Estimating metabolic rate in wild, free‐swimming fish is inherently challenging. Here, we explored using surgically implanted heart rate biologgers to estimate metabolic rate in two warmwater piscivores, bowfin Amia calva (Linneaus 1766) and largemouth bass Micropterus salmoides (Lacepède 1802). Fish were surgically implanted with heart rate loggers, allowed to recover for 24 h, exposed to a netting and air exposure challenge,...

In this study, we investigated the effects of acoustic tag implantation on standard and routine metabolic rate (SMR and RMR, estimated via oxygen consumption), critical swimming speed ( U crit ), survival and growth in juveniles of rainbow trout Oncorhynchus mykiss and lake trout Salvelinus namaycush . Tag burdens ranged from 1.8% to 7.5% across the two species. Growth rates in acoustic‐tagged fish were equal to or higher than...

This study examined whether polyandrous female Chinook salmon Oncorhynchus tshawytscha obtain benefits compared with monandrous females through an increase in hatching success. Both of the alternative reproductive tactics present in male O. tshawytscha (large hooknoses and small, precocious jacks) were used, such that eggs were either fertilized by a single male (from each tactic) or multiple males (using two males from the sa...

Intraspecific hybridisation may result in hybrid offspring exhibiting superior (heterosis) or inferior (outbreeding depression) fitness relative to their parental populations. As both have been demonstrated in salmonids, consequences of interbreeding between divergent populations are relevant to their conservation. Atlantic salmon Salmo salar L. were extirpated from Lake Ontario by the late 19th Century due to anthropogenic ca...

The influences of additive, non‐additive and maternal effects on early survival (uneyed embryo survival, eyed embryo survival, alevin survival and overall survival to first feeding) were quantified in lake trout Salvelinus namaycush using a 7 × 7 full‐factorial breeding design. Maternal effects followed by non‐additive genetic effects explained around one third of the phenotypic variance of the survival traits. Although the am...

This paper reports recent developments in Rapfish, a normative, scalable and flexible rapid appraisal technique that integrates both ecological and human dimensions to evaluate the status of fisheries in reference to a norm or goal. Appraisal status targets may be sustainability, compliance with a standard (such as the UN code of conduct for responsible fisheries) or the degree of progress in meeting some other goal or target....

A study was undertaken to examine sperm morphometry in relation to sperm velocity and sperm longevity in the redside dace Clinostomus elongatus . There was significant between‐male variance in sperm size and shape metrics (total sperm length, sperm head length, flagellum length and sperm head length to width ratio) and positive relationships were found between these morphometrics and sperm velocity. There were no significant r...

A study was undertaken to examine secondary sexual characters (spawning colouration and overall body size) in relation to sperm metrics in one alternative reproductive tactic of coho salmon Oncorhynchus kisutch : large hooknose males that spawn in dominance‐based hierarchies. Males with less intense red spawning colouration had higher sperm velocities than males with darker red spawning colouration. There was no relationship b...

The relationships among the area, hue, saturation and brightness of orange colouration and sperm traits in the guppy Poecilia reticulata were investigated. Males with greater areas of orange colouration had significantly larger sperm loads, more motile sperm and longer sperm relative to males with relatively little orange colouration. Males with greater areas of orange colouration did not possess more viable sperm than males w...

A single‐sex model is presented that calculates the probability of detecting multiple mating ( PrDM ) given genetic data from the single genetic parent and a sample of its offspring. The model incorporates the effects of numbers of loci, alleles, offspring and genetic parents contributing to the multiple mating, all of which effect PrDM . The model is used to determine the actual number of loci and offspring that are required...

The onset of sexual behaviour in three age classes of male guppy Poecilia reticulata occurred in synchrony with the appearance of body colouration and anal fin differentiation but not with sperm production. There was also a positive correlation between sperm production and sexual behaviour in the two older age classes.

Data from biological, economic, sociological, and technological attribute lists for 32 African lake fisheries were analysed with multivariate statistics. Multidimensional scaling (MDS) was used to create two‐dimensional graphic ordinations of the fisheries for each of these four attributes lists. An overall MDS ordination was also generated, based on the fisheries’ scores in the four ordinations. Groupings in each MDS ordinati...

Predator inspection behaviour at different levels of attack motivation (attack status of the predator) was investigated in European minnows Phoxinus phoxinus from a population sympatric with pike Esox lucius , during controlled laboratory experiments. Shoals of minnows performed more predator inspections and formed larger inspection group sizes shortly after an attack by a pike. After inspection, minnows returned to the safety...