21
the size, testis mass vary largely between immature, with 52.3 g (±33.5), and mature
animals, with 2.270 g (±0.86) (Fig. 2.4). The testis mass correspond to 0.11% of
body mass in immature and 2.52% in mature individuals, keeping these proportions
throughout the year, with no apparent seasonality in testis activity detected. Female,
just as with other Delphinidae, have bipartite uterus (Fig. 2.5) with the shape of a
small almond (Rosas and Monteiro-Filho 2002; Rosas and Barreto 2008). The
authors detected little variation in ovary morphometric, ranging from 2.3 cm (±0.5)
long and 1 cm (±0.2) wide in immature to 3 cm (±0.4) long and 1.7 cm (±0.3) wide
in mature animals. Differently, ovary masses increase significantly, from 1.6 g (±1)
Fig. 2.4 Testis of Sotalia
guianensis of a sexually
mature specimen dissected
after necropsy. Specimen
was found during beach
monitoring activities at
Cananéia estuary (Photo:
IPeC)
Fig. 2.5 Ovaries and
bipartite uterus of Sotalia
guianensis of a sexually
mature specimen dissected
after necropsy. Specimen
was found during beach
monitoring activities at
Cananéia estuary (Photo:
IPeC)
2 Long-Term Monitoring of Dolphins in a Large Estuarine System of Southeastern…