Anguilliformes: G I A1

Unknown

Eels

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
1970-3490	multiple	70	segmented	wide	dispersed	76% of NL	80+

Egg: As noted with other eel eggs (DIA1, FIA1), these tend to have a green tint to the yolk and embryo. They are usually very large, in the region of 3mm diameter, but can be only 2mm. When fresh the yolk measures 55-61% of egg diameter. Incubation time is uncertain, but probably exceeds 80 hours (24°C).

Larva: Larvae reared from these eggs all have clusters of green or black pigment dotted along the ventral edge of the notochord (B, C & D). The larva is elongate and blade-like, with not yet fully pigmented eyes, and a partly developed mouth. By day 2 the eyes are fully pigmented, but the mouth is still forming (C). At 4 days the mouth appears fully formed (D). B: NH, C: 2 days, D: 4 days (24°C).

No attempt was made to rear this larva. DNA barcoding of these larvae is the surest way to link larva to adult. Nine hatched larvae have been sequenced, indicating 6 different species, but no matches have been found, within the limited adult sequences currently available (BOLD).

This egg is not common in the Park Rynie samples, and when seen, it is usually only one or two. Spawning occurs through the warmer months from December to March, extending into May (blue graph). They were not encountered in the DHM samples. The annual catch of eggs off Park Rynie, shows a steady decline over the 25 year period, except for the past two years (white graph). In the Park Rynie linked samples, 76% were offshore, which puts them between kob and geelbek in the inshore to offshore spawning zones, around the 50m contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

Linked samples	Offshore	Inshore
Eggs	65	20
Hits	49	18