BULLETIN FLORIDA STATE MUSEUM


Table 9-Matrix of covariance comparisons of maxillary length regression equations (Table
 2) for populations of Chasmodes saburrae (P<0.001). Comparisons above the
 diagonal are between males in the different populations, and those below the
 diagonal between females (see Table 3 for explanation of abbreviations).
 0 = coincident regression lines; = noncoincident but parallel lines; + = noncoin-
 cident and nonparallel lines.
 SS SN ST SC SE SM SF
 SS 0 0 0 0 0 0
 SN 0 0 0 0 0 -
 ST 0 0 0 0 0 0
 SC 0 0 0 0 0 0
 SE 0 0 0 0 O 0
 SM 0 0 0 0 0 0
 SF 0 0 0 0 0 0

length comparisons is shown (Table 7) between the population in the
southern Laguna Madre Bay (LL) and the population in the area of sympa-
try (LS). The lack of significant difference between any of the adjacent
populations, coupled with the difference between LL and LS, suggests the
existence of an east-west dine within this subspecies (see Table 8). This
type of variation in maxillary length is not found in C. b. bosquianus or C.
saburrae (Tables 7, 9) and may be related to character displacement in the
area of sympatry (discussed later).
 ECOLOGY AND DISTRIBUTION.-Like Chasmodes bosquianus bosquianus,
C. b. longimaxilla typically inhabits the estuarine areas that have either a
rock-shell bottom or a grassbed habitat. Unlike C. b. bosquianus, this
subspecies has not been collected in salinities less than 10 ppt. It is usually
captured in salinities ranging from 18 to 28 ppt.
 Based on my observations, together with information from preserved
specimens, the spawning season of Chasmodes bosquianus longimaxilla
begins in March and extends over the summer months into October or early
November. The longer spawning season may be attributable to water
temperature. Water temperature in the northern Gulf of Mexico often
remains warm until October or November (Bault 1972).
 Male Chasmodes bosquianus longimaxilla over 35 mm SL are highly
aggressive and maintain territories year-round. Females seek shelter
among rocks and shells, but normally do not actively defend a territory.
Females are constantly on the move during the spawning season. At their
reproductive peak in early summer, I have noted one female spawning
with more than one male. On several occasions, I have seen different
females spawning with the same male. Each female laid a number of eggs
on the inner surfaces of the shell being defended by the male, where he
would then fertilize them. Thus, neither male nor female shows a prefer-
ence for one partner during the spawning season.
 The fish's pigmentation pattern renders it practically invisible against a


VOL. 29, NO. 2