Why is Pacific salmon movement into freshwater streams considered migration if the salmon die at the head of the stream and never return to the ocean?
A) It is not considered migration but immigration.
B) Migration is a one-way movement.
C) Because their offspring return to the ocean, the entire population participates in the migratory event via different life stages.
D) Most male adult fish survive reproduction and return to the ocean.
C
You might also like to view...
Arabidopsis is a model organism for the study of ________
Fill in the blank(s) with correct word
________ glands are a form of epithelial tissue that secretes substances through a duct
Fill in the blank(s) with correct word
Blood pressure drives the first step in urine formation, called _____________________.
A. tubular reabsorption B. antidiaresis C. tubular secretion D. glomerular filtration E. aldosterone processing
Consider a stable frog population living at carrying capacity in a pond. If an average female produces 6,000 eggs during her lifetime and an average of 300 tadpoles hatch from these eggs, how many of these tadpoles will, on average, survive to reproduce?
A) 0 B) 2 C) 10 to 20 D) more than 100