426
12 Species Case Studies
ranged from a few hundred to many thousands of individuals (Johannes et al. 1999 ;
Palau Conservation Society 2010 ; Paul McKenzie and Serge Planes, personal communication), while approximately 1,900 individuals were reported from an aggregation in the Seychelles (Robinson et al. 2008a, b ) , about 200 from one site in Fiji
and about 500 at a second site in Fiji (Yvonne Sadovy de Mitcheson unpublished
data; Chap. 12.8 , Fig. 12.15).
The seasonal and lunar timing of aggregation formation and spawning varies
across the geographic range of the species, from just before new moon in Palau
(Johannes et al. 1999 ) and the Seychelles (Robinson et al. 2008a, b ) , to just prior to
full moon in Pohnpei and Fiji (Rhodes and Sadovy 2002a ; Fiji-Yvonne Sadovy de
Mitcheson unpublished data). In most areas surveyed, aggregations form over
2–3 months, with peaks in abundance during a single month. Variation occurs in
arrival times between males and females, with males commonly present at the
spawning site for longer periods and arriving prior to females (Rhodes and Sadovy
2002a ; Robinson et al. 2008a, b ; Chap. 8 , Fig. 8.10).
Some evidence of reproductive migratory corridors has been recorded from
acoustic telemetry studies. Small groups of adult camoufl age grouper were observed
moving along common routes toward the aggregation site prior to reproductive periods in Pohnpei from up to 8 km away from aggregation sites. In Fiji, one tagged fi sh
was recaptured 15 km away from an aggregation site (Yvonne Sadovy de Mitcheson
unpublished data). Spawning site fi delity has been demonstrated from both conventional (spaghetti) (Johannes et al. 1999 ; Robinson et al. 2008a, b ) and acoustic tagging studies (KLR unpublished data), with inter-annual site fi delity recorded. In the
Seychelles, two tagged individuals returned over two consecutive reproductive
months and at least one individual showed inter-annual site fi delity 352 day after
initial tagging (Robinson et al. 2008a, b ) . In Pohnpei, one acoustically tagged female
returned to the aggregation 1 year after tagging and was present for 4 days. In Palau,
multi-year tagging studies suggested that (1) individuals may return to spawning
sites over multiple (2–3) months within the spawning season, (2) at least some individuals return to the same site inter-annually, (3) individuals may travel at much as
5–10 km from spawning sites between reproductive and non-reproductive periods
and, (4) individuals appear not to utilize more than one spawning site during
reproduction, even though a number of aggregations may form in relatively close
proximity (Johannes et al. 1999 ) .
Camoufl age grouper spawning aggregations are typically found on seaward-facing portions of reefs or channels at 4–40 m depths (e.g. Rhodes and Sadovy 2002b ;
Robinson et al. 2008a, b ) . During aggregation periods, territorial disputes are frequent among males. Disputes typically involve two individuals facing each other in
a cheek-to-cheek position, with occasional bouts of pushing by one individual at the
other’s vent or abdomen (Chap. 9 , Fig. 9.6). Snout-to-snout snapping and sidling is
also common within aggregations. Colour changes involve blanching to a pale grey
or whitish color with a prominent black saddle, a blackish ‘slash’ through the eyes
and darkened nostrils (Rhodes and Sadovy 2002a ; Robinson et al. 2008a, b ) .
Examination of oocyte development in Pohnpei suggests spawning occurs nocturnally between dusk and dawn (Rhodes and Sadovy 2002a, b ) . In Palau, observations
12 Species Case Studies
ranged from a few hundred to many thousands of individuals (Johannes et al. 1999 ;
Palau Conservation Society 2010 ; Paul McKenzie and Serge Planes, personal communication), while approximately 1,900 individuals were reported from an aggregation in the Seychelles (Robinson et al. 2008a, b ) , about 200 from one site in Fiji
and about 500 at a second site in Fiji (Yvonne Sadovy de Mitcheson unpublished
data; Chap. 12.8 , Fig. 12.15).
The seasonal and lunar timing of aggregation formation and spawning varies
across the geographic range of the species, from just before new moon in Palau
(Johannes et al. 1999 ) and the Seychelles (Robinson et al. 2008a, b ) , to just prior to
full moon in Pohnpei and Fiji (Rhodes and Sadovy 2002a ; Fiji-Yvonne Sadovy de
Mitcheson unpublished data). In most areas surveyed, aggregations form over
2–3 months, with peaks in abundance during a single month. Variation occurs in
arrival times between males and females, with males commonly present at the
spawning site for longer periods and arriving prior to females (Rhodes and Sadovy
2002a ; Robinson et al. 2008a, b ; Chap. 8 , Fig. 8.10).
Some evidence of reproductive migratory corridors has been recorded from
acoustic telemetry studies. Small groups of adult camoufl age grouper were observed
moving along common routes toward the aggregation site prior to reproductive periods in Pohnpei from up to 8 km away from aggregation sites. In Fiji, one tagged fi sh
was recaptured 15 km away from an aggregation site (Yvonne Sadovy de Mitcheson
unpublished data). Spawning site fi delity has been demonstrated from both conventional (spaghetti) (Johannes et al. 1999 ; Robinson et al. 2008a, b ) and acoustic tagging studies (KLR unpublished data), with inter-annual site fi delity recorded. In the
Seychelles, two tagged individuals returned over two consecutive reproductive
months and at least one individual showed inter-annual site fi delity 352 day after
initial tagging (Robinson et al. 2008a, b ) . In Pohnpei, one acoustically tagged female
returned to the aggregation 1 year after tagging and was present for 4 days. In Palau,
multi-year tagging studies suggested that (1) individuals may return to spawning
sites over multiple (2–3) months within the spawning season, (2) at least some individuals return to the same site inter-annually, (3) individuals may travel at much as
5–10 km from spawning sites between reproductive and non-reproductive periods
and, (4) individuals appear not to utilize more than one spawning site during
reproduction, even though a number of aggregations may form in relatively close
proximity (Johannes et al. 1999 ) .
Camoufl age grouper spawning aggregations are typically found on seaward-facing portions of reefs or channels at 4–40 m depths (e.g. Rhodes and Sadovy 2002b ;
Robinson et al. 2008a, b ) . During aggregation periods, territorial disputes are frequent among males. Disputes typically involve two individuals facing each other in
a cheek-to-cheek position, with occasional bouts of pushing by one individual at the
other’s vent or abdomen (Chap. 9 , Fig. 9.6). Snout-to-snout snapping and sidling is
also common within aggregations. Colour changes involve blanching to a pale grey
or whitish color with a prominent black saddle, a blackish ‘slash’ through the eyes
and darkened nostrils (Rhodes and Sadovy 2002a ; Robinson et al. 2008a, b ) .
Examination of oocyte development in Pohnpei suggests spawning occurs nocturnally between dusk and dawn (Rhodes and Sadovy 2002a, b ) . In Palau, observations