Growth curve of the body weight, body length and tail length in the cotton rat (Sigmodon hispidus)

Abstract

The body weight (BW), body length (BL) and tail length (TL) of 202 cotton rats, 102 males and 100 females. were measured. Significant sex differences in the BW were observed 3 weeks after birth. The BLs in one-day-old males and females were 8.33 = 0.36 cm and 7.82 +/- 0.69 cm respectively, while the TLs were 2.98 +/- 0.12 cm and 2.88 + 0.28 cm. Growth of the BL and TL was rapid until about 8th week of age, when a steady length was reached. The equations in males were BL (em) = 8.07 + 0.23 x BW (g) - 0.00068 x BW (g)2, TL (em) = 2.79 + 0.11 x BW (g) -0.00037 x BW (g)2 and TL (cm) = — 2.21 + 0.67 x BL (em) — 0.0068 >< BL (cm)2. Correlations among the BW, BL and TL in male and female cotton rats were all highly significant (r 20.98, P < 0.001).