Figure 4.

Larval Perissodus microlepis individuals exhibit discrete pharyngeal skeletal asymmetries. A clutch of P. microlepis was collected from the mouth of a wild-caught female and staged to the late larval period. Skeletal preparations revealed clear asymmetries in a subset of these individuals (A, B), including sided differences in the shape of Meckel's (me) and ceratohyal (ch) cartilages. The degree of asymmetry for each individual was quantified following Hori et al. [19], in which the differences in the angle from the preorbital processes to the premaxillary symphysis was determined. Unlike that found for adult fish, the distribution of larval asymmetries is unimodal (C). The arrow indicates mean laterality for the clutch. Abbreviation: pt, pharyngeal teeth.