Supplementary Information Ronco et al. | DOI: 10.1098/rspb.2019.1050

Supplementary Information

A functional trade-off between trophic adaptation and parental care predicts sexual dimorphism in fish

Fabrizia Ronco1*, Marius Roesti1,2* & Walter Salzburger1*

1 Zoological Institute, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland 2 Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T1Z4, Canada 3 Current address: Institute of Ecology and Evolution, University of Bern, 3012, Switzerland * All authors contributed equally to this work

Authors for correspondence: Fabrizia Ronco e-mail: [email protected] Marius Roesti e-mail: [email protected] Walter Salzburger e-mail: [email protected]

Sampling procedure Fish were caught using gill nets while snorkeling or scuba diving, or bought from local fishermen. After euthanasia with clove oil, specimens were measured (standard length = SL) and the sex was determined whenever possible. For subsequent morphological measurements, the entire gill apparatus was extracted and stored in 96% EtOH. For the stable isotope analysis, entire specimens were fixed in 10% formalin for 4 days, rinsed with water and transferred to 70% EtOH.

CT-scanning (figure b2 ) The mouthbrooding female (Paracyprichromis sp.) was euthanised on ice, fixed in 10% formalin and then gradually transferred to 100% EtOH. To increase contrast of the surface of the developing eggs in the buccal cavity, the mouth was rinsed repeatedly with 5% Lugol’s iodine (I3K). CT-scanning of the head region was carried out on a Bruker Skyscan 1174v2, at 50kV, 800µA using a 0.25mm Aluminium filter and 4500ms exposure time. Voxel size was 29.8µm with 600 projections. Reconstruction was performed using NRecon (Version: 1.6.10.2), post-processing and visualisation was done in CTvox (Version: 3.3). Eggs and gill rakers were afterwards highlighted on the image using Adobe Photoshop (CC 2017).

1 Supplementary Information Ronco et al. | DOI: 10.1098/rspb.2019.1050

a 1 0.5 0 0.5 1

erc 2 1

δ1 δ15 eoo lestr 1 0.5 sccr abr oblab eoon teor eotet a cabe ensp alac etac arooale epelo eo lpol elo cbel splep ren reca eose eopro rear ltas eppro etpol reac ren 0 arrale 0 rooo elteOpnas pb eta eosa stbr etep etas lorn eor epatt

2 22. nape acalnaper ar ltco Open apc este Intloo ltcal le enor pcol 1 nael 0.5 enla eopl cbr plep eoca

2 1 enthic pelaic

2 1 0 1 2 1 . .5

ren● .0 este ● ● reac .5 le ●● apc ●pcol .0 ● ●cbr acal ● plep● ltco● enor cbel nape eopl ● ●● ● epatt ●pb 2.5 ltcal●ltas ● ● ● teor Open ● eosa naper ●●epelo ● lestr eose●oblab ●eoca erc ● ● rear eoon aroo eopro● ● ● etas elte● ● ● ren● stbr ● Intloo eotet ● ● ●a ● ● 2.0 reca eo ●●Opnas eor elo sccr ● eoo ● rooo nael lorn etac ● ●● ● ● ● ale●ar ● ecorrecte ll raer lent ● ●etep ensp ● cabe 1.5 eta alac ●ar ● ● abr lpol ● splep ●● rale ● enla etpol ● 1.0 eppro enthic pelaic

−3.5 −3.0 −2.5 −2.0 −1.5 −1.0 −0.5 0 0.5 1.0 1.5 2.0 Trophic ecology (PC1 of δ15 δ1 c este reac abr lorn eotet aroo elte reca naper cbel enor erc plep Open splep ensp rooo bparental otbrooers Intloo nonotbrooers nape nparental otbrooers teor

rbes atbatn prcron cton aprolon ersson aplocron / ropen entocron potlapn reton nocron reatocarn locron

Figure S1: Trophic ecology of 65 Tanganyikan cichlid species, its correlation with gill raker morphology, and the distribution of the different breeding modes across the phylogeny (See supplementary table S1 for full species names): (a) A scaled Principal Component Analysis (PCA) of stable isotope measurements (δ15N and δ13C, species means) was used to infer the major axis of variation across two major components of aquatic ecology: the benthic-pelagic (δ13C) and trophic (δ15N) position. We used PC1-scores (equally loaded with two components (δ15N: 0.71, δ13C: -0.71)) in downstream analyses as a univariate proxy for trophic ecology. (b) Phenotype-environment correlation between gill raker length and trophic ecology across 65 Tanganyikan cichlid species. Gill raker length (species mean) is positively associated with PC1-scores of stable isotope data. (c) The phylogenetic structure of the three different breeding modes.

2 Supplementary Information Ronco et al. | DOI: 10.1098/rspb.2019.1050

a

sprotilapia leptra

retmos cyanosticts

nathochromis permaillaris

reenooochromis ellcrossi

bparental Perissos microlepis otbrooers enotilapia spilopters

halinochromis richari

liochromis ornats

eolamprolos tetracanths non elmatochromis temporalis

otbrooers ariailichromis moorii

enthochromis horii 15

tenochromis horei 2580

yprichromis leptosoma 510

nathochromis peeri 200

emiates stenosoma 2

nterochromis looci nparental

otbrooers Ophthalmotilapia ventralis 101

rematocara macrostoma

rophes moori 51

0. 0. 0.2 0.0 0.2 0. 0. 0 1 2 3 4 Derence n secorrecte Mean gill raker length (mm) ll raer lent

Figure S2: Sexual dimorphism in gill raker lengths. (a) Mean gill raker length for either sex of each species, illustrating the extent and the direction of sexual dimorphism with respect to the actual gill raker length. The realized trait value in females (mouthbrooding sex) in respect to males does not show a shift in trait values towards a certain gill raker length across all spe- cies (optimum), suggesting more than one optimum for mouthbrooding. (b) Difference in size-corrected gill raker length for each species. Numbers next to the data points indicate clutch size [1].

sprotilapia leptra

retmos cyanosticts

nathochromis permaillaris

reenooochromis ellcrossi

bparental Perissos microlepis otbrooers enotilapia spilopters

halinochromis richari

liochromis ornats

eolamprolos tetracanths non elmatochromis temporalis

otbrooers ariailichromis moorii

enthochromis horii

tenochromis horei

yprichromis leptosoma

nathochromis peeri

emiates stenosoma

nterochromis looci nparental

otbrooers Ophthalmotilapia ventralis

rematocara macrostoma

rophes moori

−1 −0.5 0 −0.5 1 ce erence PC1-scores of δ15 δ13

Figure S3: Niche divergence between males and females: Difference in PC1-scores (δ15N and δ13C stable isotope signatures) between the sexes showed no evidence for niche divergence between males and females in uni-parental mouthbrooders that are sexually dimorphic in gill raker morphology. Due to missing sex information in the stable isotope data only a subset of species was tested with a very reduced sample size per species (see supplementary table S1). Note that in Ophthalmotilapia ventrails, the only species with divergent niche use, males and females differ in habitat preference: While males are territorial in the shallows, females school in deeper waters. Therefore, it is not surprising that the sexes differ in their stable isotope signatures (especially in δ13C).

3 Supplementary Information Ronco et al. | DOI: 10.1098/rspb.2019.1050

Table S1. Overview of all 65 Tanganyika cichlid species investigated in this study, including information on (species and tribes), breeding mode, and sample sizes. Number of gill raker measurements taken from Muschick et al. [2] are given in brackets.

species information gill raker measurements stable isotope analysis Ntotal comments food type species (data from [1]) full name tribe breeding mode Nmales Nfemales newly aquired taken from Nmales Nfemales Ntotal abb. total for this study [2] Altcal Altolamprologus calvus Lamprologini non-mouthbrooder (substrate brooder) 0 1 0 (+1) 1 3 NA 10 Altcom Altolamprologus compressiceps Lamprologini non-mouthbrooder (substrate brooder) 2 1 3 (+11) 14 NA 1 10 Asplep Asprotilapia leptura bi-parental mouthbrooder 14 15 27 (+8) 35 4 5 10 tested for sexual dimorphism aufwuchs Astbur Astatotilapia burtoni Haplochromini uni-parental mouthbrooder (maternal) 6 2 0 (+10) 10 4 3 10 Auldew Aulonocranus dewindti Ectodini uni-parental mouthbrooder (maternal) 1 NA 1 (+11) 12 2 3 10 Benhor Benthochromis horii Benthochromini uni-parental mouthbrooder (maternal) 14 7 19 (+3) 22 6 4 10 tested for sex dimorphism zooplankton Calmac Callochromis macrops Ectodini uni-parental mouthbrooder (maternal) 1 NA 0 (+10) 10 5 2 10 Chabri Chalinochromis brichardi Lamprologini non-mouthbrooder (substrate brooder) 5 5 9 (+4) 13 3 1 10 tested for sex dimorphism picks sponges & inverebrates Cphgib Cyphotilapia gibberosa Cyphotilapiini uni-parental mouthbrooder (maternal) 2 4 0 (+8) 8 4 1 10 picks tiny shrimps & sift Ctehor Ctenochromis horei Tropheini uni-parental mouthbrooder (maternal) 16 16 30 (+10) 40 6 NA 10 tested for sex dimorphism worms from sand Cyafur Cyathopharynx furcifer Ectodini uni-parental mouthbrooder (maternal) 4 NA 0 (+9) 9 6 4 10 Cypcol Cyprichromis coloratus Cyprichromini uni-parental mouthbrooder (maternal) 2 1 3 3 5 2 10 Cyplep Cyprichromis leptosoma Cyprichromini uni-parental mouthbrooder (maternal) 17 15 31 (+11) 42 5 4 10 tested for sexual dimorphism zooplankton Enamel Enantiopus melanogenys Ectodini uni-parental mouthbrooder (maternal) 1 5 0 (+7) 7 9 1 10 Erecya Eretmodus cyanostictus Eretmodini bi-parental mouthbrooder 15 15 30 (+9) 39 4 6 10 tested for sexual dimorphism filamentous algae sucks tiny invertebras from Gnaper Gnathochromis permaxillaris Limnochromini bi-parental mouthbrooder 19 16 35 35 NA NA 10 tested for sexual dimorphism muddy bottom picks shrimps form the Gnapfe Gnathochromis pfefferi Tropheini uni-parental mouthbrooder (maternal) 7 12 18 (+8) 26 2 2 10 tested for sexual dimorphism substrate Gralem Grammatotria lemairii Ectodini uni-parental mouthbrooder (maternal) NA 1 0 (+4) 4 3 2 10 Gwcabe Greenwoodochromis abeelei Limnochromini bi-parental mouthbrooder 2 6 8 8 4 1 10 small fish or shrimps Gwcbel Greenwoodochromis bellcrossi Limnochromini bi-parental mouthbrooder 15 7 22 22 1 1 10 tested for sexual dimorphism (speculative) Hapmic Haplotaxodon microlepis Perissodini bi-parental mouthbrooder 1 2 0 (+15) 15 7 2 10 Hemste Hemibates stenosoma Bathybatini uni-parental mouthbrooder (maternal) 13 11 25 25 6 4 10 tested for sexual dimorphism small fish Intloo Interochromis loocki Tropheini uni-parental mouthbrooder (maternal) 17 15 31 (+10) 41 1 2 10 tested for sexual dimorphism diatoms & cyanobacteria Julorn Julidochromis ornatus Lamprologini non-mouthbrooder (substrate brooder) 5 3 7 (+8) 15 NA NA 10 tested for sexual dimorphism picks sponges & inverebrates Lamcal Lamprologus callipterus Lamprologini non-mouthbrooder (substrate brooder) 5 NA 3 (+12) 15 1 4 10 Lamlem Lamprologus lemairii Lamprologini non-mouthbrooder (substrate brooder) 1 NA 1 (+5) 6 3 2 10 Lepatt Lepidiolamprologus attenuatus Lamprologini non-mouthbrooder (substrate brooder) NA NA 0 (+10) 10 4 3 10 Lepelo Lepidiolamprologus elongatus Lamprologini non-mouthbrooder (substrate brooder) NA 1 0 (+10) 10 1 1 10 Leppro Lepidiolamprologus profundicola Lamprologini non-mouthbrooder (substrate brooder) 2 2 0 (+5) 5 3 6 10 Limdar Limnotilapia dardennii Tropheini uni-parental mouthbrooder (maternal) NA 2 2 (+8) 10 3 5 10 Loblab Lobochilotes labiatus Tropheini uni-parental mouthbrooder (maternal) NA 3 0 (+15) 15 1 2 10 Neocau Neolamprologus caudopunctatus Lamprologini non-mouthbrooder (substrate brooder) 1 5 5 (+10) 15 2 4 10 Neofas Neolamprologus fasciatus Lamprologini non-mouthbrooder (substrate brooder) 5 1 5 (+10) 15 5 NA 10 Neofur Neolamprologus furcifer Lamprologini non-mouthbrooder (substrate brooder) NA NA 0 (+1) 1 4 3 10 Neomod Neolamprologus modestus Lamprologini non-mouthbrooder (substrate brooder) 3 NA 3 (+9) 12 6 1 10 Neomon Neolamprologus mondabu Lamprologini non-mouthbrooder (substrate brooder) NA NA 0 (+4) 4 5 5 10 Neomux Neolamprologus mustax Lamprologini non-mouthbrooder (substrate brooder) NA NA 0 (+2) 2 4 3 10 Neopro Neolamprologus prochilus Lamprologini non-mouthbrooder (substrate brooder) NA NA 0 (+1) 1 4 4 10 Neopul Neolamprologus pulcher Lamprologini non-mouthbrooder (substrate brooder) 2 NA 2 (+11) 13 NA NA 10 Neosav Neolamprologus savoryi Lamprologini non-mouthbrooder (substrate brooder) 2 NA 1 (+11) 12 3 NA 10 Neosex Neolamprologus sexfasciatus Lamprologini non-mouthbrooder (substrate brooder) NA 2 0 (+8) 8 5 2 10 Neotet Neolamprologus tetracanthus Lamprologini non-mouthbrooder (substrate brooder) 5 4 8 (+6) 14 2 NA 10 tested for sexual dimorphism snails Ophnas Ophthalmotilapia nasuta Ectodini uni-parental mouthbrooder (maternal) NA 2 0 (+5) 5 5 5 10 Ophven Ophthalmotilapia ventralis Ectodini uni-parental mouthbrooder (maternal) 16 12 27 (+11) 38 5 5 10 tested for sexual dimorphism phytoplankton & aufwuchs Pcybri Paracyprichromis brieni Cyprichromini uni-parental mouthbrooder (maternal) 1 NA 1 (+5) 6 4 4 10 Permic Perissodus microlepis Perissodini bi-parental mouthbrooder 15 21 30 (+10) 40 1 1 10 tested for sexual dimorphism fish scales Peteph Petrochromis ephippium Tropheini uni-parental mouthbrooder (maternal) NA 1 0 (+5) 5 NA NA 10 Petfam Petrochromis famula Tropheini uni-parental mouthbrooder (maternal) NA 3 0 (+10) 10 3 NA 10 Petfas Petrochromis fasciolatus Tropheini uni-parental mouthbrooder (maternal) 1 0 1 1 3 3 10 Petmac Petrochromis macrognathus Tropheini uni-parental mouthbrooder (maternal) NA 2 0 (+10) 10 6 3 10 Petpol Petrochromis polyodon Tropheini uni-parental mouthbrooder (maternal) 2 NA 0 (+7) 7 2 4 10 Plestr Plecodus straeleni Perissodini bi-parental mouthbrooder NA 2 0 (+10) 10 6 2 10 Psccur Pseudosimochromis curvifrons Tropheini uni-parental mouthbrooder (maternal) 3 2 0 (+10) 10 5 4 10 Simdia Simochromis diagramma Tropheini uni-parental mouthbrooder (maternal) NA 2 0 (+10) 10 1 5 10 Teldho Telmatochromis dhonti Lamprologini non-mouthbrooder (substrate brooder) 3 0 3 3 NA NA 10 Teltem Telmatochromis temporalis Lamprologini non-mouthbrooder (substrate brooder) 5 4 9 (+4) 13 6 NA 10 tested for sexual dimorphism filamentous algea, plankton fish or zooplankton Tremac Trematocara macrostoma Trematocarini uni-parental mouthbrooder (maternal) 8 7 15 15 6 4 10 tested for sexual dimorphism (speculative) Tremar Trematocara marginatum Trematocarini uni-parental mouthbrooder (maternal) 0 1 1 1 7 5 12 Trenig Trematocara nigrifrons Trematocarini uni-parental mouthbrooder (maternal) 0 12 12 12 5 15 20 Treuni Trematocara unimaculatum Trematocarini uni-parental mouthbrooder (maternal) 7 3 10 10 4 2 9 Tromoo Tropheus moorii Tropheini uni-parental mouthbrooder (maternal) 15 16 30 (+10) 40 2 NA 10 tested for sexual dimorphism filamentous algea Tylpol Tylochromis polylepis Tylochromini uni-parental mouthbrooder (maternal) NA NA 0 (+3) 3 6 2 10 filamentous algea, diatoms, Varmoo Variabilichromis moorii Lamprologini non-mouthbrooder (substrate brooder) 6 9 9 (+10) 19 NA NA 10 tested for sexual dimorphism ostracods Xenfla Xenotilapia flavipinnis Ectodini bi-parental mouthbrooder 1 1 0 (+7) 7 NA NA 10 insect larvea, rarely Xenspi Xenotilapia spilopterus Ectodini bi-parental mouthbrooder 17 15 31 (+5) 36 1 1 10 tested for sexual dimorphism zooplankton Total 65 species 13 tribes 3 breeding modes 305 295 508 (+427) 935 224 161 661 20 species

4 Supplementary Information Ronco et al. | DOI: 10.1098/rspb.2019.1050

Table S2: Summary tables of tests for sexual dimorphism in 20 cichlid species, and for the association (a) between sexual dimorphism and breeding mode. Statistically significant p-values (p < 0.05) are highlighted breeding difference in bold.species (a) Testing for a difference in mean size-correctedCImin gill raker lengthCImax betweenp -valuefemales and males within mode each species. (b) Testing mean dimorphismf-m per breeding mode for deviation from zero. (c) ANOVA statistics (a) on Asprotilapiamean absolute leptura dimorphism among the 0.031breeding modes.-0.014 (d) Pairwise0.077 comparisons0.208 of absolute difference in (a)breeding meanEretmodus sexual cyanostictus dimorphism in gill raker lengthdifference0.015 among breeding-0.029 modes. 0.058 0.535 species CImin CImax p -value breedingmode Gnathochromis permaxillaris difference0.000f-m -0.128 0.134 0.998 ((a)speciesa) CImin CImax p -value mode GreenwoodochromisAsprotilapia leptura bellcrossi -0.0590.031f-m -0.218-0.014 0.0930.077 0.4760.208

bi-parental Asprotilapiabreeding leptura 0.031 difference-0.014 0.077 0.208 PerissodusEretmodus cyanostictusmicrolepisspecies -0.0190.015 -0.077-0.029 CImin0.0410.058 CImax0.5710.535 p -value mouthbrooders mode f-m XenotilapiaGnathochromisEretmodus cyanostictusspilopterus permaxillaris 0.0020.0000.015 -0.027-0.128-0.029 0.0310.1340.058 0.8950.9980.535 Asprotilapia leptura 0.031 -0.014 0.077 0.208 ChalinochromisGreenwoodochromisGnathochromis permaxillarisbrichardi bellcrossi -0.038-0.0590.000 -0.099-0.218-0.128 0.0200.0930.134 0.2760.4760.998

bi-parental Eretmodus cyanostictus 0.015 -0.029 0.058 0.535 JulidochromisPerissodusGreenwoodochromis microlepis ornatus bellcrossi -0.059-0.007-0.019 -0.120-0.077-0.218 0.0930.041 0.8890.5710.476 mouthbrooders

bi-parental Gnathochromis permaxillaris 0.000 -0.128 0.134 0.998 XenotilapiaPerissodus microlepisspilopterus -0.0190.002 -0.027-0.077 0.0310.041 0.8950.571

mouthbrooders Neolamprologus tetracanthus -0.047 -0.152 0.044 0.391 non- Greenwoodochromis bellcrossi -0.059 -0.218 0.093 0.476 TelmatochromisChalinochromisXenotilapia spilopterus brichardi temporalis -0.005-0.0380.002 -0.059-0.099-0.027 0.0440.0200.031 0.8530.2760.895 bi-parental Perissodus microlepis -0.019 -0.077 0.041 0.571 mouthbrooders mouthbrooders VariabilichromisJulidochromisChalinochromis ornatus brichardi moorii -0.038-0.009-0.007 -0.076-0.120-0.099 0.0600.0930.020 0.8280.8890.276 Xenotilapia spilopterus 0.002 -0.027 0.031 0.895 NeolamprologusJulidochromis ornatus tetracanthus -0.007-0.047 -0.152-0.120 0.0440.093 0.3910.889

non- Benthochromis horii -0.205 -0.437 0.029 0.126 Chalinochromis brichardi TelmatochromisNeolamprologus temporalistetracanthus -0.047 -0.038-0.152 -0.0990.044 0.0200.391 0.276 non- Ctenochromis horei -0.0050.139 -0.0590.044 0.2320.044 0.0060.853 Julidochromis ornatus -0.007 -0.120 0.093 0.889 mouthbrooders CyprichromisVariabilichromisTelmatochromis leptosoma temporalismoorii -0.005-0.201-0.009 -0.315-0.076-0.059 -0.0870.0600.044 0.0030.8280.853

mouthbrooders Neolamprologus tetracanthus -0.047 -0.152 0.044 0.391 GnathochromisBenthochromisVariabilichromisnon- horiipfefferi moorii -0.009-0.2050.017 -0.094-0.437-0.076 0.1190.0290.060 0.7580.1260.828 Telmatochromis temporalis -0.005 -0.059 0.044 0.853 HemibatesCtenochromisBenthochromis stenosoma horei horii -0.2050.2370.139 -0.035-0.4370.044 0.5240.2320.029 0.0060.1110.126 mouthbrooders Variabilichromis moorii -0.009 -0.076 0.060 0.828 InterochromisCyprichromisCtenochromis leptosoma horeiloocki -0.2010.0570.139 -0.036-0.3150.044 -0.0870.1500.232 0.0030.0060.252 uni-parental Benthochromis horii -0.205 -0.437 0.029 0.126 mouthbrooders OphthalmotilapiaGnathochromisCyprichromis leptosoma pfefferi ventralis -0.2010.0460.017 -0.110-0.094-0.315 -0.0870.2330.119 0.0030.6110.758 Ctenochromis horei 0.139 0.044 0.232 0.006 TrematocaraHemibatesGnathochromis stenosoma macrostoma pfefferi -0.3410.2370.017 -0.563-0.035-0.094 -0.1220.5240.119 0.0140.1110.758 Cyprichromis leptosoma -0.201 -0.315 -0.087 0.003 TropheusInterochromisHemibates moori stenosoma loocki -0.0450.0570.237 -0.134-0.036-0.035 0.0450.1500.524 0.2520.1110.34 uni-parental Gnathochromis pfefferi 0.017 -0.094 0.119 0.758 mouthbrooders OphthalmotilapiaInterochromis loocki ventralis 0.0460.057 -0.110-0.036 0.2330.150 0.6110.252 uni-parental

mouthbrooders Hemibates stenosoma 0.237 -0.035 0.524 0.111 TrematocaraOphthalmotilapia macrostoma ventralis -0.3410.046 -0.563-0.110 -0.1220.233 0.0140.611 Interochromis loocki 0.057 -0.036 0.150 0.252 (b ) TropheusTrematocarauni-parental moori macrostoma -0.341-0.045 -0.134-0.563 -0.1220.045 0.0140.34 Tropheusmouthbrooders mooriOphthalmotilapia ventralis -0.045 0.046-0.134 -0.1100.045 0.2330.34 0.611 breeding modeTrematocara macrostoma meanmode -0.341CImin -0.563CImax -0.122p -value 0.014 Tropheus moori -0.045 -0.134 0.045 0.34 (b ) bi-parental mouthbrooders -0.005 -0.029 0.015 0.722 (b ) non-mouthbrooders -0.021 -0.037 -0.006 0.068 (breedinguni-parentalb) mode mouthbrooders mean-0.033mode -0.152CImin 0.079CImax p0.617-value (bi-parentalbreedingb ) mode mouthbrooders mean-0.005mode -0.029CImin 0.015CImax p0.722-value non-mouthbroodersbi-parental mouthbrooders -0.005-0.021 -0.037-0.029 -0.0060.015 0.0680.722 breeding mode meanmode CImin CImax p -value (c ) uni-parentalnon-mouthbrooders mouthbrooders -0.021-0.033 -0.152-0.037 -0.0060.079 0.6170.068 uni-parental mouthbroodersbi-parental mouthbrooders -0.033 -0.005-0.152 -0.0290.079 0.0150.617 0.722 non-mouthbrooders -0.021p -value -0.037p-value -0.006 0.068 model F-statistics uni-parental mouthbrooders -0.033lm() phylANOVA()-0.152 0.079 0.617 (c ) (c ) (abs(dimorphism)c) ~ mode F = 6.19 0.007 0.17 p -value p-value model F-statistics p -valuelm() phylANOVA()p-value (modelc ) F-statistics abs(dimorphism) ~ mode F = 6.19 0.007lm() phylANOVA()0.17 p -value p-value abs(dimorphism)model ~ mode F = 6.19 F-statistics0.007 0.17 (d ) (d) lm() phylANOVA() abs(dimorphism) ~ mode mean F = p6.19-value 0.007p-value 0.17 comparison difference lm() phylANOVA() (d ) difference abs(UNI) vs. abs(BI) 0.122 0.015 0.031 (d ) difference abs(UNI) vs. abs(NON) mean0.122 p0.022-value p-value0.172 comparison difference abs(NON) vs. abs(BI) difference<0.001mean p0.995-valuelm() phylANOVA()p-value1.000 (comparisond ) difference abs(UNI) vs. abs(BI) difference0.122 0.015lm() phylANOVA()0.031 mean p -value p-value difference abs(comparisonUNI) vs. abs(NONBI) ) 0.122 0.0150.022 0.0310.172 difference abs(NONUNI) )vs. vs. abs( abs(NONBI) ) <0.0010.122 difference0.0220.995 lm()1.0000.172 phylANOVA() difference abs(differenceNON) vs. abs(UNIBI) ) vs. abs(BI) <0.001 0.1220.995 0.0151.000 0.031 difference abs(UNI) vs. abs(NON) 0.122 0.022 0.172 difference abs(NON) vs. abs(BI) <0.001 0.995 1.000

5 Supplementary Information Ronco et al. | DOI: 10.1098/rspb.2019.1050

Table S3: Summary of the break-point model fitted to investigate the association between sexual dimorphism in gill raker length with trophic ecology within uni-parental mouthbrooders. Statistically significant p-values (p < 0.05) are highlighted in bold.

lm() davies.test() segmented.lm() phylANOVA() model R2 adjusted R2 F-statistics p -value p -value R2 breakpoint adjusted R2 t-statistics p -value

dimorphUN I ~ PC1UN I 0.56 0.50 8.92 0.020 0.044 0.87 0.344 0.796 - -

dimorphUNI(PC1<0.34) vs. ------4.8 0.001 dimorphUNI(PC1>0.34)

References

1. Konings A. 2015 Tanganyika in their natural habitat. 3th Editio. El Paso: Cichlid Press. 2. Muschick M, Nosil P, Roesti M, Dittmann MT, Harmon L, Salzburger W. 2014 Testing the stages model in the adaptive radiation of cichlid fishes in East African . Proc. R. Soc. B Biol. Sci. 281, 20140605–20140605. (doi:10.1098/rspb.2014.0605)

6