Cyclicity
Sexual reproduction of H. leucospilota is a result of seasonal spawning, with restricted spawning periods seen within populations (Purwati & Luong-van 2003). Populations have been shown to simultaneously develop gonadal tubules and become fecund in less than a year, demonstrating reproductive cycles within populations. A study by Purwati & Luong-van (2003), in Darwin, Australia, showed a spawning period restricted to approximately two weeks for the species. However, spawning patters vary across the globe and may be subject to local environmental conditions, with longer periods occurring in populations in areas such as Hong Kong and Vietnam. The general opinion is that this species spawns over several months (Dabbagh et al. 2011).
Oocytes and sperm are released into the water column, by males and females independently, and are then subjected to complex oceanic currents. Hence, eggs must be successfully fertilized by the sperm externally, then develop into the pelagic larval phase (Dabbagh et al. 2011., Taquet 2011). Fertilized eggs go through seven developmental stages; cleavage, morula, blastula, gastrula, early uricholaria, uricholaria and late uricholaria larva (Soltani et al. 2010). Larvae must then undergo settlement and then survive the juvenile phase, before reaching adulthood. There is evidence that spawning may result in aggregation sites, with evidence of H. leucospilota nurseries presented by Taquet et al. (2011). This research discovered about 100 individual juveniles per square metre, in a site around Manado (north Sulawesi) (Taquest 2011).
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