Emmelichthyidae: E III A9
Emmelichthys struhsakeri Heemstra & Randall, 1977.
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 |
745-820 |
1 |
170-190 |
segmented |
narrow |
bow |
44% of NL |
25-26 |
Egg: The yolk is lightly segmented, and has a granulated surface when viewed under alternate black/white backgrounds. Fine black pigment spots on the embryo, are not dense, and there are none on the oil globule. No yellow pigment was seen in the egg. Incubation is about 26 hours.
Larva: The NH larva (B) has a line of fine, stellate black dots along the ventral edge of the notochord (B). At 4 days, the black pigment has consolidated over the gut (C), but in some specimens, forms one or more patches posterior to the anus (C, upper specimen). B & B1: 1 day, C & C1: 4 days (24-25°C).
This species shows strong affinities to EIIIA8, but the oil globule of EIIIA9 is smaller. It also shows certain similarities with KIIIA9, except for the segmented yolk. A total of 17 larvae from these eggs, from 5 different sample dates, listed as KIIIA9 but noted as having a segmented yolk, and, therefore, which should have been assigned to EIIIA9, have matched E. struhsakeri in BOLD. A further 27 hatched larvae, submitted as EIIIA9, have matched these. Yet they do not match the sequence of 4 adult E. nitidus collected locally, which in turn match a number of E. nitidus in BOLD, from various localities, including Australia and New Zealand. Evidently (if the BOLD identification is accurate), E. struhsakeri occurs, and spawns, in our waters, although it is not listed in Smiths' Sea Fishes (Smith & Heemstra 1986).
No particular pattern of spawning is apparent from the sparse data (blue graph).The egg was not seen often, but when present, has been found in fairly large numbers. More have been seen in the last few years than in all the 23 years before that. . The egg was not seen in the DHM samples. Linked samples had 81% of the eggs in offshore samples, suggesting spawning around the 40-50m depth contours. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.
linked samples |
Offshore |
Inshore |
Eggs |
765 |
176 |
Hits |
16 |
8 |