DEDICATION

ACKNOWLEDGEMENTS

TABLE OF CONTENTS

INTRODUCTION

ZOOGEOGRAPHY

ECOLOGY

BIOLOGY AND BEHAVIOR

VALUE OF FISH RESOURCES

CONSERVATION AND MANAGEMENT

DANGEROUS MARINE FISHES

HOW TO USE THIS BOOK

BIBLIOGRAPHY

SPECIES INDEX

CHAMORRO NAMES

POMACENTRIDAE (DAMSELFISHES)

Stegastes nigricans (Lacepède)
(Dusky Farmerfish; Fomho)
SL: to 11 cm (photo: 7 cm SL, Apra Harbor, 8 m)

This rather drab species is a common inhabitant of shallow protected reefs from depths of 1 to 10 m.  It is extremely pugnacious and territorial and occurs in small groups that occupy and subdivide patches of branching corals.  Fishes of this genus are herbivorous and have the curious habit of cultivating preferred species of algae by “weeding” – literally removing and discarding – undesired species of algae; hence their name “farmer-fishes.”  They aggressively drive away all intruders, particularly other herbivores, and will even nip at humans.  A similar species, S. lividus, attains a larger size and is even more aggressive.  It is distinguished by possessing a diffuse, rather than distinct, black spot at the base of its posteriormost dorsal fin rays.  It is the dominant Stegastes of staghorn Acropora thickets.  Both species are quite variable in coloration, ranging from light tan to almost black.

INDO-PACIFIC: E. Africa to the Tuamotus, Marquesas, and Line Is., n. to the Ryukyus and Bonins, s. to New Caledonia.