Biology of Finfish and Shellfish

Mugilidae

• Mugilid larvae are elongate to moderate in depth and compressed, but after flexion, they deepen somewhat.
• There are 24-25 myomeres(12-15+9-13).
• The gut is straight (2.4mm) but a single coil develops by 2.7mm.
• The massive under slung gut reaches 56-78% BL; The gas bladder is usually small but, in larvae greater than 10mm; it may be large.
• The head becomes broad dorsally from 10-13mm.
• The short snout is initially concave and becomes convex in postflexion larvae.
• The mouth initially reaches the anterior edge of pupil, but it becomes relatively smaller from 7-9mm and thereafter falls short of the eye.
• The eye is often slightly elongate and varies in size from moderate to large.
• Dorsal-and anal-fin also develop during flexion and by the time flexion is complete, incipient rays are present.
• The four spines in the separate and posteriorly-placed first dorsal fin start to form in early post flexion larvae.
• During the flexion stage small pelvic-fin buds appear at about mid-gut, well posterior to the pectoral-fin base.
• Scales may begin to form from as early as 6.2mm to as late as 14mm. Mugilid larvae are moderately to heavily pigmented.
• Melanophores are usually present along the dorsal, lateral midlines of the trunk, tail along the ventral midline, on the dorsal surface of the gut and brain and on the snout tip.