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- Näslund, Joacim
(författare)
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Pugheadedness in Fishes
- 2022
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Ingår i: Reviews in Fisheries Science & Aquaculture. - : Informa UK Limited. - 2330-8249 .- 2330-8257. ; 30, s. 306-329
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Tidskriftsartikel (refereegranskat)abstract
- This review summarizes the current state of knowledge of pugheadedness in fish. Records in the scientific literature range from detailed descriptions to brief notes and mere remarks. In total, at least 164 species from 60 families were identified to exhibit pugheadedness, with records published over a span of 465 years (1555 - 2020). The main osteological feature behind pugheadedness appears to be shortening or deformation of the parasphenoid bone, which leads to additional deformations of the ethmovomer- and frontal region. Several other deformations and abnormalities of other cranial bones, eyes, and tongue are occasionally observed, depending on the severity of the pugheadedness. Possible cases in elasmobranchs are also encountered, although the developmental causation may differ from actinopterygians, since their crania have a different organization. Natural cases of pugheadedness are found world-wide, covering a wide range of environments and lifestyles (freshwater-, brackish- and marine environments; benthic, neritic and pelagic species). Cases are found in all life-stages, from embryo to mature adults, suggesting that it does not necessarily lead to early-life mortality. There is some evidence for natural selection acting against pugheaded individuals, likely because of e.g. inappropriately functioning mouth parts, sense organs, and possibly brain deformation. High numbers of pugheads are mainly found in aquaculture, but moderate numbers have been found at some localities also in the wild. Abnormally high occurrence in the wild is commonly attributed to pollution, non-normal water chemistry parameters, or temperature. The causation, however, it typically speculated upon. Based on the reviewed literature, there is support for several causative factors, including genetic mutation and embryonic environmental conditions (toxic and non-toxic) affecting development. Pugheadedness, as the term has been used in the literature, is not a single well-defined pathology, but rather a suite of pathological conditions with similar phenotypic expression.
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| 2. |
- Sarà, G., et al.
(författare)
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The Synergistic Impacts of Anthropogenic Stressors and COVID-19 on Aquaculture : A Current Global Perspective
- 2022
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Ingår i: Reviews in Fisheries Science & Aquaculture. - : Informa UK Limited. - 2330-8249 .- 2330-8257. ; 30:1, s. 123-135
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Tidskriftsartikel (refereegranskat)abstract
- The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector.
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