Stromateidae: F II A3

Hyperoglyphe antarctica (Carmichael, 1818)

Antarctic butterfish

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
1250-1345	1	360-410	segmented	narrow	stern	55% of NL	28-30

Egg: This egg (A) always needs to be hatched to confirm identification. At a stage, black pigment forms two lines on the embryo, and speckles the yolk and oil globule, making the latter look dark brown (B). Incubation can be as long as 86-94 hours (21°C).

Larva: The newly hatched larva has unpigmented eyes and an unformed mouth. Pigmentation includes a patchy white edge to the notochord dorsally, matched ventrally only near the tip (C). The white pigment persists to  day 4, and the black pigment intensifies to a dense band along the notochord (G, G1 & G2). A larva was reared to 30 days (21°C), at which stage flexion appears to have just been completed (H).  C & D: NH, E: 1 day, F: 2 days, G: 4 days, H: 30 days (21°C).

This species can be confused with FIIA5, which has less black pigment and more yellow pigment in the 1-4 day larva. The identification of this species is based on DNA barcoding, although the myomere count appears a little high for this species, listed as having 24-25 vertebrae by Horn (1984). Two larvae have been sequenced, and a match was found with adult material in BOLD, collected off Australia. At least three more larvae will be sequenced if the opportunity arises.

The limited data indicate that this species spawns in winter (blue graph). The Park Rynie linked samples had 88% offshore, as would be expected of an offshore species that is trawled in 300m deep water (Haedrich, 1986). See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples

linked samples	Offshore	Inshore
Eggs	15	2
Hits	7	2