The effect of light intensity on development and hatching success of lingcod, Ophiodon elongatus (Girard), eggs

摘要

The influence of incubation light intensity on development and hatching success of the lingcod (Ophiodon elongates Girard) was studied by determining time to hatch, per cent hatch (total and viable) and per cent of deformities for embryos incubated at three different light intensities: similar to0, 1, and 563 lux. Photoperiod for the last two treatments was 16 h dark: 8 h light. Chemical parameters throughout incubation remained within acceptable ranges. Hatching in all treatments began 43 days post fertilization (353 degreesC days) and was complete on day 46 (377 degreesC days), with peak hatch for all treatments on day 44 (361 degreesC days). Per cent viable hatch for eggs incubated in the 1 lux treatment (88.6 +/- 2.1%; mean +/- SEM) was significantly greater than eggs incubated in the similar to0 lux (59.6 +/- 11.3%) and 563 lux (61.4 +/- 9.2%) treatments. A significantly greater per cent of deformed embryos with curled bodies occurred at 563 lux (9.5 +/- 2.6%) compared with the 1-lux treatment (2.5 +/- 0.6%). No significant differences for the other categories of deformities (ball, short, distended gut) were detected among treatments. Total deformities (all categories combined) for similar to0 lux (16.0 +/- 4.2%) and 563 lux (17.2 +/- 3.3%) were significantly greater than total deformities for 1 lux (5.0 +/- 1.4%).