Sphyraenidae: E III A3A

Sphyraena sp.

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

840-890

1

215-240

segmented

narrow

bow

60% of NL

ca25

Egg: This species is another in this group of eggs with a segmented yolk, and a relatively large, clear oil globule. My notes describe the yolk as misty, and the embryo and oil globule sparsely dotted with black pigment. Due to its rare appearance in samples, no photograph of the egg is currently available. Incubation is about 30 hours.

Larva: The NH larva has no yellow pigment in the finfolds; it is all on the notochord, eye sockets and oil globule (A). During the next three days the yellow pigment spreads across the whole notochord behind the pectoral fins (E & F). A: NH,  B & B1: 1 day, C, C1 & D: 3days, E & F 4 days (23°C). Note: A, B C, C1 & F are a series from the same egg batch. Likewise are B1, D & E.

This species has been provisionally identified as a Sphyraena, because it has all their egg and larval attributes, and in the dendrogram they cluster as one species, among adult Sphyraena, closest to S. acutipinnis (BOLD). See also EIIIA2A. It is very like EIIIA7A in its early stages, but the 4-5 day larva separates them. Ten hatched larvae have been successfully sequenced, but no match with an adult has been found in BOLD.

This egg has a peculiar seasonal distribution, having been collected mostly in May and November (blue graph). It was not recorded in the first 10 years of the study, but has become more common recently (white graph). In the linked samples, of the 41 eggs seen so far, 75% were in offshore samples, suggesting spawning around the 40m contour, in the area where kob spawn. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.