110
J.H. Choat
and confi ned to the Atlantic and East Pacifi c. Although a comprehensive phylogenetic
analysis is not available for Lutjanus spp. the most derived clade is a complex of
relatively small species also confi ned to the IWP (Miller and Cribb 2007 ) . However
a more informed analysis of transient spawning in each ocean requires a better
database on the age-specifi c dynamics and abundance estimates (densities) of the
main species, especially the larger groupers, including the Nassau grouper.
Although there are a number of studies on the behaviour and spawning patterns
(Sadovy and Colin 1995 ; Sadovy and Eklund 1999 ; Erisman et al. 2009 ) we are
largely ignorant of the life span and age specifi c reproductive schedules of this
iconic species.
4.7.3 Lack of Information
Our capacity to understand the biological basis of spawning aggregations is compromised by the paucity of information on the anatomy and physiological processes associated with the annual reproductive cycles especially of the larger
groupers and snappers. This includes information on the costs of reproduction in
both resident and transient spawning groups in the context of income or capital
breeding systems.
There are a number of management and conservation implications in this
approach. If, as suggested, Indo-Pacifi c species and especially groupers are mainly
resident spawners with a smaller mean size than those of the tropical Atlantic then
protection of individual reefs (i.e. spatial approaches) may be an appropriate management response. This is especially true for the leopard coralgrouper, one of the
most important species in the live reef fi sh trade which attain high abundances compared to the larger Atlantic species and appear to form numerous small resident
spawning aggregations (see Chap. 8 ). For tropical Atlantic groupers which achieve
large size, occur in habitats with relatively small areas of reef environment and
exhibit transient spawning, more extensive areas, possibly in addition to other management measures, would need to be protected (Chap. 11 ).
A fi nal caveat concerns our coverage of the reproductive biology of reef fi shes.
As Tables 4.1 – 4.3 demonstrates the examples for which we have verifi ed examples
of spawning behaviour cover a tiny fraction of the reef fi sh fauna. However, regardless of the coverage we require better information on the trophic ecology, reproductive cycles and the wet machinery of internal nutrient storage and allocation. These
are the areas currently neglected in reef fi sh ecology. An appropriate end point is a
quotation from Munday et al. ( 2006a ) in a discussion on the adaptive signifi cance of
sex change. “This will require detailed information about sex-specifi c fecundity,
growth, mortality and movement patterns at the individual level. Only then can we
really assess how reproductive value is affected by the different breeding tactics
(male, female or non-breeder) that individuals can use.” This also applies to the
study of spawning aggregations.
J.H. Choat
and confi ned to the Atlantic and East Pacifi c. Although a comprehensive phylogenetic
analysis is not available for Lutjanus spp. the most derived clade is a complex of
relatively small species also confi ned to the IWP (Miller and Cribb 2007 ) . However
a more informed analysis of transient spawning in each ocean requires a better
database on the age-specifi c dynamics and abundance estimates (densities) of the
main species, especially the larger groupers, including the Nassau grouper.
Although there are a number of studies on the behaviour and spawning patterns
(Sadovy and Colin 1995 ; Sadovy and Eklund 1999 ; Erisman et al. 2009 ) we are
largely ignorant of the life span and age specifi c reproductive schedules of this
iconic species.
4.7.3 Lack of Information
Our capacity to understand the biological basis of spawning aggregations is compromised by the paucity of information on the anatomy and physiological processes associated with the annual reproductive cycles especially of the larger
groupers and snappers. This includes information on the costs of reproduction in
both resident and transient spawning groups in the context of income or capital
breeding systems.
There are a number of management and conservation implications in this
approach. If, as suggested, Indo-Pacifi c species and especially groupers are mainly
resident spawners with a smaller mean size than those of the tropical Atlantic then
protection of individual reefs (i.e. spatial approaches) may be an appropriate management response. This is especially true for the leopard coralgrouper, one of the
most important species in the live reef fi sh trade which attain high abundances compared to the larger Atlantic species and appear to form numerous small resident
spawning aggregations (see Chap. 8 ). For tropical Atlantic groupers which achieve
large size, occur in habitats with relatively small areas of reef environment and
exhibit transient spawning, more extensive areas, possibly in addition to other management measures, would need to be protected (Chap. 11 ).
A fi nal caveat concerns our coverage of the reproductive biology of reef fi shes.
As Tables 4.1 – 4.3 demonstrates the examples for which we have verifi ed examples
of spawning behaviour cover a tiny fraction of the reef fi sh fauna. However, regardless of the coverage we require better information on the trophic ecology, reproductive cycles and the wet machinery of internal nutrient storage and allocation. These
are the areas currently neglected in reef fi sh ecology. An appropriate end point is a
quotation from Munday et al. ( 2006a ) in a discussion on the adaptive signifi cance of
sex change. “This will require detailed information about sex-specifi c fecundity,
growth, mortality and movement patterns at the individual level. Only then can we
really assess how reproductive value is affected by the different breeding tactics
(male, female or non-breeder) that individuals can use.” This also applies to the
study of spawning aggregations.