The role of fanning behavior in water exchange by a nest‐guarding benthic fish before spawning

Abstract

Lay Abstract In some species of fish, males provide parental care and fan within nests before eggs are deposited. Courtship fanning behavior by the male may serve to advertise to females both his ability to disperse reproductive chemical signals and to ventilate eggs once deposited in the nest. We used a technique, called particle image velocimetry, to visualize and characterize flow both in and out of a nest generated by courting Round Goby males, a bottom‐dwelling fish. Once flow was characterized, we conducted a laboratory experiment to determine if caudal and pectoral fanning behavior was influenced by the presence of a female near the nest. The presence of a single female in the vicinity of the nest had no effect on fanning rates. However, there were significant differences between fanning behavior between types of fins. Fanning by caudal fins (with the tail at the nest entrance) resulted in water being pushed out of the nest. We estimated that caudal fanning currents propagated over a distance of at least 34 cm from the nest entrance (2–3 times the body length of an adult Round Goby). In contrast, fanning by pectoral fins (with the head at the nest entrance) resulted in flow entering the nest. Flow entering the nest was much lower than flow being pushed out of the nest. We speculate that by pumping water out of the nest with their tail, males disperse odors to guide reproductive females to the nest; whereas pectoral fanning serves mainly to ventilate the nest, denoting specialization of these locomotive structures as pumping and water stirring appendages.

High levels of metacercarial infestation (family: Diplostomidae) do not affect host energetics and swimming performance in the Epaulette goby (Coryogalops sordidus, Gobiidae)

“…C. sordidus utilized the slipping behavior, to a greater degree than N. melanostomus , to achieve critical station‐holding ability. The pelvic fin of gobies is not only used for anchoring the fish to the substrate but also allows for guarding of eggs laid on the underside of rocks (Butler, 1980; Meunier et al, 2013). The greater slipping behavior of C. sordidus can therefore be interpreted as the species having weak pelvic fin anchoring ability similar to C. caffer (Butler, 1980).…”

Evidence of sperm removal behaviour in an externally fertilizing species and compensatory behaviour for the risk of self-sperm removal

“…The effect of the number of injected sperm was treated as an explanatory variable. Male body size (TL) was included in this model as an explanatory variable because body size may affect the water exchange effect in the nest [46]. To examine the effect of tail-fanning behaviour on paternity defence of the nestholding males, a GLM with a binomial distribution and logit link function was performed in the semen injecting experiments.…”

Water turbidity constrains male mating success in a marine fish

“…A characteristic of male parental care behaviour in fish is fanning. Fanning is thought to oxygenate the eggs, to disperse chemical signals, and to remove silt and waste products (Potts et al 1988;Green and McCormick 2005;Meunier et al 2013). Larger egg clutches need more oxygen, so they also increase the need for fanning (van Iersel 1953;Reebs et al 1984;Coleman and Fischer 1991;Lindström and Wennström 1994).…”