95
4 Spawning Aggregations in Reef Fishes; Ecological and Evolutionary Processes
4.3.2 Variation in Reproductive Behaviour
Any classifi cation of reef fi sh reproductive biology must acknowledge the intraspecifi c
variation that occurs in population biology and reproductive parameters (Warner
1984 ; Clifton 1995 ; Gust 2004 ; Robertson et al. 2005 ; Ruttenberg et al. 2005 ; Trip
et al. 2008 ; McCormick et al. 2010 ) . Variation in local densities is an important
driver of reproductive behaviour and population biology (Peterson and Warner
2002 ; Gust et al. 2003 ; McCormick et al. 2010 ) , and may also infl uence patterns of
male recruitment (Munday et al. 2006b ) . As just one example the plasticity of reproductive biology in surgeonfi shes is high, ranging from pair-spawning to large aggregations and group-spawning within a single species at the same locality (Robertson
1983 ; Myrberg et al. 1988 , Chap. 12.20 ).
Robertson ( 1983 ) recorded a variety of spawning behaviours in two species,
brown surgeonfi sh, Acanthurus nigrofuscus , and striated surgeonfi sh, Ctenochaetus
striatus , in the western Indian Ocean ranging from localized pair spawning to large
resident aggregations comprising thousands of fi sh and group-spawning. Spawning
generally occurred on ebb tides leaving a mass of fertilized eggs to be transported
seawards by the tidal fl ow, a process well described by Hamner et al. ( 2007 ) . For
both brown and striated surgeonfi shes, localized group spawning and pair spawning
were recorded. In brown surgeonfi sh a lead female and groups of 6–15 males per
episode resulted in polyandrous matings. Large males set up feeding territories on
reef fl ats and pair spawned with individual females within the territory. Males may
also migrate short distances to set up lekking systems and pair-spawn with adjacent
females. In contrast group-spawning in large aggregations was achieved by migrations from reef fl at and crest feeding sites to outer reef slopes 0.3–0.4 km from
inshore habitats. Pair-spawning occurred within feeding territories. Streak or interference spawning by males from adjacent territories was observed. Although the
tropical Atlantic supports only three abundant species of surgeonfi sh, two species at
least, ocean surgeonfi sh, A. bahianus , and blue tang, A. coeruleus, maintain resident
spawning aggregations of thousands of individuals (Colin and Clavijo 1988 ,
Chap. 12.20 , Domeier and Colin 1997 ) . Both species have complex foraging and
feeding behaviour patterns and display the same levels of reproductive complexity
as their Indo-Pacifi c congeners.
Scarine labrids also exhibit intra-specifi c variation in spawning patterns
(Kuwamura et al. 2009 ) . The tropical Atlantic labrids, the redfi n parrotfi sh, Sparisoma
rubrippine (Randall and Randall 1963 ) , stoplight parrotfi sh, Sparisoma viride
(Van Rooij et al. 1996 ) , and striped parrotfi sh, Scarus iserti (Colin 1978 ) also display
aggregative spawning and complex reproductive behaviour. In the stoplight parrotfi sh
spawning behaviour varied from pair-spawning in haremic territories to multiple
male and female spawning groups.
Spawning usually occurred in deeper parts of the habitat at specifi c sites although
the extent to which local densities were enhanced by aggregation was unclear.
However in the case of the redfi n parrotfi sh, large resident spawning aggregations
were formed (Randall and Randall 1963 ) . Localized complexity in reproductive
4 Spawning Aggregations in Reef Fishes; Ecological and Evolutionary Processes
4.3.2 Variation in Reproductive Behaviour
Any classifi cation of reef fi sh reproductive biology must acknowledge the intraspecifi c
variation that occurs in population biology and reproductive parameters (Warner
1984 ; Clifton 1995 ; Gust 2004 ; Robertson et al. 2005 ; Ruttenberg et al. 2005 ; Trip
et al. 2008 ; McCormick et al. 2010 ) . Variation in local densities is an important
driver of reproductive behaviour and population biology (Peterson and Warner
2002 ; Gust et al. 2003 ; McCormick et al. 2010 ) , and may also infl uence patterns of
male recruitment (Munday et al. 2006b ) . As just one example the plasticity of reproductive biology in surgeonfi shes is high, ranging from pair-spawning to large aggregations and group-spawning within a single species at the same locality (Robertson
1983 ; Myrberg et al. 1988 , Chap. 12.20 ).
Robertson ( 1983 ) recorded a variety of spawning behaviours in two species,
brown surgeonfi sh, Acanthurus nigrofuscus , and striated surgeonfi sh, Ctenochaetus
striatus , in the western Indian Ocean ranging from localized pair spawning to large
resident aggregations comprising thousands of fi sh and group-spawning. Spawning
generally occurred on ebb tides leaving a mass of fertilized eggs to be transported
seawards by the tidal fl ow, a process well described by Hamner et al. ( 2007 ) . For
both brown and striated surgeonfi shes, localized group spawning and pair spawning
were recorded. In brown surgeonfi sh a lead female and groups of 6–15 males per
episode resulted in polyandrous matings. Large males set up feeding territories on
reef fl ats and pair spawned with individual females within the territory. Males may
also migrate short distances to set up lekking systems and pair-spawn with adjacent
females. In contrast group-spawning in large aggregations was achieved by migrations from reef fl at and crest feeding sites to outer reef slopes 0.3–0.4 km from
inshore habitats. Pair-spawning occurred within feeding territories. Streak or interference spawning by males from adjacent territories was observed. Although the
tropical Atlantic supports only three abundant species of surgeonfi sh, two species at
least, ocean surgeonfi sh, A. bahianus , and blue tang, A. coeruleus, maintain resident
spawning aggregations of thousands of individuals (Colin and Clavijo 1988 ,
Chap. 12.20 , Domeier and Colin 1997 ) . Both species have complex foraging and
feeding behaviour patterns and display the same levels of reproductive complexity
as their Indo-Pacifi c congeners.
Scarine labrids also exhibit intra-specifi c variation in spawning patterns
(Kuwamura et al. 2009 ) . The tropical Atlantic labrids, the redfi n parrotfi sh, Sparisoma
rubrippine (Randall and Randall 1963 ) , stoplight parrotfi sh, Sparisoma viride
(Van Rooij et al. 1996 ) , and striped parrotfi sh, Scarus iserti (Colin 1978 ) also display
aggregative spawning and complex reproductive behaviour. In the stoplight parrotfi sh
spawning behaviour varied from pair-spawning in haremic territories to multiple
male and female spawning groups.
Spawning usually occurred in deeper parts of the habitat at specifi c sites although
the extent to which local densities were enhanced by aggregation was unclear.
However in the case of the redfi n parrotfi sh, large resident spawning aggregations
were formed (Randall and Randall 1963 ) . Localized complexity in reproductive