Goniopora: light response is not a universal spectrum target
Goniopora columna
Names as reported by the authors; no accepted-taxon or specimen-identity claim.
Reading the evidence
These records describe traits and results under specific study conditions. They do not establish recommended aquarium settings.
What the study tells us
Spectrum and photon flux were not isolated. Short polyp-extension responses and eight-week growth are different endpoints; neither establishes a universal PAR or photoperiod target.
Study conditions
Farm-derived, fragmented colonies studied for eight weeks under six LED colors at 6 or 12 hours per day plus darkness. Daily proprietary feed; temperature 26.41 ± 0.04 degrees C; salinity 35.19 ± 0.42 PSU. Blue PAR approximately 67–68, purple 70–71, white 101–102, red 44 and green 46–48 micromol m−2 s−1. Authors report 30 colonies per group across three experiments; separate 30-minute extension assay after dark adaptation.
Methods and evidence class
controlled captive experiment
Weekly polyp photographs/counts and weights over eight weeks; separate filmed 30-minute extension assay; two-way ANOVA and Duncan comparisons. Means and SDs as reported.
Findings
obs-pmc8833557-01
Under the fed eight-week design, blue illumination groups reached 41.00 ± 1.03 and 41.67 ± 1.78 polyps under six and twelve hours respectively; the authors report higher polyp counts than other groups, but no significant difference between those two photoperiods.
Measurements and uncertainty
{"group": "blue 6 h / blue 12 h", "metric": "polyp count", "uncertainty": "SD per statistical methods", "unit_as_published": "polyps", "value_as_published": "41.00 ± 1.03 / 41.67 ± 1.78"}
Where to find it in the paper
3. Results / 3.1. Effects of Different Types of Illumination on G. columna Growth and Survival | ./body/sec[3]/sec[1]/p[1]
In the separate short behavioral assay, blue-lit polyps attained full extension by 30 minutes and purple-lit polyps by 20 minutes; darkness controls remained contracted. These are behavioral responses, not long-term acclimation or care thresholds.
Measurements and uncertainty
{"group": "blue / purple", "metric": "time to full extension", "uncertainty": "not stated for time", "unit_as_published": "min", "value_as_published": "30 / 20"}
Where to find it in the paper
3. Results / 3.4. Effects of Light Wavelength on Coral Photoacclimation | ./body/sec[3]/sec[4]/p[1]
Spectrum was not isolated from photon flux: PAR differed materially among colors. Not proof of a universal optimal wavelength or PAR.
Proprietary feed composition is undisclosed; three repeats do not establish the number of independent donor genotypes or tanks.
The Methods report one hundred source colonies, but later treatment and separate assay counts are larger. Allocation of donor colonies remains unclear.
Eight weeks, one farm species; six versus twelve hours without significant difference does not establish six hours as a minimum safe photoperiod.
The 2021 feeding study and this light study use the same farm permit and proprietary feed; genetic/stock independence between them is unverified.
Growth, survival, digestive enzymes and extension share source material; the extension assay is separate but not an independent farm-population replication.
Evidence family: study-pmc8833557
Method passage locators
2. Materials and Methods / 2.1. Biological Material | ./body/sec[2]/sec[1]/p[1]
2. Materials and Methods / 2.2. Experimental Conditions | ./body/sec[2]/sec[2]/p[1]
2. Materials and Methods / 2.3. Determination of Polyp Count, Growth, and Survival Rate | ./body/sec[2]/sec[3]/p[1]
2. Materials and Methods / 2.4. Photoacclimation of G. columna | ./body/sec[2]/sec[4]/p[1]
2. Materials and Methods / 2.7. Analysis of Zooxanthellae Density and Chlorophyll a | ./body/sec[2]/sec[7]/p[1]
2. Materials and Methods / 2.8. Statistical Analysis | ./body/sec[2]/sec[8]/p[1]