Scorpaenidae: ABH III A1

Scorpaena scrofa Linnaeus, 1758 & Parascorpaena mossambica (Peters, 1855).

Bigscale scorpionfish & Golden scorpionfish

Egg size 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
870-1000 x 650-870	0	N/A	clear	narrow	N/A	48% of NL	24

Egg: This egg is initially spawned as a cluster containing several thousand eggs in a gelatinous ball that is sufficiently robust to hold in the cupped hand. Within 24 hours in a bowl of seawater, the gel dissolves, leaving small oval eggs, which appear to have undergone little development. Incubation takes about 30 hours after release from the gel-sac.

Larva: Newly hatched larvae have no pigmentation, and a rough finfold surface (E). At 6 days some black pigment develops over the gut and around the notochord, about halfway between anus and notochord tip (E & F). At 8 days a black trim develops on the pectoral fins (G).  C: 1day, D: 4 days, E & F 6days, G: 8 days.

For the size of the egg, these larvae are slow developing. In most larvae from eggs this size, such as sparids and haemulids, eyes and mouth are developed about day 4, but at that stage these larvae still have unpigmented eyes. Pigmented eyes and a functional mouth only develop 24-48 hours later. Two larval DNA barcodes have matched an adult Parascorpaena mossambica (BOLD reference). Four other larvae, 3 collected in September 2006, and 1 in November 2007, all sequenced as the same species, and match the only adult Scorpaena scrofa sequence currently available (BOLD archive). A single larva hatched from an egg collected in March 2010 has matched a single adult Trachyscorpia eschmeyeri collected on the Agulhas Bank (BOLD).

Linked samples	Offshore	Inshore
Eggs	1085	71
Hits	23	34

These eggs were found to be common both offshore (blue graph) and in DHM samples (green graph). In the DHM samples, gel-sacs were common, with some evening sampling tows yielding 4 gel-sacs in a 10 minute haul. At other times, and in all offshore samples except the big peak in July 1989 (graph above), only individual eggs were found. The data probably involves several species, given the wide range in egg size noted above.

A far higher number were found offshore, in the Park Rynie linked samples (96%), which suggests these eggs are mostly from deep-water species, spawning outside the 50m contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

The higher number of hits inshore indicated that, though more frequently present, they only averaged about 2 eggs per sample. This conflicting distribution ( more common in Park Rynie’s offshore samples, yet common in Durban Harbour Mouth) supports the suggestion that this is a complex of species.