Serranidae: L III D2

E. poecilonotus (Temminck & Schlegel, 1842), and Epinephelus rivulatus (Valenciennes, 1830), among others.

rockcod

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
815-910	1	180-190	clear	narrow	stern	52% of NL	24

Egg: The yolk has a rough surface, the oil globule is clear, and there are usually no pigments visible in the egg, when viewed on a white background. Just prior to hatching, fine black dots (almost imperceptible) may be seen down the length of the embryo, and a light smudge of yellow may be visible on the notochord in mid-tail. Incubation is 24-30 hours, so in summer these eggs are often hatching during the sorting and cataloguing process.

Larva: The 1-day larva (C) has yellow pigment in mid-tail, comprised of 1 or 2 spots. Some are also seen with a few spots in the dorsal finfold above the yolk, and ventrally on the notochord in mid-yolk (may be another species, see LIIID4). By day 4, the notochord in mid-tail is brown/black, with a pair of white wedges in the finfolds (D), and a dark patch over the gut. A single larva was taken to 18 days, at which point the elongate dorsal and pelvis spines were well developed, but the larva was still preflexion (E).  B: NH, C: 1 day, D: 4 days, E: 18 days (22-23°C).

Thirtyfive hatched larvae have been barcoded, 18 of which matched 5 Epinephelus poecilonotus adults. Twelve match 5 adult E. rivulatus , and 3 matched 3 adult E. fasciatus. One each matches E tukula and E. posteli adults (BOLD). All adult material was collected locally.

Linked samples	Offshore	Inshore
Eggs	523	261
Hits	92	73

This egg was fairly common off Park Rynie, and was seen most months of the year, with a spring and summer peak (blue graph). The egg was only seen 3 times in the DHM samples (green graph), but numbered over 50 eggs on two of those occasions. Annual abundance of the eggs in Park Rynie plankton samples appears to be steady (white graph), The Park Rynie linked samples had more eggs offshore (67%), but still inshore of the two indicator species, suggesting spawning around the 40m depth contour. The distribution of this egg is likely to be unreliable however, since while rivulatus and fasciatus are seen in 20m-40m water depth, poecilonotus is generally caught at about 100m water depth. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.