Callionymidae: D III A3

Callionymus marleyi Regan, 1919

Sand 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
680-740	0	n/a	segmented	narrow	n/a	50% of NL	22

Egg: When fresh, the small size, coarse segmentation of the yolk, and lack of an oil globule (A ), set this egg apart from all others found in the area, except for DIIIA1, a clupeiform, CDIIIA1 (reticulated chorion) and DIIIA4 (flat spots on chorion). As the egg develops, both the embryo and yolk surface become covered with yellow-brown spots (B), whereas the clupeiform develops into an elongate embryo without yellow pigment.  Eggs hatched in about 25 hours (23°C).

Larva: The newly hatched larva is compact, and is peppered with yellow-brown pigment dots, more concentrated along the edge of the finfolds (C). This finfold pigment remains with the larva through to 6 days, concentrating in 4 patches (F). Eye pigment and a functional mouth are present at 4 days (E). C: NH, D: 1 day, E: 3 days, F: 6 days, G: 42 days.

This was the smallest egg I managed to rear, mainly because the first-feeding larva (4-6 days) has a generous mouth. From a batch collected in November 1988. and successfully reared, the three surviving juveniles settled over 2 days, 28-29 days post-hatch. Five larvae have been barcoded, 4 clustering as 1 species, and 1 as another closely related. species, neither matching any adult material currently in BOLD.

 

This was one of the more common eggs in Park Rynie samples (Introductory notes: Section 7, Table 3), with some 1370 taken during the study. The species spawned all year round, with a spring and early summer maximum (blue graph). The egg was seen in the DHM samples on only four occasions (green graph). Catches off Park Rynie show a progressive drop over the period of the study (white graph). The Park Rynie linked samples had 67% of the eggs offshore, suggesting spawning occurs inshore of the two indicator species, around the 30m depth contour. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

Linked samples	Offshore	Inshore
Eggs	567	278
Hits	59	98