445
12 Species Case Studies
need to continue and expand the geographic coverage to evaluate recruitment
success and predict trends in adult population size. More detailed information,
rather than just landings data, is needed regarding the status of the stock based on
the percentage catch of (1) mature fi sh caught; (2) individuals with optimum length;
and (3) large spawning fi sh in the catch, based on the work of Froese ( 2004 ) .
Management plans need to be based on the outcomes of such alternative stock
assessments that will ensure adequate sex ratios for successful spawning and fertilization of eggs. The habitats used by juvenile gag need to be more carefully mapped
and their loss reduced by working with developers, local governments, the US Army
Corps of Engineers and other partners to deter development in sensitive areas. Given
the prospects for continued development, there is a pressing need to designate and
implement marine reserves that protect all sensitive life stages, including prespawning habitat, spawning habitat, shallow seagrass (early juveniles) and nearshore reef
(late juveniles) nursery habitat.
12.8 Squaretail Coralgrouper – Plectropomus areolatus
Kevin L. Rhodes and Yvonne Sadovy de Mitcheson
College of Agriculture, Forestry and Natural Resource Management ,
University of Hawaii at Hilo , 200 W. Kawili St., Hilo , HI , USA
e-mail: klrhodes_grouper@yahoo.com
School of Biological Sciences , The University of Hong Kong , Hong Kong , China
e-mail: yjsadovy@hku.hk
12.8.1 General
The squaretail coralgrouper, Plectropomus areolatus (Rüppell 1830), is a widely
distributed and commercially important medium-sized grouper that occurs in lagoon
and seaward coral-rich areas of the tropical Indo-Pacifi c at a depth of 5 to more than
50 m (Heemstra and Randall 1993 ; Hutchinson and Rhodes 2010 ) . The squaretail
coralgrouper is distributed from the Red Sea to the Phoenix Islands and Samoa,
north to the Ryukyu Islands and south to Australia, with populations in the Maldives
and Chagos Island. Its distribution is disjunct at the coast of Southeast Asia
(Myanmar and Thailand). Squaretail coralgrouper feeds exclusively on fi shes.
Tupper ( 2007 ) found early juveniles almost exclusively in coral rubble habitats on
the slopes of tidal channels, at a narrow depth range of 5–7 m. In Manus, Papua New
Guinea, early juveniles were found in rubble habitat in back reef sandy bottom
‘pools’ surrounded by low-growing coral (Rick Hamilton, personal communication). The maximum reported size for squaretail coralgrouper is 73.0 cm total length
12 Species Case Studies
need to continue and expand the geographic coverage to evaluate recruitment
success and predict trends in adult population size. More detailed information,
rather than just landings data, is needed regarding the status of the stock based on
the percentage catch of (1) mature fi sh caught; (2) individuals with optimum length;
and (3) large spawning fi sh in the catch, based on the work of Froese ( 2004 ) .
Management plans need to be based on the outcomes of such alternative stock
assessments that will ensure adequate sex ratios for successful spawning and fertilization of eggs. The habitats used by juvenile gag need to be more carefully mapped
and their loss reduced by working with developers, local governments, the US Army
Corps of Engineers and other partners to deter development in sensitive areas. Given
the prospects for continued development, there is a pressing need to designate and
implement marine reserves that protect all sensitive life stages, including prespawning habitat, spawning habitat, shallow seagrass (early juveniles) and nearshore reef
(late juveniles) nursery habitat.
12.8 Squaretail Coralgrouper – Plectropomus areolatus
Kevin L. Rhodes and Yvonne Sadovy de Mitcheson
College of Agriculture, Forestry and Natural Resource Management ,
University of Hawaii at Hilo , 200 W. Kawili St., Hilo , HI , USA
e-mail: klrhodes_grouper@yahoo.com
School of Biological Sciences , The University of Hong Kong , Hong Kong , China
e-mail: yjsadovy@hku.hk
12.8.1 General
The squaretail coralgrouper, Plectropomus areolatus (Rüppell 1830), is a widely
distributed and commercially important medium-sized grouper that occurs in lagoon
and seaward coral-rich areas of the tropical Indo-Pacifi c at a depth of 5 to more than
50 m (Heemstra and Randall 1993 ; Hutchinson and Rhodes 2010 ) . The squaretail
coralgrouper is distributed from the Red Sea to the Phoenix Islands and Samoa,
north to the Ryukyu Islands and south to Australia, with populations in the Maldives
and Chagos Island. Its distribution is disjunct at the coast of Southeast Asia
(Myanmar and Thailand). Squaretail coralgrouper feeds exclusively on fi shes.
Tupper ( 2007 ) found early juveniles almost exclusively in coral rubble habitats on
the slopes of tidal channels, at a narrow depth range of 5–7 m. In Manus, Papua New
Guinea, early juveniles were found in rubble habitat in back reef sandy bottom
‘pools’ surrounded by low-growing coral (Rick Hamilton, personal communication). The maximum reported size for squaretail coralgrouper is 73.0 cm total length