Sparidae: L II B4

Diplodus hottentotus (Smith, 1844).

Zebra

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
960-1060	1	190-220	clear	narrow	stern	38% of NL	24

Egg: This egg was always difficult to distinguish from D. capensis (LIIIC1), because the advanced embryo posesses the four yellow pigment spots in the head, which are diagnostic of both species (A, but see also LIIIC1). Thus size becomes the key character within the genus, as D. capensis eggs are generally smaller (LIIIC1). The oil globule is pale amber. Black pigment is seen on a white background, more evenly spread on the embryo. Incubation is about 35 hours.

Larva: The yellow pigment pattern of the early larva (B & C) is quickly lost, except for the head and trunk region, and a single mid-tail spot that straddles the notochord (D). Black pigment collects densely over the gut, and in a fine line, ventrally, down the notochord. At 22 days the larva was postflexion, both in a runt (E) and a larger specimen (F). B: NH, C: 1 day, D: 5 days, E&F: 22 days (26°C). Plate E is tentatively placed in this series as it was from the same reared batch, but does not fit Brownell’s (1979) series. F1 is the same juvenile as F, after preservation, from which fin-counts can be made.

The egg size agrees well with Brownell (1979), as does the pigmentation of the 22-day postflexion juvenile, which has more advanced fin development than his 32-day juvenile, due to the difference in rearing-tank water temperature. Fourteen larvae submitted as LIIB4 have been sequenced, 11 of which matched the sequences of 5 locally collected D. hottentotus adults (BOLD). The other 3 matched Polysteganus coeruleopunctatus (1) and Polyamblyodon gibbosum (2). Another 10 larvae have matched D. hottentotus, although submitted for barcoding under the larval code LIIIC1, confirming the eggs are difficult to separate, as noted above.

linked samples	Offshore	Inshore
Eggs	93	240
Hits	25	50

This species was not common off Park Rynie, but could have been undercounted because of the likeness to D. capensis . It is a winter spawner (blue graph), confirmed by the few eggs that were recorded in the DHM samples (green graph). Off Park Rynie, the egg has become more common recently (white graph). The Park Rynie linked samples had many more eggs inshore (72%), suggesting most are spawning inside the 20m contour. This fish is seenboth in the surf and on reefs in 40m depth off Park Rynie; the high incidence of eggs inshore may indicate that adults move inshore to spawn. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.