7230

• UCREFRP Catalog Number: 7230
• Author: Karp, C. A. and H. M. Tyus
• Title: Behavioral Interactions between Young Colorado Squawfish and Six Fish Species
• USFW Year: 1990
• USFW - Doc Type: Copeia
• Copyright Material: YES

30
COPEIA, 1990, NO. 1
TABLE 1. RATES OF INTERSPECIFIC AND INTRASPECIFIC AGONISTIC BEHAVIORS BETWEEN SPECIES IN MIXED
SPECIES PAIRS. First fish in each species pair initiated the action.

Species pairs
Chases Number of agonistic acts per minute'
Threats
Total
Tank 1
Ptychocheilus lucius-P. lucius 0.03 0.10 0.13
P. lucius-Catostomus latipinnis 0.00 0.00 0.00
C. latipinnis-C. latipinnis 0.00 0.08 0.08
C. latipinnis-P. lucius 0.00 0.00 0.00
Tank 2
P. lucius-P. lucius 0.02 0.02 0.04
P. lucius-Pimephales promelas 0.00 0.00 0.00
P. promelas-P. promelas 0.20 0.04 0.24
P. promelas-Ptychocheilus lucius 0.18 0.06 0.23
Tank 3
P. lucius-P. lucius 0.00 0.06 0.06
P. lucius-Notrapis lutrensis 0.00 0.03 0.03
N. lutrensis-N. lutrensis 0.11 0.11 0.22
N. lutrensis-P. lucius 0.11 0.04 0.15
Tank 4
P. lucius-P. lucius 0.01 0.17 0.18
P. lucius-Richardsonius balteatus 0.00 0.00 0.00
R. balteatus-R. balteatus 0.01 0.01 0.02
R. balteatus-P. lucius 0.00 0.09 0.09
Tank 5'
P. lucius-P. lucius 0.02 0.04 0.06
P. lucius-Ameiurus melas 0.00 0.00 0.00
A. ~nelas-A. melas 0.04 0.01 0.05
A. melas-P. lucius 0.05 0.01 0.05
Tank 6'
P. lucius-P. lucius 0.02 0.02 0.04
P. lucius-Lepomis cyanellus 0.01 0.01 0.02
L. cyanellus-L. cyanellus 0.22 0.02 0.24
L. cyanellus-P. lucius 0.32 0.10 0.42
Fish densities in tanks 5 and 6 are half those in tanks 1-4.
Only N. lutrensis, Pimephales promelas, and C.
latipinnis significantly increased their activity
levels and range of movement during feedings
(N. lutrensis: activity-Student's t = 3.81, df =
31, P < 0.01, range-Student's t = 2.58, df =
31, P < 0.05; P. promelas: activity-Student's t
= 5.61, df = 31, P < 0.01, range-Student's t
= 3.02, df = 30, P < 0.01; C. latipinnis: activi-
ty-Student's t = 2.34, df = 31, P < 0.05,
range-Student's t = 3.59, df = 31, P < 0.01).
However, the increased activity of these fishes
was not greater than that of Ptychocheilus lucius
in the C. latipinnis tank (Student's t < 1.2, df =
2, P > 0.05).
All fishes except C. latipinnis and A. melas were
observed to attack the razorback sucker larvae,
but only P. lucius, L. cyanellus, N. lutrensis, and
R. balteatus consumed the larvae. Lepomis cy-
anellus, N. lutrensis, and R. balteatus initiated
attacks during the 4 min interval immediately
following prey addition, and consumed 90%,
20%, and 10% of the prey items, respectively.
Ptychocheilus lucius consumed 50% of the prey,
but this occurred during the 20-40 min period
following food addition.
DISCUSSION
Each species appeared to use the available
vertical space in a unique manner, although