Aploactinidae: H II A3A

Cocotropus monacanthus (Gilchrist, 1906)

Roughskin scorpionfish

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








45% of NL

ca 28

Egg: This egg is very similar to the previous species, but the spotting on the yolk is finer (A). The advanced embryo is covered in yellow pigment. Incubation is about 50 hours. Big pectoral fin-buds can be seen on the larva before hatching.

Larva: Big pectoral fin-buds on the newly hatched larva (B), quickly form distinctive, spotted pectorals in the 4-day (D) larva, which allow positive separation from HIIA3. The larva appears to have completed flexion of the caudal at 15 days (E). B: NH, D: 4 days, E: 15 days, F & F1: 30 days G: 120 days (24°C).

The fish featured in the sequence above, is Cocotropus monacanthus. The specimens shown in F and G are both preserved as voucher specimens. One larva has been sequenced, but no match has been found in the BOLD archive. An adult C. monacanthus has not yet been collected locally, for DNA sequencing.

At Park Rynie, this egg was rare, and little sense can be made of the spawning pattern (blue graph). It was only seen once in the DHM samples (October). In the Park Rynie linked samples, the eggs were more common offshore (71%), but numbers are too low to be meaningful. This species is however, known from the seaweed beds on Aliwal Shoal (Phil & Elaine Heemstra pers. comm.), which is 4-5km offshore, so some eggs might be expected in offshore samples. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

Linked samples