A method to evaluate body length of live aquatic vertebrates using digital images

Abstract

The role of body size in shaping the form and function of animals has attracted the attention of scientists for decades (Calder, 1996).Larger body size provides crucial benefits including higher fitness and fecundity (Barneche et al., 2018), and competitive advantages within (Newman, 1956) and among species (Persson, 1985). A reduction in body size has been proposed as the third universal response of animals to the warming climate (Daufresne et al., 2009). Yet, empirical evidence to test this hypothesis at broader spatiotemporal contexts is lacking in freshwater ecosystems.Traditional methods of measuring fish and amphibians often involve use of anesthetics and prolonged handling (Bonar et al.

Salamanders aid research into mechanisms of non‐canonical organ regeneration for clinical applications

“…The current difficulties in the study of non-canonical organ regeneration in salamanders are mainly due to: (1) The small number of researchers; (2) The lack of technical means for the study; and (3) The lack of background and resources for the study. Recent progress in embryo, tissue and cell transplantation [58,[64][65][66][67][68][69], virusmediated cell labeling [70,71], transgenic [72][73][74][75][76][77][78][79], tissue clearing [80][81][82][83] and live imaging [77,[83][84][85][86], gene editing [87][88][89][90], de novo sequencing [88,[91][92][93][94][95][96][97], singlecell [7,[98][99][100][101][102][103][104]…”

“…The current difficulties in the study of non‐canonical organ regeneration in salamanders are mainly due to: (1) The small number of researchers; (2) The lack of technical means for the study; and (3) The lack of background and resources for the study. Recent progress in embryo, tissue and cell transplantation [58, 64–69], virus‐mediated cell labeling [70, 71], transgenic [72–79], tissue clearing [80–83] and live imaging [77, 83–86], gene editing [87–90], de novo sequencing [88, 91–97], single‐cell [7, 98–105] and spatiotemporal [7, 103–107] multi‐omics technologies (Figure 2) have dramatically expanded knowledge about embryonic and tissue development, and the evolution of animal behavior and have advanced human understanding of the spatiotemporal dynamics of cells and genes at the genetic, transcriptional, and protein levels during the regeneration of canonical organs in salamanders, and their regulation of regeneration. Currently, models of pneumonectomy, hepatectomy, nephrectomy, and renal drug injury have been successfully constructed in salamanders, based on which we have discovered the regenerative potential of salamander alveolar epithelial cells, hepatocytes, and other cells and structures such as the alveoli, glomeruli, and renal tubules.…”

Interactive abiotic and biotic stressor impacts on a stream‐dwelling amphibian

“…Videos from the escape behavior assays were analyzed in Fiji (ImageJ) using the FFmpeg package. For each video, the scale of pixels to mm was set using the known length of the salamander in the video (Arismendi et al., 2021 ). After the scale was set, the distance and duration traveled were calculated to determine the speed of the salamander following each disturbance.…”