|
Vol. 42 No. 1, 2003
Identification of Scleractinian Coral Recruits from Indo-Pacific Reefs
Russ C. Babcock1, Andrew H. Baird2,*, Srisakul Piromvaragorn2, Damian P. Thomson2 and Bette L. Willis2
1University of Auckland, Leigh Marine Lab, Warkworth, New Zealand
2School of Marine Biology and Aquaculture, James Cook University, Townsville 4811, Australia
Russ C. Babcock, Andrew H. Baird, Srisakul Piromvaragorn, Damian P. Thomson and Bette L. Willis (2003) Study
of the early life history of scleractinian corals has been hampered by
the inability to identify recently settled juveniles. To increase
taxonomic resolution of coral recruits, we compared the morphology of
the skeleton of juveniles raised from known parents for 29 species in
21 genera and 12 families. Juveniles from only 3 families could be
reliably distinguished throughout their 1st year of life: the
Acroporidae, which have a porous coenosteum, prominent septa, and no
columella; the Pocilloporidae, which have a solid coenosteum, prominent
septa and a prominent columella; and the Poritidae, which have septa
with prominent teeth. Juveniles in the remaining families examined
could not be consistently distinguished. In these taxa, the skeleton
began as an epitheca with little internal structure, growth was slow,
and the pattern of septal development was similar. Within the 3
distinctive families, a number of other taxa could be recognized when
juveniles were young. Genera of the Pocilloporidae could be
distinguished by size differences in the diameter of the primary
corallite. Isopora, Acropora, and Montipora juveniles could be distinguished by differences in the size of the corallum at settlement. Juveniles of the broadcast spawning Porites appear to be distinguished from those of brooding Porites
by the pattern of septal development and by the small size at
settlement. The number of taxa that could be distinguished was highest
when juveniles were between 4 and 8 wk old. After this time, variation
in the growth rates of individuals and thickening of the skeleton
obscured differences between the taxa.
Key words: Development, Ontogeny, Recruitment, Settlement, Taxonomy.
*Correspondence:
Current address: Centre for Coral Reef Biodiversity, School of Marine
Biology and Aquaculture, James Cook University, Townsville, Qld 4811,
Australia. Tel: 61-7-47814857. Fax: 61-7-47251570. E-mail:
ahbaird@sigmaxi.org
|
