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R.J. Tregonning, D.J. Gaughan, W.J. Fletcher 
lies close to the yolk (or yolk-sac membrane), the 
tail has grown completely around the yolk and 
overlaps the head, but the mouth has not 
developed and the eyes are not yet pigmented. The 
2-3 small melanophores on the dorsal surface of 
the tail near the tip of the notochord are 
characteristic of H. vittatus larvae, and whilst 
illustrated here (Figure lg), they were often not 
visible in preserved eggs. 
Description of yolk-sac larvae 
Newly-hatched larvae were 2.6 mm BL and had 
typical clupeid characteristics, including a long 
slender body, a long straight gut and light 
pigmentation (Figure lh). The pre-anal length is 
70 - 79% BL. 
The oil globule is located near the posterior end 
of the yolk-sac. A patch of yellow pigment, which 
is often only obvious in fresh or recently preserved 
specimens, was observed immediately posterior to 
the oil globule (Figure lh,i). Newly hatched // 
vittatus larvae have very fine melanophores 
scattered over the body, particularly over the head 
However, these melanophores are difficult to 
observe after preservation, so only the denser 
concentrations on the head have been illustrated. 
Moreover, they have 2-3 distinct melanophores 
on the dorsal side of the trunk near the notochord 
tip which are homologous to those observed in 
well developed embryos within late-stage eggs (cf. 
Figure lg). 
At the time of hatching, larvae had neither 
pigmented eyes nor a mouth (Figure lh). Larvae 
placed in the constant temperature tank (18°C) had 
utilised their yolk, developed pigmented eyes and 
appeared to have a functional mouth after 5-7 
Table 1 The major distinguishing features of the pelagic eggs of clupeids which are common in marine waters of 
southern Western Australia. The eggs of each species have segmented yolks. The measures of egg and yolk 
diameter for S. sagax from New Zealand (Baker 1972), and egg diameter for E. teres from South Africa 
(O'Toole and King 1974) are presented below those recorded in the present study. 
Species 
Egg diameter 
Oil 
Yolk diameter 
Perivitelline space 
Diagrammatic 
(mm) 
globule 
(mm) 
(% of diameter) 
representations 
range (mode) 
range (mode) 
range (mode) 
Hyperlophus 
0.83-0.95 (0.93) 
yes 
0.50-0.87 (0.83) 
8.6 - 30.9 (14.5) 
m 
vittatus 
n = 73 
Sardinella 
lemuru 
n = 40 
1.15-1.32 (1.30) 
yes 
0.69-0.82 (0.75) 
34.2 - 44.8 (39.7) 
(H) 
Sardinops 
1.34-1.58 (1.44) 
yes 
0.62-0.85 (0.69) 
42.2 - 57.9 (49.4) 
f 
sagax 
1.32-1.70 (1.53) 
0.71-0.83 
\ \ 
n = 30 
(Baker 1972) 
l 
Etrumeus 
1.24-1.48 (1.35) 
no 
0.99-1.28 (1.12) 
7.1 - 22.6 (18.7) 
■V 
■ 
\ i j i 
teres 
n = 52 
1.32-1.47 (1.37) 
(O'Toole and 
King 1974) 
