Bothidae: L III G7

Crossorhombus valderostratus (Alcock, 1890)

Broadbrow 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








50% of NL



Egg: This egg is always identifiable by its small size, and the salmon-pink to orange pigment that can be seen, scattered along the late embryo, and on the oil globule (A). No black pigment is seen in the embryo. The oil globule is clear. Incubation is 22-26 hours. The egg is seen in the blastula and about to hatch/ just hatched stages. Thus spawning is occurring morning and evening.

Larva: The orange pigment turns more yellow by day 2, and consolidates around the oil globule/anus (often with a small blotch in the dorsal finfold), and in a midtail blotch (B). Both dorsal and ventral finfolds have a strongly spined edge (B1). By day 4 the mouth is quite protruding, and the dorsal finfold spot persists (C).  B: 2 days, C: 4 days, (26°C).

Brownell described an egg virtually identical to this one, except his was a little larger (720-780µm), which he believed to be Arnoglossus capensis (Boulenger, 1898). Eight larvae have been successfully barcoded, and match 3 locally collected adult C. valderostratus (BOLD).


Linked samples Offshore Inshore
Eggs 7884 7441
Hits 245 389

This was the 11th most common egg off Park Rynie (Introductory Notes; Table 3), with a summer peak, although seen all year round (blue graph). Also common in the DHM samples, confirming a summer peak (green graph). Seen fairly consistently off Park Rynie over the study period (white graph), although 2002- 2004 were not good years. Park Rynie linked samples showed almost equal offshore (51%) and inshore, suggesting the majority of spawning is occurring around the 30m depth contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.