Monodactylidae: F II A9

Monodactylus falciformis Lacepede, 1800

Kitefish or Cape moony

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








48% of NL


Egg: If collected fresh, these eggs often have a multiple oil globule, which quickly coalesces.  They soon become covered in stellate yellow pigment spots, on the yolk, embryo and oil globule, overlaying finer black pigment dots (A). The egg often has a slight blue tint, and segmentation is usually most conspicuous around the edge of the yolk. Incubation is about 40 hours (23°C).

Larval: The newly hatched larva has a conspicuous black pigment blotch in the lower finfold, surrounding the anus (C1), which serves to differentiate it from early larvae of pempherids (LIIA2 & MIIA5). The 5-day larva does not show the conspicuous early pelvic fin development of pempherids (D), although by day 12, the pelvic fins are a conspicuous feature of monodactylids (E).  B: 1 day, C: 2 days, D: 5 days (dead specimen), E: 14 days, F: 20 days, G: 40 days (25°C). H is from the Lovu estuary, showing the early juvenile pattern.

This species proved easy to rear, and a number were released back to local estuaries. The 5-6mm stage (F) is the stage at which they recruit to KZN estuaries. Recruitment to the local Mkomazi and Lovu estuaries (Introductory Notes: Methods Section 2.3) each spring tide during 2005 (mauve graph) matches the offshore spawning (blue graph). Due to their nearshore spawning preference, and all year spawning pattern, these eggs became an indicator of inshore water, like a biological driftcard; their appearance in offshore samples indicating that inshore waters had been driven offshore (see also MIIIA4).

Six larvae have been sequenced, and matched the sequences of 4 locally collected adults (BOLD).

recruitment pattern

Linked samples









This species spawns all year round (blue graph), with a slight winter/spring peak. The egg was also fairly common in the DHM samples, with more of a winter/spring peak (green graph). The pattern of egg collection at Park Rynie over the years (white graph), shows an increase in eggs from 1993, but that was the time when inshore sampling became routine. Since then it has remained fairly constant.

This egg has consistently showed the highest percentage of all species found in the Park Rynie area, at 93%. This indicates spawning close to the surfzone. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.