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








50% of NL



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.