Abstract

Settlement dynamics of the bicolor damselfish, Stegastes partitus (Pomacentridae), were determined by otolith shape and microstructure analysis and compared among different coral reef areas (Windward, reef Lagoon and Leeward) of Chinchorro Bank (northern Meso-American Barrier Reef System, eastern Yucatan Peninsula). Estimated age, settlement time, size at settlement, and larval otolith growth rates were compared. Significant differences in planktonic larval duration were found, with 28.8, 30.3 and 32.7 mean days spent at Windward, Lagoon and Leeward, respectively. Individuals with shorter larval durations (at Windward) showed faster otolith growth rates and settled at relatively smaller sizes than those with longer larval durations (at Lagoon and Leeward). However, there was no significant difference in otolith growth rates among reef areas, and there was no clear evidence for delay in metamorphosis. Based on both the planktonic larval duration and the prevalent current pattern in the area, it appears that strong northwesterly currents passively transport S. partitus larvae into Chinchorro Bank. Larvae may enter at Windward, passing through the reef Lagoon, and leave by the Leeward. Longer PLDs for S. partitus settling at Leeward are not due to differences in larval growth rates but more likely to a lack of access to suitable settlement habitat by the time the larvae is passing throughout the reef system. An otolith shape (Fourier) analysis also revealed a clear differentiation between otoliths from the three reef areas, suggesting that the environmental influence on otolith shape of S. partitus is relatively uniform, which means that this fish is affected by similar local environmental conditions within each reef area

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