Invasive species are a growing global economic and ecological problem. Invasive Indo-Pacific lionfish (Pterois spp.) are known to have extreme negative effects on coral-reef communities in the Bahamas, so understating their distribution within and among reefs, what limits their local movements, and the effects they have on native prey species...
Although only a minority of introduced species become established and have noticeable consequences in their new communities, some can displace native species, alter food webs, and cause local extinctions. Studying these invasive species can provide new insights into basic ecological questions as well as inform management strategies. Pacific lionfish (Pterois...
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MarkA. Hixon
Although only a minority of introduced species become established and
Biological invasions have been identified as one of the prominent drivers of global environmental change. In particular, invasive predators typically have substantial negative effects on populations of native prey, even driving species to extinction in extreme cases. However, beyond direct predatory effects, little is understood regarding the specific mechanisms by...
What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red lionfish (Pterois volitans). To assess the role of parasites in contributing to the success of this invasion, I...
Patterns of settlement of larvae and population dynamics
of juveniles are poorly known for coral reef fishes. During
1987 to 1989, I studied these phenomena in the domino
damselfish (Dascyllus albisella), a species endemic to the
Hawaiian Islands. Larvae settle onto branching coral heads
as new recruits (10-15 mm in...
Early theoretical models for the evolution of male-female
pairing were based largely on studies of birds. These models
assumed that biparental care of eggs and young was an
essential component of pairing. However, male-female pairing
is also a relatively common social system in coral-reef
fishes, and biparental care of young...
Ecologists have long questioned why fluctuating populations tend to persist rather than go extinct. Populations that persist indefinitely are regulated by mechanisms that cause demographic density dependence, which works to bound fluctuation above zero. In a series of studies, I have sought to determine the processes and mechanisms that regulate...
I examined two aspects of the reproductive behavior of the garibaldi, Hypsypops rubicundus, a temperate marine damselfish with male parental care. My primary objective was to determine the relationship between female choice and male parental investment in the care of offspring. In particular, I sought to determine: (1) how the...
The threespot damselfish, Stegastes planifrons,
maintains individual territories that are clustered on
coral patch reefs. My objective was to understand the
effects of territory clustering on behavior and fitness.
Fish with territories in the center of a cluster had
(relative to edge fish): higher mating success (number of
eggs), higher...
Understanding the dynamics of open marine populations is difficult. Ecological processes may vary with the spatial structure of the habitat, and this variation may subsequently affect demographic rates. In a series of observational and experimental studies in the Bahamas, I examined the roles of emigration, mortality, and predation in the...