Callionymidae: CD III A1

Draculo celetus (Smith, 1963), and another

Dainty dragonet

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
620-760	0	N/A	segmented	narrow	N/A	47% of NL	22

Egg: The small size, lack of an oil globule, and distinct “fuzziness” of the chorion, due to fine reticulation, are distinctive. The yolk state cannot be seen through the patterned chorion, but is likely to be segmented, as in other callionymids (See DIIIA3). As the egg develops, yellow-brown pigment spots spread across the embryo and yolk (A). This is one of only a few small eggs (< 750 µm) I have encountered, in which the larva hatches and leaves an empty chorion that can be identified.

Larva: The newly hatched larva is compact, with yellow pigment along the outer edge of both finfolds. The gut is tucked in behind the yolk (B, white arrow). The 5-day larva has well developed eyes and mouth (C), and first feeding occurs between 4 and 5 days post-hatch.

Some eggs were more difficult to classify as reticulated, due to the fineness of the hexagonal pattern, and the small size of the egg (which may also suggest at least two species). Adding to the difficulty is that these eggs hatch in 24 hours. When hatching occurs while samples are being sorted, the chorion is lost. Some confusion could therefore have arisen between this species and DIIIA3. The egg was not seen in the DHM samples, surprising, since the habitat is intertidal. Eight larvae hatched from eggs listed as CDIIIA1 and 1 as DIIIA3, have barcoded as the same species, and match 3 adult Draculo celetus collected locally in sandy intertidal pools. In another grouping, 2 CDIIIA1, and 5 DIIIA3 have barcoded as another species, either highlighting the difficulty of seeing the reticulation on the egg, or indicating that there is some variation within both species. No match to adult fish, has been found in BOLD, for the second group, although closely associated with other Callionymidae.

The species is a winter-spring spawner (blue graph). Due to the low numbers of eggs collected, eggs of both callionymid types were combined to draw the eggs per year graph (white graph).This shows reduced catches in the late 1990’s which has improved in the past 8 years. The linked samples (this egg only) from Park Rynie showed  slightly less eggs offshore (46%), indicating spawning is quite shallow, in the 20-30m depth contour. Given the intertidal habitat of D. celetus, this suggests the other species has a more subtidal distribution. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

linked samples	Offshore	Inshore
Eggs	109	127
Hits	16	39