@article {7896, title = {The onset of piscivory in a freshwater fish species: analysis of behavioural and physiological traits}, journal = {Journal of Fish Biology}, volume = {96}, year = {2020}, month = {Jan-06-2020}, pages = {1463 - 1474}, abstract = {The onset of piscivory in fish, resulting in a shift from zooplankton or invertebrate to fish prey, was studied on pikeperch (Sander lucioperca) larvae displaying and not dis- playing piscivorous behaviour at different ages (23, 30, 37, 44 and 52 days post- hatching) using behavioural (attack, capture and swimming activity), morphological (allometry) and digestive enzymatic (trypsin,\ α-amylase and pepsin) analyses. The shift from zooplanktonic food items (Artemia\ nauplii) to a piscivorous diet did not occur at the same time for all individuals within the same cohort. Predation tests, conducted under controlled conditions (20C;\ ad libitum\ feeding), showed that some larvae attacked fish prey as early as the age of 3 weeks [11.0 {\textpm} 1.3 mm total length (TL)], whereas others did not start until the age of 6 weeks (16.6 {\textpm} 1.9 mm TL). Piscivorous individuals were bigger, with larger heads, longer tails, higher acid protease and lower alkaline protease activities, than non-piscivorous conspecifics. In conclusion, high interindividual variability in morphological and digestive system developments linked to the development of predatory abilities could induce cannibalism in fish.}, keywords = {behavioural tests, early life stages, freshwater fish, predatory behaviour, Sander lucioperca}, issn = {0022-1112}, doi = {10.1111/jfb.v96.610.1111/jfb.14322}, url = {https://onlinelibrary.wiley.com/toc/10958649/96/6}, author = {Tatiana Colchen and Dias, Andr{\'e}a and Gisbert, Enric and Teletchea, Fabrice and Fontaine, Pascal and Pasquet, Alain} } @article {5925, title = {Phylogeography of Eleotris fusca (Teleostei: Gobioidei: Eleotridae) in the Indo-Pacific area reveals a cryptic species in the Indian Ocean.}, journal = {Conservation genetics}, volume = {19}, year = {2018}, pages = {1025-1038}, abstract = {

\ Indo-Pacific insular freshwater systems are mainly dominated by amphidromous species. Eleotris fusca\  is a widespread one, its life cycle is characterised by a marine pelagic larval phase allowing the species to disperse in the ocean and then to recruit to remote island rivers. In the present study, the population structure of E. fusca\  over its Indo-Pacific distribution range (Western Indian Ocean to French Polynesia, Pacific Ocean) was evaluated. We analysed a section of mitochondrial COI\  of 557 individuals sampled from 28 islands to visualise the population structure. Haplotypes diversity (Hd) was between 0.458 and 1 and, nucleotide diversity (π) was between 0.001 and 0.02. Two distinct genetic groups appeared, one in the Indian Ocean and the other in the Pacific Ocean (FST\  mean = 0.901; 5.2\% average divergence). Given these results, complete mitogenomes (mtDNA) were sequenced and combined with the nuclear Rhodopsin (Rh) gene for a subset of individuals. The two phylogenetic trees based on each analysis showed the same genetic pattern: two different groups belonging to the Indian and the Pacific oceans (6.6 and 1.6\% of divergence for mtDNA and Rh gene respectively), which supported species level differentiation. These analyses revealed the presence of two sister species confounded until present under the name of Eleotris fusca. One of them is cryptic and endemic of the Indian Ocean and the other one is the true E. fusca, which keeps, nevertheless, its status of widespread species.

}, keywords = {Amphidromous, Complete mitogenome, freshwater fish, Nuclear gene}, author = {Marion Mennesson and C{\'e}line Bonillo and Eric Feunteun and Philippe Keith} } @article {4280, title = {Trans-Amazonian natal homing in giant catfish}, journal = {Journal of Applied Ecology}, volume = {53}, year = {2016}, pages = {1511-1520}, abstract = {

1.Knowledge of fish migration is a prerequisite to sustainable fisheries management and preservation, especially in large international river basins. In particular, understanding whether a migratory lifestyle is compulsory or facultative, and whether adults home to their natal geographic area is paramount to fully appraise disruptions of longitudinal connectivity resulting from damming.2.In the Amazon, the large migratory catfishes of the Brachyplatystoma genus are apex predators of considerable interest for fisheries. They are believed to use the entire length of the basin to perform their life cycle, with hypothesized homing behaviours. Here we tested these hypotheses, using the emblematic B. rousseauxii as a model species.3.We sampled adults close to major breeding areas in the Amazon basin (upper Madeira and upper Amazonas) and assessed their lifetime movements by measuring variations in 87Sr/86Sr along transverse sections of their otoliths (ear stones) using laser ablation multicollector mass spectrometry (LA-MC-ICPMS).4.We demonstrate that larvae migrate downstream from the Andean piedmont to the lower Amazon, where they grow over a protracted period before migrating upstream as adults. Contrary to prevailing inferences, not all fish spend their nursery stages in the Amazon estuary. By contrast, the passage in the lower or central Amazon seems an obligate part of the life cycle. We further evidence that most adults home to their natal geographic area within the Madeira sub-basin. Such long-distance natal homing is exceptional in purely freshwater fishes.5.Synthesis and applications. By using otolith microchemistry, we were able to demonstrate a seemingly compulsory basin-wide migratory life cycle of large Amazonian catfishes. This makes them the organisms performing the longest migrations (\>8000 km) in fresh waters. This exceptional life history is already jeopardized by two dams recently built in the Madeira River, which block a major migration route and access to a substantial part of their spawning grounds. Major impacts can be anticipated from the current and forthcoming hydroelectric development in the Amazon basin, not only on the populations and fisheries of this apex predator, but also on Amazonian food webs through trophic cascades.This article is protected by copyright. All rights reserved.

}, keywords = {87Sr/86Sr ratios, Amazon, anthropogenic activities, Brachyplatystoma spp, freshwater fish, giant catfish, hydroelectric dams, Migration, otoliths}, issn = {1365-2664}, doi = {10.1111/1365-2664.12665}, url = {http://dx.doi.org/10.1111/1365-2664.12665}, author = {Fabrice Duponchelle and Marc Pouilly and Pecheyran, Christophe and Hauser, Marilia and Renno, Jean-Francois and Panfili, Jacques and Darnaude, Audrey M. and Garc{\'\i}a-Vasquez, Aurea and Carvajal-Vallejos, Fernando and Carmen Garc{\'\i}a-D{\'a}vila and Doria, Carolina and B{\'e}rail, Sylvain and Donard, Ariane and Sondag, Francis and Santos, Roberto V. and Jesus Nu{\~n}ez-Rodriguez and Point, David and Labonne, Maylis and Baras, Etienne} }