Triglidae: L II B5

Lepidotrigla faurei Gilghrist & Thompson , 1914.

Prickly gurnard

 

Egg diameter in m

Number of oil globules

Diameter of oil globule in m

Yolk texture

Perivitelline space

Position of oil globule at hatch

Gut length at eye- pigment stage

Myomeres

920-1320

1

230-265

clear

narrow

stern

38% of NL

32

 

Egg: This egg has a wide size range, and may prove to be 2 (or more) species. In its size range, after about 24 hours incubation (A), the egg can be separated, on white background, from a host of sparids, sciaenids and especially Scomber (LIIA7), by the presence of fine black dots scattered on the yolk, precursors to the stellate lemon yellow spots that develop later (A1). At 24 hours, the embryo is covered in fine yellow and black spots. The chorion has a pattern of fine dots, best seen on the discarded shell after the larva has hatched (B). The oil globule is initially pink, becoming light amber. Incubation takes 40-50 hours, depending on time of year (and therefore, temperature).

Larva: The big stellate lemon yellow pigment pattern of the early larva (C) is quickly lost, except for the finfold edge and large, mustard-yellow, darker-edged pectorals, which along with the large mouth (D), easily identify this species. There is often a black spot on the tip of the lower jaw. At 15 days the larva is still preflexion (F). C: 1 day, D: 5 days, E: 6 days, F: 15 days (25C).

Despite many attempts, I was only able to take this species past first-feeding once, to 15 days. Barcodes of 13 larvae hatched from this egg, match the barcodes of 3 locally collected Lepidotrigla faurei (BOLD). Initially I divided the species into two based on egg size (1100-1200m and ca1000m), but all 8 larvae from the larger egg group, and all 3 from the smaller egg group have yielded essentially the same sequence.

The upper limit of egg size agrees well with a triglid egg illustrated by Brownell (1979), which he assigned to Chelidonichthys capensis (Cuvier 1829), using the earlier name Trigla capensis, but 5 adults of C. capensis, from the Agulhas Bank, and 1 from KZN waters, do not match the barcode of my 13 hatched larvae .

Linked samples Offshore Inshore
Eggs 931 393
Hits 150 94

This species was common off Park Rynie, spawning all year round, with a slight winter to early summer maximum (blue graph). The egg only appeared twice in the DHM samples, in August and October. Off Park Rynie, the annual catch has been fairly steady, with a slight increase from 1996-2004(white graph). The Park Rynie linked samples had more eggs offshore (70%), but the percentage is below the two indicator species, indicating spawning on and about the 40m contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples