Many species use color change to optimize body coloration to changing environmental conditions, and drivers of rapid color change in natural populations are numerous and poorly understood. We examined factors influencing body coloration in the Water Anole (Anolis aquaticus Taylor, 1956), a lizard possessing color-changing stripes along the length of its body. We quantified the color of three body regions (the eye stripe, lateral stripe, and dorsum) before and after exposure to a mild stressor (handling and restraint). Based on current understanding of the genus Anolis Daudin, 1802, we hypothesized that exposure to a stressor would generate genus-typical skin darkening (i.e., increased melanism). Contrary to expectations, stress consistently brightened body coloration: eye and lateral stripes transitioned from brown to pale blue and green and the dorsum became lighter brown. Sex, size, and body temperature did not correlate with any aspect of body coloration, and a laboratory experiment confirmed that light exposure did not drive brightening. We propose that color change may serve to reduce conspicuousness through disruptive camouflage; lizards tended to display brighter stripes on mottled green-brown substrates. Together, these results improve our understanding of Anolis color change diversity and emphasize the need for a broader interpretation of the mechanism and functions of color change across taxa.Key words: Anolis (Norops) aquaticus, Water Anole, cryptic, metachrosis, physiological color change, stress.Résumé : Si de nombreuses espèces se servent des changements de couleur pour optimiser la coloration de leur corps en réponse à des conditions ambiantes changeantes, les facteurs menant à des changements de couleur rapides dans les populations naturelles sont nombreux et mal compris. Nous avons examiné les facteurs qui influencent la coloration du corps chez l'anolis aquatique (Anolis aquaticus Taylor, 1956), un lézard présentant des bandes de couleur changeante parallèles à la longueur de son corps. Nous avons quantifié la couleur de trois régions du corps (bande oculaire, bande latérale et région dorsale) avant et après une exposition à un facteur de stress léger (manipulation et retenue). À la lumière de la compréhension actuelle du genre Anolis Daudin, 1802, nous avions postulé que l'exposition à un facteur de stress produirait un assombrissement de la peau typique du genre (c.-à -d., mélanisme accru). Contrairement à ces attentes, le stress s'est uniformément traduit par une coloration plus pâle du corps, les bandes oculaires et latérales passant du brun aux bleu et vert pâles et le brun de la région dorsale devenant plus pâle. Le sexe, la taille et la température du corps n'étaient corrélés à aucun aspect de la coloration du corps, et une expérience en laboratoire a confirmé que l'exposition à la lumière ne causait pas de pâlissement. Nous proposons que les changements de couleur pourraient servir à rendre les individus moins faciles à détecter grâce au camouflage disruptif; les lézards avaie...

No abstract

Deep-water snapper fisheries in the Mariana Archipelago are important commercial, recreational and subsistence fisheries. <i>Pristipomoides zonatus</i>, one of the top four deep-water snapper species harvested in Guam, lacked life-history information. To fill this gap, a comprehensive life-history assessment for <i>P. zonatus</i>, which included age, growth, mortality and reproduction, was conducted in Guam. The size range of <i>P. zonatus</i> sampled for life history was from 11.5cm to 40.4cm (fork length), with ages ranging from 0.5 to 30 years. Von Bertalanffy growth model-combined sex parameters were <i>L</i>_&#x221e;=36.91cm and <i>K</i>=0.29. Males obtained a larger average size and a larger asymptotic size (+3.03cm) than did females. <i>Pristipomoides zonatus</i> matures at a small size and age (<i>L</i>₅₀ &#x2264; 24.0cm and <i>A</i>₅₀ &#x2264; 2.1 years) relative to their maximum size (40.4cm) and age (30 years). Additionally, <i>P. zonatus</i> has a long spawning season and a short spawning interval, suggesting high reproductive output. Our results expand knowledge on <i>Pristipomoides</i> life history (fast early growth, moderately long-lived, high productivity), providing the necessary information for the management of <i>P. zonatus</i> in Guam.

Deep-water snapper fisheries in the Mariana Archipelago are important commercial, recreational and subsistence fisheries. Pristipomoides zonatus, one of the top four deep-water snapper species harvested in Guam, lacked life-history information. To fill this gap, a comprehensive life-history assessment for P. zonatus, which included age, growth, mortality and reproduction, was conducted in Guam. The size range of P. zonatus sampled for life history was from 11.5 cm to 40.4 cm (fork length), with ages ranging from 0.5 to 30 years. Von Bertalanffy growth model-combined sex parameters were L∞ = 36.91 cm and K = 0.29. Males obtained a larger average size and a larger asymptotic size (+3.03 cm) than did females. Pristipomoides zonatus matures at a small size and age (L50 ≤ 24.0 cm and A50 ≤ 2.1 years) relative to their maximum size (40.4 cm) and age (30 years). Additionally, P. zonatus has a long spawning season and a short spawning interval, suggesting high reproductive output. Our results expand knowledge on Pristipomoides life history (fast early growth, moderately long-lived, high productivity), providing the necessary information for the management of P. zonatus in Guam.