CB1 :

Very interesting. If the reply to your question was correct then you may be on to something. I am going to speculate a little below but it is worth checking on. Greg asked me to look into Blueback herring and I posted some of the results. I will find the link and add to the end of this post. In doing the research I found info on BBH and on alewives another form of herring. One of the things I noticed on the nutrition level of the articles was the high content of lipids in herring when compared to say BG or shad. I think but am not sure that RT are like herring in this respect. If so it may be that high lipid content from sea run type fish is higher and contains something extra that makes LMB grow.

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=5;t=000411;p=1#000000

This is one of the studies I found --look where it is from and what it is about !!!

Assessing the Contribution of Anadromous Herring to Largemouth Bass Growth
Lisa A. Yako and Martha E. Mather

Massachusetts Cooperative Fish and Wildlife Research Unit, USGS-BRD, Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, Massachusetts 01003, USA

Francis Juanes

Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, Massachusetts 01003, USA

Abstract.—Juvenile anadromous river herring (alewife Alosa pseudoharengus and blueback herring A. aestivalis) spend the first 3 to 7 months of life in headwater lakes of coastal systems. Systems that support herring often produce trophy largemouth bass Micropterus salmoides. Even though biologists, managers, and anglers have speculated about the value of anadromous herring as a key prey for resident predators, the contribution that herring make to the diets of these predators has not been assessed. Herein, we quantified largemouth bass diets in two coastal lakes, Santuit and Coonamessett ponds, that contained anadromous herring, and we used bioenergetics modeling to evaluate the importance of herring prey to largemouth bass growth. During May through November 1994, largemouth bass diets consisted of various fish species, crayfish, and other invertebrates. Although not the most important prey overall, herring were the most important fish prey consumed in both lakes based on number of individuals consumed. In both lakes, herring were primarily eaten by largemouth bass that were fewer than 300 mm in total length after mid-August. Coonamessett Pond largemouth bass ate more herring and other fish prey and achieved better growth than did those in Santuit Pond. Bioenergetics modeling simulations revealed that water temperature does not explain the presence of trophy largemouth bass in southeastern Massachusetts. Because largemouth bass grow better on a diet that includes herring, we conclude that juvenile herring are an energetically valuable and a potentially key prey for largemouth bass. However, factors other than energetics mediate the use of herring by these resident predators. Further investigations into spatial dynamics, size structure, and foraging behavior are necessary to understand the mechanisms that drive interactions between largemouth bass and anadromous herring.

Received: August 19, 1998; Accepted: March 1, 1999