Increased parental care cost for nest-guarding fish in a lake with hyperabundant nest predators

Abstract

Although parental care increases offspring survival, providing care is costly, reducing parental growth and survival and, thereby, compromising future reproductive success. To determine if an exotic benthic predator might be affecting parental care by nest-guarding smallmouth bass (Micropterus dolomieu), we compared nest-guarding behavior and energy expenditures in two systems, one with a hyperabundant recently introduced predator, the round goby (Neogobious melanostomus). In Lake Erie, USA, smallmouth bass vigorously defended their nests from benthic round gobies. In Lake Opeongo, Canada, smallmouth bass were exposed to fewer and predominantly openwater predators and were less active in their nest defense. From scuba and video observations, we documented that nest-guarding smallmouth bass chased predators (99% of which were round gobies) nine times more frequently in Lake Erie than in Lake Opeongo. This heightened activity resulted in a significant decline in weight and energetic content of guarding males in Lake Erie but no change in Lake Opeongo males. Bioenergetic simulations revealed that parental care increased smallmouth bass standard metabolic rate by 210% in Lake Erie but only by 28% in Lake Opeongo. As energy reserves declined and offspring became increasingly independent, males in both lakes consumed more prey and spent more time foraging away from their nests; however, nest-guarding smallmouth bass consumed few prey and, in Lake Erie, rarely consumed round gobies. Therefore, increased parental care costs owing to the presence of round gobies could affect future growth, reproduction, and survival if smallmouth bass approach critically low energy reserves.

Reproductive behavior of the Amazonian dwarf cichlid Apistogramma hippolytae Kullander, 1982: offsetting costs and benefits

“…The energy spent during brood care is possibly balanced by a specific behavioral mechanism, such as an increase in the feeding rate immediately after fry desertion. The negative relationship between feeding frequency and attacks on intruders also suggests that nests that are more exposed may compromise the nutritional status and reproductive potential of females (e.g., Steinhart et al 2004;Desjardins et al 2008). This set of conditions could result in a preference for A. hippolytae females to mate with males with better or more sheltered territories, which may produce the observed female aggregations and ultimately the evolution of a harem-style reproductive behavior.…”

“…Reproductive trade-offs have been documented for many animal taxa (e.g., Sadras 2007;Stiver and Alonzo 2009;Székely and Cuthill 2000;Tallamy and Denno 1982) including fishes (Steinhart et al 2004;Steinhart et al 2008; see review by Kolm and Ahnesejo 2005). Cichlid fishes are remarkable for their complex behavioral repertoire that includes elaborated forms of parental care (Keenleyside 1991) and sophisticated breeding systems (Baerends and Baerends-van Roon 1950;Desjardins et al 2008;Nakazawa and Yamamura 2009;Nelissen 1991).…”

Oxidative stress during courtship affects male and female reproductive effort differentially in a wild bird with biparental care

“…Basal metabolic rate increases during parental care (Nilsson, 2002;Steinhart et al, 2005). This increase in energy demand stimulates ATP production, and as a consequence, might increase the release of reactive species.…”

Challenges in merging fisheries research and management: the Upper Mississippi River experience

“…A management plan has been recently developed for these carp species (Conover et al, 2007), which includes directed harvest as a mechanism for control. Effects of round gobies in the UMRS are uncertain, although they do interfere with nesting centrarchids in the Great Lakes via nest predation (Steinhart et al, 2004(Steinhart et al, , 2005 and likely have similar effects in rivers.…”