Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

Table 1 Mate choice trials among populations of Pseudotropheus zebra and related species in large arena tanks.

Dam Population	Majority Sire Population		Binomial Test one-tailed P	Wilcoxon Test one-tailed P	Fisher's Exact Test one-tailed P
	NB	SB
NB	4	0	0.063	Z = 1.826, P = 0.068
SB	0	5	0.031	Z = 2.023, P = 0.043
					< 0.01
	NO	SO
NO	6	0	0.016	Z = 2.201, P = 0.028
SO	2	5	0.227	Z = 0.507, P = 0.612
					0.016
	SB	SO
SB	2	2	0.500	Z = 0.000, P = 1.000
SO	0	4	0.063	Z = 1.826, P = 0.068
					0.214
	NB	NO
NB	4	0	0.063	Z = 1.618, P = 0.106
NO	2	5	0.227	Z = 0.676, P = 0.499
					0.045

Forty-nine broods from dams or sires involved in previous spawnings were eliminated from the original dataset to ensure data independence. The results were inconsistent with the predictions of the hypothesis of parallel speciation by divergence of male colour and associated female preference, with significant assortative mating between geographically and phylogenetically more distant populations with similarly-coloured males [northern orange P. emmiltos (NO) v southern orange P. thapsinogen (SO); northern blue P. zebra from Nkhata Bay (NB) v southern blue P. zebra from Chiofu Bay (SB)] but not between more closely related and geographically proximal populations with differently-coloured males (SO v SB; NO v NB). Shown are the frequencies with which males were estimated to have sired the majority of the offspring genotyped in a clutch. The Binomial Test and Fisher Exact Tests were based on these figures, while the Wilcoxon Test was based on the actual numbers of eggs typed for each clutch assigned to sires of the two populations. Significant p-values (α = 0.05) are in bold.

ISSN: 2730-7182