Exocoetidae: H I A1

Exocoetus monocirrhus Richardson, 1846

Two-wing flyingfish

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








68% of NL


Egg: In early developing eggs, black stellate spots cover the yolk near the embryo, and laterally on the embryo. One egg collected with a thin embryo already formed (Plate A, right egg), took 9 days to hatch (23°C).

Larva: The newly hatched larva has pigmented eyes, and blue pigment dorsally (B). Enlarged pelvic fins can be seen in the 5 & 6 day larvae (C& D), and a pale saddle dorsally over the gut. B: NH, C: 5 days, D: 6 days (23°C).

Ikeda & Mito (1988) show two exocoetid eggs with no spikes on the chorion, Exocoetus volitans and E. monocirrhus, both of which occur in our waters. Three larvae from this egg have been barcoded (one wrongly coded as CDIA1), matching 3 E. monocirrhus adults collected locally (BOLD).

This egg has only been collected on 8 occasions off Park Rynie, all in August to November (blue graph).