Introduction to Marine Biology 4th Edition by George Karleskint,Richard Turner,James Small

Exercise 15

Does the area of overlap in Figure indicate that species A and species B have overlapping niches and will be in direct competition under those conditions? Why or why not?
Figure A NICHE. An organism's niche is determined by a variety of abiotic and biotic factors acting together on the organism. This three-dimensional graph shows how several factors (food size, salinity, and size of sediment particles) interact to form niches for two species of burrowing worm. On the basis of this graph, we can see that species A prefers to burrow in substratum composed of smaller sediment particles where the salinity of the water is low and prefers to feed on medium- to large-sized food items. Species B, on the other hand, prefers coarser sediments where the salinity of the water is higher and prefers smaller food items. The zone of overlap indicates the combination of sediments, salinity, and food that would meet the requirements of both organisms.