Morphometric tools for landmark data: geometry and biology

Life in Moving Fluids—The physical biology of flow

Nonindigenous fishes introduced into inland waters of the United States /; Pam L. Fuller, Leo G. Nico, James D. Williams.

Structural environmental enrichment, that is, a deliberate addition of physical complexity to the rearing environment, is sometimes utilized to reduce the expression of the undesirable traits that fish develop in captivity. Increasing demands and regulations regarding usage of enrichment to promote fish welfare also make investigations on the effects of enrichment important. Here, we sythesize the current state-of-the-art knowledge about the effects of structural environmental enrichment for fish in captive environments. We find that enrichment can affect several aspects of the biology of captive fish, for example, aggression, stress, energy expenditure, injury and disease susceptibility. Importantly, these effects are often varying in direction and magnitude, and it is clear that just addition of structure is not a solution to all problems in fish rearing. Each species and life stage needs special consideration with respect to its natural history and preferences. A multitude of different enrichment types has been investigated and many studies investigate several enrichment components at the same time, making comparisons among studies difficult. To the present date, the majority of efforts have been directed to investigate salmonid fish in stock-fish hatcheries and cichlids from a basic research perspective. Some contexts are under-studied with respect to environmental enrichment, for instance effects on results in basic research and welfare effects in display aquaria. There are many research opportunities left within this field. However, future studies could utilize experimental designs which make it possible to discriminate between effects of different environmental manipulations to a higher degree than what has been performed to this date.

Environmental enrichment for fish in captive environments: effects of physical structures and substrates

Methods of Multivariate Analysis

Predation can cause morphological divergence among populations, while ontogeny and sex often determine much of morphological diversity among individuals. We used geometric morphometrics to characterize body shape in the livebearing fish Brachyrhaphis rhabdophora to test for interactions between these three major shape-determining factors. We assessed shape variation between juveniles and adults of both sexes, and among adults for populations from high- and low-predation areas. Shape differed significantly between predation regimes for all juveniles regardless of sex. As males grew and matured into adults, ontogenetic shape trajectories were parallel, thus maintaining shape differences in adult males between predation environments. However, shape of adult females between predation environments followed a different pattern. As females grew and matured, ontogenetic shape trajectories converged so that shape differences were less pronounced between mature females in predator and nonpredator environments. Convergence in female body shape may indicate a trade-off between optimal shape for predator evasion versus shape required for the livebearing mode of reproduction.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.278

Ontogeny and sex alter the effect of predation on body shape in a livebearing fish: sexual dimorphism, parallelism, and costs of reproduction

The process of dispersal is determined by the interaction of individual (intrinsic) traits and environmental (extrinsic) factors. Although many studies address and quantify dispersal, few evaluate both intrinsic and extrinsic factors jointly. We test the relative importance of intrinsic traits (exploration tendency and size) and extrinsic factors (population density and habitat quality) on dispersal of a medium-sized western United States minnow, southern leatherside chub Lepidomeda aliciae. A generalized linear model with a binomial response was used to determine the probability of individuals dispersing one year after tagging. Medium-sized individuals that were more prone to explore novel environments were 10.7 times more likely to be recaptured outside of their original capture area after a year (dispersal) compared to non-explorer individuals of the same size class. Differences be- tween explorer classifications within the small and large size classes were negligible. Open habitat within 50 m upstream also in- creased the probability of dispersal relative to controls. Relative location within the study reach, and population density were not significantly related to dispersal probabilities of individuals. Our results indicate that understanding of personality may illuminate patterns of dispersal within and among populations (Current Zoology 58 (2): 260270, 2012).

/pdf/dispersal-behavior-correlates-with-personality-of-a-north-zpuu685z0v.pdf

Dispersal behavior correlates with personality of a North American fish

Movement of organisms is an important activity that has ecological and evolutionary implications, including individual reproductive success and survival, population growth and persistence, local adaptation, and gene flow. Expression of movement behavior has traditionally been termed dispersal and measured relative to home ranges. This simplistic approach belies the complexity of the process. Movement of freshwater stream fish has been at times viewed as predominantly restricted in nature, but recent research challenges this paradigm since some distribution of movement exists in every population. A better research approach is to understand the drivers that promote or limit movement. Drivers of movement can be categorized as extrinsic ecological factors (context dependent), e.g., habitat quality, habitat variability, and the presence of predators, and intrinsic traits of the fish (condition dependent), such as body size and condition. One intrinsic trait that has received relatively little attention...

Individual Movement of Stream Fishes: Linking Ecological Drivers with Evolutionary Processes

Recovery plans for many endangered fishes include production of large numbers of individuals in hatcheries to augment wild populations. However, effects of hatchery culture on phenotypic development are poorly documented for most species. June sucker (Chasmistes liorus) is an endangered lake sucker endemic to Utah Lake (Utah, USA), and recovery plans include raising thousands of juveniles to stock in the lake. To determine effects of hatchery culture on morphology of young June sucker, we raised individuals from four different families in both lake and hatchery environments and compared shape variation among families and between environments. We compared shape from three perspectives: lateral body, ventral mouth, and lateral head views. Mean shape varied between hatchery-reared and lake-reared individuals in each of the three views. In addition, hatchery-reared individuals exhibited higher variance in shape both within and among families compared with shape variance in lake-reared individuals. Hatchery-re...

Hatchery-induced morphological variation in an endangered fish: a challenge for hatchery-based recovery efforts

Stocking of artificially propagated fish has been adopted by many endangered fish recovery programs as a key component of their recovery plans However, quantifying successful recruitment of individuals to the adult population is difficult, especially in long-lived species To eval- uate the effect of the rearing environment on recruitment in the native environment, we compared post-stocking survival of the endangered June sucker Chasmistes liorus reared under conventional hatchery practices to those reared in 2 reservoirs We used logistic regression analysis to compare patterns of survival among populations including total length and condition at the time of stocking as continuous covariates The estimated probability of survival for reservoir-reared fish from Red Butte and Camp Creek Reservoirs was 019 and 005, respectively, compared to 005 for hatchery-reared fish Length and condition were positively related to post-stocking survival On average, reservoir- reared fish performed better than hatchery-reared fish It is not clear what mechanism led to increased survival for the Red Butte source, but several studies have demonstrated the importance of acclimation to the physical environment and the threat of predation We suggest that augmentation procedures would produce more recruits to the adult population if they incorporate grow-out or at least acclimation in more natural environments than that provided by hatcheries prior to release in Utah Lake

https://www.int-res.com/articles/esr2009/8/n008p225.pdf

Josh E. Rasmussen

Papers

Ontogeny and sex alter the effect of predation on body shape in a livebearing fish: sexual dimorphism, parallelism, and costs of reproduction

Dispersal behavior correlates with personality of a North American fish

Individual Movement of Stream Fishes: Linking Ecological Drivers with Evolutionary Processes

Hatchery-induced morphological variation in an endangered fish: a challenge for hatchery-based recovery efforts

Endangered species augmentation: a case study of alternative rearing methods