Ecological conditions affect behavioral and morphological trait variability of lake sturgeon (Acipenser fulvescensRafinesque, 1817) yolk-sac larvae

Abstract

Summary The effects of stream environmental conditions on inter individual variability were quantified for lake sturgeon, Acipenser fulvescens (Rafinesque, 1817) yolk sac larvae in the expression of behavioral and morphological traits. Simulated experimental treatments including food availability (brine shrimp), presence of chemosensory predator cues (adult crayfish and odonate larvae), and conspecific density (2 verses 1 larvae) were applied to determine the effects on the duration of time in substrates following hatch and growth from hatch until emergence. In spring 2010, larvae from two full‐sib families were individually placed into 240 mL perforated plastic containers (n = 263) with gravel substrate immediately following hatch. Containers were maintained in stream water at ambient temperatures and constant flow (~0.03 m/sec) in 4 m experimental flowing streams. Duration of time (days) each individual remained in the substrate was recorded. Morphological traits including total length (mm), body area (mm2), and yolk‐sac area (mm2) were measured at hatch and at the time of emergence from substrate to compare growth and amount of endogenous yolk reserves used in individuals among experimental treatments. Environmental conditions significantly affected emergence time. Individuals emerged earlier in treatments exposing larvae to chemosensory predator odorants and higher conspecific density. Use of endogenous reserves (yolk‐sac area) at the time of emergence did not differ among treatments. Growth was significantly greater when individuals were provided a food source compared to all other treatments. Quantifying the magnitude and direction of phenotypic responses to environmental conditions is important to understand potential factors affecting survival during early life stages and population viability under conditions of increasing environmental variability.

Effects of garlic powder on feeding attraction activity, growth and digestive enzyme activities of Japanese seabass, Lateolabrax japonicus

“…Previous reports indicated that certain medicinal plants could induce appetite in aquatic animals (Harada, 1991;Harada, Miyasaki, & Tamura, 1993;Zhang, Zeng, Zhang, Ai, & Mai, 2008), act as feeding attractants by chemically stimulating fish feeding behaviour and so increase their growth performance (Aguila et al, 2007;Callier et al, 2018;Harada & Akishima, 1985;Harada, Miyasaki, Kawashima, & Shiota, 1996;Luo, Tan, Liu, & Wen, 2011), and help to decrease the water pollution in culture systems through improved feed utilization (Francis, Makkar, & Becker, 2005;Wang et al, 2018Wang et al, , 2013. Some researchers demonstrated that odorants in fish feeds could affect the foraging behaviours of some species (Hara, 1994;Jay, Mcguire, & Scribner, 2017;Valdés, Olivares, Ponce, & Schmachtenberg, 2015;Velez et al, 2011). Therefore, the formulation of fish feeds using plants with distinct smells merits investigation to discover beneficial effects on feeding attractant activity, growth performance or digestive enzyme activities.…”

Biotic influences on drift behaviour of larval white sturgeon (Acipenser transmontanus)

“…This explanation is consistent with the trend in mass at emergence; the starved treatments emerged at the same mass as the fed treatments despite a lack of food. In contrast, Jay et al (2018) found no difference in emergence time between lake sturgeon larvae that were provided with food upon hatch and those that were starved. Jay et al (2018) also found that the presence of a conspecific led to earlier drift when comparing single and pairs of larvae.…”

“…In contrast, Jay et al (2018) found no difference in emergence time between lake sturgeon larvae that were provided with food upon hatch and those that were starved. Jay et al (2018) also found that the presence of a conspecific led to earlier drift when comparing single and pairs of larvae.…”

Aquatic insects differentially affect lake sturgeon larval phenotypes and egg surface microbial communities

“…Larvae emerge from stream substrate and disperse to depositional downstream regions of the stream to exogenously feed [ 78 ]. Previously, we have documented plasticity in emergence associated with stream physical environmental conditions (temperature and discharge, [ 79 ]) and with predator cues [ 45 ]. Here we quantify a high degree of behavioral and physiological plasticity in response to non-lethal effects of Perlid predators and to a lesser extent by facultative predatory Isonychiidae.…”

“…Empirical data are needed that can evaluate the relative lethal and non-lethal effects of multiple trophic levels in stream communities on fish phenotypic and behavioral trait variation across ontogenetic stages [ 45 ]. Understanding how and under what circumstances fish, aquatic insects, and microbes interact positively or negatively under future environmentally-induced changes in freshwater aquatic ecosystems is essential to ecosystem sustainability [ 46 ], and to the ability of aquatic ecosystems to provide essential ecosystem services [ 32 ].…”