Water Mites in the Diet of Largemouth Bass

Abstract

Water mites (Hydracarina) are not consumed by some fish because of their distastefulness or toxicity. We obtained evidence that some individual largemouth bass (Micropterus salrnoides) specifically targeted mites as prey in a small unproductive and unexploited lake in Michigan's Upper Peninsula, USA. Bass stomachs that contained water mites tended to have high numbers of mites, with up to 780 mites in individual stomachs. Stronger evidence for foraging specialization was provided by repeated examination of stornacb contents from recaptured bass; many bass contained water mites more often than would be expected by chance (one-sample t-test [Ho=O], t = 3.54, P <0.0001). Also, there was no correlation between bass density and the percentage of bass consuming mites (r = 0.0 183) further suggesting that foraging on mites was an individual rcsponse rather than a population strategy.

Filial cannibalism by largemouth bass (Micropterus salmoides): a three-decade natural history record from a small northern temperate lake

“…Those individuals who were recaptured on two or more occasions with YOY in their stomach contents had significantly greater TL than individual non-cannibals or fish that had ingested YOY on only one sampling occasion (Figure 8). Our findings provide additional evidence that the foraging flexibility of largemouth bass in Paul Lake allows individuals to specialize on subsets of prey resources available to the population (Schindler et al 1997;Hodgson et al 2008;Rick et al 2011). In other populations, largemouth bass that transition to piscivory during their first summer have growth rates approaching two to three times that of their non-cannibalistic conspecifics (Shelton et al 1979;Olson 1996).…”

“…Recent findings suggest that diet consistency in individual recaptured largemouth bass (e.g. water mites and Chaoborus larvae) was the result of active selection of particular prey types rather than simple opportunistic encounters (Schindler et al 1997;Hodgson et al 2008;Rick et al 2011). Individual foraging consistency may help bass exploit alternative resources during periods when intraspecific competition is intense and may explain how they are able to sustain relatively high population densities when their preferred prey (i.e.…”

“…In this study, we report on a 29-year natural history record (27 continuous years of marked and recaptured fish) of the population dynamics and occurrence of cannibalism for largemouth bass in Paul Lake, which is located in the Upper Peninsula of Michigan. The lake resides at the northern edge of the species' range and the foraging ecology of this population has been extensively documented (Hodgson and Kitchell 1987;Hodgson et al 1993;Xe et al 1994;Hodgson and Kinsella 1995;Schindler et al 1997;Hodgson and Hodgson 2000;Post 2003;Hodgson and Hansen 2005;Hodgson et al 2008;Rick et al 2011;Purdom et al 2015;Brosseau and Hodgson 2016).…”

Episodic zooplanktivory by largemouth bass (Micropterus salmoides) on Daphnia: a 25-year natural history record from a small northern temperate lake

“…For instance, by using individual records in lieu of population interpretations, some Paul Lake LMB have previously been shown to develop dietary specialization on high-cost metalimnetic Chaoborus spp. larvae (Rick et al 2011) and water mites (Hydracarina) (Hodgson et al 2008), which are typically distasteful to LMB (Kerfoot et al 1980). These results signify deviations from expected foraging behaviors based on body size, ontogeny, and avoidance.…”

“…Then, we examined how episodic zooplanktivory affects the body condition of LMB. In combination with the Paul Lake LMB foraging records of Hodgson et al (2008), Rick et al (2011), andDassow et al (2018), which show individual predator preference, the broad history of prey choice and energetic yield elucidates vital information about long-term population dynamics of a piscivore.…”