The role of progeny quality and male size in the nesting success of smallmouth bass: integrating field and laboratory studies

Abstract

Smallmouth bass display size-specific variation in reproductive success with larger broodguarding males in a population more likely to rear offspring to independence than smaller individuals. The exact mechanisms responsible for this sizespecific increase in reproductive output have yet to be identified. To assist in this process, we investigated the relationship between the size of brood-guarding male smallmouth bass and offspring quality (in this case, egg physiology, egg morphology, egg size, hatching success and lab survival). Further, we examined how factors such as egg physiology, egg morphology and egg size influenced reproductive success in the wild and hatching success in a controlled laboratory environment. Nesting male smallmouth bass that successfully reared their offspring to independence spawned earliest in the nesting period were the largest individuals, and guarded eggs with greater concentrations of cortisol compared to males that abandoned their offspring prematurely. Offspring survival in the laboratory was not correlated with offspring survival in the wild, indicating that caution should be used interpreting studies that attempt to relate laboratory-derived survival metrics to the wild. Together, results demonstrate size-specific differences in offspring quality for nesting smallmouth bass, which are correlated with higher concentrations of cortisol in eggs. However, hatching success under laboratory conditions was dissimilar to nesting success in the field relative to cortisol concentrations.

Intraguild predation between spawning smallmouth bass (Micropterus dolomieu) and nest‐raiding crayfish (Orconectes rusticus): implications for bass nesting success

“…Our data did not suggest such a trend among Lake Ottawa bass, although Lake Ottawa spawning males (total length = 328–460 mm) fall in the upper end of size ranges reported in other studies ( c . 275–455 mm and 280–430 mm, Steinhart et al ., ; 234–464 mm, Gingerich & Suski, ). We would expect smaller bass to be more likely to abandon their nests under the conditions in Lake Ottawa, but we did not have the opportunity to test this.…”

“…Several previous studies found a positive relationship between bass size and nesting success (Suski & Ridgway, ; Steinhart et al ., ; Gingerich & Suski, ). Our data did not suggest such a trend among Lake Ottawa bass, although Lake Ottawa spawning males (total length = 328–460 mm) fall in the upper end of size ranges reported in other studies ( c .…”

Predator burden and past investment affect brood abandonment decisions in a parental care‐providing teleost

“…), a multivariate principal component analysis (PCA) was used to reduce blood plasma variables into newly defined terms. Principal components (PCs) with eigenvalues >1·0 were retained and rotated orthogonally, and parameters were considered to contribute maximally to each PC if rotated eigenscores were >0·40 or <−0·40 (Green ; Peres‐Neto, Jackson & Somers ; Gingerich & Suski ).…”

“…Due to high dimensionality and the potential for biological interrelatedness among the 10 physiological variables quantified (Table 1) (Zera & Harshman 2001;Travers et al 2010), a multivariate principal component analysis (PCA) was used to reduce blood plasma variables into newly defined terms. Principal components (PCs) with eigenvalues >1Á0 were retained and rotated orthogonally, and parameters were considered to contribute maximally to each PC if rotated eigenscores were >0Á40 or <À0Á40 (Green 1991;Peres-Neto, Jackson & Somers 2003;Gingerich & Suski 2011).…”

The influence of brood loss on nest abandonment decisions in largemouth bass Micropterus salmoides

“…salmoides may be attributed to the inherently high cost of reproduction for the species, particularly at northern latitudes where males are unlikely to attempt more than a single breeding event within a given reproductive season (Suski et al , ; Magee & Neff, ; Steinhart et al , ). Because partial brood loss occurs naturally for centrarchids due to natural nest depredation, storm events, egg fungal infection and potentially poor egg quality (Knotek & Orth, ; Steinhart et al , ; Steinhart et al , ; Gingerich & Suski, ), the capacity for brood loss before a male abandons a brood is limited in M . salmoides .…”