Journal article
Byssus production in six age classes of the silver-lip Pearl oyster, Pinctada maxima (Jameson)
Journal of Shellfish Research, Vol.16(1), pp.97-101
1997
Abstract
Two experiments were conducted to study byssus production of silver-lip (or gold-lip) pearl oysters, Pinctada maxima, from six different age classes. In the first experiment, 75- or 120-day-old P. maxima were removed from their point of attachment by severing of the byssus and were placed in clear plastic Petri dishes. The production of byssal threads and the behavior of the pearl oysters were monitored over a 120-h period. Emerging byssal threads were pinkish before changing to green. Juveniles at 75 days of age began reattaching faster than 120-day-old juveniles. However, after the first 12 h, older individuals had produced significantly more (p < 0.001) byssal threads than the younger individuals and produced significantly more (p < 0.001) byssal threads over the 120-h period. Additionally, byssal thread production for the younger juveniles did not increase significantly (p > 0.05) after 48 h, whereas byssal thread production from older animals continued to increase significantly (p < 0.001) after this period. The maximum number of threads produced by a single individual in the older age class was 30, compared with 16 in the younger age class. Juvenile P. maxima were observed to voluntarily eject the byssal apparatus, move, and reattach within 24 h. Reattachment after voluntary ejection of the byssus was faster than that after mechanical severing. In the second experiment, older P. maxima aged 7, 9, 11, or 13 mo were removed from their nets after severing of the byssus with a scalpel. These oysters were placed in nets in an area of either strong (2.5-3.5 knots h-1) or mild (<1 knot h-1) current. Pearl oysters placed in a mild current reattached faster than those in a strong current. However, after 4 days, pearl oysters aged 13 mo in strong current had produced significantly more threads (p < 0.05) than those in the mild current, and the same was true for 11-mo-old pearl oysters by Day 5. From Day 5 onward, there were generally more threads produced by pearl oysters in strong current compared with mild current; however, these differences were not significant (p > 0.05) for pearl oysters aged 9 and 7 mo. By the end of the 11 -day experiment, 9-mo-old oysters had produced significantly more byssal threads than any other age class, and there were significant differences between all age classes in the number of threads produced. The results of these simple experiments provide useful information on the time for reattachment of different age classes of P. maxima in a variety of culture conditions after mechanical severing of the byssus.
Details
- Title
- Byssus production in six age classes of the silver-lip Pearl oyster, Pinctada maxima (Jameson)
- Authors
- J J Taylor (Author) - James Cook UniversityR A Rose (Author) - James Cook UniversityPaul C Southgate (Author) - James Cook University
- Publication details
- Journal of Shellfish Research, Vol.16(1), pp.97-101
- Publisher
- National Shellfisheries Association, Inc.
- Date published
- 1997
- ISSN
- 0730-8000
- Copyright note
- Copyright © 1997 National Shellfisheries Association. Reproduced with permission of the publisher.
- Organisation Unit
- School of Science and Engineering - Legacy; Australian Centre for Pacific Islands Research; University of the Sunshine Coast, Queensland; School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 99449134602621
- Output Type
- Journal article
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