Carangidae: E III A5

Trachurus trachurus (Linnaeus, 1758), & Decapterus russelli (Ruppell, 1830) among others (see also E III A6)

Maasbanker

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

850-900

1

210-220

segmented

narrow

bow

56% of NL

24

Egg: The embryo in the egg (A), usually has 4-5 pairs of bright, white/yellow pigment, and the oil globule is clear, with a couple of white/yellow pigment spots, very much like EIIIA6. Yolk segmentation is conspicuous. Incubation is 25-30 hours.

Larva: The early larva has the basic yellow pigment pattern shown in (B), which moves out into the finfolds over the next 1-2 days (C & D). The broken line of black pigment, both dorsally and ventrally along the notochord, and elongate gut, identify this stage larva (E & F). B: 1 day, C & D: 2 days, E & F: 4-5 days (23°C).

This egg is part of a complex that include the maasbanker Trachurus trachurus, and probably several species of Decapterus, as well as possibly other small shoaling carangids. DNA sequences are available for 3 larvae; 2 match 5 adult Decapterus russelli.and 1 matches 4 adult Trachurus trachurus (BOLD). Since it has yielded nothing different to species listed in EIIIA6, it should be merged.

Linked samples

Offshore

Inshore

Eggs

139

162

Hits

8

13

This egg was fairly common off Park Rynie, and might have been more so, but for possible lumping with EIIIA6, due to the uncertainty of identification, if the eggs are not hatched and reared for 4-5days (see also, comments on EIIIA3). The species appears to be a winter/spring spawner, although the data is sparse (blue graph). This egg was not seen in the DHM samples. The Park Rynie linked samples had 54% inshore, indicating spawning in shallow water (20-30m) on the shelf. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.