Bothidae: L III E9

Pseudorhombus elevatus Ogilby, 1912.

Ringed flounder

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
730-810	1	50-90	clear	narrow	see notes	60% of NL	32

Egg: There is a red sheen to the chorion. The unusually tiny oil globule is often difficult to see (A, arrows). A few black pigment spots appear dorsally on the embryo, mostly post-anus, with a few on the side of the head. Incubation is 25-30 hours. The position of the oil globule is normally astern, but about 10% of newly hatched larvae have the oil globule up front. These have been combined, but will be separated if DNA shows otherwise.

Larva: The NH larva has just a couple of spots of black pigment (B), with dorsal finfold edge pigment at 3 days. Less dense pigment can be seen on the head and around the shrinking yolksac (C3). The pigmentation of 2-day larvae seems quite variable (Plates C - C3, but note that Plates C and C3 are of the same larva).  B: NH, C: 2 days, D: 3 days (22°C)..

The variable pattern of the 2-day larva may indicate at least two species. Also the oil globule position in the newly hatched larva, is variable. Only 2 larva have been successfully barcoded so far, and they matched 8 P. elevatus adults (BOLD reference). Further larval sequences are also needed to confirm the match.

Linked samples	Offshore	Inshore
Eggs	107	46
Hits	37	29

This unusual egg was seldom seen in numbers, but did turn up fairly regularly off Park Rynie, mostly in the cooler months (blue graph). It was not seen in the 1990-1994 Durban Harbour mouth samples, but the single DNA sequence mentioned above, was from an egg collected in the DHM on 21 October 2005. The egg numbers have remained fairly constant off Park Rynie through the study (white graph). The Park Rynie linked samples showed a predominance of eggs in the offshore samples (70%), suggesting the species is spawning in the region of the 30m contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.