Platycephalidae: L III A5

Cociella heemstrai Knapp, 1996

Spotfin flathead

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
910-985	1	190-240	clear	narrow	stern	50% of NL	27

Egg: My notes often describe this egg as pretty, due to the yellow pigment on the larva, oil globule and yolk (A). Black pigment is present, with the same distribution. The oil globule is light amber. Initially I had difficulty separating this egg from smaller eggs of LIIB5, but then noted that the black pigment spots on the yolk, appeared dark red on a white background, and have found this a reliable means of separation. Incubation is about 35 hours.

Larva: The NH larva looks much like LIIB5 and even FIIA9 (though the segmented yolk separates the latter egg), but quickly forms a diagonal through the body, posterior to which there is no yellow pigment (C, D & E). At 5 days, the tip of the lower jaw often bears a black spot. B: NH, C: 2 days, D: 3 days, E: 4 days, F: 32 days, (23-24°C).

This larva proved quite difficult to rear, but on one occasion a larva was taken through to 32 days before being sacrificed to provide a voucher specimen. Six larval DNA barcode sequences are available, all matching the sequence of 5 adult C. heemstrai collected locally (BOLD reference).

Linked samples	Offshore	Inshore
Eggs	114	296
Hits	36	76

This was a common egg off Park Rynie, with spawning all year round (blue graph). It was also seen 6 times in the DHM samples (green graph). The occurrence of these eggs at Park Rynie, through the 19 years of sampling, has shown a steady presence, after initially perhaps being confused with LIIB5 (white graph). The Park Rynie linked samples showed more of these eggs inshore (67%), indicating spawning within the 20-30m depth contours. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.