360 
Fishery Bulletin 96(2), 1998 
Males 
Females 
Sex unknown 
Age class (yr) 
Figure 2 
Age distribution of bottlenose dolphins, Thrsiops truncatus, stranded along the coast of Texas from 
1981 to 1990. 
Table 2 
Parameter values and their asymptotic standard errors ( SE ) from the Gompertz growth model fit to two sets of length-at-age data 
from bottlenose dolphins, Tursiops truncatus, stranded along the coast of Texas. The first set included all the available data; the 
second set was a subset of the first set that excluded specimens <1.0 yr of age. A = asymptotic length, b = the constant of 
integration, and k = the rate of growth constant, n = number of dolphins in each sample. 
n 
A± SE 
b ± SE 
K± SE 
Female length 
All data 
78 
244.7 ± 1.90 
0.755 ± 0.0423 
0.497 ± 0.0490 
Specimens of age <1.0 yr excluded 
68 
246.7 ± 2.22 
0.482 ± 0.0873 
0.294 + 0.0655 
Male length 
All data 
75 
263.5 ± 2.93 
0.785 ± 0.0308 
0.351 ± 0.0313 
Specimens of age <1.0 yr excluded 
54 
268.0 ± 3.64 
0.592 ± 0.0679 
0.2341 0.0388 
model excluded specimens less than 1-yr-old extrapo- 
lation to age 0 to estimate length at birth was inap- 
propriate. The ratio of mean length at birth to as- 
ymptotic length was 40.8% for males and 44.4% for 
females. 
The mode in strandings of neonates (n=12 of 21) 
and specimens <0.1 year of age (n=ll of21) occurred 
in March (Fig. 4). In both data sets, 86% of the speci- 
mens stranded during March and April. Except for 
five specimens found in November and December, 
all neonates stranded from February through June. 
Sexual and physical maturation 
Because reproductive data were collected from only 
57 females (Table 4), the sample size was too small 
to estimate the mean age and length at sexual matu- 
ration. Only seven pregnant females were noted; the 
smallest was 233 cm and the longest was 335 cm. 
The latter, an extremely large female, also had the 
largest fetus (122-cm male) recorded in the TMMSN 
stranding database. Teeth were available for three 
of the seven pregnant females, and they were esti- 
