Larval development of Microgobius tabogensis Meek Hildebrand, 1928

In fish, the larval stage constitutes the most vulnerable phase in the life cycle and reveals important ecological and evolutive information of fish and fundamental data to manage marine ecosystems. However, their identity is one of the biggest gaps in knowledge, particularly for the Microgobius genus, where only three of 15 species have been described. In this study, the larval development of Microgobius tabogensis was described based on 116 specimens (2.75-14.20 mm standard length) from Ensenada de La Paz, Mexico. The typical gobiid body shape characterized larvae, a well-developed dorsally pigmented gas bladder, a curve at the hindgut, and 27 myomeres. The pigmentation pattern in M. tabogensis consisted of a series of melanophores along the ventral postanal midline, increasing from three to seven during the preflexion stage and up to 16 in the postflexion stage. It had three to five melanophores on the ventral preanal midline, one at the jaw angle and one on the dorsal postanal midline. Through all stages, one of the ventral melanophores was normally stellate, bigger than the others, and extended between the myomeres. A dorsal melanophore was located near the end of the intestine in the preflexion stage but disappeared with growth. Notochord flexion started at approximately 4.3 mm and ended at 5.1 mm. Anal fin development started at the beginning of the flexion stage, followed by the dorsal fin. All elements of the fins were formed by the late postflexion stage (14.2 mm).