Data from: Neglected patterns of variation in phenotypic plasticity: age- and sex-specific antipredator plasticity in a cichlid fish

The ability of organisms to plastically respond to changing environments
is well studied. However, variation in phenotypic plasticity during
ontogeny is less well understood despite its relevance of being an
important source of phenotypic variation in nature. Here, we
comprehensively study ontogenetic variation in morphological antipredator
plasticity across multiple traits in Pelvicachromis taeniatus, a Western
African cichlid fish with sexually dimorphic ornamentation. In a
split-clutch design, fish were raised under different levels of perceived
predation risk (conspecific alarm cues or distilled water). Morphological
plasticity varied substantially across ontogeny: it was first observable
at an early juvenile stage where alarm cue-exposed fish grew faster.
Subsequently, significant plasticity was absent until the onset of sexual
maturity. Here, alarm-cue-exposed males were bigger than control males,
which led to deeper bodies, longer dorsal spines, bigger caudal peduncles
and increased eye diameters. Sexual ornamentation emerged delayed in alarm
cue-exposed males. In later adulthood, the plastic responses receded.
Despite small effect sizes, these responses represent putative adaptive
plasticity as they are likely to reduce predation risk. In females, we did
not observe any plasticity. In accordance with theory, these results
suggest fine-tuned expression of plasticity that potentially increases
defenses during vulnerable developmental stages and reproductive output.