Maternal and paternal effects determine size, growth and performance in larvae of a tropical reef fish

Larval mortality in marine fishes is strongly linked to individual life history traits such as size and growth, but the processes that influence variability in these traits are poorly understood. We explore the relative importance of maternal and paternal influences and water temperature on the larval growth and performance characteristics of the tropical clownfish Amphiprion melanopus (Pomacentridae). Larvae were reared from an incomplete 4 male × 4 female diallel breeding cross at 2 temperatures (25 and 28°C). Paternity interacted with maternity and affected traits immediately prior to and after hatching. Size of larvae at metamorphosis was primarily affected by maternal and paternal influences, but not by rearing temperature. Paternity explained 52% of the variance in growth rates to metamorphosis, while the combination of paternity, maternity and temperature explained 30%. This strong paternal influence may be due to the extensive role males play in nesttending coupled with the relatively long embryonic duration of the species. A negative relationship between larval growth rate and mortality within a tank emphasised the importance of these parental effects to larval survival and also provides support for the ‘bigger is better’ hypothesis.