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Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km−2 and a population size of 1.55 × 106 in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4°C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430–725 m. Where N. yaldwyni occurred, crab traces were abundant, megafaunal diversity reduced and echinoderms absent, suggesting that the crabs have major ecological impacts. Antarctic Peninsula shelf waters are warming at approximately 0.01°C yr−1; if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400–600 m depths) within 1–2 decades. The Palmer Deep N. yaldwyni population provides an important model for the potential invasive impacts of crushing predators on vulnerable Antarctic shelf ecosystems. [ABSTRACT FROM AUTHOR]

Abstract Background  Most uveal melanomas are currently treated by eye-preserving radiotherapies. However, for melanomas of the largest size or with initial complications, enucleation remains the reference treatment. Enucleation is called primary when it is proposed as the only local treatment option for a melanoma. There is very little literature on the use of primary enucleation after the introduction of conservative treatments. Our main goal was to evaluate the survival of melanoma patients treated by primary enucleation since the introduction of proton-beam therapy in France in 1991. Methods  All melanoma patients undergoing primary enucleation in our department between 1991 and 2002 were included in this retrospective study. The 5-year melanoma-specific survival rate was calculated using the Kaplan–Meier method. The multivariate prognostic analysis was performed using the Cox proportional hazards model. Results  Forty patients, representing 8% of all patients with choroidal uveal melanoma diagnosed and followed up in our department during an 11-year period, were included in the study. No patient was lost to follow-up. The 5-year melanoma-specific survival rate was 31.45% (SE: 7.8) after primary enucleation. Significant prognosis factors in the multivariate analysis were: tumor thickness > 12 mm (p = 0.03), anterior margin of the tumor involving the iris (p = 0.018), and presence of epithelioid cells (p = 0.02). Conclusions  The very low survival rate reported reflects the evolution of primary enucleation, which is currently indicated only for melanomas with the worst prognosis. The knowledge of current post-enucleation survival rates represents an essential achievement for both correct assessment of conservative therapies and patient counseling. [ABSTRACT FROM AUTHOR]