Figure 2:
1. Leptocephalus larva of Anguilla (freshwater eel), showing the major features of a typical eel-larva.
2. Head region of same.
3. Viscera of a muraenid leptocephalus.
4. Leptocephalus of Cyema atrum (Cyemidae), a deep sea mesopelagic eel.
5. Head of a nettastomatid leptocephalus (Nettastomatidae), a deep sea mesopelagic family of eels (rostrum not completely shown).
6. Leptocephalus of same, collected off Cape Brett, New Zealand.
7. Leptocephalus of a worm eel (Ophichthidae), showing the characteristic festooned intestine.
8. Generalised growth curves for (a) noith Atlantic Anguilla, and (b) a tropical shallow water congrid (Ariosoma), both showing the essential features of growth including the reduction of length of the leptocephalus during metamorphosis.
Abbreviations: af—anal fin, b—brain, br—branchiostegal rays, da—dorsal aorta, df—dorsal fin, e—eye, gb—gall bladder, h—heart, i—intestine, im—intestinal melanophore, l—liver, lm—lateral melanophore, It—larval teeth, m—mesonephros, my—myomere (lateral muscle), n—olfactory organ, p—pronephros, pc — pyloric caecum, pd — pronephric duct, pf — pectoral fin, r—rostrum, rbv—renal blood vessel (its position along the body is of considerable importance in the identification of larvae), te—telescopic eye, v—vent, vc—vertebral column.