491
12 Species Case Studies
12.15.1 General
Bolbometopon muricatum (Valenciennes 1839) , the largest of the scarine labrids
(Choat et al. 2006 ) , is an excavating parrotfi sh (Scaridae). The genus is monotypic
comprises a distinct lineage within the group and is notable for its massive jaws
and associated musculature (Bellwood 1994 ) . The evolutionary history of the scarine labrids identifi es them as a geographically widespread but relatively recent
group, confi ned mainly to coral reefs. The lineage containing Bolbometopon
diverged approximately 13 my bp (Alfaro et al. 2009 ) . Although the parrotfi shes
have a number of distinctive morphological and nutritional traits recent phylogenetic analyses place them within the broader grouping of the Family Labridae
(Westneat and Alfaro 2004 ) . We now know that large wrasses such as Cheilinus
undulatus (Chap. 12.13 ) are more closely related to large parrotfi shes such as
Bolbometopon than they are to many of the smaller wrasses that inhabit coral reefs.
B. muricatum is widespread on Indo-Pacifi c coral reefs with a distribution covering
37.6 × 10
6 km
2 and extending from the Red Sea through the Indian Ocean and IndoAustralian archipelago to the central and southern Pacifi c excluding the Hawaiian
Islands and the Marquesas. There is also some doubt as to whether this species
occurs in the Society Islands (Rob Myers, personal communication in 2009).
B. muricatum is readily recognized by its large size with mature males often
exceeding 1 m in total length. The largest recorded specimen is from the Solomon
Islands; (1,390 mm, fork length, weight 52 kg). B. muricatum is a major contributor
to the production of sediment on reefs and individuals can remove an average of 5.7
tonnes of carbonate material from reef surfaces per year of which up to 50% may be
in the form of living coral (Bellwood et al. 2003 ) . In areas of high abundance schools
of this species may remove ~280 tonnes of carbonate material per hectare per year.
The main nutritional activity is scavenging protein by consuming sessile animals
(including coral), detritus and elements of the epilithic algal complex on shallow
reef surfaces which is processed in the pharyngeal mill before digestion.
Adult B. muricatum consistently form schools for feeding and reproductive purposes (Hamilton et al. 2008 ) , and is inactive nocturnally (a labrid trait) sleeping in
schools in shallow water. The primary adult habitats are reef fronts and crests usually on exposed reefs. It is commonly observed feeding on reef surfaces and live
coral between 5 and 15 m although feeding schools will move into shallow water
(1–2 m) with the rising tide. Although the lower depth range is in the vicinity of
40 m the feeding activities are largely restricted to shallow reef fronts and crests.
School size varies from approximately 8–10 individuals up to large groups of
100–150 adults (Dulvy and Polunin 2004 ) ; in an unfi shed population on the Great
Barrier Reef (GBR), Australia, schools ranged from 1 to 79 individuals with a mean
of 36. Mean abundance on outer reefs of the GBR was 30 individuals per hectare.
Solomon Islands and Papua New Guinea (PNG) populations are subject to fi shing
including night spearing. Here densities varied from 0 per ha in the Autonomous
Region of Bougainville to 14 per ha in the Western Province of Solomon Islands,
with other fi shed areas ranging from 0.3 to 4.2 per hectare. Numbers in Fiji and
12 Species Case Studies
12.15.1 General
Bolbometopon muricatum (Valenciennes 1839) , the largest of the scarine labrids
(Choat et al. 2006 ) , is an excavating parrotfi sh (Scaridae). The genus is monotypic
comprises a distinct lineage within the group and is notable for its massive jaws
and associated musculature (Bellwood 1994 ) . The evolutionary history of the scarine labrids identifi es them as a geographically widespread but relatively recent
group, confi ned mainly to coral reefs. The lineage containing Bolbometopon
diverged approximately 13 my bp (Alfaro et al. 2009 ) . Although the parrotfi shes
have a number of distinctive morphological and nutritional traits recent phylogenetic analyses place them within the broader grouping of the Family Labridae
(Westneat and Alfaro 2004 ) . We now know that large wrasses such as Cheilinus
undulatus (Chap. 12.13 ) are more closely related to large parrotfi shes such as
Bolbometopon than they are to many of the smaller wrasses that inhabit coral reefs.
B. muricatum is widespread on Indo-Pacifi c coral reefs with a distribution covering
37.6 × 10
6 km
2 and extending from the Red Sea through the Indian Ocean and IndoAustralian archipelago to the central and southern Pacifi c excluding the Hawaiian
Islands and the Marquesas. There is also some doubt as to whether this species
occurs in the Society Islands (Rob Myers, personal communication in 2009).
B. muricatum is readily recognized by its large size with mature males often
exceeding 1 m in total length. The largest recorded specimen is from the Solomon
Islands; (1,390 mm, fork length, weight 52 kg). B. muricatum is a major contributor
to the production of sediment on reefs and individuals can remove an average of 5.7
tonnes of carbonate material from reef surfaces per year of which up to 50% may be
in the form of living coral (Bellwood et al. 2003 ) . In areas of high abundance schools
of this species may remove ~280 tonnes of carbonate material per hectare per year.
The main nutritional activity is scavenging protein by consuming sessile animals
(including coral), detritus and elements of the epilithic algal complex on shallow
reef surfaces which is processed in the pharyngeal mill before digestion.
Adult B. muricatum consistently form schools for feeding and reproductive purposes (Hamilton et al. 2008 ) , and is inactive nocturnally (a labrid trait) sleeping in
schools in shallow water. The primary adult habitats are reef fronts and crests usually on exposed reefs. It is commonly observed feeding on reef surfaces and live
coral between 5 and 15 m although feeding schools will move into shallow water
(1–2 m) with the rising tide. Although the lower depth range is in the vicinity of
40 m the feeding activities are largely restricted to shallow reef fronts and crests.
School size varies from approximately 8–10 individuals up to large groups of
100–150 adults (Dulvy and Polunin 2004 ) ; in an unfi shed population on the Great
Barrier Reef (GBR), Australia, schools ranged from 1 to 79 individuals with a mean
of 36. Mean abundance on outer reefs of the GBR was 30 individuals per hectare.
Solomon Islands and Papua New Guinea (PNG) populations are subject to fi shing
including night spearing. Here densities varied from 0 per ha in the Autonomous
Region of Bougainville to 14 per ha in the Western Province of Solomon Islands,
with other fi shed areas ranging from 0.3 to 4.2 per hectare. Numbers in Fiji and