Title

Fragmentation As A Strategy For Caulerpa Species: Fates Of Fragments And Implications For Management Of An Invasive Weed

Keywords

Algae; Biological invasion; Caulerpa prolifera; Caulerpa taxifolia; Caulerpa verticillata; Vegetative fragmentation

Abstract

The successful growth of fragments to full size macroalgal clones is well known for many taxa in mariculture. From an ecological context, however, few studies relate success by invasive species to the ability to fragment readily, disperse widely or re-attach rapidly - obvious hallmarks of weedy species. This study compares morphologically and ecologically distinct species of the green alga Caulerpa: in the Mediterranean, Caulerpa taxifolia is well known as an invasive weed; Caulerpa prolifera grows around or inside seagrass beds and is not apparently invasive; Caulerpa verticillata is among the most diminutive species, with potentially the most restricted reef distribution. We tested three hypotheses: (i) fragment success is independent of size, (ii) fragment success is independent of position within the plant and (iii) fragments from all species will be equally successful in establishing rhizoids, the first step to re-attachment. The success of small fragments (5-40 mm lengths) cut from distinct locations within replicate plants was scored for survival and establishment of rhizoids in bioassays. Additionally, for C. taxifolia, estimates were made of the force needed to puncture upright and prostrate axes, thereby estimating forces required to generate fragments from these two sources. Among the three species, only upright axes of C. taxifolia readily recovered from fragmentation stress for fragment sizes > 10 mm. The forces required to fragment upright axes were substantially less than for comparable rhizome portions. Fragments of C. prolifera were viable only for rhizome portions; fragments of C. verticillata were not viable at any size examined in this study. Estimates of viable fragment size, origin and force required to fragment axes for C. taxifolia support existing field data suggesting that fragmentation is the effective propagation mechanism underlying the spread of this invasive weed.

Publication Date

12-1-1999

Publication Title

Marine Ecology

Volume

20

Issue

3-4

Number of Pages

307-319

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1046/j.1439-0485.1999.2034079.x

Socpus ID

0033491807 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0033491807

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