Labridae: K III C3

Thalassoma lunare (Linnaeus, 1758) T. trilobatum (Lacepede, 1801), T. purpureum (Forsskal 1775) & Coris caudimaculata (Quoy & Gaimard, 1834)

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 only be resolved by DNA barcoding. Eight larvae have been sequenced, 4 of which match 3 locally colected adult Thalassoma lunare, 2 match adult T. trilobatum in the BOLD archive (not from South Africa), and one each match adult T. purpureum and Coris caudimacula (BOLD). These identifications are thus tentative, pending further barcodes.

 

Linked samples Offshore Inshore
Eggs 69 258
Hits 11 75

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.