Current status and potential contributions of fisheries statistics from artisanal fisheries for managing juvenile istiophorid billfishes in Southern Brazil.

Billfishes are considered important fishery resources and the identification of aggregation sites is imperative for proper management. Here we present evidence of a seasonal aggregation site for juvenile istiophorid billfishes in southern Brazil. We discuss the results as they relate with the need for management at a local scale and participatory monitoring with artisanal fishing communities as a way to ensure access to data on the occurrence and population status in the long term.

Biomarkers of homeostasis, allostasis, and allostatic overload in decapod crustaceans of distinct habitats and osmoregulatory strategies: an empirical approach.

The term "allostasis", meaning the assumption that homeostasis may not be as static as the term implies, has been vastly employed for mammals, and other vertebrates, for which the degree of internal stability is maximal, according to their higher complexity. We have here investigated how these states of homeostasis, allostasis, and allostatic overload could be diagnosed in decapod crustaceans, upon acute salinity challenges. Decapods of distinct lineages and habitats have been submitted to 3 salinity levels for 6 and 12 h. The first salinity was the habitat salinity (control), considered as the one that allows the homeostatic condition. The next salinity represented a mild challenge, that would potentially lead to allostasis, and the third salinity was intended to represent an overload, albeit not lethal. Species used were: the marine crab Hepatus pudibundus (Hp, osmoconformer, salinities 33, 25, and 20‰), the marine/estuarine swimming crab Callinectes danae (Cd, weak regulator, salinities 30, 20, and 10‰), and the diadromous freshwater prawn Macrobrachium acanthurus (Ma, strong regulator, salinities <0.5, 15, and 30‰). These 3 species follow a sequence of growing regulatory capacity (Hp