Nomeidae: L III F3
Cubiceps pauciradiatus Günther, 1872
Longfin fathead
|
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 |
|
720-820 |
1 |
190-210 |
clear |
narrow |
stern |
50% of NL |
31 |
.
Egg: These eggs were always seen just prior to hatching, and the striking feature was the dense band of red-brown or chocolate pigment dorsally down the length of the larva (from nose to tail), and on the oil globule, with a few stellate spots on the yolk (A). The yolk has a rough surface. Incubation is 24-28 hours.
Larva: The 1-day larva has pale yellow-brown pigment around the yolksac and oil globule, and down the ventral edge of the notochord (D), which persists to at least day 4 (E). Flexion is complete by 28 days (F). C: NH, D: 1 day, E: 4 days, F: 28 days, G: 32 days (25°C). Dorsal and anal fincounts for F & G were D X/I 16-18, and A II, 15.
This egg was relatively rare, but hardy, allowing the juvenile in Plate G to be reared from a batch of only 11 eggs. The juvenile in Plate F was reared from a batch of 45 eggs. Four hatched larvae have been barcoded, but no adult C. pauciradiatus sequences are currently available for comparison (BOLD).
Two eggs collected in January 2012 have yielded barcodes matching Erythrocles schlegelii (BOLD), the fincounts of which are different to those given above. The identification is supported by the barcodes being closely associated with Emmelichthys struhsakeri in my barcode tree. Clearly these two eggs should not have been catalogued as LIIIF3.
| linked samples | Offshore | Inshore |
| Eggs | 117 | 42 |
| Hits | 21 | 7 |
Rarely seen off Park Rynie, mostly in the spring and summer months (blue graph). Not seen in the DHM samples. The Park Rynie linked samples showed most eggs offshore (74%), but the inshore catch was biased by a single sample containing 36 eggs, on a day when not a single fish egg was found in the offshore sample, and a strong inshore current was noted. Without that sample the proportion would have been 95%, consistent with the circum-tropical oceanic habitat of this species. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.