Acanthuridae: L III E10

Zebrasoma gemmatum (Valenciennes, 1835)

Spotted tang

Egg diameter in µm	Number of oil globules	Diameter of oil globule in µm	Yolk texture	Perivitelline space	Position of oil globule at hatch	Gut length   at eye- pigment stage	Myomeres
665-770	1	150-190	clear	narrow	stern	50% of NL	24

Egg: This egg has a yellow-amber oil globule, and the only pigment on the developing embryo, is tiny, pale yellow dots, mostly in the tail, just before hatching. Incubation is about 25hours.

Larva: The 1-day larva has 4 blotches of whitish yellow pigment along the notochord, from eyes to midtail (B), and may also have a line dorsally on the finfold edge, similar to Plate D1. A dense patch of red-brown pigment forms over the gut later (C, D & D1). 3-4 day larvae develop an unusually serrate outer edge to the finfold, particularly the lower edge midtail, with some "spicules" almost as long as pupil diameter. B: 1 day, C: 2 days, D & D1: 4 days, E: 3 days(25°C).

The egg is rather epinepheline in appearance, and the larva has epinepheline and anthiine features (see KIIIC1, KIIIC1A and KIIIC2, LIIIB4, LIIID2). But 8 larvae hatched from this egg, have matched the barcode of a single Zebrasoma gemmatum collected on the Aliwal Shoal (BOLD).

linked samples	Offshore	Inshore
Eggs	164	13
Hits	8	7

This egg was seldom seen off Park Rynie, but the sparse records show a summer spawner (blue graph). It was not seen in the DHM samples. The Park Rynie linked samples showed a predominance of eggs offshore (93%), suggesting spawning occurs outside the 50m contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.