Lutjanidae: K III A8

Paracaesio xanthura (Bleeker, 1869)

Protea bream

 

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

820-910

1

120-145

clear

narrow

bow

42% of NL

24-25

 

Egg:. This egg has a relatively small oil globule, and a feintly amber hue to the larva. Having an incubation period of <48 hours, I always see this egg in a fairly advanced stage of incubation, not due to hatch for another 12 hours or so, implying evening spawning. The embryo is peppered with black dots; more and bigger towards the tail, and on the yolk near the trunk of the embryo. Incubation is about 35 hours. There are usually 1 or 2 black spots on the oil globule, which is clear. The PVS can be wider than usual in some eggs.

Larva: This larva was separated from the next (KIIIA9), by the presence of a line of black on the anal tube (C, D & E, arrowed), and a slightly broader girth. At 4 days, the larva retains the dark spot at the anus (G). C: NH, D: 1 day, E: 2 days, F: 3 days, G: 4 days (24°C).

All attempts to rear this egg were unsuccessful. The DNA barcode sequences of over 70 hatched larvae, are currently available. They match 4 locally collected P. xanthura adult sequences (BOLD, but see also KIIIA9), and two from Walters Shoal. Difficulty separating these eggs from eggs of the closely related P. sordida, and eggs of Caesio xanthalytos, has caused some confusion in the barcoding and presence records of these 3 species. Clearly I need to combine KIIIA8 and part of KIIIA9. P. xanthura is by far the most common lutjanid off Park Rynie, with shoals commonly seen over high profile reefs at 30-50m.

The egg showed a summer presence off Park Rynie (blue graph). It was only seen once in the DHM samples, in January. At Park Rynie, the egg has shown an erratic presence(white graph), but this is probably partly due to the learning curve involved with trying to separate P. xanthura and Caesio xanthalytos. In the Park Rynie linked samples, the eggs were more common inshore (56%), indicating spawning on the 20-30m contours. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.

Linked samples

Offshore

Inshore

 Eggs

813

1038

Hits

32

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