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The growth rates of juvenile smalltooth sawfish Pristis pectinata collected in Florida waters between 1999 and 2006 were investigated using length-frequency and tag-recapture data. Stretched total length (L ST ) data from 144 smalltooth sawfish (690-4960 mm) and 28 recaptures (775-2150 mm) were used for the analyses. Both methods indicated that growth was rapid during the first 2 years after birth. The L ST increased by 650-850 mm in the first year, and by 480-680 mm in the second year. Data for animals >2200 mm were limited, so growth beyond 2 years of age was uncertain. The von Bertalanffy growth parameters estimated from L ST frequency data were L N ¼ 6000 mm, K ¼ 0Á140 year À1 and t 0 ¼ À0Á863 years. Growth rates over the size range for which tag-recapture data were available were similar to that from L ST frequency data. The growth rates reported are substantially faster than those previously assumed for this species and may have important implications for the recovery of this endangered species. There are conflicting data regarding the growth rates of older P. pectinata which need to be resolved with more data from the wild population before a complete understanding of the conservation implications can be obtained.

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“Perfect comb” graft copolymers are synthesized via acyclic diene metathesis (ADMET) polymerization using well-defined ruthenium catalyst systems to yield precisely spaced polyethers along an unsaturated polyolefin backbone. The graft is placed in a symmetrical α,ω-diene prior to ADMET polymerization to ensure exact graft placement at each functional site along the polymer backboneno mistakes are made. The polyether grafts are essentially monodisperse as shown by MALDI analysis, while the polyolefin backbone exhibits a dispersity of 2.0. Such well-defined poly(ethylene-graft-ethylene oxide) copolymers will be interesting in several applications.

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