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Charybdis hellerii is an invasive swimming crab widely disseminated in the western Atlantic. This species became a threat to colonized ecosystems, competing with local species for resources. The extension of distribution and increasing population size of C. hellerii has been associated with the scarcity of indigenous predators and cases of predation report octopuses as the main native predators. In this study, we present the first evidence that native fish can consume C. hellerii. 53 individuals of the goldspotted snake eel, Myrichthys ocellatus, were collected at seagrass and macroalgal beds in Pernambuco State, Brazil, and had their stomach contents analyzed. Three juvenile C. hellerii were found along with native prey. Myrichthys ocellatus feeds mainly on small crabs, thus C. hellerii individuals were consumed before reaching sexual maturity. Oppositely to octopuses and other crab predators, M. ocellatus is of little fishing interest and is commonly found in macroalgae beds, seagrass meadows and sandy areas near reefs. Our results suggest that a higher number of carcinophagous taxa may prey on this invasive crab and we emphasize that the conservation of these species is paramount for controlling C. hellerii populations in invaded areas. [ABSTRACT FROM AUTHOR]

Archaeological approaches to stone-walled tidal fish traps of Indigenous Australians focus on technology and subsistence, with chronological development linked to demands of increased food production associated with demographic change and social intensification. For the Yanyuwa 'Saltwater People' of tropical northern Australia, old stone-walled fish traps found within the intertidal zone are associated with the creative acts of ancestral spirit beings. As such, these fish traps are imbued with spiritual potency and agency such that use requires specialized ritual practices (involving ochre and smoke) by senior men who also prescribe who can and cannot use the traps and eat the resulting catch. Today these traps lie dormant, not because the demand for fish has decreased but because of the demise of old highly initiated men of Law. These senior men not only possessed the requisite ritual knowledge to repair and activate the traps but also the specialized social and political knowledge to ensure adherence to strict and religiously codified laws and rules governing fish catch consumption amongst the community. The Yanyuwa teach us that socio-religious and socio-political factors can in certain contexts be of equal or greater importance than socio-economic factors in understanding why peoples of the past decided to use and dis-use fish trap facilities. [ABSTRACT FROM AUTHOR]

Discovered in the late 1920s, 3,4-didehydroretinol (DROL, vitamin A2) plays a significant biological role in freshwater fish. The functions of this vitamin have been investigated but to a far lesser extent than those of retinol (ROL, vitamin A1). A recent study indicating all-trans DROL has 119-127% vitamin A biological activity compared to that of all-trans ROL suggests the significance of DROL for addressing vitamin A deficiency (VAD) in comparison to ROL may be currently overlooked. Freshwater fish such as small indigenous fish species (SIS), with high DROL content can be a promising dietary source for reducing VAD in areas where SIS are readily available and consumed. In this paper, the discovery and biological relevance of DROL are reviewed and furthermore, the vast potential of production and consumption of DROL-rich SIS in food-based strategies to combat VAD in Bangladesh and other developing countries with high prevalence of VAD is highlighted. [ABSTRACT FROM AUTHOR]