Biology of Finfish and Shellfish (2+1)

Holocentridae

• Larvae have a deep head, trunk and a slender tail.
• There are 25-27 myomeres (6-11+14-20).
• The gut of small preflexion larvae may be tightly coiled or initially straight with coiling beginning at about 2mm.
• When the gut is fully coiled, the preanal length is 42-70% BL.
• A small gas bladder, which is covered by pigment and appears to be conspicuous only in larvae the snout is short and truncate, but it becomes elongate and bulbous as the rostral spine develops.
• The mouth is small and initially terminal but becomes inferior with development of the rostral complex.
• The eye is round and large.
• The spine reaches maximum relative length shortly after notochord flexion.
• A smooth spine at the angle of the preopercle and a supraoccipital crest with one posterior-directed spine and one small dorsal spine are present in 1.9mm larvae.
• By 2.2mm two small dorsal spines may be associated with the crest.
• The soft dorsal, anal, and pectoral fins appear concurrently with initial ossification of the dorsal-fin spines.
• By 7.6mm all elements of the soft dorsal fin, pelvic fins, and anal fin are complete. Scale first form at 6.0-7.5mm and are strongly ctenoid.
• Young larvae are lightly pigmented but quickly become moderately to heavily pigmented on the gut and develop several moderate-size melaophores on the brain.
• Melanophores may also occur on the ventral edge of the tail, on the pelvic buds and fins, on the tip of the rostral spine, and on the dorsal surface of the trunk.
• In larger postflexion larvae, pigment covers the entire body surface with the exception of the soft dorsal fins and the posterior portion of the tail.