ABSTRACT
Zebrafish are small, active, schooling fish with 5 to 7 bilateral horizontal stripes on either side of their bodies (Spence et al. 2008). They have 3 unpaired fins and 2 paired fins. Zebrafish also have 2 pairs of barbels on the ventral lateral aspect of the oral cavity (Barman 1991; Hansen et al. 2002; Spence et al. 2008)
One-year-old zebrafish can measure between 25 mm to 35 mm in length (Spence et al. 2008). Zebrafish growth rate is fastest during the first 3 months of life and approaches zero by about 18 months of age (Spence et al. 2008; Spence et al. 2007). The growth rate of laboratory-raised zebrafish is greater than the growth rate of wild zebrafish (Spence et al. 2008). Females are larger than male zebrafish regardless of whether they originate from the wild or the laboratory (Eaton and Farley 1974; Spence et al. 2008). Males are more slender than females, have a yellowish cast on their abdomens, and tend to have larger anal fins than do females (Figures 65 and 66) (Spence et al. 2008; Laale 1977).
