Environmental Morphological Divergence and Its Integration With Collective Behavior in Cooperative Pseudoscorpions

ABSTRACT Ecological heterogeneity may be associated with morphological divergence and with the integration of morphology and collective behavior are integrated within social groups. We tested the hypothesis that the proportional development of the prey‐capture apparatus forms part of an integrated colony phenotype in the cooperative pseudoscorpion Paratemnoides nidificator . We quantified the cephalothorax and three pedipalp structures of 1,092 individuals from 39 colonies inhabiting an urban street‐tree matrix, an urban forest park, and a peri‐urban natural reserve in Central Brazil. We predicted morphological differentiation among areas and sexes and, critically, that colonies with proportionally more developed pedipalps would express a more proactive collective phenotype. Colony‐aware geometric morphometric analyses revealed marked shape differentiation among areas in all four structures and consistent sexual dimorphism, although the pattern of shape dimorphism did not vary among areas. As predicted, relative pedipalp development covaried positively with a predefined collective‐behavior index: colonies with proportionally more developed pedipalps responded faster, recruited more attackers, and persisted longer during collective prey capture. This association was robust to alternative definitions of relative morphology and involved all three pedipalp structures, whereas absolute pedipalp and cephalothorax size were unrelated to behavior. We also explored whether local resource composition could account for morphological variation. Prey availability showed a nominal within‐area association with multivariate chela shape, but this relationship was not supported after family‐wise correction; realized diet and prey‐selection profiles showed no consistent associations morphological associations. Our findings support an integrated colony phenotype linking proportional prey‐capture morphology to collective behavioral strategy.