Hi Jackie,
The blue whale is the largest whale. Generally only about 10% of the food energy is transferred from one level of the food web to the next. That means that as you move up the web (further away from the primary producers, usually plants) the less mass associated with the level. For example, if you start with 1000 pounds of plants you expect about 100 pounds of plant eaters and 10 pounds of the species that eats the plant eaters (that's why there are relatively few carnivores). Blue whales need a lot of food to survive -- eating low in the food web is where the most volume of food is.
Killer whales (Orcus) are called killers because they are carnivores -- they eat seals, sea lions, dolphins, porpoises and fish.
Hope this helps,
Cathy
Cathy Schaeff
Associate Professor and Chair
Department of Biology
American University
101 Hurst Hall, 4400 Mass. Ave. NW,
Washington DC 20016-8007
p: 202.885.2194, f: 202.885.2182
schaeff@american.edu
-----"King, Jacqueline" <KingJ@Merrimack.edu> wrote: -----
To: <schaeff@american.edu>
From: "King, Jacqueline" <KingJ@Merrimack.edu>
Date: 03/05/2005 10:07PM
Subject: Whales
Dear Cathy-
I have a few questions regarding whales. Is the blue whale the largest of the whale family, and if it is so large, how does only eating plankton keep it satisfied? Also, why are killer whales called "killer" when you don't hear of them kiling humans? Thank you for your time! -Jackie King-