Scale of analysis
# sites [# spp]
SES
Prob of Cobs>Csim
Result
Regional (lake-wide)
18 [12]
1.58
p=0.077
NULL
Subregion – North
11 [8]
1.00
p<0.87
NULL
Subregion – South
7 [3]
0.00
p<0.99
NULL
Table S1. EcoSim analysis of Lake Malawi cichlid ‘core’ species’ (n = 12) observed co-occurrence matrix
vs. 10,000 randomized matrices. Scale of analysis is in descending order, # sites [# spp] denotes the
number of sites or depths and ‘core’ species used at each scale, SES is standardized effect size (see
methods) of observed C-score compared to mean of simulated matrices, Probability of Cobs > Csim is the
probability of an observed C-score being greater than the average of random matrices, Result is
determination of random or structured community based on analysis. Listed values correspond to fixedfixed model (SIM9; Gotelli 2000). All p-values are corrected for multiple tests within a scale.
Figure S1. Species abundance kite plots as presented in Ribbink et al. (1983). Horizontal axis represents
water depth in meters, vertical axis denotes species present at site. Width of kites represents species
abundance relative to scale bar. Measurements of species abundance were made at sampling depths in
Ribbink et al. (1983) as described in methods.
Figure S2. Frequency of species site-occupancy. The majority (54%) of species in Lake Malawi are
endemic to a single site (‘singletons’). The distribution is well fit to a power function.
Legends:
Table S1. EcoSim analysis of Lake Malawi cichlid ‘core’ species’ (n = 12) observed co-occurrence matrix vs. 10,000
randomized matrices.
Scale of analysis is in descending order, # sites [# spp] denotes the number of sites or depths and ‘core’ species used at
each scale, SES is standardized effect size (see methods) of observed C-score compared to mean of simulated matrices,
Probability of Cobs > Csim is the probability of an observed C-score being greater than the average of random matrices,
Result is determination of random or structured community based on analysis. Listed values correspond to fixed-fixed
model (SIM9; Gotelli 2000). All p-values are corrected for multiple tests within a scale.
Figure S1. Species abundance kite plots as presented in Ribbink et al. (1983).
Horizontal axis represents water depth in meters, vertical axis denotes species present at site. Width of kites represents
species abundance relative to scale bar. Measurements of species abundance were made at sampling depths in Ribbink et
al. (1983) as described in methods.
Figure S2. Frequency of species site-occupancy
The majority (54%) of species in Lake Malawi are endemic to a single site (‘singletons’). The distribution is well fit to a
power function.