Captive breeding conditions decrease metabolic rates and alter morphological traits in the endangered Spanish toothcarp, Aphanius iberus

Abstract

Physiological features of species can determine the resilience and adaptation of organisms to the environment. Swimming capacity and metabolic traits are key factors for fish survival, mating and predator-prey interactions. Individuals of the same species can display high phenotypic variation often in response to varying environmental conditions. We investigated the effects of captive breeding conditions on swimming capacity, metabolic traits and morphology by comparing a captive population with a wild population of the endangered Spanish toothcarp (Aphanius iberus). We measured swimming capabilities and oxygen-uptake rates simultaneously, the latter as a proxy for metabolic rate, using a swim tunnel respirometer. Results showed significant differences in standard metabolic rate (SMR), maximum metabolic rate (MMR) and absolute aerobic scope (AAS) between populations, as well as differences in morphological features between populations and sexes. In contrast, we did not find significant differences in critical swimming speed between populations or sexes. Differences in SMR between sexes were found in the captive population, and males showed nearly a twofold increase in SMR when compared with females. SMR, MMR and AAS were, on average, twofold lower for the captive population in comparison with the wild population. These differences in metabolic traits likely reflected captivity conditions, which were low food availability and the absence of predators, which in turn, may have influenced morphological traits, such as body and caudal peduncle shape and head size. At the same time, morphological traits also influenced metabolic traits of the populations. The lower SMR and MMR of captive individuals may be related to their deeper body shapes. Taken together, our results suggested that captive breeding conditions caused significant physiological and morphological changes in the endangered Spanish toothcarp. Reduced metabolic traits and changes in morphology may affect fitness-related traits of the captive populations once reintroduced into the wild, thereby compromising conservation efforts. We therefore recommend to experimentally testing for the effects and consequences of captive breeding conditions

Intraspecific Shape Analysis of Bali Sardinella (Sardinella lemuru) Using Geometric Morphometrics Collected in the Coast of Cabadbaran, Agusan Del Norte, Philippines

“…These conditions were associated with lengthy swimming ability but the existing gap during these stages are shape and metabolism which may contribute to morphological differences (Latorre et al, 2020). 3).…”

A review and meta-analysis of the environmental biology of bleak Alburnus alburnus in its native and introduced ranges, with reflections on its invasiveness

“…Moreover, the species' standard metabolic rate is also influenced by body shape (Table 4). Similarly, deep-bodied fish have been found to attain lower standard metabolic rate than shallowbodied fish (Pettersson and Brönmark 1999;Latorre et al 2020a). Propulsive ratio (measured as propulsive body area/total body area), which represents the proportion of the fish's body able to be used for swimming (Fisher and Hogan 2007), can also increase markedly the variation in standard metabolic rate (Table 4).…”

“…This mobility is complemented by plasticity of several biological traits that facilitate adaptation and invasion to new environments, such as high fecundity, an omnivorous diet, and a broad temperature tolerance (Fig. 3) (Chappaz et al 1987;Latorre et al 2016Latorre et al , 2018Latorre et al , 2020a. Indeed, temperature tolerances of A. alburnus (Kuttel et al 2002) indicate that eggs are able to withstand water temperatures of 14-31 °C (Alabaster and Lloyd 1980), with optimal embryonic development at 21-27 °C (Alabaster and Lloyd 1980).…”

“…As an omnivorous planktivore, A. alburnus occupies a relatively-low trophic position (Almeida et al 2014;Latorre et al 2016Latorre et al , 2018Latorre et al , 2020a, which an afford a fish species greater efficiency in obtaining energy from basal trophic groups (Gido and Franssen 2007). During the early stages of A. alburnus invasions, different life traits are important along the invasion stage, from recently introduced to well-established populations (Ribeiro et al 2008).…”

A conservation genetics perspective on supportive breeding: A case study of the common nase (Chondrostoma nasus)

“…In this case, often only a small proportion of juvenile fish accepts the food (Klupp & Geist, 2018). The genetic effects of maladaptation can cause significant physiological and morphological changes (Latorre et al, 2020), eventually resulting in lowered lifetime success compared with individuals hatched in the wild and reduced adaptive potential to changing environmental conditions (Fraser et al, 2019). The use of only a limited number of broodstock individuals not fully representing the genetic diversity of the original population can enhance genetic drift and inbreeding in the offspring (Franklin, 1980; Brown et al, 2000).…”