Temporal links in daily activity patterns between coral reef predators and their prey

Area of Science:

• Marine biology
• Behavioral ecology
• Coral reef ecosystems

Background:

• Diel cycles are critical for predator-prey dynamics in coral reefs.
• Limited research exists on the 24-hour activity patterns of common reef predators and prey.
• Understanding temporal niche partitioning is key to reef fish community structure.

Purpose of the Study:

• To document and compare the diel activity patterns of two reef predators, Cephalopholis cyanostigma (rockcod) and Pseudochromis fuscus (dottyback).
• To compare predator activity patterns with those of a common prey species, juvenile Pomacentrus moluccensis (lemon damselfish).
• To investigate the behavioral adaptations of prey in response to predator activity over a 24-hour cycle.

Main Methods:

• Field observations of fish behavior over 24-hour periods.
• 24-hour infrared video recordings in a laboratory setting.
• Analysis of feeding strikes, aggression, shelter proximity, and boldness in prey species.

Main Results:

• Cephalopholis cyanostigma exhibited continuous 24-hour activity, with feeding peaks at dusk and increased activity at dawn and dusk.
• Pseudochromis fuscus was inactive at night, with peak feeding activity at midday.
• Pomacentrus moluccensis reduced foraging and aggression at dawn and dusk, and decreased boldness at dusk, opposing predator activity.

Conclusions:

• Predator activity patterns are influenced by physiological factors (vision, circadian rhythms) and ecological factors (hunting success, predation risk).
• Prey behavior, like that of juvenile Pomacentrus moluccensis, is a strategic response to minimize predation risk.
• Temporal niche partitioning is a significant factor structuring coral reef fish communities and interactions.