Abstract The larval development of the New Zealand geoduck, Panopea zelandica, grown under culture conditions, was described through measurements of shell morphometry using video image analysis, photomicrographs, and scanning electron microscopy (SEM). Gametes were stripped from ripe broodstock and eggs fertilised with a dilute sperm solution. Developing larvae were maintained at 17 ± 1°C. Fertilised eggs developed into trochophores within 12 h and to D-stage larvae (105.3 µm shell length) within 24 h. Larvae spontaneously settled after c. 16 days at c. 247 µm shell length. Measurements of shell morphology, including total length, total height, hinge length, length of anterior end, and umbo length and height were adequate descriptors of larval development. SEM indicated that the provinculum of D-stage and developing veliger larvae lacked any teeth, although there was some development of a small lamelliform tooth on the hinge structure of newly settled post-larvae. Prominent spines common on dissoconch shells of other hiatellid clams were absent in newly settled post-larvae of P. zelandica. The data presented here are the first description of the larval development and larval biology of P. zelandica. The relative ease of spawning and rearing of P. zelandica suggests that the development of commercial hatchery technology for this species warrants further investigation.
Keywords geoduck; Panopea zelandica; larval development; larval biology; SEM; hiatellid; morphometrics; video image analysis; photomicrographs
M02092 Received 14 November 2002; accepted 28 February 2003; Published
20 June 2003
New Zealand Journal of Marine and Freshwater Research, 2003, Vol. 37:
231-239
0028-8330/03/3702-0231 $7.00 © The Royal Society of New Zealand
2003
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