Developmental stages of endemic bilih fish larvae (Mystacoleucus padangensis) from Singkarak Lake, West Sumatra, Indonesia

Larvae developmental stages was studied in the endemic bilih fish (Mystacoleucus padangensis Bleeker, 1852) from Singkarak Lake, West Sumatera, Indonesia. We obtained the study material by artificial insemination. The fertilized eggs were incubated in dechlorinated tap water under temperature 26-28°C. Ten to twenty larvae were collected everyday on the first week and then weekly till juvenile. Larvae development stages was assigned using dissecting microscope, determined and named by body total length and morphological features. The result showed that the early juvenile reached at 11.1 mm (5 week post hatching, wph) and scale juvenile at 35.36 mm total length (16 wph) through stages are total length 2.44 mm (pectoral fin bud), 2.85 mm (gill vesicle), 3.24 mm (caudal fin development biginning), 3.60 mm (pectoral fin ray), 3.75 mm (jaw has formed completely), 3.9 mm (caudal fin primordia rounded), 4.12 mm (beginning of notochord flexi), 4.69 mm (dorsal and anal fin development), 6.18 mm (primordia hypural bone), 11.1 mm (skin finfold has disappeared), 14.92 mm (caudal fin completely developed), 16.85 mm (primordia scale developed), 18.32 mm (scale pattern pigmented area has reached lateral line).