Size‐selective harvesting in commercial fisheries can induce rapid changes in biological traits. While experimental and wild harvested populations often exhibit clear shifts in body size and maturation associated with fishing pressure, the relative contributions of genetic and environmental factors to these shifts remain uncertain and have been much debated. To date, observations of so‐called fisheries‐induced evolution (FIE) have been based solely on phenotypic measures, such as size data. Genetic data are hitherto lacking. Here, we quantify genetic versus environmental change in response to size‐selective harvesting for small and large body size in guppies (Poecilia reticulata) across three generations of selection. We document for the first time significant changes at individual genetic loci, some of which have previously been associated with body size. In contrast, variation at neutral microsatellite markers was unaffected by selection, providing direct genetic evidence for rapid evolution induced by size‐selective harvesting. These findings demonstrate FIE in an experimental system, with major implications for the sustainability of harvested populations, as well as impacts on size‐structured communities and ecosystem processes. These findings highlight the need for scientists and managers to reconsider the capacity of harvested stocks to adapt to, and recover from, harvesting and predation.

Rodrigues, F.M., Silva, F.M.O., Trompieri-Silveira, A.C., Vergara-Parente, J.E., Miglino, M.A. and Guimarães, J.P. 2015. Morphology of accessory structures of the humpback whale (Megaptera novaeangliae) eye. -Acta Zoologica (Stockholm) 96: 328-334.The humpback whale (Megaptera novaeangliae) has a cosmopolitan distribution and inhabits coastal and oceanic habitats, being present in polar and tropical waters. In aquatic mammals, vision has an important role in the perception of photoperiod changes. Due to lack of information on the morphology of Mysticetes, this study aimed to provide a morphological description of the adnexal structures of the humpback whale eye. Three newborn female specimens, stranded on the coast of Sergipe, Brazil, were used. Samples were fixed in a 10% formalin solution, dissected and photographed, and all the structures were collected and analysed using different light microscopy techniques. Eyelids were characterized by a palpebral fissure, a palpebral opening, two grooves (dorsal and ventral) and the presence of mechanoreceptors in the dermis. Some fibres of the four recti muscles had palpebral, scleral and glandular insertions. The Harderian gland filled the area between the orbit wall and the eyeball. Two vascular networks separated the extraocular retractor muscle of the eye and surround the optic nerve. The morphology of the accessory structures of the humpback whale eye was similar to that of other cetaceans, which suggests an adaptation to diving during migration, contributing to the perception of temperature difference in different regions.Juliana P. Guimarães, N ucleo de Estudo dos Efeitos Antropogênicos nos Recursos Marinhos/Fundac ßão Mam ıferos Aqu aticos, Av. Tancredo Neves,

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Aquatic mammals underwent morphological and physiological adaptations due to the transition from terrestrial to aquatic environment. One of the morphological changes regards their vision since cetaceans' eyes are able to withstand mechanical, chemical, osmotic, and optical water conditions. Due to insufficient information about these animals, especially regarding their sense organs, this study aimed to describe the morphology of the Humpback whale (Megaptera novaeangliae) eyeball. Three newborn females, stranded dead on the coast of Sergipe and Bahia, Brazil, were used. Samples were fixed in a 10% formalin solution, dissected, photographed, collected, and evaluated through light and electron microscopy techniques. The Humpback whale sclera was thick and had an irregular surface with mechanoreceptors in its lamina propria. Lens was dense, transparent, and ellipsoidal, consisting of three layers, and the vascularized choroid contains melanocytes, mechanoreceptors, and a fibrous tapetum lucidum. The Humpback whale eyeball is similar to other cetaceans and suggests an adaptation to diving and migration, contributing to the perception of differences in temperature, pressure, and lighting.