Nomeidae: F II A6

Psenes pellucidus Lutken 1880

Blackrag


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

1225

1

310

segmented

narrow

stern

52% of NL

ca40

Egg: Black, spidery pigment blotches on the oil globule, embryo and a few on the yolk, is the description in my notes on this egg. The yolk was segmented and milky, the surface granular. The oil globule was clear, but later becamedensely covered in black pigment, which also formed two dense rows on the embryo (A). Twenty-four hours later, five big blotches of black pigment were seen on the embryo (B).

Larva: The only larva seen was 1 day PH (21°C). The distinctive pattern of black pigment is shown (C & D). An egg collected in October 2006 yielded the additional images, at 2days, and the last 3 show different aspects of the same larva at 4days.

This egg has only been seen 4 times, in May 1991, and October 2006 and 2010, and September 2011. Two have been sequenced, 1 of which matches 1 Tetragonurus cuvieri adult from South Africa, but I have no voucher, only a tissue sample taken on a research vessel, when an error may have been made. A wider search within the sequence archive of BOLD, yielded a match for the other with Psenes pellucidus. Confirmation must await further sequences, to resolve this identification, but the latter is accepted as correct, given the early developing pelvic fin which is absent in Tetragonurus (see FIIA8A).