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 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) B: 1 day, C: 2 days, D & D1: 4 days (25°C).

The egg is distinctly epinepheline, and the larva has epinepheline and anthiine features (see KIIIC1, KIIIC1A and KIIIC2, LIIIB4, LIIID2). But 6 larvae hatched from eggs collected 6th February 2009 have matched the barcode of a single Zebrasoma gemmatum collected on the Aliwal Shoal (BOLD reference). This identification is tentative, awaiting further larval and adult barcodes.

linked samples	Offshore	Inshore
Eggs	104	8
Hits	4	4

This egg was seldom seen off Park Rynie, and the records are too sparse to indicate a spawning pattern (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.