Spawning behavior of bullethead parrotfish (Scarus sordidus)(10.1MB, 00:02:00)Shot Date: 2005 Shot Location: Iriomote Is., Okinawa, Japan | ||
| species Scarus sordidus Key Words | ||
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Animalia >Chordata >Osteichthyes >Perciformes >Scaridae >Scarus >
Earlier reports state that parrotfishes spawn around the time of high tides. At Iriomote, however, they spawn most actively between 7 and 8 o¡Çclock in the morning. Every morning terminal-phase (TP) males of about ten species, such as Scarus dimidiatus, S. bowersi, S. psittacus, and S. sordidus, migrate to the reef edge and establish temporal spawning territories. TP males are males that are more brightly colored than females. Males that have coloration similar to that of females are called initial-phase (IP) males.
In this video picture, you see courtship display of a S. sordidus TP male. Flapping its pectoral fins up and down, it is circling several meters above the reef bottom. You see its feces, a cloud of white particles. These particles are coral skeletons broken into powder (See also a video picture ¡ÆFeeding behavior of parrotfish¡Ç). Females are below the displaying male. A female ready to spawn swims up to the male and spawning takes place. The male courts next female and spawns. A white cloud of eggs and sperm is clearly visible. In summary, a heterosexual pair goes up in the water column and releases gametes, and eggs are externally fertilized. Fertilized eggs are buoyant and are swept away by the current. As long as females keep coming to the territory, a male spawns with one female to another, sometimes mating with several tens of females. Streaking is also observed in this species. An IP male is dashing to the spawning pair from the left. A TP male is also dashing to the pair. This is a TP male holding an adjacent territory. In other words, TP males sometimes sneak-spawn as well. Another type of spawning is group spawning. A group of IP males follow a female and about ten fish rush up in the water to spawn. At low tape speed, you can see about ten males releasing sperm for eggs of a single female. (translated by Asoh)
(Data No.momo060212ss01b)
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