Creediidae/Trichonotidae: M III A4

Unknown

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
960-1010	2	120-170	clear	narrow	bow & stern	52% of NL	50+

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Egg: This unique egg, with two bright golden amber oil globules, and pale yellow-white pigmented embryo, is unmistakable (A). Incubation is 30-35 hours.

Larva: The 1-day larva is elongate, with a moderately long gut and prominent pale yellow pigment patches on the finfold edge and notochord (B). By day 4 the yellow pigment is confined to and below the notochord, the latter in a series of 8 patches, with just a trace on the finfold edges posteriorly (D). B: 1 day, C: 3 days, D: 4 days (24°C).

Attempts to rear this egg were unsuccessful. Ten larvae have been successfully barcoded, and they do not match the barcodes of 2 adult Limnichthys nitidus, the only adult creediid from South Africa, currently in BOLD. This is not surprising, because Limnichthys has <50 myomeres (Leis & Rennis 1983). They also do not match the sequence of a single Trichonotus marleyi, recently collected locally. Leis & Rennis show a creediid with a multiple oil globule in the yolksac, so, after ruling out Trichonotus, I have assumed this egg belongs to Apodocreedia vanderhorsti. CO1 barcode sequences of adult A. vanderhorsti are presently not available..

Due to their nearshore distribution, and all year spawning pattern, these eggs are an indicator of inshore water. Like a biological driftcard, their appearance in offshore samples indicates that inshore waters had been driven offshore in the previous 24-36 hours (see also FIIA9). Most sampling is done between 11am and 2pm, and these eggs always contain a well developed larva, when processed the same evening. Occasional sampling between 3 and 4pm has yielded fresh eggs with the oil globules in a central cluster or spread in a ring around the edge of the yolk.

Linked samples	Offshore	Inshore
Eggs	42	194
Hits	27	117

This species spawns all year round, but the eggs are never seen in big numbers (blue graph). Apart from the years 2003 and 2004, the eggs have remained fairly constant at Park Rynie over the study period (white graph). They were not seen in the first three years of the study, mainly because regular nearshore sampling was only begun in early 1994 (see Section 7.3 of the Introductory Notes). The egg was only seen once in the DHM samples, which is puzzling, when the Park Rynie linked samples had the overwhelming majority of these eggs inshore (82%). Perhaps the species prefers an exposed coastal habitat, as opposed to the protected nature of the Durban Harbour mouth. See Section 7.3 and Table 1 of the Introductory Notes, for more information on the linked samples.