Carangidae: E II A4

Seriola dumerili (Risso, 1810) & Seriola rivoliana Valenciennes, 1833.

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

1000-1175

1

260-270

segmented

narrow

bow

60% of NL

24

Egg: This egg will always need to be hatched to confirm identification. Often, the oil globule gives the impression of positioning itself astern in the developing embryo, and the bright yellow pigment is reminiscent of Scomber (LIIA7), but the densely segmented yolk will rule out Scomber. The oil globule becomes evenly peppered with black pigment spots ventrally. Incubation takes about 45 hours..

Larva: The strikingly pigmented 1-day larva is always spectacular (B). The 5-day larva is a mixture of grey pigments (D & E), similar to other Seriola species (EIIA2). B: 1 day, C: 2 days, D & E: 5 days (25°C).

Rearing attempts were unsuccessful. Nine egg-hatched larval DNA sequences are currently available. Four match 5 locally collected adult S. rivoliana, and 5 match S. dumerili (BOLD). Clearly there is a size overlap, within the eggs of S. dumerili, leading to confusion between EIIA2 and this species.

 

Linked samples

Offshore

Inshore

Eggs

576

64

Hits

28

20

This species is a summer spawner in KZN waters (blue graph). The egg was not seen in DHM samples. The Park Rynie eggs per year trend, shows a patchy presence (white graph). The Park Rynie linked samples had 90% offshore, indicating spawning to seaward of kob and geelbek), in 50m water depth, and deeper. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.