Environmental Biology of Fishes

, Volume 57, Issue 4, pp 393–400

Habitat Partitioning in a Patchy Environment: Considering the Role of Intraspecific Competition

  • Anthony P. Spina

DOI: 10.1023/A:1007682010268

Cite this article as:
Spina, A.P. Environmental Biology of Fishes (2000) 57: 393. doi:10.1023/A:1007682010268


Coexistence of many size groups of conspecifics in habitat patches may complicate resource partitioning and increase intraspecific interactions. The objectives of my study were to determine partitioning of habitat among age groups of rainbow trout, Oncorhynchus mykiss, coexisting in pool habitat of a headwater stream, and to determine the role of intraspecific competition for such resource partitioning. The trout population showed size and age specific patterns of habitat use, and trout selected locations based on depth and longitudinal position. This habitat use pattern decreased intraspecific overlap among the trout age groups for use of pool space. I used a removal experiment to determine if two-year old trout constrained habitat use by the smaller conspecifics. Although the experimental results imply that recent intraspecific competition was not present, the absence of competitive exclusion was not clearly demonstrated because of low experimental power. While this study identified habitat partitioning among the trout age groups, it remains unclear whether biotic interactions or size specific requirements were causing the habitat use patterns.

stream fish headwater stream biotic interaction size specific habitat use removal experiment 

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Anthony P. Spina
    • 1
  1. 1.Department of Biological SciencesCalifornia State Polytechnic UniversityPomonaU.S.A.
  2. 2.Habitat Conservation DivisionNational Marine Fisheries ServiceLong BeachU.S.A.