Early development of Forsterygion varium, Gilloblennius decemdigitatus, and G. tripennis (Pisces: Tripterygiidae)

In the Wellington area (central New Zealand) Forsterygion varium (Forster, in Bloch & Schneider 1801) spawns from early June to late November, Gilloblennius decemdigitatus (Clarke, 1879) from early June to early October, and G. tripennis (Forster, in Bloch & Schneider 1801) from July to October. They deposit their eggs on firm substrates below the low tide level. Egg clusters are attended by an adult fish until hatching, which in the laboratory at 11.5–13.5°C, occurs after 18 days for F. varium and 20 days for G. decemdigitatus. Development to hatching for G. tripennis takes about 21 days at 13–15°c. The egg development of all three species is illustrated. The yolk‐sac larvae (prolarvae) of F. varium, G. decemdigitatus, and G. tripennis at hatching average 5.85, 5.03, and 5.72 mm standard length respectively. Yolk‐sac larvae of F. varium have a single row of 9–17 small, stellate melanophores along the ventral midline of the tail. The yolk‐sac larvae of G. tripennis have up to nine melanophores along the ventral midline of the tail, a medium‐sized melanophore above the optic lobes, and a further two above the medulla. The yolk‐sac larvae of G. decemdigitatus have three large mid‐dorsal melanophores interspersed with five smaller, paler pigment cells, and three large mid‐ventral melanophores interspersed with three of the smaller cells.

Keywords:

• Pisces
• Tripterygiidae
• egg development
• embryology
• yolk‐sac larvae
• Forsterygion varium
• Gilloblennius decemdigitatus
• Gilloblennius tripennis

Notes

Present address: Wellington Polytechnic, Private Bag, Wellington, New Zealand