Mugilidae: L II B9

Liza tricuspidens (Smith, 1935), and Myxus capensis (Valenciennes, 1836)

Striped mullet and Freshwater mullet

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
985-1060	1	340-360	clear	narrow	stern	59% of NL	24

Egg: Mugilid eggs are easy to identify as they have larger oil globules, relative to egg diameter, than any other species in their size range (A).  In advanced incubation eggs, yellow pigment, mixed with black, densely covers the embryo and oil globule, and a few scattered across the yolk (A). Incubation is about 45 hours. These eggs are very buoyant in seawater, and tend to break the surface in the hatching bowl, to the detriment of hatchability.

Larva: The early larva has dense pigment along the notochord, and yellow patches in the finfolds (B). The finfold pigment disappears by day 4 or 5 (C & D).  B: 1 day, C: 3 days, D: 4 days (23°C).

Although mullet were found to be easy to rear (LIIIA7 & LIIIB7), this bigger egg was too infrequently seen, and was not reared. Eleven hatched larvae have been sequenced, 8 of which match the sequence of the only adult Liza tricuspidens I have collected locally (BOLD).The other three match the sequences of 6 locally collected adult Myxus capensis.

Linked samples	Offshore	Inshore
Eggs	68	60
Hits	13	30

This was an uncommon egg off Park Rynie, with spawning showing a peak in the winter/spring period (blue graph). It was seen twice in the DHM samples, in September and October. The Park Rynie linked samples showed slightly more of these eggs offshore (53%), but biased by a single sample of 51 eggs in the offshore sample of 14 July 2011. Nevertheless it indicates spawning inside the 30m contour, and more likely, within the 20m contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.