92
J.H. Choat
where it co-occurs at the same aggregation site as a large squaretail coralgrouper,
Plectropomus areolatus , aggregation in the Solomon islands (Alec Hughes personal
communication), as well as with the brown-marbled grouper, Epinephelus
fuscoguttatus , and the camoufl age grouper, E. polyphekadion , in Palau (Yvonne
Sadovy, 2010, Chap . 12.23 ). Up to 500 individuals may occur in an area 800 m
2
from 6 to 25 m depth. Pair-spawning is suggested by numerous observations (Alec
Hughes personal communication). It is noteworthy that the largest triggerfi sh aggregate at the same site as transient spawning groupers adjacent to reef passes on the
outer reef slope (Alec Hughes personal communication). Colin (Chap. 12.23 )
reports a similar reproductive pattern for the yellowmargin triggerfi sh in Palau.
Rabbitfi shes are moderately sized (mean 28, range 18–39 cm) with aggregations
reported for nine species (SCRFA 2009 www.SCRFA.org ). However at least one
species Siganus argenteus produces dispersive eggs while others ( S. luridus, S, rivulatus, S. guttatus ) produce demersal adhesive eggs (Popper et al. 1979 ; Juario et al.
1985 ) . The mode of spawning is unclear although both pair- and group-spawning in
small groups within the aggregation have been inferred. Aggregations of Siganus
fuscescens have been described in Palau (Chap. 12.22 ).
4.3.1 Pelagic Egg Development
Pelagic egg development is the dominant mode in reef fi shes of intermediate
(19–38 cm) and large (>38 cm) size (Chap. 7 ). The former size class includes wrasses,
surgeonfi shes, butterfl yfi shes (Chaetodontidae), angelfi shes (Pomacanthidae), anthiids
(Serranidae; Anthiinae), and sandperches (Pinguipedidae) and the latter size group
includes groupers, snappers, jacks (Carangidae), wrasses, emperors (Lethrinidae),
grunts (Haemulidae) and large wrasses. Although small wrasses, particularly the
bluehead wrasse, Thalassoma bifasciatum , participate in resident spawning migrations (Warner 1995 ) most species at or below this size range spawn within the
normal foraging area (Robertson 1972 ; Walker and McCormick 2009 ; McCormick
et al. 2010 ) . The smaller (<19 cm) representatives, especially wrasses, sandperches
and some surgeonfi shes and scarine labrids [old name Scaridae – parrotfi shes and
hereafter referred to as parrotfi shes ], undergo localized pair spawning, frequently in
a haremic social structure without migration within the reef systems (Robertson
1983 ; Kuwamura et al. 2009 ; Walker and McCormick 2009 ) . Non-aggregative pair
spawning is prevalent in butterfl yfi shes (Colin 1989 ; Lobel 1989 ) which establish
long-term pair relationships, while angelfi shes are predominantly haremic spawners
(Allen et al. 1998 ) as are anthiids and sandperches (Walker and McCormick 2009 ) .
The major reproductive and biological characteristics of demersal and pelagic
spawning species are summarized in Table 4.8 . This predictably relates small size to
high levels of species diversity and increased abundances. Despite the apparent
ubiquity of pelagic spawning it is noteworthy that on coral reefs the majority of
species and individuals are demersal pair-spawners.
J.H. Choat
where it co-occurs at the same aggregation site as a large squaretail coralgrouper,
Plectropomus areolatus , aggregation in the Solomon islands (Alec Hughes personal
communication), as well as with the brown-marbled grouper, Epinephelus
fuscoguttatus , and the camoufl age grouper, E. polyphekadion , in Palau (Yvonne
Sadovy, 2010, Chap . 12.23 ). Up to 500 individuals may occur in an area 800 m
2
from 6 to 25 m depth. Pair-spawning is suggested by numerous observations (Alec
Hughes personal communication). It is noteworthy that the largest triggerfi sh aggregate at the same site as transient spawning groupers adjacent to reef passes on the
outer reef slope (Alec Hughes personal communication). Colin (Chap. 12.23 )
reports a similar reproductive pattern for the yellowmargin triggerfi sh in Palau.
Rabbitfi shes are moderately sized (mean 28, range 18–39 cm) with aggregations
reported for nine species (SCRFA 2009 www.SCRFA.org ). However at least one
species Siganus argenteus produces dispersive eggs while others ( S. luridus, S, rivulatus, S. guttatus ) produce demersal adhesive eggs (Popper et al. 1979 ; Juario et al.
1985 ) . The mode of spawning is unclear although both pair- and group-spawning in
small groups within the aggregation have been inferred. Aggregations of Siganus
fuscescens have been described in Palau (Chap. 12.22 ).
4.3.1 Pelagic Egg Development
Pelagic egg development is the dominant mode in reef fi shes of intermediate
(19–38 cm) and large (>38 cm) size (Chap. 7 ). The former size class includes wrasses,
surgeonfi shes, butterfl yfi shes (Chaetodontidae), angelfi shes (Pomacanthidae), anthiids
(Serranidae; Anthiinae), and sandperches (Pinguipedidae) and the latter size group
includes groupers, snappers, jacks (Carangidae), wrasses, emperors (Lethrinidae),
grunts (Haemulidae) and large wrasses. Although small wrasses, particularly the
bluehead wrasse, Thalassoma bifasciatum , participate in resident spawning migrations (Warner 1995 ) most species at or below this size range spawn within the
normal foraging area (Robertson 1972 ; Walker and McCormick 2009 ; McCormick
et al. 2010 ) . The smaller (<19 cm) representatives, especially wrasses, sandperches
and some surgeonfi shes and scarine labrids [old name Scaridae – parrotfi shes and
hereafter referred to as parrotfi shes ], undergo localized pair spawning, frequently in
a haremic social structure without migration within the reef systems (Robertson
1983 ; Kuwamura et al. 2009 ; Walker and McCormick 2009 ) . Non-aggregative pair
spawning is prevalent in butterfl yfi shes (Colin 1989 ; Lobel 1989 ) which establish
long-term pair relationships, while angelfi shes are predominantly haremic spawners
(Allen et al. 1998 ) as are anthiids and sandperches (Walker and McCormick 2009 ) .
The major reproductive and biological characteristics of demersal and pelagic
spawning species are summarized in Table 4.8 . This predictably relates small size to
high levels of species diversity and increased abundances. Despite the apparent
ubiquity of pelagic spawning it is noteworthy that on coral reefs the majority of
species and individuals are demersal pair-spawners.