Abstract
Embryonic, larval and juvenile morphologies of the freshwater goby Odontobutis hikimius, reared in an aquarium, were observed and described. The egg mass (ca. 200 eggs), spawned on the glass wall of the tank, were cared for by the male. The eggs were ellipsoid in shape, 3.74-3.80mm (long axis) by 2.20-2.35mm (short axis), and attached to the glass wall with adhesive threads. Larvae hatched out 14-16 days after spawning. Just-hatched larvae were 6.04-6.11mm in body length (BL), with 18+12=30 myomeres, completed notochord flexion, and all fins represented. However fin ray numbers were not completed. Melanophores were present on the head, cheek, trunk below the first and second dorsal fins, and caudal peduncle. Eleven days after hatching, juveniles of ca. 8.45-8.75mm BL had full fin ray complements. They grew to ca. 11-12mm BL after one month from hatching, ca. 50-60mm BL after 6 months and ca. 70-115mm BL after one year. The cephalic sensory papillae developed in 11-day-old juveniles at ca. 8.6mm BL. Opercular papillae group 17 was clearly connected with group 19 over ca. 11mm BL, such being an important character for distinguishing adults of this species from similarly-sized O. obscura. Sensory canal c was apparent in specimens over ca. 70mm BL.
