Labridae: K III C3

Thalassoma trilobatum (Lacepede, 1801)

Ladder wrasse

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
550-625	1	120-145	clear	narrow	bow	56% of NL	25-26

Egg: This tiny egg with its light to bright amber oil globule (A), is usually seen fresh, and does not hatch until the day after capture. For such a small egg, which would probably hatch in 24 hours, this suggests early morning spawning. Dorsally, the embryo becomes densely covered in splashy black pigment spots prior to hatching (A1).

Larva: Dorsally, the newly hatched larva is densely covered in black pigment from head to tail (B). The gut is relatively long, and dorsal and ventral finfolds are serrated (C). At the eyed stage, the black pigment has all moved over the gut, except for a patch in the dorsal finfold (D). B: NH, C: 1 day, D: 3 days (25°C).

The relatively long gut, serrated finfold, and myomere count suggest this is another labrid, but the identity will probably only be resolved by DNA barcoding. Two larvae have been sequenced, and a match has been found with an adult T. trilobatum in the BOLD archive (not from South Africa). The identification is thus tentative, pending further specimens.

Linked samples	Offshore	Inshore
Eggs	16	60
Hits	6	26

The seasonal presence of this egg in the plankton off Park Rynie, suggests a summer spawner (blue graph). The egg was seen twice in the DHM samples, in October and January. The Park Rynie linked samples data shows the majority in inshore samples (79%). See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.