Serranidae: F III A1

Acanthistius sp (Heemstra and Randell 1986 species No. 166.2)

Scalyjaw koester

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
940-985	1	190-240	segmented	narrow	stern	51% of NL	24

Egg: The identifying features of this egg are size, segmented yolk and just a few scattered stellate yellow pigment spots on the yolk (A). The developing embryo has 6-7 yellow pigment patches along the body. Black pigment spots are mostly dorsal on the embryo. There are a few black pigment spots on the oil globule but none on the yolk. The oil globule is usually pale amber to clear. Segmentation of the yolk is often confined to the edge. Incubation time is about 40 hours (22-23°C).

Larva: The distinctive yellow pigment pattern of the 1-day (B) and more especially the 3-day (C) larvae, quickly confirm the identity of Acanthistius. The 5-day larva develops a pair of white patches into the finfolds in mid-body, which has been seen in other serranid larvae (E). At 11 days the larva was just starting flexion (F), while at 21 days the larva was fully post-flexion (G). At 75 days the juvenile is assuming the colours of the adult (I). B 1 day, C: 2 days, D: 3 days, E: 5 days, F: 11 days, G: 21 days, H: 37 days, I: 75 days (22°C).

The larva proved quite easy to rear, despite seldom taking large numbers of eggs. Adults are fairly common on reefs at 30-40m off Park Rynie, but are usually only seen singly. Thirteen larvae hatched from this egg, have been barcoded, matching a single adult collected locally.

Spawning occurs all year round, with a definite increase in the colder months, from April to October (blue graph). They were not seen in the DHM samples. No pattern is discernible in the numbers of these eggs collected over the study period (white graph).

Linked samples	Offshore	Inshore
Eggs	540	24
Hits	46	12

 Among the more common eggs in the Park Rynie linked samples, this was the egg with the highest percentage offshore (96%). This is surprising, given that they are fairly common on reef at 30-40m (personal observations), but perhaps reflects a wider distribution across the shelf. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.