and subsequ ent dissection. Results revealed that, in spite of the intra- and inte rspecific variation observed, C. russula and Sorer species shared cert ain arterial features, such as the presence of cranial gluteal, obtura tor and external pudendal arteries as constant components of the inter nal iliac artery, or of its tributaries. Available information suggest s that, within mammals, the origin of the obturator artery from the ca udal gluteal artery and the presence of the external pudendal artery a s a vessel of the internal iliac artery constitute distinctive feature s of shrews. Divergences between C. russula and Sorex species are main ly centered on the blood supply to the prostate, ductus deferens and v agina, and on the presence of the deep femoral artery in C. russula. T he former divergence is connected with the different anatomical dispos ition and size of the prostate and the morphology of the ductus defere ns in the two genera; the latter distinguishing trait is not related t o function, but probably to the evolutionary history of soricidae.