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Table 3 A summary of sampling techniques and sample sizes used for estimating variables

From: Alternative reproductive tactics and inverse size-assortment in a high-density fish spawning aggregation

Variable

Sampling technique

Sample size and factors

Tests performed

Annual peak aggregation density

UVC permanent belt transects (transect volume = 50*10*5 m3)

N = 10 transects

Year (2013, 2014)

Habitat (slope, shelf)

–

Size-assortment: male and female density distribution

UVC points (point volume = π*5*5 m3)

N = 23 points

Year (2013, 2014),

Habitat (shelf, slope)

Size (large, small)

Negative-binomial glm, likelihood ratio tests

Frequency of male courtship tactics

Focal individual sampling, 1 min underwater observations

N = 72 (2014) focal males

Habitat (shelf, slope)

2 × 2 Contingency table, Fisher’s exact test

Benefits: association rates (potential mating opportunities)

Focal individual sampling, 1 min underwater observations

N = 72 (2014) focal males

Habitat (shelf, slope)

95% Bootstrapped confidence intervals

Costs: intra-sexual competition

Focal individual sampling,

Activity budgets, 5 min videos

N = 65 (2014) focal male videos

Habitat (shelf, slope)

Quasibinomial glms, likelihood ratio tests