advances.sciencemag.org/cgi/content/full/5/9/eaav8681/DC1

Supplementary Materials for

Unexpected fish diversity gradients in the Amazon basin

Thierry Oberdorff*, Murilo S. Dias*, Céline Jézéquel, James S. Albert, Caroline C. Arantes, Rémy Bigorne,

Fernando M. Carvajal-Valleros, Aaike De Wever, R. G. Frederico, Max Hidalgo, Bernard Hugueny, Fabien Leprieur, Mabel Maldonado, Javier Maldonado-Ocampo, Koen Martens, Hernan Ortega, Jaime Sarmiento, Pablo A. Tedesco,

Gislene Torrente-Vilara, Kirk O. Winemiller, Jansen Zuanon

*Corresponding author. Email: thierry.oberdorff@ird.fr (T.O.); murilosd@hotmail.com (M.S.D.)

Published 11 September 2019, Sci. Adv. 5, eaav8681 (2019)

DOI: 10.1126/sciadv.aav8681

This PDF file includes:

Fig. S1. Names, sampling effort, and longitudinal position of the 97 sub-basins. Fig. S2. Principal water quality of major subdrainages within the Amazon basin. Fig. S3. Delimitation of the Pebas lake ∼23 to 10 Ma ago and Purus Arch. Fig. S4. Surfaces of the current Amazon basin covered by seawater under 25- and 100-m sea-level rises. Table S1. Environmental predictors used to explain fish diversity and endemism in the Amazon basin. Table S2. Correlation coefficients among input variables and components for each of the PCAs performed. Table S3. Coefficients and SEs from the GLMs performed for total and endemic richness. Table S4. Coefficients and SEs (log link scale) from the GLMs for the richness of each of the 15 most abundant families (raw data). Table S5. Coefficients and SEs (log link scale) from the GLMs for species richness estimated from SDMs of each of the 15 most abundant families. Table S6. Families, genera, and number of species found exclusively west and east of the Purus Arch.

A B

C

Fig. S1. Names, sampling effort, and longitudinal position of the 97 sub-basins. (A) Names

of the sub-basins, (B) Number of sampling sites weighted by the surface area of each sub-basin

(i.e. Density of sampling sites in each sub-basin). (C) Main tributaries longitudinal position

within the Amazon basin. Tributaries with large and small values correspond to upstream and

downstream tributaries, respectively. Sub-basins located in the river mainstem received the code

belonging to the main tributary upstream of the sub-basin.

Density of sites

Low (0.01-0.18)

Medium (0.19-0.6)

High (0.7-1)

Very High (1.1-7)

Fig. S2. Principal water quality of major subdrainages within the Amazon basin. Black,

white and clear waters have been included in our models as categorical variables (after (2, 74)).

Fig. S3. Delimitation of the Pebas lake ∼23 to 10 Ma ago and Purus Arch. Pebas lake (blue),

Purus Arch (red line), current sub-basins considered to have been historically connected to the

Pebas system (light brown) and current sub-basins supposed to have belonged to the eastward-

flowing proto-Amazon River (green) (after (6)).

Fig. S4. Surfaces of the current Amazon basin covered by seawater under 25- and 100-m

sea-level rises. These surfaces have been projected using a digital Elevation Model (DEM) with

a 30 meters resolution.

Table S1. Environmental predictors used to explain fish diversity and endemism in the

Amazon basin. Raw data name, source, applied transformation (ShannonDiv =

ShannonDiversity(x); Arc-Sin = Arc-Sin(x); SqRt = SquareRoot(x); log = log(x+1); scaled = [x

– Mean(x)]/[2*StandardDeviation(x)]) and main hypothesis tested.

Raw data Source variable name Transformation Hypothesis

Surface area of sub-drainages (km2) HydroBASIN (Lehner & Grill 2013) Area_log log, scaled Habitat size/Diversity Estimated number of waterfall (disruption >30m in

elevation) Number of Global Waterfall Database (HydroFALLS), our

data set Chut_hydrofall log, scaled Habitat size/Diversity Length of riverine network (km) divided by surface area

(km2) HYBAM digitalized from a JERS-1 SAR (http://www.ore-

hybam.org/index.php/eng) NetworkDensity scaled Habitat size/Diversity Global Soil Classification ISRIC – World Soil Information 2013. SoilGrids SoilDiv ShannonDiv, scaled Habitat size/Diversity

Relative Forest Type cover ESA – Global Land Cover v1.6 ShanDiv ShannonDiv, log,

scaled Habitat size/Diversity

Black/Clear/White waters

Junk et al., 2015. A classification of the major habitats of

Amazonian black-water river floodplains and a comparison

with their white-water counterparts, Wetlands Ecology and

Management 23(4): 677-693 Venticinque et al. 2016. An Explicit GIS-Based River Basin

Framework for Aquatic Ecosystem Conservation in the

Amazon. Earth System Science Data 8(2): 651–661. Water Color none Habitat size/Diversity Proportion sub-drainage slope>=15% (CSup15) Harmonized World Soil Database v 1.2 PC1_elev scaled Fragmentation/Isolation

Elevation (min, max, range, mean, SD) Elevation Model srtm30v8 PC1_elev scaled Fragmentation/Isolation Proportion of sub-drainage area above 1000m in altitude Elevation Model srtm30v8 PC1_elev Arc-Sin, SqRt, scaled Fragmentation/Isolation Distance from sub-drainages to the Amazon river mouth HydroBASIN, our data set DistMouth_km scaled Positionning

Tributary position of major Amazon tributaries Our data set TributaryPosition scaled Positionning

Run Off (mean) UNH/Composite Runoff Field and QUEST GSI/Simulated

global river runoff data PC1_PC2_water scaled Current climate_Water Precipitation (min, max, annual, CV) WorldClim Version 1 PC1_PC2_water scaled Current climate_Water Temperature (min, max, mean, CV) WorldClim Version 1 PC1_PC2_temp scaled Current climate_Temperature

Solar Radiation (mean, CV) WorldClim Version 1 PC1_PC2_temp scaled Current climate_Temperature Actual Evapotranspiration (min, max, annual, CV) WorldClim Version 1 PC1_PC2_energ scaled Current climate_Energy

Potential Evapotranspiration (min, max, annual, CV) WorldClim Version 1 PC1_PC2_energ scaled Current climate_Energy Net Primary Productivity (mean, SD, CV) WorldClim Version 1 PC1_PC2_energ scaled Current climate_Energy

Connection to Pebas Lake 23Mya (0/1 variable)

Hoorn et al. 2010. Amazonia Through Time: Andean Uplift,

Climate Change, Landscape Evolution, and Biodiversity.

Science 330(6006): 927-931 PebasLake scaled Historical: Past Event Proportion of surface covered by salt water due to Marine

Incursions (5 and 10Mya) Miller KG et al. (2005) The Phanerozoic record of global sea-

level changes. Science 310, 1293-1298 Sea-level+25m and Sea-

level+100m Arc-sin, SqRt, scaled

and scaled Historical: Past Event Temperature (min, max, mean) MIROC, CCSM, MPI models PC1_PC2_PC3_ClimCurrPast_diff scaled Historical: Past Event Precipitation (min, max, annual) MIROC, CCSM, MPI models PC1_PC2_PC3_ClimCurrPast_diff scaled Historical: Past Event

Number of sampled sites divided by surface area (km2) Our data set SamplingEff log, scaled Sampling effort Total fish species richness Our data set Richness log, scaled Regional species pool

Table S2. Correlation coefficients among input variables and components for each of the

PCAs performed. Water, Temp, Energy, and CurrentPast are major groups of ecological and

historical hypotheses. AET, PET, and NPP stands for Actual Evapotranspiration, Potential

Evapotranspiration, and Net Primary Productivity; Min, Max, Mean, Annual, CV, and SD stands

for minimum, maximum, mean, total annual, Coefficient of Variation, and Standard Deviation;

Diff stands for Differences between Current and LGM values (i.e. Current – LGM values).

Variables PC1_water PC2_water PC1_temp PC2_temp PC1_energy PC2_energy PC1_CurrentPast PC2_CurrentPast PC3_CurrentPast PC1_Elevation

Precipitation Min 0.47 -0.41 - - - - - - - -

Precipitation Max 0.31 0.67 - - - - - - - -

Precipitation Annual 0.54 0.12 - - - - - - - -

Precipitation CV -0.45 0.50 - - - - - - - -

RunOff Mean 0.43 0.33 - - - - - - - -

Temperature Min - - -0.48 0.19 - - - - - -

Temperature Max - - -0.33 0.58 - - - - - -

Temperature Mean - - -0.43 0.42 - - - - - -

Temperature CV - - 0.40 0.37 - - - - - -

Solar Radiation Mean - - -0.43 -0.39 - - - - - -

Solar Radiation CV - - 0.37 0.40 - - - - - -

AET Min - - - - 0.35 0.27 - - - -

AET Max - - - - 0.27 -0.32 - - - -

AET Annual - - - - 0.42 0.04 - - - -

AET CV - - - - -0.29 -0.38 - - - -

PET Min - - - - 0.29 -0.34 - - - -

PET Max - - - - -0.01 -0.48 - - - -

PET Annual - - - - 0.14 -0.46 - - - -

PET CV - - - - -0.36 -0.10 - - - -

NPP Mean - - - - 0.21 0.30 - - - -

NPP SD - - - - -0.32 0.15 - - - -

NPP CV - - - - -0.40 0.07 - - - -

Diff_Temperature Min - - - - - - -0.14 0.29 -0.87 -

Diff_Temperature Max - - - - - - -0.57 -0.12 -0.01 -

Diff_Temperature Mean - - - - - - -0.52 -0.16 -0.21 -

Diff_Precipitation Min - - - - - - 0.45 -0.20 -0.39 -

Diff_Precipitation Max - - - - - - -0.27 -0.66 -0.02 -

Diff_Precipitation Annual - - - - - - 0.32 -0.63 -0.21 -

Elevation Min - - - - - - - - - 0.31

Elevation Max - - - - - - - - - 0.39

Elevation Range - - - - - - - - - 0.39

Elevation Mean - - - - - - - - - 0.38

Elevation SD - - - - - - - - - 0.38

Elevation PropAbove1000_asin - - - - - - - - - 0.40

CSup15 - - - - - - - - - 0.38

Proportion of Variance 0.65 0.26 0.64 0.27 0.42 0.34 0.46 0.26 0.16 0.84

Cumulative Proportion 0.65 0.91 0.64 0.91 0.42 0.76 0.46 0.72 0.88 0.84

Table S3. Coefficients and SEs from the GLMs performed for total and endemic richness.

The total and endemism richness were modeled (GLMs with Negative-Binomial distributions)

against covariates of the current climate, habitat size/diversity and historical descriptors (a). As

some of our explanatory descriptors showed multicollinearity problems (factors with VIF > 10;

(i.e. DistMouth, PC1_water, PC1_energ and PC1_elev) we refit the models without these

descriptors (b). Models following both procedures gave very similar responses. Note that in the

Total Richness model (b) the descriptor DistMouth is significantly replaced by its related

descriptor TributaryPosition (see Materials and Methods). Moran’s I statistics (and

corresponding P-values) were calculated using the inverse of the watercourse distances among

sub-basins as weights; Pseudo-R2 has been estimated through model deviances: [(Null-

Residual)/Null] * 100. Cells show mean estimate ± standard error (the Wald’ z statistic and

corresponding P value). z and associated P values are derived from standard GLM output; z

values are calculated by dividing the regression coefficients by the estimated standard errors; P

values determine whether estimated coefficients are significantly different from zero.

a) b)

NegBin NegBin NegBin NegBin

Variables Total Richness Total Endemics Total Richness Total Endemics

(Intercept) 5.53±0.11(51.35;0.00)*** 0.69±0.40(1.75;0.08)P 5.52±0.11(49.12;0.00)*** 0.66±0.39(1.69;0.09)P

PebasLake -0.09±0.11(-0.87;0.38) -0.26±0.40(-0.65;0.52) 0.03±0.10( 0.34;0.73) -0.04±0.34(-0.11;0.92)

Sea-level+25m -0.19±0.12(-1.62;0.11) -0.09±0.50(-0.19;0.85) -0.13±0.11(-1.17;0.24) -0.04±0.47(-0.09;0.93)

Sea-level+100m -0.02±0.13(-0.16;0.87) -0.46±0.52(-0.88;0.38) -0.03±0.11(-0.27;0.79) -0.73±0.45(-1.62;0.11)P

PC1_ClimCurrPast_diff -0.10±0.13(-0.82;0.41) 0.02±0.39( 0.06;0.95) -0.12±0.10(-1.26;0.21) 0.11±0.31( 0.36;0.72)

PC2_ClimCurrPast_diff 0.00±0.11(0.03;0.97) 0.77±0.36( 2.10;0.04)* -0.10±0.10(-0.99;0.32) 0.79±0.32( 2.47;0.01)*

PC3_ClimCurrPast_diff -0.14±0.11(-1.31;0.19) 0.88±0.35(2.48;0.01)* -0.14±0.10(-1.38;0.17) 0.66±0.34(1.97;0.05)*

DistMouth 0.86±0.33(2.58;0.01)* 0.66±1.14(0.57;0.57) - -

TributaryPosition -0.05±0.23(-0.22;0.83) -0.28±0.75(-0.37;0.71) 0.30±0.15( 2.02;0.04)* -0.29±0.48(-0.61;0.54)

Area_log 0.92±0.09( 9.95;0.00)*** 1.80±0.47(3.83;0.00)*** 0.76±0.08( 9.57;0.00)*** 1.45±0.40( 3.61;0.00)***

Waterfall_log 0.01±0.08(0.14;0.89) 0.66±0.24(2.71;0.01)** 0.03±0.08( 0.33;0.74) 0.60±0.24(2.54;0.01)**

NetworkDensity -0.03±0.07(-0.39;0.70) -0.12±0.23(-0.50;0.62) 0.02±0.07( 0.26;0.79) 0.01±0.22( 0.05;0.96)

PC1_elev -0.50±0.20(-2.51;0.01)* -0.83±0.64(-1.30;0.19) - -

SoilDiv 0.03±0.08(0.38;0.70) -0.29±0.24(-1.23;0.22) 0.09±0.08(1.12;0.26) -0.26±0.23(-1.10;0.27)

ShanDiv_log 0.05±0.11(0.40;0.69) -0.21±0.35(-0.61;0.54) 0.05±0.11(0.41;0.68) 0.04±0.33(0.12;0.90)

WaterColorClear 0.04±0.14(0.26;0.79) 0.18±0.52(0.34;0.74) 0.01±0.15(0.07;0.95) 0.21±0.50(0.42;0.68)

WaterColorWhite 0.15±0.12(1.20;0.23) -0.63±0.46(-1.38;0.17) 0.18±0.13(1.45;0.15) -0.57±0.46(-1.25;0.21)

PC1_water -0.09±0.23(-0.41;0.68) 0.79±0.68(1.16;0.25) - -

PC2_water 0.22±0.16(1.36;0.17) -1.19±0.51(-2.31;0.02)* 0.05±0.12(0.42;0.68) -1.10±0.39(-2.81;0.01)**

PC1_temp -1.17±0.29(-4.08;0.00)*** -0.52±0.96(-0.54;0.59) -0.78±0.16(-4.79;0.00)*** 0.49±0.60(0.82;0.41)

PC2_temp 0.53±0.13(3.98;0.00)*** -0.65±0.50(-1.31;0.19) 0.62±0.11(5.58;0.00)*** -0.14±0.43(-0.33;0.74)

PC1_energ -0.43±0.32(-1.34;0.18) -2.19±1.08(-2.04;0.04)* - -

PC2_energ 0.55±0.24(2.32;0.02)* -0.47±0.77(-0.61;0.54) 0.25±0.14(1.75;0.08)P -0.08±0.44(-0.19;0.85)

SamplingEff 1.20±0.09(13.87;0.00)*** 1.11±0.52(2.14;0.03)* 1.08±0.08(13.36;0.00)*** 0.83±0.50(1.67;0.10)P

Richness_log - 1.38±0.60(2.29;0.02)* -

1.69±0.62(2.71;0.01)**

VIF 10±10 14±13 3.7±1.7 5.5±2.7

Overdispersion parameter 15.50±2.44 5.54±2.34 13.85±2.17 4.78±1.88

Pseudo-R2 82 69 80 68

Moran’s I -0.0014 -0.057P -0.012 -0.028

P: 0.05 < p < 0.1; *p < 0.05; **p < 0.01; ***p < 0.001

Table S4. Coefficients and SEs (log link scale) from the GLMs for the richness of each of the

15 most abundant families (raw data). Also given are the coefficients and standard errors (log

link scale) from the GLMs for the total richness estimated from SDMs (based on the 1351 species

having more than 10 occurrence points in our database; Est Richness_SDM) and the the total

richness for the same 1351 species but using raw-data (Raw Est Richness_1351sp). Moran’s I was

calculated based on model residual from the full model and aquatic distances between sub-

drainage basins; Pseudo-R2 has been estimated through model deviances: [(Null-Residual)/Null] *

100. Cells show mean estimate ± standard error (the Wald’ z statistic and corresponding P value).

Z and P values are derived from standard GLM output; z values are calculated by dividing mean

estimates by standard errors; P values determine whether estimated coefficients are significantly

different from zero. P: 0.05 < P < 0.10; *P < 0.05; **P < 0.01; ***P < 0.001 NegBin NegBin NegBin NegBin NegBin NegBin NegBin

Variables Est Richness_SDM

Raw Est Richness_1351sp Characidae Loricariidae Cichlidae Callichthyidae Anostomidae (Intercept)

6.55±0.05(138.44;0.00) 5.40±0.11(48.36;0.00) 3.80±0.11(34.08;0.00) 2.89±0.15(18.85;0.00) 3.27±0.09(35.52;0.00) 1.58±0.21( 7.41;0.00) 2.09±0.15(13.75;0.00) PebasLake

0.05±0.05( 1.10;0.27) -0.08±0.11(-0.74;0.46) -0.20±0.11(-1.79;0.07)P -0.11±0.15(-0.73;0.47) -0.02±0.09(-0.26;0.79) -0.37±0.20(-1.85;0.06)P -0.19±0.14(-1.32;0.19) Sea-level+25m

-0.07±0.05( -1.33;0.18) -0.20±0.12(-1.69;0.09)P -0.07±0.12(-0.62;0.54) -0.20±0.16(-1.25;0.21) -0.07±0.10(-0.70;0.49) -0.22±0.23(-0.96;0.34) -0.19±0.16(-1.22;0.22) Sea-level+100m

-0.03±0.06( -0.47;0.64) -0.02±0.13(-0.17;0.87) -0.04±0.13(-0.32;0.75) -0.03±0.18(-0.16;0.87) 0.13±0.11( 1.21;0.23) -0.01±0.24(-0.03;0.97) -0.33±0.17(-1.89;0.06)P PC1_ClimCurrPast_diff.

-0.08±0.06( -1.39;0.16) -0.13±0.13(-1.02;0.31) -0.08±0.13(-0.61;0.54) -0.33±0.18(-1.82;0.07)P -0.19±0.12(-1.66;0.10)P -0.44±0.26(-1.71;0.09)P 0.10±0.18( 0.56;0.57) PC2_ClimCurrPast_diff.

0.08±0.05( 1.63;0.10)P -0.01±0.11(-0.09;0.93) -0.16±0.12(-1.39;0.17) 0.21±0.16( 1.37;0.17) -0.20±0.11(-1.91;0.06)P 0.04±0.24( 0.15;0.88) 0.06±0.15( 0.37;0.71) PC3_ClimCurrPast_diff.

-0.09±0.05( -1.79;0.07)P -0.14±0.11(-1.24;0.21) -0.10±0.11(-0.93;0.35) -0.25±0.15(-1.67;0.09)P -0.08±0.10(-0.77;0.44) -0.06±0.20(-0.31;0.76) -0.08±0.15(-0.54;0.59) DistMouth

-0.33±0.15( -2.26;0.02)* 0.78±0.35( 2.26;0.02)* 1.15±0.34( 3.40;0.00)*** 1.57±0.46( 3.42;0.00)*** 0.05±0.29( 0.16;0.87) 2.68±0.61( 4.39;0.00)*** 0.74±0.45( 1.64;0.10) TributaryPosition

0.28±0.10( 2.77;0.01)** 0.03±0.24( 0.13;0.90) -0.19±0.23(-0.83;0.40) -0.42±0.32(-1.33;0.18) 0.33±0.20( 1.65;0.10) -1.07±0.43(-2.49;0.01)* -0.20±0.30(-0.64;0.52) Area_log

0.22±0.04( 5.45;0.00)*** 0.91±0.10( 9.47;0.00)*** 0.86±0.09( 9.12;0.00)*** 1.23±0.13( 9.55;0.00)*** 0.73±0.08( 8.96;0.00)*** 1.45±0.18( 8.25;0.00)*** 0.84±0.12( 6.81;0.00)*** Waterfall_log

0.09±0.03( 2.77;0.01)** 0.01±0.08( 0.07;0.94) -0.03±0.08(-0.32;0.75) -0.06±0.11(-0.54;0.59) 0.06±0.07( 0.88;0.38) -0.08±0.16(-0.52;0.60) 0.02±0.10( 0.23;0.81) NetworkDensity.s

-0.02±0.03( -0.67;0.50) -0.03±0.07(-0.38;0.71) -0.09±0.07(-1.36;0.18) -0.07±0.09(-0.78;0.43) -0.10±0.06(-1.65;0.10)P -0.24±0.14(-1.73;0.08)P -0.04±0.09(-0.45;0.65) PC1_elev

-0.02±0.09( -0.26;0.80) -0.51±0.21(-2.44;0.01)* -0.09±0.20(-0.43;0.67) -0.32±0.28(-1.12;0.26) -0.22±0.20(-1.09;0.27) -1.45±0.41(-3.52;0.00)*** -0.72±0.30(-2.36;0.02)* SoilDiv

0.05±0.03( 1.51;0.13) 0.05±0.08( 0.66;0.51) 0.05±0.08( 0.65;0.51) -0.10±0.11(-0.96;0.34) 0.13±0.07( 1.96;0.05)* 0.15±0.14( 1.05;0.30) -0.02±0.10(-0.19;0.85) ShanDiv_log

-0.03±0.05( -0.50;0.61) 0.05±0.12( 0.41;0.68) -0.12±0.11(-1.04;0.30) -0.10±0.16(-0.62;0.53) -0.13±0.11(-1.19;0.23) -0.14±0.21(-0.67;0.50) 0.18±0.16( 1.15;0.25) WaterColorClear

-0.06±0.06( -0.91;0.36) 0.01±0.15( 0.04;0.97) 0.15±0.15( 1.02;0.31) 0.12±0.20( 0.59;0.55) -0.03±0.12(-0.25;0.81) -0.03±0.28(-0.11;0.91) 0.36±0.19( 1.88;0.06) WaterColorWhite

0.09±0.05( 1.65;0.10) 0.14±0.13( 1.09;0.28) 0.23±0.13( 1.85;0.06) 0.29±0.17( 1.70;0.09) -0.03±0.10(-0.28;0.78) 0.25±0.23( 1.05;0.29) 0.28±0.17( 1.67;0.10) PC1_water

-0.09±0.10( -0.92;0.36) -0.15±0.24(-0.64;0.52) 0.07±0.23( 0.29;0.77) -0.10±0.31(-0.33;0.74) 0.10±0.20( 0.53;0.60) 0.71±0.43( 1.65;0.10)P -0.17±0.30(-0.56;0.57) PC2_water

0.03±0.07( 0.36;0.72) 0.24±0.17( 1.44;0.15) 0.23±0.16( 1.42;0.16) 0.03±0.23( 0.11;0.91) 0.06±0.15( 0.40;0.69) -0.26±0.32(-0.80;0.42) 0.38±0.22( 1.71;0.09)P PC1_temp

-0.47±0.13( -3.71;0.00)*** -1.21±0.30(-4.08;0.00)*** -1.02±0.29(-3.53;0.00)*** -1.31±0.40(-3.31;0.00)*** -1.32±0.28(-4.72;0.00)*** -1.55±0.55(-2.80;0.01)** -0.91±0.42(-2.18;0.03)* PC2_temp

0.31±0.06( 5.28;0.00)*** 0.62±0.14( 4.40;0.00)*** 0.23±0.14( 1.64;0.10) 0.30±0.20( 1.49;0.14) 0.81±0.16( 5.04;0.00)*** 0.35±0.32( 1.10;0.27) 0.60±0.24( 2.47;0.01)* PC1_energ

-0.05±0.14( -0.37;0.71) -0.39±0.33(-1.17;0.24) -0.40±0.32(-1.22;0.22) -0.54±0.44(-1.22;0.22) -0.63±0.29(-2.14;0.03)* -1.19±0.60(-1.99;0.05)* -0.06±0.44(-0.15;0.88) PC2_energ

0.24±0.10( 2.35;0.02)* 0.60±0.24( 2.45;0.01)* 0.08±0.24( 0.34;0.74) 0.40±0.33( 1.20;0.23) 0.39±0.21( 1.82;0.07)P 0.43±0.46( 0.94;0.35) 0.65±0.31( 2.09;0.04)* SamplingEff

0.16±0.04( 4.33;0.00)*** 1.22±0.09(13.63;0.00)*** 1.05±0.09(11.69;0.00)*** 1.48±0.13(11.72;0.00)*** 0.92±0.08(11.49;0.00)*** 1.40±0.18( 7.90;0.00)*** 1.07±0.12( 8.78;0.00)*** Richness_log - - - - - - -

VIF 10±10 10±10 10±9.9 10±9.7 9.2±8.1 9.7±8.6 9.2±8.1 Overdispersion parameter 83.95(±13.76) 14.51(±2.30) 19.56(±4.15) 12.19(±2.87) 58.92(±25.93) 12.23(±4.33) 27.15(±13.97)

Pseudo-R2 83 82 76 74 85 74 67 Moran’s I -0.0053 0.0013 -0.039 -0.031 0.0097 -0.029 -0.035

Continued Poisson NegBin Poisson Poisson Poisson NegBin NegBin Variables Rivulidae Doradidae Heptapteridae Auchenipteridae Trichomycteridae Serrasalmidae Curimatidae (Intercept)

0.78±0.25( 3.10;0.00) 2.35±0.18(12.87;0.00) 1.61±0.17( 9.62;0.00) 2.09±0.13(16.58;0.00) 1.58±0.17( 9.45;0.00) 2.00±0.16(12.82;0.00) 2.58±0.12(20.99;0.00) PebasLake

-0.13±0.24(-0.56;0.58) 0.14±0.18( 0.77;0.44) -0.04±0.15(-0.27;0.78) 0.04±0.12( 0.31;0.75) -0.13±0.14(-0.89;0.37) -0.11±0.14(-0.78;0.44) -0.11±0.12(-0.90;0.37) Sea-level+25m

-0.42±0.29(-1.46;0.14) -0.27±0.20(-1.35;0.18) -0.15±0.17(-0.89;0.38) -0.12±0.14(-0.89;0.37) -0.36±0.17(-2.10;0.04)* -0.16±0.16(-1.02;0.31) -0.11±0.13(-0.81;0.42) Sea-level+100m

0.31±0.31( 1.02;0.31) -0.01±0.22(-0.06;0.95) 0.20±0.19( 1.06;0.29) 0.02±0.15( 0.16;0.87) 0.28±0.19( 1.44;0.15) -0.10±0.18(-0.54;0.59) -0.15±0.15(-1.03;0.30) PC1_ClimCurrPast_diff.

-0.23±0.32(-0.73;0.47) -0.44±0.23(-1.89;0.06)* -0.14±0.19(-0.76;0.45) -0.11±0.16(-0.68;0.50) -0.16±0.20(-0.83;0.41) -0.26±0.19(-1.40;0.16) -0.48±0.16(-3.09;0.00)** PC2_ClimCurrPast_diff.

-0.22±0.28(-0.77;0.44) 0.12±0.20( 0.60;0.55) -0.27±0.19(-1.46;0.14) -0.23±0.16(-1.48;0.14) 0.24±0.18( 1.31;0.19) -0.52±0.19(-2.78;0.01)** -0.27±0.15(-1.77;0.08)P PC3_ClimCurrPast_diff.

0.48±0.27( 1.80;0.07)P -0.18±0.20(-0.91;0.36) 0.07±0.16( 0.45;0.65) -0.24±0.13(-1.83;0.07)P -0.32±0.17(-1.92;0.05)P -0.31±0.15(-2.00;0.05)* -0.16±0.13(-1.26;0.21) DistMouth

0.50±0.79( 0.63;0.53) 0.85±0.58( 1.47;0.14) 0.91±0.48( 1.90;0.06)P 0.62±0.39( 1.58;0.11) 1.36±0.49( 2.79;0.01)** 0.50±0.46( 1.11;0.27) 0.65±0.38( 1.71;0.09)P TributaryPosition

-0.35±0.55(-0.63;0.53) 0.09±0.40( 0.23;0.82) -0.58±0.34(-1.72;0.09)P -0.35±0.27(-1.30;0.19) -0.35±0.34(-1.02;0.31) -0.41±0.32(-1.28;0.20) -0.06±0.26(-0.22;0.82) Area_log

0.88±0.23( 3.85;0.00)*** 1.13±0.16( 6.93;0.00)*** 0.81±0.14( 5.81;0.00)*** 0.77±0.11( 7.16;0.00)*** 1.02±0.14( 7.12;0.00)*** 0.92±0.13( 7.20;0.00)*** 0.81±0.11( 7.49;0.00)*** Waterfall_log

-0.03±0.20(-0.15;0.88) 0.00±0.14( 0.01;0.99) 0.21±0.12( 1.78;0.08)P 0.05±0.09( 0.49;0.62) 0.12±0.12( 0.99;0.32) 0.03±0.11( 0.30;0.77) -0.07±0.09(-0.69;0.49) NetworkDensity.s

-0.07±0.17(-0.43;0.67) -0.13±0.13(-1.01;0.31) 0.03±0.11( 0.27;0.79) 0.01±0.09( 0.15;0.88) 0.06±0.11( 0.51;0.61) -0.03±0.10(-0.26;0.79) 0.06±0.08( 0.75;0.45)

PC1_elev 0.39±0.57( 0.69;0.49) -1.25±0.43(-2.91;0.00)** -0.36±0.30(-1.20;0.23) -0.50±0.28(-1.80;0.07)P -0.73±0.32(-2.28;0.02)* -0.31±0.33(-0.94;0.35) -0.52±0.26(-1.97;0.05)P

SoilDiv 0.11±0.19( 0.56;0.58) 0.09±0.14( 0.67;0.50) 0.06±0.11( 0.57;0.57) 0.10±0.09( 1.16;0.25) -0.04±0.11(-0.32;0.75) -0.08±0.11(-0.77;0.44) 0.03±0.09( 0.29;0.77)

ShanDiv_log 0.08±0.30( 0.27;0.78) -0.17±0.21(-0.79;0.43) -0.03±0.17(-0.20;0.84) -0.27±0.14(-1.92;0.05)P -0.01±0.17(-0.07;0.95) 0.02±0.16( 0.14;0.89) 0.12±0.14( 0.86;0.39)

WaterColorClear 0.01±0.33( 0.04;0.97) -0.13±0.24(-0.55;0.58) 0.05±0.21( 0.25;0.80) 0.07±0.16( 0.46;0.64) -0.13±0.22(-0.61;0.54) 0.45±0.20( 2.28;0.02) -0.01±0.16(-0.03;0.97)

WaterColorWhite -0.06±0.28(-0.22;0.82) -0.04±0.20(-0.17;0.86) 0.28±0.19( 1.49;0.14) 0.11±0.14( 0.78;0.44) 0.29±0.18( 1.56;0.12) 0.45±0.17( 2.63;0.01) 0.07±0.14( 0.48;0.63)

PC1_water 0.26±0.53( 0.49;0.62) 0.31±0.40( 0.76;0.45) 0.38±0.32( 1.20;0.23) 0.02±0.27( 0.08;0.93) -0.11±0.34(-0.33;0.74) 0.07±0.32( 0.21;0.84) 0.38±0.26( 1.46;0.14)

PC2_water -0.25±0.41(-0.61;0.54) 0.24±0.30( 0.82;0.41) -0.16±0.24(-0.67;0.51) -0.03±0.20(-0.13;0.90) 0.03±0.25( 0.10;0.92) 0.14±0.23( 0.61;0.54) -0.05±0.20(-0.26;0.80)

PC1_temp -3.12±0.79(-3.94;0.00)*** -1.85±0.58(-3.16;0.00)** -1.00±0.42(-2.40;0.02)* -1.05±0.39(-2.73;0.01)** -0.80±0.43(-1.87;0.06)P -1.22±0.44(-2.77;0.01)** -1.04±0.35(-2.94;0.00)**

PC2_temp 1.08±0.48( 2.27;0.02)* 1.09±0.36( 3.03;0.00)** 0.20±0.22( 0.94;0.35) 0.92±0.23( 3.98;0.00)*** 0.49±0.23( 2.11;0.04)* 1.39±0.26( 5.29;0.00)*** 0.80±0.21( 3.88;0.00)***

PC1_energ -1.37±0.84(-1.63;0.10) -1.00±0.58(-1.72;0.09)P -0.91±0.47(-1.94;0.05)P -0.33±0.40(-0.84;0.40) -0.71±0.48(-1.48;0.14) -0.18±0.45(-0.39;0.70) -0.33±0.37(-0.87;0.38)

PC2_energ 0.46±0.57( 0.80;0.42) 0.84±0.44( 1.93;0.05)P 0.22±0.34( 0.65;0.52) 0.64±0.29( 2.22;0.03)* 0.69±0.38( 1.85;0.06)P 1.27±0.33( 3.87;0.00)*** 0.64±0.28( 2.31;0.02)*

SamplingEff 0.73±0.23( 3.21;0.00)** 1.63±0.16(10.04;0.00)*** 1.13±0.14( 8.06;0.00)*** 1.16±0.11(10.50;0.00)*** 1.43±0.15( 9.72;0.00)*** 1.20±0.13( 9.29;0.00)*** 1.01±0.11( 9.49;0.00)***

Richness_log - - - - - - -

VIF 10±9.1 9±7.6 10±9.7 9.4±8.1 10±11 9.5±8.4 9.4±8.3 Overdispersion parameter - 8.74(±2.47) - - - 20.58(±9.16) 39.51(±21.44)

Pseudo-R2 52 75 63 76 69 71 74 Moran’s I -0.014 -0.015 0.014 0.0075 0.0008 -0.013 -0.0057

Continued NegBin NegBin Poisson Variables Apteronotidae Pimelodidae Lebiasinidae (Intercept)

1.74±0.29( 5.96;0.00) 2.45±0.18(13.74;0.00) 1.61±0.15(10.58;0.00) PebasLake

0.55±0.29( 1.92;0.05)P 0.08±0.17( 0.48;0.63) 0.06±0.15( 0.42;0.68) Sea-level+25m

-0.24±0.31(-0.78;0.44) -0.19±0.19(-1.02;0.31) -0.02±0.16(-0.12;0.90) Sea-level+100m

0.21±0.36( 0.59;0.56) -0.10±0.21(-0.46;0.64) 0.29±0.18( 1.56;0.12) PC1_ClimCurrPast_diff.

-1.03±0.37(-2.76;0.01)** -0.50±0.22(-2.27;0.02)* 0.18±0.19( 0.94;0.34) PC2_ClimCurrPast_diff.

0.61±0.31( 1.95;0.05)P 0.23±0.19( 1.25;0.21) -0.02±0.18(-0.09;0.93) PC3_ClimCurrPast_diff.

-0.05±0.33(-0.15;0.88) 0.00±0.19(-0.01;0.99) -0.47±0.18(-2.67;0.01)** DistMouth

-0.24±0.95(-0.25;0.80) 0.68±0.55( 1.23;0.22) 0.03±0.50( 0.05;0.96) TributaryPosition

1.21±0.66( 1.82;0.07)P 0.56±0.39( 1.45;0.15) 0.48±0.34( 1.44;0.15) Area_log

1.13±0.27( 4.16;0.00)*** 0.86±0.16( 5.48;0.00)*** 0.67±0.14( 4.93;0.00)*** Waterfall_log

0.53±0.23( 2.32;0.02)* 0.17±0.14( 1.28;0.20) -0.09±0.12(-0.76;0.45) NetworkDensity.s

0.02±0.21( 0.08;0.93) 0.06±0.12( 0.51;0.61) -0.11±0.11(-1.02;0.31) PC1_elev

-2.09±0.64(-3.28;0.00)** -0.72±0.38(-1.89;0.06)P 0.13±0.37( 0.36;0.72) SoilDiv

0.17±0.23( 0.73;0.47) 0.07±0.13( 0.49;0.62) 0.03±0.12( 0.23;0.82) ShanDiv_log

0.11±0.34( 0.34;0.74) 0.07±0.20( 0.38;0.71) -0.18±0.19(-0.97;0.33) WaterColorClear

-0.37±0.40(-0.94;0.35) -0.09±0.24(-0.36;0.72) 0.11±0.20( 0.54;0.59) WaterColorWhite

-0.12±0.33(-0.36;0.72) 0.16±0.20( 0.78;0.44) 0.14±0.17( 0.84;0.40) PC1_water

0.14±0.67( 0.21;0.83) -0.01±0.39(-0.02;0.99) 0.01±0.33( 0.02;0.98) PC2_water

-0.01±0.50(-0.02;0.98) 0.27±0.28( 0.96;0.34) 0.27±0.26( 1.04;0.30) PC1_temp

-0.89±0.85(-1.04;0.30) -1.53±0.51(-2.98;0.00)** -1.62±0.52(-3.09;0.00)** PC2_temp

-0.10±0.47(-0.22;0.83) 0.93±0.29( 3.21;0.00)** 1.05±0.30( 3.53;0.00)*** PC1_energ

-1.42±0.94(-1.51;0.13) -0.67±0.54(-1.23;0.22) -0.81±0.52(-1.54;0.12) PC2_energ

0.87±0.76( 1.15;0.25) 0.80±0.41( 1.93;0.05)P 0.58±0.38( 1.52;0.13) SamplingEff

1.73±0.27( 6.47;0.00)*** 1.30±0.15( 8.45;0.00)*** 0.64±0.13( 4.82;0.00)*** Richness_log - - -

VIF 9.9±8.9 9.6±8.6 9.3±7.9 Overdispersion parameter 3.07(±0.77) 8.92(±2.29) -

Pseudo-R2 64 69 73 Moran’s I -0.021 -0.012 -0.017

Table S5. Coefficients and SEs (log link scale) from the GLMs for species richness estimated

from SDMs of each of the 15 most abundant families. Models (GLMs with Poisson) have been

performed using the 1351 species having more than 10 occurrence points in our database).

Moran’s I was calculated based on model residual from the full model and aquatic distances

between sub-drainage basins; Pseudo-R2 has been estimated through model deviances: [(Null-

Residual)/Null] * 100. Cells show mean estimate ± standard error (the Wald’ z statistic and

corresponding P value). Z and P values are derived from standard GLM output; z values are

calculated by dividing mean estimates by standard errors; P values determine whether estimated

coefficients are significantly different from zero. P: 0.05 < P < 0.10; *P < 0.05; **P < 0.01; ***P <

0.001 Poisson

Poisson Poisson Poisson Poisson Poisson Variables

CharacidaeSDM LoricariidaeSDM CichlidaeSDM CallichthyidaeSDM AnostomidaeSDM RivulidaeSDM (Intercept)

4.83±0.04(134.41;0.00) 4.18±0.05(84.67;0.00) 4.21±0.05(90.41;0.00) 2.64±0.11(24.23;0.00) 3.33±0.07(45.62;0.00) 1.16±0.20( 5.84;0.00) PebasLake

0.00±0.03( 0.08;0.94) 0.00±0.05( 0.01;0.99) 0.05±0.05( 1.02;0.31) -0.09±0.10(-0.86;0.39) -0.02±0.07(-0.30;0.76) -0.15±0.19(-0.80;0.42) Sea-level+25m

0.02±0.04( 0.45;0.65) -0.03±0.05(-0.59;0.55) -0.07±0.05(-1.37;0.17) -0.01±0.11(-0.09;0.93) -0.06±0.08(-0.74;0.46) -0.13±0.20(-0.63;0.53) Sea-level+100m

-0.02±0.04( -0.48;0.63) -0.01±0.06(-0.15;0.88) 0.01±0.06( 0.18;0.86) -0.28±0.13(-2.18;0.03)* 0.00±0.09(-0.01;0.99) 0.14±0.23( 0.58;0.56) PC1_ClimCurrPast_diff.

-0.06±0.04( -1.36;0.17) -0.09±0.06(-1.57;0.12) -0.04±0.06(-0.76;0.45) -0.41±0.13(-3.14;0.00)** -0.09±0.09(-1.07;0.29) 0.22±0.24( 0.91;0.36) PC2_ClimCurrPast_diff.

0.02±0.04( 0.49;0.63) 0.06±0.05( 1.18;0.24) 0.04±0.05( 0.84;0.40) 0.06±0.11( 0.59;0.55) 0.01±0.07( 0.14;0.89) 0.08±0.19( 0.41;0.68) PC3_ClimCurrPast_diff.

-0.01±0.04( -0.20;0.84) -0.03±0.05(-0.60;0.55) -0.06±0.05(-1.16;0.25) 0.00±0.11(-0.03;0.98) -0.05±0.08(-0.63;0.53) -0.03±0.22(-0.12;0.90) DistMouth

-0.09±0.11( -0.79;0.43) -0.05±0.15(-0.35;0.72) -0.48±0.15(-3.21;0.00)** 0.19±0.32( 0.59;0.55) -0.25±0.23(-1.08;0.28) -0.38±0.63(-0.60;0.55) TributaryPosition

0.13±0.07( 1.73;0.08)P 0.14±0.10( 1.41;0.16) 0.25±0.10( 2.47;0.01)* 0.01±0.22( 0.03;0.98) 0.07±0.16( 0.42;0.67) 0.38±0.43( 0.88;0.38) Area_log

0.24±0.03( 8.11;0.00)*** 0.29±0.04( 7.00;0.00)*** 0.23±0.04( 5.65;0.00)*** 0.32±0.09( 3.62;0.00)*** 0.21±0.06( 3.45;0.00)*** 0.25±0.17( 1.48;0.14) Waterfall_log

0.08±0.03( 3.32;0.00)*** 0.09±0.03( 2.70;0.01)** 0.08±0.03( 2.39;0.02)* 0.18±0.08( 2.26;0.02)* 0.07±0.05( 1.35;0.18) -0.03±0.14(-0.20;0.84) NetworkDensity.s

-0.04±0.02( -1.86;0.06)P -0.05±0.03(-1.50;0.13) -0.01±0.03(-0.32;0.75) -0.03±0.07(-0.48;0.63) 0.02±0.05( 0.52;0.61) 0.03±0.13( 0.26;0.80) PC1_elev

0.08±0.07( 1.23;0.22) 0.01±0.09( 0.16;0.87) -0.02±0.10(-0.16;0.87) -0.26±0.20(-1.25;0.21) -0.02±0.15(-0.16;0.87) -0.19±0.44(-0.43;0.67) SoilDiv

0.09±0.03( 3.36;0.00)*** 0.05±0.04( 1.48;0.14) 0.04±0.04( 1.12;0.26) 0.16±0.07( 2.16;0.03)* 0.04±0.05( 0.76;0.44) -0.01±0.15(-0.06;0.96) ShanDiv_log

-0.04±0.04( -1.12;0.26) 0.00±0.05(-0.04;0.97) 0.01±0.05( 0.16;0.87) 0.05±0.11( 0.48;0.63) 0.05±0.08( 0.66;0.51) -0.10±0.23(-0.44;0.66) WaterColorClear

-0.03±0.05( -0.60;0.55) -0.02±0.06(-0.30;0.76) -0.05±0.06(-0.88;0.38) -0.19±0.14(-1.32;0.19) 0.01±0.09( 0.07;0.95) 0.18±0.25( 0.72;0.47) WaterColorWhite

0.13±0.04( 3.25;0.00) 0.14±0.06( 2.52;0.01) 0.08±0.05( 1.51;0.13) 0.16±0.12( 1.31;0.19) 0.11±0.08( 1.32;0.19) 0.23±0.22( 1.03;0.30) PC1_water

0.07±0.07( 0.96;0.34) -0.07±0.10(-0.69;0.49) -0.15±0.10(-1.50;0.13) 0.44±0.22( 1.99;0.05)* -0.02±0.16(-0.15;0.88) -0.18±0.43(-0.43;0.67) PC2_water

-0.02±0.05( -0.34;0.73) 0.01±0.07( 0.14;0.89) 0.04±0.07( 0.56;0.57) -0.31±0.16(-1.87;0.06)P -0.03±0.11(-0.27;0.79) 0.35±0.31( 1.14;0.25) PC1_temp

-0.39±0.10( -4.03;0.00)*** -0.34±0.13(-2.53;0.01)* -0.48±0.14(-3.35;0.00)*** -0.51±0.28(-1.80;0.07)P -0.57±0.21(-2.65;0.01)** -0.78±0.63(-1.24;0.21) PC2_temp

0.08±0.05( 1.77;0.08)P 0.10±0.06( 1.53;0.13) 0.37±0.07( 5.02;0.00)*** 0.18±0.15( 1.18;0.24) 0.30±0.11( 2.62;0.01)** 0.36±0.32( 1.12;0.26) PC1_energ

-0.14±0.11( -1.33;0.18) 0.02±0.15( 0.16;0.88) 0.08±0.15( 0.51;0.61) -0.18±0.31(-0.58;0.56) 0.00±0.23( 0.01;0.99) -0.45±0.65(-0.69;0.49) PC2_energ

-0.04±0.08( -0.58;0.56) 0.07±0.11( 0.64;0.52) 0.31±0.11( 2.81;0.00)** 0.02±0.23( 0.08;0.94) 0.04±0.16( 0.27;0.79) 0.29±0.46( 0.63;0.53) SamplingEff

0.17±0.03( 6.08;0.00)*** 0.23±0.04( 5.96;0.00)*** 0.16±0.04( 4.29;0.00)*** 0.29±0.08( 3.49;0.00)*** 0.15±0.06( 2.64;0.01)** 0.29±0.16( 1.82;0.07)P Richness_log

- - - - - -

VIF 10±9.7 9.9±9.5 9.1±8.3 9.7±8.9 9.0±8.1 8.7±7.7 Overdispersion parameter

- - - - - - Pseudo-R2

74 69 84 70 83 81 Moran’s I

-0.016 -0.022 0.016 -0.008 -0.002 -0.011

Continued Poisson Poisson Poisson Poisson Poisson Poisson

Variables DoradidaeSDM HeptapteridaeSDM AuchenipteridaeSDM TrichomycteridaeSDM SerrasalmidaeSDM CurimatidaeSDM

(Intercept) 3.60±0.06(57.36;0.00) 2.76±0.10(28.21;0.00) 3.26±0.07(44.58;0.00) 2.69±0.10(26.65;0.00) 3.37±0.07(46.96;0.00) 3.58±0.07(54.29;0.00)

PebasLake 0.09±0.06( 1.37;0.17) -0.01±0.09(-0.10;0.92) 0.10±0.07( 1.31;0.19) 0.11±0.10( 1.11;0.27) 0.11±0.07( 1.49;0.14) 0.06±0.07( 0.89;0.37)

Sea-level+25m -0.16±0.07(-2.29;0.02)* -0.12±0.10(-1.13;0.26) -0.08±0.08(-1.02;0.31) -0.07±0.11(-0.67;0.50) -0.07±0.08(-0.93;0.35) -0.06±0.07(-0.89;0.37)

Sea-level+100m -0.05±0.08(-0.62;0.54) -0.02±0.11(-0.17;0.87) 0.06±0.09( 0.67;0.50) 0.02±0.12( 0.13;0.89) -0.03±0.09(-0.33;0.74) -0.07±0.08(-0.89;0.37)

PC1_ClimCurrPast_diff. -0.08±0.08(-1.05;0.29) -0.15±0.12(-1.24;0.21) 0.02±0.09( 0.21;0.84) -0.09±0.12(-0.73;0.46) -0.08±0.09(-0.95;0.34) -0.12±0.08(-1.49;0.14)

PC2_ClimCurrPast_diff. 0.13±0.07( 1.91;0.06)P 0.08±0.10( 0.77;0.44) 0.09±0.08( 1.20;0.23) 0.10±0.10( 0.98;0.33) 0.01±0.07( 0.09;0.93) 0.09±0.07( 1.24;0.21)

PC3_ClimCurrPast_diff. -0.14±0.07(-2.01;0.04)* -0.07±0.10(-0.73;0.47) -0.09±0.08(-1.10;0.27) -0.08±0.11(-0.80;0.42) -0.04±0.08(-0.53;0.59) -0.05±0.07(-0.66;0.51)

DistMouth -0.34±0.20(-1.69;0.09)P -0.19±0.30(-0.64;0.52) -0.46±0.23(-1.96;0.05)P -0.18±0.31(-0.57;0.57) -0.50±0.23(-2.18;0.03)* -0.15±0.21(-0.74;0.46)

TributaryPosition 0.24±0.14( 1.76;0.08)P 0.16±0.21( 0.76;0.45) 0.38±0.16( 2.36;0.02)* 0.33±0.22( 1.53;0.13) 0.17±0.16( 1.11;0.27) 0.19±0.14( 1.32;0.19)

Area_log 0.17±0.05( 3.19;0.00)** 0.22±0.08( 2.65;0.01)** 0.17±0.06( 2.62;0.01)** 0.24±0.09( 2.76;0.01)** 0.13±0.06( 2.13;0.03)* 0.14±0.06( 2.48;0.01)*

Waterfall_log 0.06±0.05( 1.35;0.18) 0.10±0.07( 1.36;0.17) 0.05±0.06( 0.92;0.36) 0.06±0.07( 0.79;0.43) 0.08±0.05( 1.48;0.14) 0.07±0.05( 1.33;0.18)

NetworkDensity.s -0.03±0.04(-0.81;0.42) 0.03±0.06( 0.47;0.64) 0.01±0.05( 0.12;0.91) -0.07±0.07(-1.06;0.29) -0.05±0.05(-1.00;0.32) 0.00±0.04( 0.06;0.96)

PC1_elev -0.14±0.14(-1.00;0.32) -0.11±0.20(-0.58;0.56) -0.15±0.16(-0.95;0.34) -0.31±0.20(-1.58;0.11) -0.11±0.16(-0.71;0.48) -0.01±0.13(-0.10;0.92)

SoilDiv 0.05±0.05( 0.98;0.33) 0.10±0.07( 1.41;0.16) 0.05±0.06( 0.84;0.40) 0.09±0.07( 1.26;0.21) 0.04±0.05( 0.79;0.43) 0.01±0.05( 0.28;0.78)

ShanDiv_log -0.04±0.07(-0.52;0.60) 0.04±0.11( 0.41;0.68) -0.03±0.09(-0.33;0.74) -0.05±0.11(-0.45;0.65) -0.02±0.08(-0.27;0.79) 0.03±0.07( 0.35;0.73)

WaterColorClear -0.09±0.08(-1.08;0.28) 0.00±0.13(-0.04;0.97) 0.00±0.10( 0.04;0.97) -0.02±0.13(-0.13;0.90) -0.05±0.09(-0.51;0.61) -0.09±0.09(-1.00;0.32)

WaterColorWhite 0.06±0.07( 0.87;0.38) 0.13±0.11( 1.19;0.23) 0.08±0.08( 0.96;0.34) 0.13±0.11( 1.18;0.24) 0.03±0.08( 0.31;0.76) 0.03±0.07( 0.38;0.71)

PC1_water -0.24±0.14(-1.70;0.09)P 0.21±0.21( 1.03;0.30) -0.10±0.16(-0.60;0.55) -0.18±0.22(-0.85;0.40) -0.14±0.16(-0.89;0.37) -0.04±0.14(-0.28;0.78)

PC2_water 0.06±0.10( 0.60;0.55) -0.08±0.15(-0.56;0.57) 0.12±0.12( 1.01;0.31) 0.19±0.16( 1.21;0.23) 0.07±0.11( 0.61;0.54) -0.02±0.10(-0.23;0.82)

PC1_temp -0.51±0.19(-2.63;0.01)** -0.44±0.27(-1.60;0.11) -0.44±0.22(-1.97;0.05)* -0.21±0.28(-0.77;0.44) -0.39±0.22(-1.78;0.07)P -0.46±0.19(-2.42;0.02)*

PC2_temp 0.43±0.10( 4.26;0.00)*** 0.32±0.14( 2.28;0.02)* 0.33±0.11( 2.84;0.00)** 0.25±0.13( 1.85;0.06)P 0.47±0.11( 4.14;0.00)*** 0.35±0.10( 3.70;0.00)***

PC1_energ 0.11±0.21( 0.54;0.59) -0.22±0.30(-0.74;0.46) -0.13±0.24(-0.55;0.58) -0.11±0.31(-0.36;0.72) 0.09±0.23( 0.38;0.70) 0.01±0.21( 0.07;0.94)

PC2_energ 0.44±0.15( 2.89;0.00)** 0.15±0.22( 0.68;0.50) 0.26±0.17( 1.46;0.14) 0.38±0.23( 1.63;0.10) 0.33±0.17( 1.96;0.05)* 0.26±0.15( 1.72;0.09)P

SamplingEff 0.13±0.05( 2.55;0.01)* 0.23±0.08( 2.95;0.00)** 0.11±0.06( 1.86;0.06)P 0.20±0.08( 2.46;0.01)* 0.10±0.06( 1.78;0.07)P 0.11±0.05( 2.03;0.04)*

Richness_log - - - - - -

VIF 9.0±8.1 9.4±8.7 9.0±8.2 9.6±9.1 8.9±8.0 9.5±8.9 Overdispersion parameter

- - - - - - Pseudo-R2

80 74 89 69 86 80 Moran’s I

-0.02 0.02 -0.0025 0.0056 -0.03 -0.028

Continued Poisson Poisson Poisson

Variables ApteronotidaeSDM PimelodidaeSDM LebiasinidaeSDM

(Intercept) 3.04±0.08(36.65;0.00) 3.60±0.07(54.65;0.00) 2.49±0.10(24.19;0.00)

PebasLake 0.18±0.08( 2.18;0.03)* 0.06±0.07( 0.88;0.38) -0.03±0.10(-0.33;0.74)

Sea-level+25m -0.09±0.09(-0.96;0.34) -0.10±0.07(-1.41;0.16) -0.14±0.11(-1.25;0.21)

Sea-level+100m 0.04±0.10( 0.36;0.72) -0.07±0.08(-0.85;0.40) -0.06±0.12(-0.50;0.62)

PC1_ClimCurrPast_diff. -0.12±0.11(-1.11;0.27) -0.13±0.08(-1.59;0.11) 0.03±0.13( 0.27;0.79)

PC2_ClimCurrPast_diff. 0.10±0.09( 1.08;0.28) 0.12±0.07( 1.70;0.09)P 0.19±0.11( 1.74;0.08)P

PC3_ClimCurrPast_diff. -0.10±0.10(-1.08;0.28) -0.09±0.07(-1.34;0.18) -0.25±0.12(-2.11;0.03)*

DistMouth -0.77±0.27(-2.82;0.00)** -0.09±0.21(-0.42;0.68) -0.19±0.33(-0.56;0.57)

TributaryPosition 0.58±0.19( 3.11;0.00)** 0.17±0.14( 1.19;0.23) 0.26±0.23( 1.14;0.26)

Area_log 0.14±0.07( 1.90;0.06)P 0.15±0.06( 2.57;0.01)* 0.29±0.09( 3.22;0.00)**

Waterfall_log 0.13±0.06( 1.99;0.05)* 0.06±0.05( 1.33;0.18) 0.01±0.08( 0.18;0.85)

NetworkDensity.s -0.04±0.06(-0.69;0.49) -0.02±0.04(-0.37;0.71) -0.02±0.07(-0.33;0.74)

PC1_elev -0.32±0.19(-1.71;0.09)P -0.10±0.13(-0.80;0.43) -0.05±0.24(-0.22;0.83)

SoilDiv 0.10±0.07( 1.49;0.14) 0.04±0.05( 0.79;0.43) 0.04±0.08( 0.44;0.66)

ShanDiv_log -0.09±0.10(-0.88;0.38) -0.01±0.07(-0.13;0.90) -0.06±0.12(-0.48;0.63)

WaterColorClear -0.15±0.11(-1.31;0.19) -0.07±0.09(-0.76;0.45) -0.03±0.13(-0.20;0.84)

WaterColorWhite -0.01±0.09(-0.07;0.95) 0.04±0.07( 0.56;0.57) 0.17±0.12( 1.43;0.15)

PC1_water -0.24±0.19(-1.25;0.21) -0.17±0.14(-1.16;0.25) -0.21±0.23(-0.89;0.37)

PC2_water 0.02±0.14( 0.14;0.89) 0.03±0.10( 0.28;0.78) 0.14±0.17( 0.84;0.40)

PC1_temp -0.23±0.26(-0.86;0.39) -0.32±0.18(-1.72;0.09)P -1.14±0.34(-3.31;0.00)***

PC2_temp 0.32±0.13( 2.41;0.02)* 0.30±0.09( 3.28;0.00)*** 0.56±0.19( 3.01;0.00)**

PC1_energ 0.02±0.28( 0.07;0.94) 0.06±0.20( 0.30;0.77) -0.21±0.36(-0.58;0.56)

PC2_energ 0.40±0.21( 1.91;0.06)P 0.34±0.15( 2.23;0.03)* 0.66±0.26( 2.58;0.01)**

SamplingEff 0.06±0.07( 0.94;0.35) 0.12±0.05( 2.21;0.03)* 0.14±0.08( 1.70;0.09)P

Richness_log - - -

VIF 9.1±8.2 9.7±9.3 9.0±8.0 Overdispersion parameter

- - - Pseudo-R2

73 69 83 Moran’s I

-0.0083 -0.021 0.017

Table S6. Families, genera, and number of species found exclusively west and east of the

Purus Arch. In gray, families occurring only West or East of the Purus Arch.

West of Purus Arch East of Purus Arch

Family Genus NbSpecies Family Genus NbSpecies Aspredinidae Acanthobunocephalus 1 Anablepidae Anableps 1 Aspredinidae Ernstichthys 2 Anostomidae Leptophilypnion 2 Aspredinidae Hoplomyzon 1 Anostomidae Sartor 2 Aspredinidae Xyliphius 2 Apteronotidae Megadontognathus 1 Astroblepidae Astroblepus 18 Aspredinidae Aspredo 1 Auchenipteridae Glanidium 1 Aspredinidae Platystacus 1 Auchenipteridae Spinipterus 1 Auchenipteridae Pseudauchenipterus 1 Callichthyidae Lepthoplosternum 4 Auchenipteridae Tocantinsia 1 Characidae Acrobrycon 2 Belonidae Strongylura 1 Characidae Astyanacinus 1 Characidae Bryconadenos 2 Characidae Attonitus 3 Characidae Bryconexodon 2 Characidae Austrolebias 1 Characidae Erythrocharax 1 Characidae Boehlkea 1 Characidae Hasemania 1 Characidae Bryconacidnus 3 Characidae Inpaichthys 1 Characidae Ceratobranchia 5 Characidae Macropsobrycon 1 Characidae Cheirodon 2 Characidae Phallobrycon 1 Characidae Gephyrocharax 2 Characidae Rhinopetitia 1 Characidae Grundulus 2 Cichlidae Araichthys 1 Characidae Markiana 1 Cichlidae Aspidoras 2 Characidae Microgenys 2 Cichlidae Curculionichthys 1 Characidae Monotocheirodon 3 Cichlidae Krobia 1 Characidae Oligosarcus 1 Cichlidae Retroculus 1 Characidae Othonocheirodus 1 Cichlidae Teleocichla 8 Characidae Ptychocharax 1 Clupeidae Rhinosardinia 1 Characidae Scopaeocharax 2 Loricariidae Baryancistrus 3 Characidae Serrabrycon 1 Loricariidae Harttia 4 Characidae Tucanoichthys 1 Loricariidae Hisonotus 4 Cichlidae Andinoacara 1 Loricariidae Hopliancistrus 1 Cichlidae Apistogrammoides 1 Loricariidae Maratecoara 1 Cichlidae Cyanogaster 1 Loricariidae Oligancistrus 1 Cichlidae Cynaogaster 1 Loricariidae Parancistrus 2 Cichlidae Heroina 1 Loricariidae Phycocharax 1 Cichlidae Nannacara 1 Loricariidae Scobinancistrus 2 Cichlidae Tahuantinsuyoa 2 Loricariidae Spectracanthicus 3 Crenuchidae Geryichthys 1 Poeciliidae Micropoecilia 1 Curimatidae Procerusternarchus 1 Poeciliidae Pamphorichthys 3 Cyprinodontidae Orestias 7 Poeciliidae Poecilia 1 Doradidae Hypodoras 1 Rhamphichthyidae Iracema 1 Doradidae Panaqolus 9 Rivulidae Melanorivulus 4 Heptapteridae Nannoglanis 1 Rivulidae Pituna 1 Heptapteridae Pariolius 1 Rivulidae Plesiolebias 1 Heptapteridae Phreatobius 3 Serrasalmidae Acnodon 2 Heptapteridae Rhamdella 2 Serrasalmidae Mylesinus 1 Lebiasinidae Piabucina 1 Serrasalmidae Ossubtus 1 Loricariidae Aposturisoma 1 Trichomycteridae Ammoglanis 1 Loricariidae Chaetostoma 22 Trichomycteridae Stegophilus 1 Loricariidae Cordylancistrus 3 Loricariidae Crossoloricaria 2 Loricariidae Etsaputu 1 Loricariidae Exastilithoxus 2 Loricariidae Fonchiiloricaria 1 Loricariidae Lipopterichthys 1 Loricariidae Loraxichthys 1 Loricariidae Neblinichthys 1 Loricariidae Niobichthys 1 Loricariidae Panqolus 1 Loricariidae Papiliolebias 3 Loricariidae Pareiorhaphis 1 Loricariidae Pseudohemiodon 3 Loricariidae Pseudolithoxus 1 Loricariidae Rhadinoloricaria 1

Loricariidae Sturisomatichthys 1 Potamotrygonidae Heliotrygon 1 Pseudopimelodidae Cephalosilurus 1 Rivulidae Andeancistrus 1 Rivulidae Aphyolebias 7 Rivulidae Austrofundulus 1 Rivulidae Neofundulus 2 Rivulidae Simpsonichthys 1 Rivulidae Trigonectes 2 Trichomycteridae Malacoglanis 1 Trichomycteridae Tridentopsis 1