Aggressive nest guarding behavior of Caribbean sergeant major damselfish (Abudefduf saxatilis) in association with fish and nest size
Abstract: Among fish that lay their eggs on the ground (demersal) and have external fertilization (oviparous), typical parental care includes building a nest, then cleaning and guarding it as an investment in the fitness and survival of their offspring. Caribbean sergeant major damselfish, Abudefduf saxatilis, exhibit this typical behavior with males taking on a darker coloration when they prepare a nest and engage in mating rituals, then guard and aerate their brood. Aggression of the guarding A. saxatilis are guarding could be linked to a number of factors, such as territory size (is a larger nest area because a fish is more aggressive or are aggressive efforts less frequent as some can be sacrificed), how large the fish is (since bigger fish may attract more mates and have more eggs in their nest), or how old the nest is (since the amount of yolk decreases while biomass of fish increases as the eggs develop). Using observational and photographic data collected on SCUBA dives in Bonaire, no statistically significant correlations were observed between the fish size, nest area, number of eggs, and age of the nest with attack rate (aggressions in 20 minutes) or average response distance (how far from the nest a perceived threat was before the guarding male was aggressive).
Ever wondered why you were under attack by a sergeant major? Come to Kayley’s presentation, tomorrow evening in our lecture halls. (18:30, CIEE RSB)