Scorpaenidae: H II A3

Choridactylus natalensis (Gilchrist 1902) and another, unmatched species.

Threestick stingfish

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
1105-1320	0	NA	clear	narrow	NA	45% of NL	ca 25

Egg: This egg, when partly incubated, has the yolk peppered with stellate yellow pigment spots (A). The embryo is also covered in yellow pigment. The spots look brown on a white background due to black pigment imbedded in each dot. The whole egg has an amber tint. Incubation is about 50 hours. Big pectoral fin-buds can be seen on the embryo before hatching. On some occasions the egg was noted as slightly oval.

Larva: Big pectoral fin-buds on the newly hatched larva (B), quickly form distinctive yellow pectorals in the 2 day (C) and 4-day (D) larva. The very elongate first pectoral ray, which differentiates  C. natalensis from other scorpaenids (Eschmeyer 1986), can be seen crossed over on the back of the reared juvenile (F). B: NH, C: 2 days, D: 4 days, E: 30 days F: 50 days (21-22°C).

Four larvae, hatched from this egg, have been barcoded, but has not found a match amongst currently available adult material (BOLD). Two adult Corydactylus natalensis have also been successfully sequenced, and the lack of a match suggests there are at least two species with similar eggs, unless the identification of the 50 day juvenile.( F above), is incorrect. A larva from the other similar egg (HIIA3A), has also been sequenced, and it did not match C. natalensis or the other hatched larvae mentioned above. Two further eggs, catalogued as this egg, barcoded as Ablabys binotatus. This was probably an oversight, as the egg of Ablabys has a very small oil globule (LIIA5A), which might have been missed, or might even be missing on occasion. Further DNA barcoding will be needed to unravel the various species.

At Park Rynie, this egg was collected in spring and early summer (blue graph). It was only seen once in the DHM samples (November). The annual catch at Park Rynie suggests a gradual decrease, but numbers are low (white graph). In the Park Rynie linked samples, the eggs were more common offshore (61%), indicating spawning inshore of the two indicator species, in 20-30m water depth. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

Pairs data	Offshore	Inshore
Eggs	19	12
Hits	17	10