Biology of Finfish and Shellfish (2+1)

Sillaginidae

• Sillaginid larvae are elongate and somewhat compressed with 32-39myomeres (11-17+19-24).
• The gut is initially straight, has a relatively large diameter and reaches to as much as 64%BL.
• The gut begins to coil during notochord flexion and the anus may be drawn anteriorly.
• In postflexion larvae, when the gut is fully coiled, the anus reaches 44-57%BL.
• The head is small to moderate in small preflexion larvae. After flexion, this gradually changes to a more-or-less straight profile.
• The mouth initially reaches about the anterior margin of the eye, but does not reach the eye in post flexion larvae longer than 8-10mm.
• Minute teeth are present in both jaws by the commencement of flexion.
• The eye is large to moderate in preflexion larvae and slightly elongate to round the long dorsal and anal fins develop early in the flexion stage.
• Full anal-fin complements are present by about 8mm. Incipient scales first appear at 12mm, with all scales present by 15mm.
• Sillaginids are lightly pigmented and are characterized by a single row of melanophores along the ventral midline of the trunk, tail and often on the head.
• The trunk pigment becomes much reduced in larger larvae.