Full description
The contribution of asexual versus sexual recruitment to populations of the mushroom coral Fungia fungites was investigated at 2 sites with contrasting sediment regimes, located 5 km apart in the Dampier Archipelago, Western Australia. One site was exposed to high levels of chronicsedimentation, and the second site received less than half the sediment load.
A total of 120 specimens (buds) were collected from each of the 2 study sites for DNA analysis and sediment deposition was also measured.
Lineage
Maintenance and Update Frequency: notPlanned
Statement: Study sites are located approximately 5 km apart in the Dampier Archipelago on the north-west coast of Western Australia (see large thumbnail). The low-sediment site is located on the leeward side of East Lewis Island, which lies north-west of the high-sediment Hamersley rocks site on the mainland. The coral communities at both sites are small (1.5 to 2 km in length), shallow (<10 m) patch reefs that are isolated from other reefs within the Archipelago.
- Sediment collection -
Fungia fungites was common at both sites, although the abundance of its life-history stages were very different. The most obvious physical difference between the reefs was their level of sedimentation. A comparative measure of sediment deposition was obtained by deploying 8 sediment traps (height 30 cm × 5 cm diameter) at each reef, for a total of 87 days. Sediment traps were deployed for a period of 7 to 14 days, every 4 to 6 months, between September 1997 and March 2000. At each collection, the sediment samples were washed through 2 mm sieves, excess water was decanted and the sediment dried at 120°C for 3 days before weighing.
- Polyp collection -
At each site, 4 locations separated by 100 m were sampled along a transect parallel to the shore. At each location, 30 of the closest polyps to co-ordinates generated from random number tables were collected from within a 1 m2 area. A total of 120 specimens were collected from each of the 2 study sites. Specimens were classified into one of 3 life-history stages: free-living polyps, buds on parent polyps, or sexual recruits. Descriptive information such as fusion between polyps, partial polyp mortality and polyp size (cm diameter) were also recorded. An additional 60 buds were collected to confirm that they were asexually derived, and not wholly or partly due to the settlement of sexual larvae onto polyp skeletons. Within each of the 4 locations at the high-sediment site, 3 buds were collected from 5 different parent polyps. All specimens were stored in liquid nitrogen before extraction and analysis.
Statement: - Electrophoresis -
Samples of tissue and skeleton were crushed, and enzyme extraction followed the methods used by Johnson & Threlfall (1987). Electrophoresis was carried out in horizontal starch gels using a tris-citrate (TC8), tris-EDTA-borate (TEB) or tris-malate (TM) buffer (buffers 5, 6 and 9 respectively of Selander et al. 1971). Enzymes investigated were glutamate dehydrogenase (EC 1.4.1.2; Gdh* locus; TC8 buffer); isocitrate dehydrogenase (EC 1.1.1.42; Idh* locus; TM buffer); malate dehydrogenase (EC 1.1.1.40; Mdhp* locus; TM buffer); phosphogluconate dehydrogenase (EC 1.1.1.44; Pdgh* locus; TC8 buffer); phosphoglucose isomerase (EC 5.3.1.9; Pgi* locus; TEB buffer); phosphoglucomutase (EC 2.7.5.1; Pgm* locus; TM buffer) and peptidase valyl-leucine (EC 3.4.-.-; Vl* locus; TEB buffer).
Staining recipes were essentially those of Richardson et al. (1986), with the exception that concentrations of the substrate, co-factor, linking enzymes and dye were increased up to 4 times when enzyme activity was low. Alleles at each locus were labeled alphabetically in order of decreasing mobility of allozymes. Variation was assumed to be allelic and the observed isozyme patterns corresponded to those described for other species with normal Mendelian inheritance.
Notes
CreditJim Stoddart: Hamersley Iron
Credit
Australian Institute of Marine Science (AIMS)
Australian Institute of Marine Science (AIMS)
Credit
Sigma Xi
Sigma Xi
Credit
The University of Western Australia (UWA)
The University of Western Australia (UWA)
Issued: 21 08 2007
Data time period: 1997-09 to 2000-03
text: westlimit=116.66; southlimit=-20.67; eastlimit=116.72; northlimit=-20.60
Subjects
11 298022 |
Asexual reproduction |
BIOSPHERE |
Biosphere | Zoology | Corals |
COMMUNITY DYNAMICS |
Coral recruitment |
EARTH SCIENCE |
ECOLOGICAL DYNAMICS |
Fungia fungites |
MARINE SEDIMENTS |
OCEANS |
Population genetics |
Sedimentation |
Species Recruitment |
oceans |
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Other Information
(PhD thesis)
Identifiers
- global : 216469b0-4fa1-11dc-87ba-00188b4c0af8
