The lumbosacral plexus in two Didelphis species (Didelphidae, Didelphimorphia): origin and nerve distribution.

Morphological studies provide knowledge that allow us to understand how animals interact with the natural environment or the captivity. The goal of this study was to describe the origin and antimeric distribution of lumbosacral plexus nerves in Didelphis aurita and D. albiventris. Fourteen adult cadavers of D. aurita, seven males and seven females, and 13 adult cadavers of D. albiventris, nine males and four females were used. The specimens were sexed, identified, fixed and dissected until the origins of the lumbosacral plexus nerves were exposed. Data were represented as absolute frequency and simple percentage. The lumbosacral plexuses derived a trunk for the femoral and obturator nerves from the ventral branches of L3-L4 (75%) in D. aurita, and in D. albiventris the femoral nerve of L3-L4 (73.1%) and the obturator nerve of L3-L4 (61.5%). In both species, formation of a lumbosacral trunk derived from L5-L6-S1 occurred in 78.6% of D. aurita and 61.5% of D. albiventris. The origin and distribution of lumbosacral plexus nerves of the studied species present similarities with domestic and wild eutherian mammals.

Anatomical characterisation of the kidneys of Didelphis aurita (Didelphimorphia: Didelphidae).

BACKGROUND: Didelphis aurita is a marsupial with wide distribution in the South American continent and highly adapted to urban centres. The objective of this study was to describe the measurements and skeletopy of the kidneys and renal vascularisation of this species. MATERIALS AND METHODS: With this aim, 29 cadavers (14 males and 15 females) of D. aurita collected on highways were analysed. The rostrum-sacral length of specimens, kidney measurements (length, width and thickness) and the length of the renal vessels were measured and the renal skeletopy registered. RESULTS: In the right kidney, average length, width, thickness and ellipsoid volume were 28.6 ± 5.0 mm, 15.6 ± 2.9 mm, 12.8 ± 3.0 mm and 3.3 ± 2.4 cm3, respectively; in the left kidney, 31.0 ± 3.8 mm, 14.5 ± 3.6 mm, 12.6 ± 2.6 mm and 3.2 ± 2.2 cm3, respectively. There was no significant difference in the comparison of averages of renal dimensions between sexes and between antimeres. The right renal artery (13.2 ± 2.6 mm) was significantly longer (p < 0.01) than the left renal artery (10.7 ± 2.3 mm). In contrast, the left renal vein (13.9 ± 3.5 mm) was longer (p < 0.01) than the right renal vein (7.0 ± 2.3 mm). The skeletopy of the right kidney predominated between T13-L1 in 58.6% of the cases and the skeletopy of the left kidney between L1-L3 in 41.4%. The average length of the kidneys corresponded to 6% to 8% of the rostrum-sacral length of the specimens. CONCLUSIONS: The data of the present study characterised the measurements and topography of kidneys and renal vessels in D. aurita and can support the interpretation of clinical, experimental and pathological findings in this species.