468
12 Species Case Studies
vulnerable on the IUCN Red List due to overfi shing, especially on its aggregations,
and lack of effective management and the species status is being updated (Lindemann
et al. 2000 ; Government of Belize 2003 ; Claro and Lindeman 2003 ; Heyman et al.
2001, 2005 ; Lindeman and DeMaria 2005 ; Claro et al. 2009 ; www.iucnredlist.org ).
12.11 The Blue-Lined Sea Bream – Symphorichthys spilurus
Jiro Sakaue, Hiroshi Akino, and Hitoshi Ida
Southern Marine Laboratory , P.O. Box 1598 , Koror , Republic of Palau 96940
e-mail: bigrun2006@hotmail.co.jp
Day Dream Palau , P.O. Box 10046 Abby’s Bld, 1st Floor, Malakal Koror ,
Republic of Palau 96940
e-mail: akino@daydream-dive.com
Kitasato University School of Marine Lifesciences , Sanriku-cho, Ofunato-shi ,
Iwate-prf. , 022-0101 , Japan
e-mail: palau-sakana@ab.cyberhome.ne.jp
12.11.1 General
The blue-lined sea bream, Symphorichthys spilurus (Günther 1874), also known as
the threadfi n bream or sailfi n snapper, is a species of the snapper family, Lutjanidae,
distributed in the subtropics and tropics of the western Pacifi c. The species is dramatically distinctive in having long fi lamentous rays on the dorsal and anal fi ns, and
occurs in shallow waters over sandy substrates around coral reefs. It is typically seen
by divers as single individuals in inshore lagoon and shallow reef areas but is known
to undergo seasonal migrations away from resident reefs to form large spawning
aggregations at specifi c times and places each year (Myers 1999 ) . In Palau these
aggregations have been known by divers for decades. The species reaches 60 cm total
length (TL) and feeds on fi shes, molluscs and sand-dwelling crustaceans. It is of
minor commercial importance in fi sheries and for the aquarium trade.
12.11.2 Reproductive Biology
The blue-lined sea bream is little studied although its reproductive biology has been
examined in Palau. The species aggregates in large numbers to spawn during a limited reproductive season each year (Fig. 12.26 ). These aggregations are a spectacle
well-known to divers for decades, and occur in at least three areas, one each to the
north, west and south of Palau. Based on the timing of aggregation formation, there
appear to be two reproductive periods, February to May and September to November.
The southern aggregation occurs at Peleliu Island and was studied from 2006 to
2009 by diving. Underwater photos were used to assist estimating fi sh numbers and
to record colouration and behaviour.
12 Species Case Studies
vulnerable on the IUCN Red List due to overfi shing, especially on its aggregations,
and lack of effective management and the species status is being updated (Lindemann
et al. 2000 ; Government of Belize 2003 ; Claro and Lindeman 2003 ; Heyman et al.
2001, 2005 ; Lindeman and DeMaria 2005 ; Claro et al. 2009 ; www.iucnredlist.org ).
12.11 The Blue-Lined Sea Bream – Symphorichthys spilurus
Jiro Sakaue, Hiroshi Akino, and Hitoshi Ida
Southern Marine Laboratory , P.O. Box 1598 , Koror , Republic of Palau 96940
e-mail: bigrun2006@hotmail.co.jp
Day Dream Palau , P.O. Box 10046 Abby’s Bld, 1st Floor, Malakal Koror ,
Republic of Palau 96940
e-mail: akino@daydream-dive.com
Kitasato University School of Marine Lifesciences , Sanriku-cho, Ofunato-shi ,
Iwate-prf. , 022-0101 , Japan
e-mail: palau-sakana@ab.cyberhome.ne.jp
12.11.1 General
The blue-lined sea bream, Symphorichthys spilurus (Günther 1874), also known as
the threadfi n bream or sailfi n snapper, is a species of the snapper family, Lutjanidae,
distributed in the subtropics and tropics of the western Pacifi c. The species is dramatically distinctive in having long fi lamentous rays on the dorsal and anal fi ns, and
occurs in shallow waters over sandy substrates around coral reefs. It is typically seen
by divers as single individuals in inshore lagoon and shallow reef areas but is known
to undergo seasonal migrations away from resident reefs to form large spawning
aggregations at specifi c times and places each year (Myers 1999 ) . In Palau these
aggregations have been known by divers for decades. The species reaches 60 cm total
length (TL) and feeds on fi shes, molluscs and sand-dwelling crustaceans. It is of
minor commercial importance in fi sheries and for the aquarium trade.
12.11.2 Reproductive Biology
The blue-lined sea bream is little studied although its reproductive biology has been
examined in Palau. The species aggregates in large numbers to spawn during a limited reproductive season each year (Fig. 12.26 ). These aggregations are a spectacle
well-known to divers for decades, and occur in at least three areas, one each to the
north, west and south of Palau. Based on the timing of aggregation formation, there
appear to be two reproductive periods, February to May and September to November.
The southern aggregation occurs at Peleliu Island and was studied from 2006 to
2009 by diving. Underwater photos were used to assist estimating fi sh numbers and
to record colouration and behaviour.