The Exotic Species of Singapore

Tuesday, January 24, 2006

Invasive coral in Brazil

Exotic soft coral species, Stereonephthya aff. curvata, from the Indo-Pacific threatens the Brazilian endemic gorgonian Phyllogorgia dilatata in the Arraial do Cabo Harvest Reserve, Rio de Janeiro.

B.G. Lages, B.G. Fleury, C.E.L. Ferreira & R.C. Pereira (2006). Chemical defense of an exotic coral as invasion strategy. Journal of Experimental Marine Biology and Ecology, 328: 127–135.

Abstract - The invasion success of exotic species has been frequently correlated to abiotic and biotic features of the receptor region and to the biological aspects of the invasive organism. There is, however, no information about defensive chemicals found in invasive species as strategy that could promote or facilitate an invasion in a marine environment. We conducted experimental field assays to verify the potential of secondary metabolites of an Indo-Pacific exotic soft coral, Stereonephthya aff. curvata, as a defensive chemical against generalist fish and as an allelopathic agent against the potential local competitor–the gorgonian Phyllogorgia dilatata–in Arraial do Cabo, on the southeastern coast of Brazil. As a result of our experiments, it was confirmed as an efficient chemical defense against fishes by crude coral hexanic extract. In addition to its role as defense against consumers, the field experimental assay also verified that chemicals from this exotic coral had an allelopatic effect causing large necrosis on tissues of the Brazilian endemic gorgonian P. dilatata. Both defensive strategies observed may facilitate the perpetuation and/or expansion and characterize an expressive, invasive facilitator for S. aff. curvata. The obtained results indicate that this exotic coral species may be a real threat to the biological integrity of the Arraial do Cabo Harvest Reserve, Rio de Janeiro. In addition, the study reveals that defensive chemicals can be used to predict the potential invasiveness of introduced species.

Saturday, January 21, 2006

Talk on Invasive Birds

‘Winged Invaders’: ‘Pest Birds’ and Humans

Prof. Navjot Sodhi, Associate Professor, Dept of Biological Sciences, NUS
Ilsa Sharp, Australia-based Author and Freelance Writer.

Date: Saturday, 25 February 2006
Time: 2 - 6 pm
Venue: Level 5, Imagination Room. National Library of Singapore

Admission is free.

See blog of National Library Board for more details!

Sunday, January 08, 2006

Green chromide

Length: 12.5cm
Sungei Buloh
Photo by K.K.P. Lim

Scientific name: Etroplus suratensis
Habitat: Freshwater and brackish water (e.g. lakes, streams and estuaries)
Ecology: Swims in small groups. Mainly herbivorous but may feed on insects. Popular aquarium fish. To about 30cm.
Origin: India and Sri Lanka, introduced for aquarium trade