The shark-tuna dichotomy: why tuna lay tiny eggs but sharks produce large offspring.

Teleosts such as tunas and billfish lay millions of tiny eggs weighing on the order of 0.001 g, whereas chondrichthyes such as sharks and rays produce a few eggs or live offspring weighing about 2% of adult body mass, as much as 10 000 g in some species. Why are the strategies so extreme, and why are intermediate ones absent? Building on previous work, we show quantitatively how offspring size reflects the relationship between growth and death rates. We construct fitness contours as functions of offspring size and number, and show how these can be derived from juvenile growth and survivorship curves. Convex contours, corresponding to Pearl Type 1 and 2 survivorship curves, select for extremes, either miniscule or large offspring; concave contours select for offspring of intermediate size. Of particular interest are what we call critical straight-line fitness contours, corresponding to log-linear Pearl Type 3 survivorship curves, which separate regimes that select for opposite optimal offspring sizes.

Fundamental insights into ontogenetic growth from theory and fish.

The fundamental features of growth may be universal, because growth trajectories of most animals are very similar, but a unified mechanistic theory of growth remains elusive. Still needed is a synthetic explanation for how and why growth rates vary as body size changes, both within individuals over their ontogeny and between populations and species over their evolution. Here, we use Bertalanffy growth equations to characterize growth of ray-finned fishes in terms of two parameters, the growth rate coefficient, K, and final body mass, m∞. We derive two alternative empirically testable hypotheses and test them by analyzing data from FishBase. Across 576 species, which vary in size at maturity by almost nine orders of magnitude, K scaled as [Formula: see text]. This supports our first hypothesis that growth rate scales as [Formula: see text] as predicted by metabolic scaling theory; it implies that species that grow to larger mature sizes grow faster as juveniles. Within fish species, however, K scaled as [Formula: see text]. This supports our second hypothesis, which predicts that growth rate scales as [Formula: see text] when all juveniles grow at the same rate. The unexpected disparity between across- and within-species scaling challenges existing theoretical interpretations. We suggest that the similar ontogenetic programs of closely related populations constrain growth to [Formula: see text] scaling, but as species diverge over evolutionary time they evolve the near-optimal [Formula: see text] scaling predicted by metabolic scaling theory. Our findings have important practical implications because fish supply essential protein in human diets, and sustainable yields from wild harvests and aquaculture depend on growth rates.

Anecortave acetate as monotherapy for treatment of subfoveal neovascularization in age-related macular degeneration: twelve-month clinical outcomes.

PURPOSE: To evaluate safety and efficacy of the angiostatic agent anecortave acetate, compared with a placebo, for treatment of subfoveal choroidal neovascularization (CNV). DESIGN: Ongoing masked, randomized, placebo-controlled, parallel evaluation of anecortave acetate (30 mg, 15 mg, and 3 mg) versus a placebo. PARTICIPANTS: There were 128 eyes of 128 patients with subfoveal CNV secondary to age-related macular degeneration who were enrolled and treated, with 80% (102/128) of eyes presenting with predominantly classic lesions at baseline. METHODS: All eyes received a posterior juxtascleral depot application of masked study medication or a placebo, with retreatment at 6-month intervals if the masked investigator believed the patient could benefit. Patients received periodic detailed ophthalmic examinations with both fluorescein and indocyanine green angiography, general physical examinations with electrocardiograms, and hematology/serum chemistry/urinalysis. All ophthalmic and systemic safety data were periodically reviewed by the Independent Safety Committee overseeing the study. MAIN OUTCOME MEASURES: Best-corrected logarithm of the minimum angle of resolution (logMAR) vision and fluorescein angiographic lesion characteristics were compared over time and among treatment groups. RESULTS: At month 12, anecortave acetate (15 mg) administered at 6-month intervals was statistically superior to the placebo for 3 measures of clinical efficacy: mean change from baseline vision (P = 0.0131), stabilization of vision (<3 logMAR line change; P = 0.0323), and prevention of severe vision loss (decrease of > or = 6 logMAR lines from baseline; P = 0.0224). Subgroup analysis of predominantly classic lesions revealed that anecortave acetate (15 mg) was also superior to the placebo at 1 year for each of these 3 measures of visual outcome (Ps = 0.0022, 0.0100, and 0.0299, respectively). Anecortave acetate (15 mg) trended toward significance over the placebo at month 12 for inhibition of total lesion growth and for inhibition of both the total CNV component and the classic CNV component in both the overall and subgroup analyses. The Independent Safety Committee identified no clinically relevant treatment-related safety issues. CONCLUSIONS: Anecortave acetate (15 mg) is safe and clinically efficacious at 1 year for maintaining vision, preventing severe vision loss, and inhibiting subfoveal CNV lesion growth.

Anecortave acetate as monotherapy for the treatment of subfoveal lesions in patients with exudative age-related macular degeneration (AMD): interim (month 6) analysis of clinical safety and efficacy.

PURPOSE: To evaluate clinical safety and efficacy of the angiostatic agent anecortave acetate for treatment of subfoveal choroidal neovascularization secondary to AMD. METHODS: 128 patients were randomized to placebo treatment or one of three anecortave acetate doses. Study medication was administered as a posterior juxtascleral injection onto the posterior scleral surface. Best-corrected logMAR vision was obtained at baseline and follow-up visits. Fluorescein angiograms were evaluated for eligibility before enrollment and posttreatment. RESULTS: Six months after a single treatment, visual acuity (mean change from baseline logMAR values) was significantly better (P = 0.003) after anecortave acetate 15 mg than placebo. More patients treated with anecortave acetate 15 mg than placebo maintained vision (88% versus 70%, P = 0.080), especially those with predominantly classic lesions (92% versus 65%, P = 0.021). Anecortave acetate 15 mg inhibited lesion growth significantly better than placebo (P = 0.001). Trends favoring the other doses over placebo were observed for vision preservation and lesion inhibition, but statistical significance was not achieved. The Independent Safety Committee overseeing this study identified no clinically relevant treatment-related changes. CONCLUSION: Anecortave acetate 15 mg is safe and effective for preserving or improving vision and for inhibiting lesion growth in patients with subfoveal AMD.