Body-generated hydrodynamic flows influence male–male contests and female mate choice in a freshwater fish

Do microplastics impair male dominance interactions in fish? A test of the vector hypothesis

“…On day 31 of the experiment, we staged paired territorial contests between control and MP‐exposed males using procedures adapted from TerMarsch and Ward (2020). Briefly, trials were conducted in 38‐L tanks (50.8 × 25.4 × 30.5 cm) covered on the sides and back with pictures of underwater foliage to mimic the natural environment of the fish.…”

“…We recorded the frequencies of aggressive behaviors performed by each male in each trial during the 5‐min baseline period before removal of the divider, and during the 5‐min trial interaction observation period after removal of the divider and subsequent 5‐min acclimation period. Aggressive behaviors were defined as follows: Tail ‐ flicking (quick, short movement of one individual's tail/caudal region); head ‐ butting (pushing of one's snout to any other part of the opponent's body); charging (quick movement of one fish toward the other); biting (open mouth‐to‐body contact between two opponents); lateral display (an individual turns its body lateral towards its opponent in a parallel orientation); lateral display with contact (an individual pushes its lateral trunk against its opponent in either a parallel or perpendicular orientation); and blocking (an individual blocks the opening to the shelter by turning its body lateral towards its opponent) (Phillips et al, 2009; Pyron & Beitinger, 1989; TerMarsch & Ward, 2020). We calculated the total number of aggressive behaviors performed by each male during each trial period; as well as the total duration of time spent engaged in aggressive interaction during the trial.…”

“…In nature, male P. promelas aggressively compete for territories underneath logs or floating materials that serve as nest sites. Females deposit eggs in a single layer to the underside of the substrate, and the male defends the nest from potential predators, including conspecifics (Clement et al, 2004;TerMarsch & Ward, 2020;Unger, 1983). Because the ability of a male to obtain a territory is a prerequisite to mating, contaminant-induced changes in male aggression and competitive ability have the potential to reduce reproductive success.…”

Male zebrafish (Danio rerio) do not preferentially associate with familiar over unfamiliar conspecifics

“…Laboratory studies of behavioural choice in fish have used a variety of metrics to assess the preference. For example, studies have inferred preference from the total amount of time that a focal animal spends with each stimulus (e.g., Dugatkin & Alfieri, 1991;Krause et al, 1999;Webster & Laland, 2013), the proportion of "active time" spent with each stimulus (i.e., disregarding time spent in a neutral no-choice zone; Gerlach et al, 2008;Krause et al, 1999;TerMarsch & Ward, 2020), which stimulus was visited first (Webster & Laland, 2013) and the latency to first visit (Webster & Laland, 2013). Similarly, studies have begun assessment immediately after introducing the focal animal into the choice arena (Dugatkin & Alfieri, 1991;Krause et al, 1999;Webster & Laland, 2013), after an acclimation period (Gerlach et al, 2008;Madeira & Oliveira, 2017;Metcalfe & Thomson, 1995), or after the focal animal has visited or detected all available stimuli (Magurran et al, 1994;TerMarsch & Ward, 2020).…”

Lateral line morphology, sensory perception and collective behaviour in African cichlid fish

“…Fishes are able to use canal neuromasts to sense vibrating obstacles [ 23 , 24 ] and neighbouring fish, and are able to use the lateral line as a whole to shoal [ 16 , 17 ]. When the sensory input from the lateral line is interrupted through surgical methods or chemical treatment, a number of behaviours are altered or lost, including normal shoaling ability [ 16 , 17 , 25 ], foraging behaviour [ 18 , 19 , 22 ], competitor assessment [ 13 , 15 ] and mate selection [ 13 , 14 ].…”